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Adakah makrofaj mendapat nilai pemakanan daripada patogen yang mereka makan?

Adakah makrofaj mendapat nilai pemakanan daripada patogen yang mereka makan?


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Saya tahu bahawa makrofaj menelan badan asing dan mengangkutnya ke pelbagai laluan perkumuhan bahan buangan (maaf jika istilahnya salah), dan jika badan asing itu bersifat selular, ia akan terperangkap dalam fagolisosom dan dihadam oleh enzim.

Adakah makrofaj mendapat apa-apa "pemakanan" dengan memusnahkan sel-sel, dengan cara yang sama seperti seseorang jika sel-sel yang sama melalui sistem pencernaan mereka? Adakah terdapat sebarang tenaga kimia yang dihasilkan oleh pemangkinan yang kemudiannya digunakan oleh makrofaj, cth. piruvat untuk mitokondrianya? Atau komponen selular yang boleh digunakan untuk membina sitoskeletonnya sendiri?


Dalam artikel ini dijelaskan bahawa makrofag yang kelaparan 'memakan' haba yang tidak aktif bakteria melalui fagositosis dengan kemampuan yang meningkat. Kelaparan juga boleh menyebabkan autophagy (makro) dan laluan disambungkan dengan fagositosis, dalam makrofaj yang disiasat menunjukkan bahawa autophagy tidak memainkan peranan dalam peningkatan keupayaan fagositosis. Makalah ini bagaimanapun tidak menyebut apa-apa mengenai makrofag yang menggunakan sumber yang diperoleh oleh pencernaan bakteria. walaupun nampak logik. Saya akan terus mencari.

Sunting:

Saya menemui sebuah buku teks yang mengatakan:

secara umum sel siri makrofaj mempunyai dua fungsi utama. Mengenai fungsi mereka, seperti yang dimaksudkan oleh nama mereka ("pemakan besar"), adalah untuk menelan dan, dengan bantuan semua enzim degradasi dalam butiran lisosom mereka, rosak bahan terperangkap dalam asid amino ismple, gula dan bahan lain, untuk perkumuhan dan penggunaan semula.

Sumber: IMMUNOLOGI Kursus pendek edisi ke-3 oleh Eli Benjamini, Geoffrey Sunshine dan Sidney Leskowitz 1996 halaman 23-24. ISBN 0-471-59791-0. Saya hanya mempunyai salinan bercetak, tetapi saya akan cuba mencari versi dalam talian. Fungsi lain ialah pembentangan antigen.

Oleh itu, saya dapat mengatakan bahawa ya makrofag dan sel lain menggunakan sumber dari patogen yang dicerna.


Saya telah menemui kertas lama menggunakan bakteria berlabel radioaktif untuk mengesan nasib mereka dalam makrofaj. Menurut data, kedua-dua $^{14}$C dan $^{32}$P digunakan semula dalam sel hos.

COHN ZA. (1963). Nasib bakteria dalam sel fagosit. I. Degradasi bakteria berlabel isotop oleh leukosit polimorfonuklear dan makrofaj. J Exp Med. 1 Jan; 117: 27-42.


Ragi adalah kulat sel tunggal yang memakan gula (karbohidrat). Ragi pemakanan merujuk kepada varieti yang ditanam secara khusus untuk penggunaan manusia. Biasanya ia dibuat dari regangan Saccharomyces cerevisiae.

Tidak seperti yis baker’s dan brewer’s yang kedua-duanya hidup, yis pemakanan telah dinyahaktifkan (dibunuh). Faedah kesihatan utamanya ialah menjadi sumber yang kaya dengan vitamin B dan mineral, dan oleh itu, namanya.

Oleh kerana yis pemakanan tidak hidup, ia tidak boleh menyebabkan atau memburukkan lagi jangkitan yis seperti Candida albicans pertumbuhan berlebihan. Walaupun beberapa sumber menyatakan bahawa bahaya itu, tidak ada sains untuk menyokongnya. Sekurang-kurangnya jika seseorang bercakap mengenai ragi pemakanan standard, yang hanya terdiri daripada kulat mati.

Nooch apa? Ia adalah nama lain untuk yis pemakanan. Nama panggilan yang paling biasa. Ia sangat popular di kalangan vegan dan mereka yang memakannya dengan kerap. Ini mungkin jenama yang paling popular.


1. Pisang yang kita makan tidak boleh membiak.

Mereka adalah contoh autopoliploid triploid. Dalam erti kata lain, mereka berakhir dengan terlalu banyak set kromosom daripada pisang lain. Itulah sebabnya pisang ditanam daripada mentol dan bukannya biji benih tidak boleh menanam lebih banyak pokok pisang. Pokok pisang, biasanya dianggap sebagai herba, ditanam oleh pekerja ladang yang mengangkut tangkai dari tumbuhan lama untuk menanam yang baru. Maklumat itu mengejutkan semua orang, terutamanya seluruh dewan kuliah pada hari kami mempelajarinya di kelas.


Terokai Vitamin dan Mineral Lain

Kemas kini bulanan yang penuh dengan berita pemakanan dan petua daripada pakar Harvard—semuanya direka untuk membantu anda makan dengan lebih sihat. Daftar di sini.

Terokai panduan yang boleh dimuat turun dengan petua dan strategi untuk pemakanan sihat dan hidup sihat.


Meneroka:

Gunakan minyak yang sihat (seperti minyak zaitun dan kanola) untuk memasak, pada salad, dan di atas meja. Hadkan mentega. Elakkan lemak trans.

Minum air, teh, atau kopi (dengan sedikit atau tanpa gula). Hadkan susu/tenusu (1-2 hidangan/hari) dan jus (1 gelas kecil/hari). Elakkan minuman manis.

Lebih banyak sayuran &mdash dan lebih banyak variasi &mdash lebih baik. Kentang dan kentang goreng tidak dikira.

Makan banyak buah-buahan dari semua warna

Pilih ikan, ayam, kekacang dan kekacang hadkan daging merah dan keju elakkan bacon, potongan sejuk dan daging diproses yang lain.

Makan pelbagai jenis bijirin (seperti roti gandum, pasta bijirin penuh dan beras perang). Hadkan bijirin yang ditapis (seperti nasi putih dan roti putih).

Masukkan aktiviti fizikal ke dalam rutin harian anda.

Kemas kini bulanan yang penuh dengan berita pemakanan dan petua daripada pakar Harvard—semuanya direka untuk membantu anda makan dengan lebih sihat. Daftar di sini.

Terokai panduan yang boleh dimuat turun dengan petua dan strategi untuk pemakanan sihat dan hidup sihat.


Vitamin A

Vitamin memainkan peranan penting dalam fungsi lyphocyte. Asid retinoik -- satu bentuk vitamin -- membimbing perkembangan sel stem sumsum tulang menjadi limfosit matang. Vitamin A juga mengaktifkan limfosit sel T supaya mereka boleh melawan jangkitan, manakala kekurangan vitamin A menghalang fungsi limfosit yang betul. Hanya menambahkan segenggam sayuran hijau atau hidangan sayuran oren untuk diet anda setiap hari membantu anda mendapatkan 2,333 IU vitamin A yang disyorkan untuk wanita dan 3,000 IU untuk lelaki. Satu hidangan setengah cawan ubi keledek atau labu mempunyai lebih daripada 3,000 IU vitamin A, manakala secawan lobak merah mempunyai kira-kira 3,200 IU. Bayam dan kangkung juga didatangkan dengan vitamin A -- setengah cawan sayur-sayuran yang dimasak masing-masing mengandungi 1,572 dan 1,475 IU.

  • Vitamin memainkan peranan penting dalam fungsi lyphocyte.
  • Bayam dan kangkung juga dibungkus dengan vitamin A - setengah cawan hijau yang dimasak masing-masing mengandungi 1,572 dan 1,475 IU.

Fakta Kulat Salji

  • Aterosklerosis dan kolesterol tinggi
  • Kanser
  • Kulit Sihat
  • Kesihatan jantung
  • Rawat keletihan
  • Meningkatkan Kekebalan tubuh
  • Meningkatkan Otak
  • Menguruskan kencing manis
  • Rawat penyakit Alzheimer
  • Meningkatkan Keanjalan Kulit
  • Mengurangkan Keradangan
  • Menyembuhkan Luka
  • Ekstrak Tremella fuciformis digunakan dalam produk kecantikan wanita & wanita dari China, Korea, dan Jepun.

Secara mikroskopik, hifa diapit dan berlaku dalam matriks agar-agar padat. Sel haustorial timbul pada hifa, menghasilkan filamen yang melekat pada dan menembusi hifa perumah. Basidia adalah tremelloid (elipsoid, dengan septa serong hingga menegak), 10–13 kali 6.5–10 μm, kadangkala bertangkai. Basidiospora berbentuk elips, licin, 5–8 kali 4–6 μm, dan bercambah melalui tiub hifa atau oleh sel yis.

Kulat mendapat nama biasa telinga kayu untuk cara ia kelihatan pada kayu balak yang mereput tempat ia tumbuh. Kulat salji berkualiti baik mempunyai warna pucat, putih kekuningan dan tekstur seperti lendir. Pakar herba Cina dan Jepun telah menggunakan kulat salji selama lebih daripada 2,000 tahun, kebanyakannya untuk meningkatkan cecair dalam badan, untuk batuk kering, dan untuk berdebar-debar. Ia telah digunakan sebagai herba tonik dan sebagai penambah kecantikan untuk meningkatkan seri wajah. Kandungan kolagennya setanding dengan sarang burung. Oleh itu, juga mengapa jamur putih digelar sebagai 'sarang burung miskin'.


Gambar 7.3: Musim penyakit manusia yang berkaitan dengan patogen bawaan makanan

Norovirus, penyebab paling biasa selesema perut, boleh disebarkan melalui pengambilan makanan yang tercemar. Walaupun norovirus secara amnya mempunyai puncak bermusim musim sejuk (lihat Rajah 7.3), perubahan parameter iklim, terutamanya suhu dan hujan, boleh mempengaruhi kejadian dan penyebarannya. Secara keseluruhan, kesan iklim setempat boleh meningkatkan hasil kesihatan (kurang kes semasa musim sejuk yang lebih panas) atau memburukkannya (penularan tinggi semasa banjir), sehingga unjuran arah aliran dalam hasil kesihatan keseluruhan untuk norovirus masih tidak jelas. 50 , 59

Peningkatan suhu laut boleh meningkatkan risiko pendedahan patogen daripada pengambilan makanan laut yang tercemar. Sebagai contoh, perairan pantai yang lebih panas dengan ketara di Alaska dari tahun 1997 hingga 2004 dikaitkan dengan wabak pada tahun 2004 Vibrio parahaemolyticus, bakteria yang menyebabkan penyakit gastrousus apabila makanan laut yang tercemar ditelan. 60 Vibrio parahaemolyticus adalah salah satu punca utama gastroenteritis berkaitan makanan laut di Amerika Syarikat dan dikaitkan dengan penggunaan tiram mentah yang dituai dari muara air suam. 61 Begitu juga, kemunculan bakteria yang berkaitan, Vibrio vulnificus, mungkin juga dikaitkan dengan suhu air yang tinggi. 42 Sementara peningkatan suhu air rata-rata terlibat dalam wabah tahun 2004, 60 suhu udara ambien juga mempengaruhi tahap patogen dari pelbagai spesies Vibrio dalam kerang. 37, 38 Contohnya, Vibrio vulnificus boleh meningkat 10 hingga 100 kali ganda apabila tiram disimpan pada suhu ambien selama sepuluh jam sebelum disejukkan. 62 Peningkatan dalam air laut ambien dan suhu udara akan mempercepatkan Vibrio pertumbuhan dalam kerang-kerangan, yang berpotensi memerlukan perubahan dalam kawalan lepas tuai untuk meminimumkan peningkatan risiko pendedahan. (Untuk maklumat lanjut tentang Vibrio dan patogen berkaitan air lain, termasuk pencemaran air rekreasi dan minuman, lihat Ch. 6: Penyakit Berkaitan Air).

Akhirnya, perubahan iklim diproyeksikan akan menghasilkan musim sejuk yang lebih panas, musim semi yang lebih awal, dan peningkatan musim tumbuh secara keseluruhan di banyak wilayah. 63 , 64 Walaupun terdapat potensi manfaat pengeluaran makanan daripada perubahan tersebut, musim tumbuh yang lebih panas dan lebih lama juga boleh mengubah masa dan kejadian penghantaran patogen dalam makanan dan peluang pendedahan kepada manusia. 65 , 66 , 67

Peristiwa Melampau

Sebagai tambahan kepada kesan peningkatan purata suhu dan kelembapan pada kemandirian dan pertumbuhan patogen, peningkatan suhu dan kerpasan yang melampau boleh menyumbang kepada perubahan dalam penghantaran, pendaraban dan kemandirian patogen. Kejadian hujan lebat yang lebih kerap dan teruk dapat meningkatkan risiko jangkitan dari kebanyakan patogen, terutama ketika mengakibatkan banjir. 68 Banjir, dan cuaca ekstrem lain, boleh meningkatkan kejadian dan tahap patogen dalam persekitaran pengeluaran, penuaian dan pemprosesan makanan. Air bawah tanah dan air permukaan yang digunakan untuk pengairan, penuaian dan pencucian boleh tercemar dengan air larian atau air banjir yang membawa sebahagian atau tidak dirawat kumbahan, baja atau sisa lain yang mengandungi bahan cemar bawaan makanan. 57 , 69 , 70 , 71 , 72 , 73 Tahap Salmonella dalam air dinaikkan pada masa hujan maksimum bulanan pada musim panas dan musim gugur 58 , 74 akibatnya kemungkinan Salmonella di perairan dapat meningkat di kawasan yang mengalami peningkatan jumlah curah hujan atau kejadian hujan lebat.

Air juga merupakan faktor penting dalam pemprosesan makanan. Iklim dan cuaca ekstrem, seperti banjir atau kemarau, boleh mengurangkan kualiti air dan meningkatkan risiko pemindahan patogen semasa pengendalian dan penyimpanan makanan selepas penuaian. 9

Kesan langsung kemarau terhadap keselamatan makanan kurang jelas. Keadaan kering boleh menimbulkan risiko penghantaran patogen disebabkan kualiti air yang berkurangan, peningkatan risiko larian apabila hujan berlaku, dan peningkatan kepekatan patogen dalam bekalan air yang berkurangan jika air tersebut digunakan untuk pengairan, pemprosesan makanan atau pengurusan ternakan. 31, 33, 57, 75 Peningkatan kekeringan secara amnya membawa kepada peningkatan risiko pendedahan kepada patogen seperti norovirus dan Cryptosporidium . 68 Walau bagaimanapun, kemarau dan kejadian haba melampau juga boleh mengurangkan kebolehmandirian patogen bawaan makanan tertentu, menjejaskan penubuhan dan penghantaran, dan dengan itu mengurangkan pendedahan manusia. 68 , 76

Mikotoksin dan Fikotoksin

Mikotoksin ialah bahan kimia toksik yang dihasilkan oleh acuan yang tumbuh pada tanaman sebelum penuaian dan semasa penyimpanan. Sebelum menuai, peningkatan suhu dan kekeringan dapat menekan tanaman, menjadikannya lebih rentan terhadap pertumbuhan acuan. 77 Keadaan panas dan lembap menyokong pertumbuhan acuan secara langsung dan menjejaskan biologi vektor serangga yang menghantar acuan kepada tanaman. Pencemaran selepas penuaian juga dipengaruhi oleh parameter persekitaran, termasuk suhu dan kelembapan yang melampau. Jika tanaman tidak dikeringkan dan disimpan pada kelembapan yang rendah, pertumbuhan acuan dan pengeluaran mikotoksin boleh meningkat kepada tahap yang sangat tinggi. 78 , 79

Fikotoksin ialah bahan kimia toksik yang dihasilkan oleh air tawar dan alga laut berbahaya tertentu yang boleh menjejaskan keselamatan air minuman dan kerang atau makanan laut lain. Contohnya, alga yang bertanggungjawab menghasilkan ciguatoxin (toksin yang menyebabkan penyakit yang dikenali sebagai keracunan ikan ciguatera) hidup subur dalam air suam (lihat juga Bab 6: Penyakit Berkaitan Air). Unjuran peningkatan suhu permukaan laut mungkin meluaskan julat endemik alga penghasil ciguatoxin dan meningkatkan kejadian keracunan ikan ciguatera selepas pengambilan. 80 Ramalan kenaikan suhu permukaan laut 4.5 ° hingga 6.3 ° F (2.5 ° hingga 3.5 ° C) boleh menghasilkan peningkatan kes keracunan ikan ciguatera dari 200% hingga 400%. 81

Sebaik sahaja dimasukkan ke dalam rantai makanan, toksin beracun ini boleh mengakibatkan hasil kesihatan yang buruk, dengan kesan akut dan kronik. Undang-undang peraturan dan strategi pengurusan semasa melindungi bekalan makanan dari mikotoksin dan fitotoksin namun, peningkatan frekuensi dan jangkauan prevalensinya dapat meningkatkan kerentanan sistem keselamatan makanan.


Adakah makrofaj mendapat nilai pemakanan daripada patogen yang mereka makan? - Biologi

Oleh Dr. Jane Parish, Profesor Lanjutan/Penyelidikan Bersekutu dan Dr. Justin Rhinehart, Penolong Profesor Lanjutan Sains Haiwan dan Tenusu. Perkhidmatan Sambungan Universiti Negeri Mississippi, MSU Cares.

Mineral dan vitamin menyumbang sebahagian kecil daripada pengambilan bahan kering harian dalam diet lembu pedaging dan kadangkala boleh diabaikan dalam program pemakanan kumpulan. Walaupun mineral dan vitamin diperlukan sebagai peratusan nutrien pemakanan yang sangat kecil, ia sangat penting dalam program pemakanan lembu pedaging untuk fungsi haiwan yang betul, seperti perkembangan tulang, fungsi imun, pengecutan otot, dan fungsi sistem saraf. Pertumbuhan lembu dan prestasi pembiakan boleh terjejas jika program mineral yang baik tidak disediakan.

Program suplemen mineral dan vitamin yang baik berharga kira-kira $15 hingga $25 setiap kepala setahun. Dengan kos tahunan pengeluaran setiap lembu secara amnya adalah beberapa ratus dolar, kos program tambahan mineral dan vitamin berkualiti tinggi adalah pelaburan yang agak kecil. Banyak campuran mineral dan vitamin pilihan percuma dirumus untuk kadar penggunaan harian 2 atau 4 auns. Untuk tujuan ilustrasi, jika seekor lembu daging mengambil 4 auns (1/4 paun) suplemen sehari selama 365 hari, maka dia mengambil 91.25 paun suplemen dalam setahun. Banyak suplemen mineral dan vitamin dibungkus dalam beg 50 paun, jadi seekor lembu daging menggunakan hampir dua beg 50 paun suplemen ini setiap tahun pada kadar penggunaan harian 4-auns. Menggandakan harga salah satu beg suplemen mineral dan vitamin ini menganggarkan kos tahunan suplemen pada asas setiap kepala.

Mineral Makromineral dan Mikromineral

Lembu daging memerlukan sekurang-kurangnya 17 unsur mineral yang berbeza dalam diet mereka. Mineral yang diperlukan dikelaskan sebagai sama ada makromineral (mineral utama) atau mikromineral (mineral surih), berdasarkan kuantiti yang diperlukan dalam diet lembu pedaging. Makromineral diperlukan dalam kuantiti yang lebih besar (gram sehari) daripada mikromineral (miligram atau mikrogram sehari).

Makromineral yang diperlukan oleh lembu daging termasuk kalsium, magnesium, fosforus, kalium, natrium, klorin, dan sulfur. Microminerals yang diperlukan termasuk kromium, kobalt, tembaga, yodium, besi, mangan, molibdenum, nikel, selenium, dan zink. Keperluan nutrien unsur mineral tertentu berbeza-beza, bergantung pada umur haiwan, berat, peringkat pengeluaran, status penyusuan, baka, tekanan, dan bioavailabiliti mineral (tahap di mana mineral tersedia kepada tisu sasaran selepas pentadbiran) daripada diet.

Keperluan makromineral biasanya dinyatakan sebagai peratusan (%) daripada jumlah diet, manakala keperluan mikromineral biasanya dinyatakan sebagai miligram per kilogram (mg/kg), iaitu bersamaan dengan bahagian per juta (ppm). Untuk menukar peratus ke ppm, gerakkan perpuluhan empat tempat ke kanan (contohnya 0.2500% = 2500 ppm).

Sumber mineral diet termasuk makanan ternakan, bahan makanan pekat, suplemen mineral dan air.

Interaksi Mineral

Mineral berinteraksi antara satu sama lain di dalam badan. Interaksi yang banyak boleh mengakibatkan unsur mineral&rsquo mengikat atau menjadikan unsur mineral lain tidak tersedia untuk fungsi badan yang penting. Dalam program pemakanan lembu daging yang praktikal, interaksi antara kalsium dan fosforus adalah contoh klasik dua mineral yang mempengaruhi tahap yang diperlukan antara satu sama lain dalam diet. Cadangan kalsium dan fosforus biasanya dinyatakan sebagai nisbah (Ca:P) kalsium kepada fosforus.

Interaksi Unsur Mineral Berpotensi

Makromineral

Kalsium adalah mineral yang paling banyak dalam badan dan terlibat dalam banyak fungsi penting badan, termasuk pembentukan dan penyelenggaraan tulang, pembangunan dan penyelenggaraan gigi, pembekuan darah, kebolehtelapan membran, pengecutan otot, penghantaran impuls saraf, pengawalan jantung, rembesan susu, hormon. rembesan, dan pengaktifan dan fungsi enzim.

Kebanyakan bekalan kalsium dalam badan terdapat dalam tulang dan gigi. Tulang boleh membekalkan kekurangan diet jangka pendek kalsium. Walau bagaimanapun, kekurangan kalsium diet jangka panjang boleh menyebabkan masalah pengeluaran yang teruk. Vitamin D diperlukan untuk penyerapan kalsium. Diet tinggi lemak boleh mengurangkan penyerapan kalsium.

Kekurangan kalsium mengganggu pertumbuhan tulang yang normal pada lembu muda dan boleh menyebabkan riket (tulang lemah dan lembut yang mudah patah tulang) dan pertumbuhan dan perkembangan yang terencat. Dalam lembu dewasa, kekurangan kalsium boleh menyebabkan osteomalacia, keadaan yang dicirikan oleh tulang yang lemah dan rapuh. Demam susu, keadaan yang biasanya dikaitkan dengan lembu tenusu, juga boleh berlaku pada lembu pedaging akibat kekurangan kalsium dan membawa kepada lembu yang turun sejurus selepas beranak. Demam susu dijelaskan secara terperinci di bahagian gangguan pemakanan dalam penerbitan ini.

Makanan ternakan umumnya lebih tinggi dalam kepekatan kalsium daripada makanan pekat (berasaskan bijirin), dengan kekacang (seperti semanggi dan alfalfa) biasanya memberikan kadar kalsium yang lebih tinggi daripada rumput. Kandungan kalsium dalam makanan berbeza-beza dengan spesies, bahagian tanaman, kematangan, jumlah kalsium yang terdapat di dalam tanah untuk pengambilan tumbuhan, dan iklim.

Lembu boleh bertolak ansur dengan kepekatan tinggi kalsium diet jika tahap mineral lain mencukupi dalam diet. Cadangan kalsium dinyatakan dalam bentuk nisbah kalsium kepada fosforus (Ca:P), di mana kira-kira 1.6:1 adalah ideal, dengan julat 1:1 hingga 4:1 boleh diterima.

Sumber kalsium tambahan termasuk kalsium karbonat, batu kapur gred suapan, dikalsium fosfat, fosfat defluorinated, monokalsium fosfat dan kalsium sulfat. Batu kapur gred makanan adalah kira-kira 34 peratus kalsium dan biasanya ditambah kepada diet lembu daging untuk meningkatkan tahap kalsium diet. Dicalcium fosfat adalah kira-kira 22 peratus kalsium dan 19.3 peratus fosforus dan ditambah kepada diet lembu daging untuk membantu mengimbangi nisbah kalsium kepada fosforus. Ia menambah kedua-dua kalsium dan fosforus kepada diet.

Fosforus (P)

Sama seperti kalsium, kebanyakan fosforus terdapat di tulang dan gigi, tetapi beberapa fosforus juga terdapat dalam tisu lembut. Fosfor diperlukan untuk pengembangan dan pemeliharaan rangka, rembesan susu normal, pembinaan tisu otot, pertumbuhan dan pembezaan sel, penggunaan dan pemindahan tenaga, penggunaan makanan yang cekap, pembentukan membran, fungsi banyak sistem enzim, pemeliharaan keseimbangan osmotik dan asid, dan pertumbuhan mikroorganisma rumen dan metabolisme. Sebilangan besar kehilangan fosforus melalui najis, sementara kehilangan fosforus kencing lebih rendah tetapi meningkat pada diet berkonsentrasi tinggi.

Keperluan fosforus sering dibentangkan dari segi nisbah kalsium kepada fosforus yang diterangkan sebelum ini. Aspek yang paling kritikal ialah tahap fosforus memenuhi keperluan lembu. Kebanyakan kehilangan fosforus adalah melalui najis, manakala kehilangan fosforus kencing adalah lebih rendah tetapi meningkat pada diet pekat tinggi. Pengambilan fosforus yang berlebihan boleh menyebabkan peningkatan pengeluaran najis fosforus ke dalam persekitaran dan mempunyai implikasi alam sekitar. Terlalu banyak fosforus dalam diet juga boleh mengakibatkan batu kencing, keadaan yang diperincikan dalam bahagian gangguan pemakanan penerbitan ini.

Kekurangan fosfor mempunyai implikasi yang luar biasa terhadap prestasi lembu sapi. Tidak memenuhi keperluan fosforus haiwan mengurangkan pertumbuhan dan kecekapan makanan, mengurangkan pengambilan bahan kering, merendahkan prestasi pembiakan, menekan pengeluaran susu, dan menyebabkan tulang lemah dan rapuh. Lembu matang boleh menggunakan rizab fosforus dalam tulang apabila diperlukan, tetapi bekalan fosforus rangka mesti diisi semula untuk mengelakkan situasi kekurangan fosforus.

Makanan ternakan biasanya rendah fosforus berbanding dengan bahan makanan pekat seperti bijirin bijirin dan makanan biji minyak (hidangan biji kapas, makanan kacang soya). Keadaan kemarau dan peningkatan kematangan makanan ternakan seterusnya mengurangkan kepekatan fosforus makanan ternakan. Ini menunjukkan bahawa suplemen fosforus yang lebih tinggi mungkin diperlukan untuk membekalkan paras fosforus diet yang meningkat apabila meragut atau memberi makan ternakan matang yang disimpan atau semasa tempoh kemarau. Dikalsium fosfat, fosfat defluorinated, monoammonium fosfat, dan fosfat fitat adalah sumber fosforus tambahan untuk ruminan. Paras fosforus yang disyorkan dalam suplemen mineral biasanya daripada 4 hingga 8 peratus, sebahagian besarnya bergantung kepada keadaan makanan ternakan dan tahap lain sumber pemakanan fosforus.

Magnesium (Mg)

Kira-kira 65 hingga 70 peratus magnesium dalam badan terdapat dalam tulang, 15 peratus dalam otot, 15 peratus dalam tisu lembut lain, dan 1 peratus dalam cecair ekstraselular. Magnesium penting untuk pengaktifan enzim, pecahan glukosa, penghantaran kod genetik, pengangkutan membran, penghantaran impuls saraf, dan perkembangan rangka.

Secara amnya, ketoksikan magnesium tidak menjadi masalah pada lembu sapi, dengan kepekatan sehingga 0.4 peratus ditoleransi. Namun pengambilan magnesium yang berlebihan boleh mengakibatkan cirit-birit yang teruk, penampilan lembap, dan mengurangkan penghadaman bahan kering.

Kekurangan magnesium, sebaliknya, boleh menjadi teruk pada lembu daging. Tanda-tanda kekurangan magnesium termasuk mudah terangsang, anoreksia, peningkatan aliran darah, sawan, berbuih di mulut, air liur yang banyak, dan kalsifikasi tisu lembut. Lembu muda boleh menggerakkan sejumlah besar magnesium daripada tulang, tetapi lembu matang tidak dapat melakukan ini, dan mereka mesti menerima bekalan magnesium yang tetap dan mencukupi daripada diet. Tetani rumput, keadaan biasa di kalangan lembu daging lembu menyusu yang meragut makanan ternakan yang subur, dicirikan oleh paras magnesium yang rendah. Tetani rumput dibincangkan secara terperinci dalam bahagian gangguan pemakanan kemudian dalam penerbitan ini.

Kepekatan magnesium foraj bergantung kepada spesies tumbuhan, tahap magnesium tanah, peringkat pertumbuhan tumbuhan, musim, dan suhu persekitaran. Kekacang biasanya mengandungi paras magnesium yang lebih tinggi daripada rumput. Bijirin bijirin mengandungi kira-kira 0.11 hingga 0.17 peratus magnesium, dan sumber protein tumbuhan mengandungi kira-kira dua kali ganda jumlah ini. Magnesium sulfat dan magnesium oksida berfungsi sebagai sumber tambahan magnesium yang baik. Cadangan untuk suplemen magnesium adalah magnesium yang ditawarkan pada kadar 2 hingga 4 peratus daripada makanan tambahan apabila ternak masing-masing menggunakan makanan rendah dan menengah. Naikkan tahap ini kepada sekurang-kurangnya 10 peratus daripada suplemen untuk mengelakkan tetani rumput pada makanan ternakan yang subur.

Sistem Pemantauan Kesihatan Haiwan Kebangsaan (NAHMS) USDA&rsquos melaporkan dalam tinjauan 1996 bahawa, mengikut wilayah geografi A.S., pengendali lembu pedaging di tenggara A.S. berkemungkinan besar menambah magnesium kepada ternakan lembu daging mereka berbanding kawasan lain. Tujuh puluh empat setengah peratus pengusaha lembu pedaging tenggara melaporkan menambah magnesium berbanding purata A.S. sebanyak 63.5 peratus. Pengeluaran makanan yang subur di tenggara bertepatan dengan musim kelahiran pada banyak operasi lembu A.S., dan banyak pengeluar menyedari keadaan ini sebagai peningkatan risiko tanaman rumput. Meningkatkan suplemen magnesium adalah tindakan pengeluar biasa untuk mencegah tetani rumput.

Kalium (K)

Mineral ketiga paling banyak dalam badan ialah kalium. Kalium berada dalam cecair intraselular dan terlibat dalam keseimbangan asid-bes, peraturan tekanan osmotik, keseimbangan air, pengecutan otot, penghantaran impuls saraf, pengangkutan oksigen dan karbon dioksida dalam darah, dan tindak balas enzim. Kalium menghalang tetani, sawan, dan gaya berjalan yang tidak stabil.

Kekurangan kalium ditunjukkan oleh pengambilan makanan yang berkurangan, selera makan yang rosak, pertambahan berat badan yang lebih rendah, bulu rambut yang kasar dan kelemahan otot. Kandungan kalium badan rendah, jadi kekurangan kalium dapat bermula dengan cepat. Kalium terutamanya dikumuhkan dalam air kencing lembu, dan rembesan kalium dalam susu agak tinggi.

Makanan ternakan adalah sumber mineral ini yang baik, selalunya antara 1 hingga 4 peratus kalium. Kandungan kalium boleh menjadi sangat tinggi di padang rumput yang subur, berpotensi menyumbang kepada permulaan tetani rumput. Makanan ternakan matang dan disimpan mengandungi kepekatan kalium yang lebih rendah.

Bijirin bijirin biasanya rendah kandungan kalium, manakala makanan biji minyak biasanya merupakan sumber yang baik. Diet pekat tinggi berkemungkinan memerlukan suplemen kalium jika sumber makanan ternakan atau protein yang mengandungi paras kalium yang mencukupi tidak disediakan. Secara amnya, suplemen kalium pada padang rumput tidak kritikal. Sumber kalium tambahan termasuk kalium klorida, kalium bikarbonat, kalium sulfat, dan kalium karbonat, yang kesemuanya merupakan bentuk pemakanan yang mudah didapati untuk lembu daging.

Natrium (Na) dan Klorin (Cl)

Natrium dan klorin adalah komponen garam putih biasa. Natrium dan klorin masing-masing berada dalam badan dalam cecair ekstraselular. Mereka penting untuk mengekalkan tekanan osmotik, mengawal keseimbangan air, mengawal keseimbangan asid-bes, mengecutkan otot, menghantar impuls saraf, dan membawa glukosa dan asid amino. Natrium diperlukan untuk operasi beberapa sistem enzim. Tindakan jantung dan penghantaran impuls saraf bergantung kepada beberapa natrium dan kalium. Klorin diperlukan untuk pengeluaran asid hidroklorik dalam abomasum (perut ruminan sebenar) dan pengaktifan amilase, enzim yang penting untuk pencernaan kanji biasa. Klorin juga membantu pertukaran gas pernafasan.

Lembu mengidamkan natrium dan akan mengambil lebih banyak garam daripada yang diperlukan apabila ia dibekalkan pilihan percuma. Kepekatan garam yang tinggi kadangkala digunakan untuk mengawal pengambilan makanan. Lembu mengambil kira-kira 0.1 paun garam setiap 100 paun berat badan dalam makanan terhad garam (0.5 paun sehari untuk 500 paun anak lembu 1.1 paun sehari untuk lembu seberat 1100 paun). Tahap pengambilan garam yang tinggi ini biasanya diterima oleh lembu apabila air yang mencukupi tersedia. Tahap garam diet sebanyak 6.5 peratus terbukti dapat mengurangkan pengambilan dan pertumbuhan makanan. Kepekatan maksimum yang boleh diterima untuk jumlah garam diet dianggarkan pada 9 peratus. Kandungan garam yang disyorkan bagi suplemen mineral dan vitamin adalah dalam lingkungan 10 hingga 25 peratus daripada suplemen.

Apabila garam terdapat dalam air minuman lembu, risiko ketoksikan garam meningkat. Kepekatan garam dalam air minuman sebanyak 1.25 hingga 2.0 peratus boleh mengakibatkan anoreksia, penurunan berat badan atau peningkatan berat badan, pengurangan pengambilan air dan keruntuhan. Malah paras garam yang lebih rendah dalam air minuman boleh mengakibatkan pengurangan makanan dan pengambilan air, penurunan pertumbuhan lembu, gangguan pencernaan dan cirit-birit.

Di Mississippi, pengeluar lembu pedaging di kawasan pantai harus berhati-hati terutamanya terhadap bekalan air tawar untuk lembu yang mungkin tercemar dengan garam selepas ribut tropika atau taufan.

Kekurangan klorin tidak mungkin berlaku dalam kebanyakan keadaan pengeluaran. Tanda-tanda kekurangan natrium termasuk pengurangan dan pengambilan makanan yang tidak normal, pertumbuhan yang terencat, dan pengeluaran susu yang berkurangan.

Kandungan natrium makanan ternakan berbeza-beza, dan bijirin bijirin dan makanan biji minyak lazimnya bukan sumber natrium yang baik. Natrium boleh ditambah sebagai natrium klorida atau natrium bikarbonat, kedua-duanya adalah bentuk yang sangat tersedia untuk lembu daging.

Sulfur (S)

Sulfur adalah bahan binaan dalam beberapa asid amino (methoinine, cysteine, dan cystine) dan vitamin B (thiamin dan biotin) bersama dengan sebatian organik lain. Sulfur berfungsi dalam tubuh dalam reaksi detoksifikasi dan diperlukan oleh mikroorganisma ruminal untuk pertumbuhan dan fungsi sel normal.

Ketoksikan sulfur dicirikan oleh kegelisahan, cirit-birit, otot berkedut, dan pernafasan yang sukar. Dalam kes yang berlarutan, ketidakaktifan dan kematian mungkin berlaku. Tahap sulfur yang tinggi dikaitkan dengan polioencephalomalacia, keadaan yang dibincangkan secara terperinci dalam bahagian gangguan pemakanan penerbitan ini.

Pengambilan sulfur yang lebih rendah dapat mengurangkan pengambilan makanan, menekan pertumbuhan, dan menurunkan kadar tembaga. Pengurangan pengambilan makanan dan air boleh berlaku apabila tahap sulfur yang tinggi digunakan dalam air minuman. Tanda kekurangan sulfur yang dilaporkan adalah anoreksia, penurunan berat badan, kelemahan, kurus kering, air liur yang banyak dan kematian. Kekurangan sulfur yang kurang teruk boleh mengurangkan pengambilan makanan, kebolehcernaan, bilangan mikroorganisma rumen, dan sintesis protein mikrob. Pengumpulan laktat dalam rumen dan darah kemudiannya boleh berkembang dengan gangguan populasi mikrob rumen.

Sulfur dalam makanan banyak didapati sebagai komponen protein. Dalam diet yang mengandungi paras makanan sorgum yang tinggi, makanan ternakan matang, makanan ternakan yang dihasilkan dalam tanah kekurangan sulfur, silaj jagung, protein pintasan rumen, atau di mana urea atau sumber nitrogen bukan protein lain menggantikan sumber protein tumbuhan, keperluan sulfur diet atau keperluan suplemen mungkin ditingkatkan. Makanan tambahan sulfur yang berpotensi termasuk natrium sulfat, amonium sulfat, kalsium sulfat, kalium sulfat, magnesium sulfat, atau unsur sulfur.

Mineral mikro

Kromium (Cr)

Kromium ialah mineral surih yang terlibat dalam pembersihan glukosa. Tindak balas imun dan kadar pertumbuhan dalam lembu tertekan telah ditunjukkan bertambah baik dengan suplemen kromium. Kromium boleh ditambah sebagai kromium picolinate atau kromium polynicotinate. Walau bagaimanapun, pengeluar lembu pedaging tidak perlu bimbang tentang suplemen kromium dalam keadaan biasa.

Kobalt (Co)

Kobalt berfungsi sebagai komponen vitamin B12 (cobalamin). Mikrob ruminan dapat mensintesis vitamin B12 jika kobalt ada. Lembu boleh bertolak ansur dengan kira-kira 100 kali ganda keperluan diet mereka untuk kobalt, jadi ketoksikan kobalt tidak mungkin melainkan ralat perumusan suplemen mineral dibuat. Tanda-tanda ketoksikan kobalt termasuk pengurangan pengambilan makanan, pengurangan berat badan, anemia, kurus kering, peningkatan yang tidak normal dalam kandungan hemoglobin sel darah merah, dan kelemahan.

Lembu muda yang sedang membesar kelihatan lebih sensitif terhadap kekurangan kobalt berbanding lembu matang. Initial cobalt deficiency signs are depressed appetite and reduced growth performance or weight loss. In cases of severe cobalt deficiency, cattle display severe unthriftiness, swift weight loss, liver breakdown, and anemia. Cobalt deficiency has also been demonstrated to compromise immune system problems and disruption of microorganism production of propionate (a volatile fatty acid important for glucose production). Legumes are usually higher in cobalt than grasses. Soil pH is a major determinant of cobalt availability in the soil. Cobalt sulfate and cobalt carbonate are examples of supplemental cobalt sources for beef cattle diets. For a mineral supplement with an expected 4-ounce daily intake, the supplement should include 15 ppm cobalt.

Copper (Cu)

Copper is an essential component of many enzymes including lysyl oxidase, cytochrome oxidase, superoxide dismutase, ceruloplasmin, and tyrosinase. Supplementing with too much copper or contaminating feeds with copper could result in copper toxicity. Copper accumulates in the liver before toxicity occurs. Large releases of copper from the liver cause red blood cell breakage elevated methemoglobin levels in the blood, impairing oxygen transport abnormally high hemoglobin content in the urine jaundice widespread tissue death and, finally, death. Young cattle are more susceptible to copper toxicity than older cattle. Cattle with a mature rumen do not absorb copper well, but the liver can store significant quantities of copper. Molybdenum, sulfur, and iron levels in the diet affect copper levels required to induce toxicity.

Copper deficiency is a widespread problem in U.S. beef cattle herds. Cattle experiencing copper deficiency exhibit anemia, reduced growth, loss of pigmentation in hair, changes in hair growth and appearance, heart failure, easily fractured bones, diarrhea, compromised immune system function, and impaired reproduction, particularly estrous cycle disruption. Breed composition of cattle also affects copper requirements. For example, Simmental and Charolais require more copper than Angus, and copper supplement levels may need to be increased by as much as 25 to 50 percent for these breeds. In cattle grazing toxic endophyte-infected tall fescue, tall fescue toxicosis may be confused for copper deficiency, based on hair coat changes. In some cases, these conditions can occur together.

Copper is more available in concentrate diets than in forage diets. Forages vary greatly in copper content and may contain variable levels of molybdenum, sulfur, and iron, which reduce usable copper levels. Molybdenum, sulfur, iron, and zinc reduce copper status in the body can impact copper requirements. Legumes typically contain higher copper concentrations compared to grasses. In addition, oilseed meals generally contain higher levels of copper than cereal grains. Copper supplements include sulfate, carbonate, oxide, and organic forms. Copper oxide is poorly available compared with other the copper forms listed. General copper supplementation recommendations are 1250 ppm copper for a supplement consumed at a rate of four ounces per day.

Iodine (I)

Iodine is a key component of thyroid hormones involved in energy metabolism rate regulation in the body. Iodine is rarely deficient in cow herds in the Southeast U.S. Calves born hairless, weak, or dead irregular cycling, reduced conception rate, and retained placenta in breeding age beef females and depressed libido and semen quality in bulls are classic iodine deficiency signs. Onset of deficiency signs may be delayed well beyond the actual initial period of iodine deficiency.

Iodine deficiency is characterized by enlargement of the thyroid (goiter). Goitrogenic substances in feeds suppress thyroid function and can affect iodine requirements. In white clover, thiocyanate is derived from cyanate and impairs iodine uptake by the thyroid. Some Brassica forages, such as kale, turnips, and rape, contain glucosinolates with goitrogenic effects, but most reports of problems are in sheep and goats. Soybean meal and cottonseed meal are also reported to have goitrogenic effects.

Iodine toxicity affects cattle by reducing weight gain, lowering feed intake, and causing coughing and undue nasal discharge.

Dietary iodine supplement sources include calcium iodate, ethylenediamine dihydroiodide (EDDI), potassium iodide, and sodium iodide. The calcium iodate and EDDI forms of iodine are very stable and have high bioavailability in cattle, while the potassium and sodium iodide forms are relatively unstable and can break down when exposed to other minerals, heat, light, or moisture. A supplementation rate of 50 ppm iodine in a 4-ounce per day intake mineral supplement is recommended. The EDDI form is an organic form that has been used for foot rot prevention. Levels of EDDI necessary for foot rot control are much higher than nutrient requirement levels. Currently, the maximum legal supplementation rate of EDDI is 50 mg per head per day. This level is not effective for foot rot control, and the Food and Drug Administration (FDA) does not allow claims of EDDI supplements to treat or prevent any animal disease.

Iron (Fe)

Iron is a critical component of hemoglobin and myoglobin, two proteins involved in oxygen transport and use. More than half of the iron in the body is in hemoglobin. This element is also an essential component of several cytochromes and iron-sulfur proteins involved in the electron transport chain. In addition, some enzymes either contain or are activated by iron.

Iron toxicity manifests as diarrhea, acidosis (digestive tract disturbance), hypothermia (lower than normal core body temperature), reduced weight gain, and depressed feed intake. Iron depletes copper in cattle and can contribute to copper deficiency if copper supplementation levels are not adjusted to compensate for copper losses. Iron deficiency causes anemia, lethargy, lowered feed intake, reduced weight gain, pale mucous membranes, and shriveling of the raised tissue structures on the tongue. Conditions that cause chronic blood loss, such as severe parasite infestations, can lead to iron deficiency. Evidence suggests iron requirements are higher for young cattle than for mature cattle. Calves raised in confinement exclusively on milk diets are more prone to iron deficiency. Iron sources include forages, cereal grains, oilseed meals, water, and soil ingestion. However, forage iron content varies greatly, and bioavailability of iron from forages is low relative to supplemental sources. Common supplemental sources include ferrous sulfate (iron sulfate), ferrous carbonate (iron carbonate), and ferric oxide (iron oxide or &ldquorust&rdquo). Bioavailability rank of these iron sources from most to least available is sulfate, carbonate, and then oxide form. Iron oxide has very little nutritional value. Iron is generally not needed from sources other than those provided by other mineral compounds commonly found in complete mineral supplements.

Manganese (Mn)

Manganese usefulness in the body is as a constituent of the enzymes pyruvate carboxylase, arginase, and superoxide dismutase and as an activator for many other enzymes, including hydrolases, kinases, transferases, and decarboxylases. Manganese is important for normal skeletal development, growth, and reproductive function.

At extremely high levels of manganese intake, growth performance and feed intake are reduced. Cattle deficient in manganese exhibit skeletal abnormalities, including stiffness, twisted legs, joint enlargement, and weak bones in young cattle. Older cattle display depressed or irregular estrus, low conception rate, abortion, stillbirths, and light birth weights when manganese intake is inadequate. Forage manganese levels vary with plant species, soil pH, and soil drainage, but forages usually contain adequate manganese levels. Corn silage manganese content is generally low. Feed-grade manganese forms include manganese sulfate, manganese oxide, manganese methionine, manganese proteinate, manganese polysaccharide complex, and manganese amino acid chelate. Bioavailability ranking from most to least available is manganese methionine, manganese sulfate, and, lastly, manganese oxide. A recommended manganese level is 2000 ppm in a 4-ounce daily intake mineral supplement.

Molybdenum (Mo)

The enzymes xanthine oxidase, sulfite oxidase, and aldehyde oxidase contain molybdenum. This element may improve microbial activity in the rumen under certain conditions.

There is no proof cattle experience molybdenum deficiency under normal production circumstances, so molybdenum supplementation is not a practical concern. Molybdenum toxicity, on the other hand, results in diarrhea, anorexia, weight loss, stiffness, and hair color alterations. Other potential effects of molybdenum toxicity include increased heifer age at puberty, decreased weight of heifers at puberty, and reduced conception rate. Calf growth performance is also slowed by excessive molybdenum levels. Copper and sulfur work against molybdenum in the body. Molybdenum contributes to copper deficiency, and copper can reduce molybdenum toxicity.

Forage molybdenum concentrates fluctuate with soil type and soil pH. Increased soil moisture, organic matter, and pH improve forage molybdenum levels. Molybdenum content in cereal grains and protein sources is more consistent.

Nickel (Ni)

The function of nickel in cattle is unknown. Yet nickel deficiency has been experimentally induced in animals. Nickel plays a role in ureolytic bacteria function as an essential component of the urease enzyme that breaks down urea (a common nonprotein nitrogen source in cattle diets). In general, nickel supplementation is not a concern on beef cattle operations under normal circumstances.

Selenium (Se)

Selenium is an important part of the enzymes glutathione peroxidase and iodothyronine 5&rsquo-deiodinase. Glutathione peroxidase helps prevent oxidative damage to tissues. The latter enzyme is involved in thyroid hormone metabolism. The functions of vitamin E and selenium are interrelated. Diets low in vitamin E may require selenium supplementation.

Signs of chronic selenium toxicosis include lameness, anorexia, emaciation, sore feet, cracked and deformed hooves, liver cirrhosis, kidney inflammation, and tail hair loss. In severe toxicity cases, difficulty breathing, diarrhea, muscle incoordination, abnormal posture, and death from respiratory failure are observed.

Selenium deficiency can lead to white muscle disease, a condition discussed in detail later in the nutritional disorders section of this publication. Calves may experience compromised immune response even when no other clinical signs of selenium deficiency are present. Unthriftiness, weight loss, and diarrhea are other deficiency signs.

Feed-grade selenium is often supplied as sodium selenite or sodium selenate, while selenomethionine is the common form in most feedstuffs. Selenium yeast is also a selenium source approved for use in cattle feed. Because of the high toxicity of selenium, it should be supplemented in a premixed form only. The FDA allows sodium selenate or sodium selenite as sources of selenium for selenium supplementation of complete feeds at a level not more than 0.3 ppm. The FDA permits up to 120 ppm selenium to be included in a salt-mineral mixture for free-choice feeding. Selenium injections are another way to provide selenium.

In some regions of the U.S., chronic selenium toxicity (alkali disease) occurs as a result of cattle&rsquos consuming forages grown on high selenium soils. Other regions of the U.S., including the southeastern U.S., are predisposed to selenium deficiency risk based on low soil and forage selenium content. In seleniumdeficiency- prone areas, use the maximum legal selenium supplement level in the feed and note that when purchasing feedstuffs from areas known to be deficient in selenium, selenium supplementation may need to be considered.

Zinc (Zn)

Zinc is a crucial component of many important enzymes and is also needed to activate other enzymes. These enzymes function in nucleic acid, protein, and carbohydrate metabolism. Zinc plays an important role in immune system development and function as well.

Quantities of zinc needed to cause toxicity are much greater than animal requirements. Signs of zinc toxicity include reduced weight gain, feed intake, and feed efficiency. Severe cases of zinc deficiency include listlessness, excessive salivation, testicular growth reduction, swollen feet, scaly lesions on feet, tissue lesions (most often on the legs, neck, head, and around the nostrils), slow healing of wounds, and hair loss. Less dramatic zinc deficiencies can cause decreased growth and lower reproductive performance.

Similar to several other minerals, zinc concentrations in forages depend on many factors, and zinc concentration in legumes is greater than in grasses. Plant proteins are typically higher in zinc levels than cereal grains. Supplemental sources of zinc include oxide, sulfate, methionine, and proteinate forms. The oxide and sulfate forms appear to have similar bioavailabilities, indicating no advantage to using zinc sulfate over zinc oxide. Zinc should be supplemented at a rate of 4000 ppm in a supplement designed for 4 ounces of intake per head per day.

Nutritional Disorders Related to Mineral Imbalances

Mineral imbalances (toxicities or deficiencies) can trigger nutritional disorders such as grass tetany, urinary calculi, polioencephalomalacia, white muscle disease, and milk fever in cattle. While these disorders can produce dramatic signs in affected cattle, mineral imbalances are often overlooked because only subclinical signs are present.

In the NAHMS 1996 survey, relatively few operations (5.2 percent) reported any known mineral deficiencies in the previous five years. However, these percentages likely severely underestimate the true magnitude of mineral deficiencies in cow-calf herds. A 1993 cow-calf study indicated that the extent of marginal and severe deficiency for copper and selenium is much more widespread.

In the absence of clinical signs, a mineral imbalance may be suspected if blood and tissue sample analysis or forage and diet mineral analysis suggests a problem. Compare levels of dietary mineral sources with cattle requirements detailed earlier in this publication to identify significant potential mineral imbalance problems. These are not always definitive for identifying mineral imbalances, though. It is important to be alert for &ldquored flags&rdquo in animal behavior and appearance to catch a problem early and minimize losses. Veterinarians should be familiar with mineralrelated disorders common in their areas and can assist with prevention and treatment. Reduced cattle performance from mineral imbalances is preventable with a good mineral nutrition program.

Grass Tetany

Cause. Grass tetany is associated with low levels of magnesium or calcium in cattle grazing annual ryegrass, small grains (such as oats, rye, wheat), and cool-season perennial grasses (such as tall fescue) in late winter and early spring. Grass tetany in Mississippi usually occurs February through April, when spring-calving cows graze on lush annual ryegrass or tall fescue. During this time of the year, there is often a flush of new forage growth. This is also the time of year many spring calves are born and nursing. Grass tetany most commonly affects lactating cattle, particularly the highest-milking animals in the herd. Magnesium and calcium requirements of lactating cattle are far greater than those of nonlactating cattle. This predisposes cattle to grass tetany during lactation. Grass tetany results when magnesium and calcium levels in forages are too low to meet the requirements of cattle and cattle do not get enough magnesium and calcium supplementation. Clinical signs of grass tetany include nervousness, muscle twitching around the face and ears, staggering, and reduced feed intake. An affected animal may go down on its side, experience muscle spasms and convulsions, and die if not treated.

Prevention. Forages grown on soils deficient in magnesium, wet soils, or soils low in phosphorus but high in potassium and nitrogen may contain very low levels of magnesium and calcium. Lime magnesiumdeficient pastures with dolomitic lime, which contains magnesium. This may not prevent grass tetany on waterlogged soils, because plants may not be able to take up enough magnesium under wet conditions.

Phosphorus fertilization may also improve forage magnesium levels. However, environmental concerns associated with excessive soil phosphorus levels should be considered. High levels of nitrogen and potassium fertilization are associated with increased grass tetany, so fertilization plans should consider this. Legumes are often high in magnesium and may help reduce the risk of grass tetany when included in the forage program. The most reliable method of grass tetany prevention is supplemental feeding of magnesium and calcium during the grass tetany season. Both can be included in a mineral mix as part of a mineral supplementation program. Initiate highmagnesium (at least 10 percent Mg and preferably 13 to 14 percent Mg) mineral feeding at least one month before grass tetany season.

Urinary Calculi or &ldquoWater Belly&rdquo

Cause. Urinary calculi (kidney stones) are hard mineral deposits in the urinary tracts of cattle. Affected cattle may experience chronic bladder infection from tissue damage produced by the calculi. In more serious cases, calculi may block the flow of urine, particularly in male animals. The urinary bladder or urethra may rupture from prolonged urinary tract blockage, resulting in release of urine into the surrounding tissues. The collection of urine under the skin or in the abdominal cavity is referred to as &ldquowater belly.&rdquo Death from toxemia may result within 48 hours of bladder rupture. Signs of urinary calculi include straining to urinate, dribbling urine, blood-tinged urine, and indications of extreme discomfort, such as tail wringing, foot stamping, and kicking at the abdomen. Phosphate urinary calculi form in cattle on high grain diets, while silicate urinary calculi typically develop in cattle on rangeland.

Prevention. Strategies to prevent problems with urinary calculi in cattle include lowering urinary phosphorus levels, acidifying the urine, and increasing urine volume. To lower urinary phosphorus levels, avoid diets high in phosphorus. Maintain a dietary calcium- to-phosphorus ratio of 2:1. This ratio is preferred over the previously mentioned 1.6:1 ratio in situations where urinary calculi risk is of concern. Acid-forming salts such as ammonium chloride may be fed to acidify the urine. Ammonium chloride may be fed at a rate of 1.0 to 1.5 ounces per head per day. Urine volume may be increased by feeding salt at 1 to 4 percent of the diet while providing enough water.

Polioencephalomalacia

Cause. Polioencephalomalacia is caused by a disturbance in thiamine metabolism. Thiamine is required for a number of important nervous system functions. This disease most commonly affects young, fast-growing cattle on a high concentrate diet and may result from a thiamine-deficient diet, an increase in thiaminase (an enzyme that breaks down thiamine) in the rumen, or an increase in dietary sulfates.

A thiamine-deficient diet is usually associated with an increase in the dietary-concentrate-to-roughage ratio. When concentrates (feed grains such as corn) are increased and roughage (forage, cottonseed hulls, etc.) are decreased in the diet, rumen pH drops. This increases the numbers of thiaminase-producing bacteria in the rumen. Thiaminase breaks down the form of thiamine the animal normally could use. Some species of plants produce thiaminase and can cause a decrease in the useable amount of thiamine when consumed. Examples of these plants include kochia, bracken fern, and equisetum.

A high sulfate diet can also inhibit an animal&rsquos ability to properly use thiamine. Feeds such as molasses, corn gluten feed, and dried distillers grains are often high in dietary sulfates. Some water sources can also contain a high amount of sulfur (such as &ldquogyp&rdquo water). When these are consumed in excessive amounts, clinical signs of polioencephalomalacia can occur.

Affected cattle usually show several signs of generalized neurological disease. These signs can include but are not limited to blindness, inconsistent and uncoordinated movements, head pressing, &ldquogoose&rdquo stepping, lying with full body contact with the ground with the head and legs extended, tetany (muscle spasms), convulsions with paddling motions, and death. These signs usually begin suddenly, with the animals typically having normal temperatures and rumen function.

Prevention. Preventative strategies should focus on the diet. Avoid risk factors such as high concentrate diets or high sulfate diets, if possible. Thiamine can also be added to a feed ration or a free-choice mineral supplement at 3 to 10 ppm, but this may not be cost effective.

White Muscle Disease

Cause. &ldquoWhite muscle disease&rdquo (enzootic nutritional muscular dystrophy) most commonly affects cardiac or skeletal muscle of rapidly growing calves. It results from vitamin E and/or selenium deficiency and causes muscle breakdown. This metabolic imbalance can be because of dietary deficiency or because of calves&rsquo being born to dams that consumed selenium-deficient diets during gestation.

Two distinct conditions of this disease are a cardiac form and a skeletal form. The cardiac form of the disease usually comes on quickly, with the most common clinical sign&rsquos being sudden death. At first, animals may exhibit an increased heart rate and respiratory distress, but they usually die within 24 hours. The skeletal form of the disease generally has a slower onset. Calves affected by the skeletal form exhibit stiffness and muscle weakness. Although these animals usually have normal appetites, they may not be able to stand for long periods and have trouble breathing if their diaphragm or chest muscles are involved. Some animals may show signs of difficulty swallowing and possible pain while swallowing if the muscles of the tongue are also affected.

Necropsy of an affected animal often reveals pale discoloration of the affected muscle. The texture of the muscle is dry with white, chalky, streaked sections representing the fibrosis and calcification of the diseased tissue. Hence, the name &ldquowhite muscle disease.&rdquo

Prevention. Supplementing vitamin E and selenium controls this disease. Salt/mineral mixtures can supplement the deficiencies. A free-choice mineral supplement with an expected intake of four ounces/head/day should contain 27 ppm of selenium. In known selenium deficient areas, it is recommended to administer 25 mg of selenium and 340 IU of vitamin E intramuscularly approximately four weeks before calving.

Milk Fever

Cause. Milk fever (parturient paresis or hypocalcemia) is generally associated with older, high-producing dairy cattle, but it may also occur with beef cattle. Milk fever occurs shortly after calving and the onset of milk production. Milk fever occurs when the lactating cow cannot absorb enough calcium from the diet or has not started mobilizing bone calcium to meet the increased calcium demand of lactation. Calcium losses from lactation coupled with inadequate supply results in a drop in blood calcium level. Because calcium is needed for muscle contraction, cows suffering from milk fever often lose their ability to stand.

Prevention. Numerous steps can be taken to prevent milk fever. The first is to raise the calcium and phosphorus levels of the diet. Too much dietary calcium in late pregnancy could leave the cow unprepared to absorb or mobilize enough calcium from bone to meet elevated requirements when lactation starts. This sometimes occurs with feeding poultry litter because of the high calcium content of the litter.

Feeding low calcium diets a month or two before calving was once thought to be the best prevention because the body would be geared to mobilizing bone calcium. This approach has had limited success and is difficult with high forage diets.

If milk fever is a common problem in the herd, feeding an anionic pre-partum diet (a negative dietary cation-anion difference, DCAD) helps prevent milk fever. Adequate vitamin D is also important in preventing milk fever but is not typically a problem with beef cattle on pasture.

Mineral Elements and Levels Toxic to Cattle

Some minerals beef cattle do not require or require only in very small quantities can be toxic when consumed above threshold toxicity levels. The National Research Council defines the maximum tolerable concentration for a mineral as &ldquothat dietary level that, when fed for a limited period, will not impair animal performance and should not produce unsafe residues in human food derived from the animal.&rdquo

Vitamin Nutrition

Vitamins are classified as either water soluble or fat soluble. Water soluble vitamins include the B complex and vitamin C. Fat soluble vitamins include A, D, E, and K. Rumen bacteria can produce the B complex vitamins and vitamin K in cattle. Vitamin supplementation is generally not as critical as mineral supplementation for beef cattle grazing actively growing forages. However, increased rates of vitamin A and E supplementation may be necessary when feeding dormant pastures or stored forages. For practical purposes, vitamins A and E should receive the most attention when planning cattle vitamin nutritional programs.

Fat Soluble Vitamins

Vitamin A

Vitamin A (retinol) is the vitamin most likely to be deficient in beef cattle diets. It is essential for normal vision, growth, reproduction, skin tissue and body cavity lining cell maintenance, and bone development. It is not in plant material, but its precursors (alpha carotene, beta carotene, gamma carotene, and cryptoxanthin) are present. These cartotene and carotenoid precursors are converted to vitamin A in the animal. Vitamin A and beta carotene play a role in disease protection and immune system function.

Exposure to sunlight, air, and high temperatures destroys carotene. Ensiling can help preserve carotene supplies. Corn is one of the few grains that contains appreciable amounts of carotene. High quality forages, on the other hand, contain large amounts of vitamin A precursors. When forage supplies are limited or low quality, vitamin A supplementation becomes critical. While the liver can store vitamin A, at most two to four months of reliance on these stored liver supplies can ward off vitamin A deficiency.

In practical production scenarios, vitamin A toxicity is rare. Rumen microorganisms can break down vitamin A, and this helps prevent vitamin A toxicity. Vitamin A deficiency is more probable when cattle are fed high concentrate diets bleached pasture or hay during drought conditions feeds excessively exposed to sunlight, heat, and air heavily processed feeds feeds mixed with oxidizing materials such as minerals or feeds stored for long periods. Calves not receiving adequate colostrum and stressed calves are at highest risk of vitamin A deficiency.

Vitamin A deficiency shows up as reduced feed intake, rough hair coat, fluid accumulation in joints and brisket, excessive tear production, night blindness, slow growth, diarrhea, seizures, poor skeletal growth, blindness, low conception rates, abortion, stillbirths, blind calves, low quality semen and infections in cattle. Night blindness is unique to vitamin A deficiency. Vitamin A can be supplied by injection or through the consumption of vitamin A precursors in green, leafy forages. In deficiency situations, injections may be more effective.

Vitamin D

Vitamin D forms include ergocalciferol (vitamin D2) found in plants and cholecalciferol (vitamin D3) found in animals. Vitamin D is needed for calcium and phosphorus absorption, normal bone mineralization, and calcium mobilization from bone. It may also function in immune response. Toxicity signs include calcification of soft tissues, bone demineralization, decreased appetite, and weight loss. Vitamin D deficiency causes rickets where bones do not use calcium and phosphorus normally. Stiff joints, irritability, anorexia, convulsions, brittle bones, decreased appetite, digestive problems, labored breathing, and weakness are deficiency signs. Cattle do not maintain body reserves of vitamin D. Yet cattle rarely require vitamin D supplementation because vitamin D is made by cattle exposed to sunlight or fed sun-cured forages.

Vitamin E

Vitamin E is in feedstuffs as alpha-tocophorol. It serves as an antioxidant in the body and is important in membrane formation, muscle structure, and muscle function. Disease resistance is tied to Vitamin E levels. Selenium is closely linked with this vitamin. Vitamin E requirements depend on concentrations of antioxidants, sulfur-containing amino acids, and selenium in the diet. And high dietary concentrations of polyunsaturated fatty acids found in corn oil and soybean oil can dramatically increase vitamin E requirements. High moisture feeds lose vitamin E quicker than drier feeds, and many other factors contribute to vitamin E breakdown in feeds. There is less toxicity risk with vitamin E than with vitamins A and D. The margin of safety with vitamin E appears to be great. Signs of vitamin E deficiency, however, are characteristic of white muscle disease described earlier. Cattle displaying deficiency signs often respond to either vitamin E or selenium supplementation. Both may be needed in some instances.

Vitamin Supplementation

Vitamins A, D, and E are often added to mineral mixes or feed supplements as an A-D-E premix package. Many commercial mineral mixes have vitamins A, D, and E added at sufficient levels. However, it is important to review the mineral tag to be sure, particularly when actively growing forage is not available to cattle. Vitamin quantities are expressed as International Units (IU), which are set amounts defined for each specific vitamin form. Reasonable rates of vitamin supplementation for cattle consuming a 4-ounce daily intake vitamin supplement are: Vitamin A, 100,000 to 200,000 IU Vitamin D, 7,500 to 20,000 IU and Vitamin E, 50 to 100 IU. Vitamins can degrade over time, so supplements purchased and stored for several months before being used may not supply adequate vitamin levels.

Interpreting Mineral and Vitamin Tags

Though the amount of information on a mineral and vitamin supplement tag may seem overwhelming at first, the tag contains valuable information about a mineral mix. There are several common sections on most mineral tags.

    Product name &ndash When a single number is present in the product name, the number represents the phosphorus content. For example, &ldquoPro 8&rdquo would contain 8 percent phosphorus. When two numbers are present in the name, the first number typically represents the calcium content, while the second number represents the phosphorus content. In most cases, if the calcium to phosphorus ratio is higher than 3:1, cattle will have to eat an excessive amount to get the phosphorus they need. Phosphorus is usually the most expensive component of a mineral supplement. Phosphorus is also very important in beef cattle diets, particularly when grazing low quality pastures. Instead of purchasing a supplement based on price alone, try to buy a reasonably-priced supplement that provides adequate levels of phosphorus and other important minerals.

Mineral and Vitamin Supplement Feeding Problems and Solutions

Fine particle size and the need to mix small quantities into bulk feed supplies make mixing a mineral and vitamin supplement with commodity-based feedstuffs difficult or impractical in some feed mixing scenarios. Unless feed mixing equipment can create a consistent mix and there is not a significant likelihood of the smaller particles in the mineral and vitamin supplement settling out of the finished feed, then consistently supplying a separate free-choice loose mineral mix or top-dressing feed may be more practical for mineral and vitamin supplement delivery in cattle diets.

Excessive intake can be a problem with mineral and vitamin supplements and can be an unnecessary expense. Cattle sometimes over consume a mineral and vitamin mix when they are first exposed to it but then drop supplement intake to appropriate levels after an adjustment period. Also, if cattle are allowed to run out of mineral and vitamin supplement, they may over compensate by increasing consumption when it is put out again. If intake does not drop to recommended levels after a month of feeding a continuous supply of mineral and vitamin supplement, try adding salt to the mineral and vitamin mix or moving the supplement feeder farther away from water sources.

Inadequate mineral and vitamin intake, on the other hand, can be addressed by adding dry molasses to the mineral and vitamin mix or by moving the supplement feeder closer to a water source or area where cattle congregate. Make sure not to provide salt separately from a free-choice mineral supplement, because cattle may consume the salt supplement and avoid the complete mineral and vitamin mix. Changing mineral mixes is another option that sometimes corrects excessive or inadequate mineral consumption.

One mineral and vitamin supplement formulation may not be ideal year-round. Mineral and vitamin supplements can be used to deliver beneficial drugs, antibiotics, and parasite control ingredients to cattle diets. Adding these products may increase the price of the mineral and vitamin supplement. In addition, these products may need only to be supplied to cattle for defined periods of time or during certain times of year. It is advisable to reformulate the mineral and vitamin supplement to remove these products when they are not needed. Mineral and vitamin composition of supplements should also be adjusted for forage conditions. For example, increased magnesium supplementation is justified during grass tetany season but should be reduced during other periods to match cattle nutrient needs better and avoid unnecessary reductions in supplement palatability often associated with high levels of magnesium.

Many mineral supplements cake and harden when allowed to get wet, causing mineral intake to drop. Magnesium supplements are particularly prone to this problem. Using covered feeders that protect from rain can help minimize mineral hardening. Commercial mineral supplements are available that better withstand rain damage and wind losses. Mineral and vitamin supplement selection should consider mineral and vitamin composition and price of the supplement as first priorities over weather protection. It is a good idea to check the mineral and vitamin supplement supply at least weekly. Break up hardened mineral as much as possible. Checking the mineral supply on a regular basis is also important in monitoring consumption and making sure cattle do not run out.

Many different mineral and vitamin supplement feeder designs are available. Examples are shown below. Consider differences in protection of the supplement from the environment, quantity of supplement the feeder can contain, ease of moving the feeder, and feeder durability. Strategic placement and positioning of open-sided mineral and vitamin supplement feeders can lessen weather effects on the supplement. For illustration, if precipitation most often falls and blows from one direction, then turning open sides of mineral and vitamin supplement feeders away from this direction is warranted.

Mineral and Vitamin Supplementation Summary

Appropriate intake of key minerals and vitamins is essential for beef cattle productivity and health. Many different commercially available mineral and vitamin supplements are marketed to beef cattle producers. Custom blends of minerals and vitamins are another option for mineral and vitamin supplementation. Not all available mineral and vitamin supplements contain enough of the minerals and vitamins beef cattle need. In selecting a mineral and vitamin supplement, consider the class of cattle being supplemented forage conditions mineral and vitamin levels in feedstuff and water sources and expected intake levels of forages, feeds, and mineral and vitamin supplements. Investing in a good mineral and vitamin nutrition program and properly managing mineral and vitamin feeding is highly recommended for both beef cow-calf and stocker operations. For more information on mineral and vitamin nutrition for beef cattle, contact an office of the Mississippi State University Extension Service.


Making Sour Cream

Is the Good Bacteria in Activia Yogurt in All Yogurts?

Sour cream is made by mixing cream with a sour milk such as buttermilk and letting it sit at room temperature for up to 24 hours. The sour milk contains bacteria that work through the cream, thus creating a uniformly thick mixture. Heating the sour cream to a high temperature for pasteurization kills off the bacteria heating the sour cream to a lower temperature will preserve some of the microorganisms.


Tonton videonya: СКАЗКА ПРО МАКРОФАГОВ. ЗАНИМАТЕЛЬНАЯ НАТУРОПАТИЯ (Disember 2022).