Influence of Various Vitamin-A-supplies on its Concentration in Liver and Plasma of Calves

摘要: Abstract Five individual feeding experiments with male calves were conducted to investigate various influencing factors on the retinol plasma level and vitamin-A-depot of liver. Liver depends carotene or vitamin-A-intake cows vitamin-A-concentration milk, respectively. Two three weeks old born during summer contained more liver-vitamin-A (>100 IU g−1) than animals winter season. Feeding first colostrum improves vitamin A supply because decrease in milk following milkings (1st milking: 100%, 2nd: 74%, 3rd: 41%). Besides liver content feeds vitamin-A-supply influenced vitamin-A-status growing cattle. About 25000 per 100 kg body weight day necessary keep depot a constant (≈ g−1). The results show homeostasis calves. concentration was ...