נגישות
menu      
חיפוש מתקדם
Journal of Steroid Biochemistry
Folman, Y., Institute of Animal Science, A.R.O., The Volcani Center, Bet Dagan, 50250, Israel
Rosenberg, M., Institute of Animal Science, A.R.O., The Volcani Center, Bet Dagan, 50250, Israel
Ascarelli, I., The Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot, 76100, Israel
Kaim, M., Institute of Animal Science, A.R.O., The Volcani Center, Bet Dagan, 50250, Israel
Herz, Z., Institute of Animal Science, A.R.O., The Volcani Center, Bet Dagan, 50250, Israel
The effects of high dietary protein concentrations, high ambient temperatures and low dietary β-carotene levels on fertility and on plasma progesterone and oestradiol-17β levels in high-yielding dairy cows, are described. High-yielding dairy cows were fed diets containing 15 or 20% crude protein. Cows fed the higher level of protein were less fertile and had a lower plasma progesterone concentration during the oestrous cycle preceding the first insemination. This phenomenon was especially pronounced in cows fed a diet containing 85% concentrates and 15% hay, where plasma progesterone levels during days 9-17 of the oestrous cycle were 2.5-3.7 ng/ml in cows fed the high level of protein and 4.0-5.5 ng/ml in cows fed the low level of protein (P < 0.05). In cows fed 50% more energy before parturition, plasma progesterone levels did not differ between animals fed the low and high protein diets. Heat stress, which caused a rise in body temperature, decreased fertility and plasma progesterone levels during the luteal phase of the oestrous cycle but increased plasma oestradiol-17β levels during the 36 h preceding the onset of oestrus from 5 to 7 pg/ml (P ≤ 0.005). The effect on fertility of supplementing the diet of dairy heifers and cows with β-carotene is reviewed. In some of the experiments where the basal plasma β-carotene levels were lower than 50μg/100ml, β-carotene supplementation significantly increased fertility. However, in no case was fertility affected when plasma β-carotene levels exceeded 150 μg/100ml. The possible relationships among body weight changes, energy balance, plasma progesterone levels and fertility of dairy cows are discussed. © 1983.
פותח על ידי קלירמאש פתרונות בע"מ -
הספר "אוצר וולקני"
אודות
תנאי שימוש
The effect of dietary and climatic factors on fertility, and on plasma progesterone and oestradiol-17β levels in dairy cows
19
Folman, Y., Institute of Animal Science, A.R.O., The Volcani Center, Bet Dagan, 50250, Israel
Rosenberg, M., Institute of Animal Science, A.R.O., The Volcani Center, Bet Dagan, 50250, Israel
Ascarelli, I., The Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot, 76100, Israel
Kaim, M., Institute of Animal Science, A.R.O., The Volcani Center, Bet Dagan, 50250, Israel
Herz, Z., Institute of Animal Science, A.R.O., The Volcani Center, Bet Dagan, 50250, Israel
The effect of dietary and climatic factors on fertility, and on plasma progesterone and oestradiol-17β levels in dairy cows
The effects of high dietary protein concentrations, high ambient temperatures and low dietary β-carotene levels on fertility and on plasma progesterone and oestradiol-17β levels in high-yielding dairy cows, are described. High-yielding dairy cows were fed diets containing 15 or 20% crude protein. Cows fed the higher level of protein were less fertile and had a lower plasma progesterone concentration during the oestrous cycle preceding the first insemination. This phenomenon was especially pronounced in cows fed a diet containing 85% concentrates and 15% hay, where plasma progesterone levels during days 9-17 of the oestrous cycle were 2.5-3.7 ng/ml in cows fed the high level of protein and 4.0-5.5 ng/ml in cows fed the low level of protein (P < 0.05). In cows fed 50% more energy before parturition, plasma progesterone levels did not differ between animals fed the low and high protein diets. Heat stress, which caused a rise in body temperature, decreased fertility and plasma progesterone levels during the luteal phase of the oestrous cycle but increased plasma oestradiol-17β levels during the 36 h preceding the onset of oestrus from 5 to 7 pg/ml (P ≤ 0.005). The effect on fertility of supplementing the diet of dairy heifers and cows with β-carotene is reviewed. In some of the experiments where the basal plasma β-carotene levels were lower than 50μg/100ml, β-carotene supplementation significantly increased fertility. However, in no case was fertility affected when plasma β-carotene levels exceeded 150 μg/100ml. The possible relationships among body weight changes, energy balance, plasma progesterone levels and fertility of dairy cows are discussed. © 1983.
Scientific Publication
You may also be interested in