Folman Y, Ascarelli I, Kraus D, Barash H
J Dairy Sci. 1987 Feb;70(2):357-66. doi: 10.3168/jds.S0022-0302(87)80017-6.
A total of 155 high yielding dairy cows were used to study the effect of dietary beta-carotene (carotene) on fertility. The diet of group 1 was supplemented with 69 mg retinyl acetate per cow daily before calving and 96 mg retinyl acetate after calving: diet of group 2 was supplemented with 500 mg carotene per cow before calving and 96 mg retinyl acetate after calving; and that of group 3 with 500 mg carotene before and 700 mg after calving. Conception rates were 53.9, 42.2, and 27.9% for cows of groups 1, 2, and 3. Days open were 110 and 112 for young (second and third lactation) and old (fourth and later lactations) cows of the group 1; 130 and 129 for young and old cows of group 2; and 133 and 166 for young and old cows of group 3. Number of inseminations per conception was 1.8 and 1.8, 2.2 and 2.2, and 2.5 and 3.4 for the same groups, respectively. Within group 3 the percent of cows pregnant 120 d after calving was 57 and 20 for the young and old cows. Correlation coefficients between plasma carotene of 53 old cows of all groups 4 and 8 wk after calving, and the number of open days and the number of inseminations per conception were significant. The intake of high carotene may have adverse effects on the fertility of dairy cows.
总共155头高产奶牛用于研究日粮β-胡萝卜素（胡萝卜素）对繁殖力的影响。第1组奶牛在产犊前每天每头补充69毫克醋酸视黄酯，产犊后补充96毫克醋酸视黄酯；第2组奶牛在产犊前每头补充500毫克胡萝卜素，产犊后补充96毫克醋酸视黄酯；第3组奶牛在产犊前后分别补充500毫克和700毫克胡萝卜素。第1、2、3组奶牛的受孕率分别为53.9%、42.2%和27.9%。第1组年轻（第二和第三胎次）和老龄（第四及以后胎次）奶牛的空怀天数分别为110天和112天；第2组年轻和老龄奶牛的空怀天数分别为130天和129天；第3组年轻和老龄奶牛的空怀天数分别为133天和166天。相同组别的每受孕输精次数分别为1.8次和1.8次、2.2次和2.2次、2.5次和3.4次。在第3组中，产犊后120天怀孕的年轻和老龄奶牛的比例分别为57%和20%。所有组53头老龄奶牛在产犊后4周和8周时血浆胡萝卜素水平与空怀天数及每受孕输精次数之间的相关系数具有显著性。高胡萝卜素摄入量可能对奶牛的繁殖力产生不利影响。
