Abstract：
The objectives of this experiment were to evaluate the effects of supplementation of Nellore (Bos indicus) cows with β-carotene + vitamins A + D3 + E + biotin on body condition score (BCS), oestrus, pregnancy, and foetal morphometry. Lactating cows (n = 497) from two herds were balanced for BCS and calving period [early calving (EC); late calving (LC)] and were assigned randomly to: Control (n = 251)-supplementation with a mineral supplement; and SUP (n = 246)-supplementation with the mineral supplement fed to control + β-carotene (150 mg/day) + vitamin A (40,000 IU/day) + vitamin D3 (5000 IU/day) + vitamin E (300 mg/day) + biotin (20 mg/day). Cows were supplemented from Days -30 to 30 (Day 0 = timed artificial insemination; TAI). Pregnancy was diagnosed 30 days after TAI and foetal crown-rump distance and thoracic diameter were measured at 30 and 77 days of gestation. Cows in the SUP treatment were more likely to have BCS ≥3.0 on Day 0 (63.0 ± 3.1 vs. 60.2 ± 3.1; p < .01) and were more likely to gain BCS from Days -30 to 30 (57.7 ± 3.3 vs. 44.1 ± 3.3%; p < .01). Fewer LC cows in the SUP treatment were detected in oestrus at the time of the first TAI (Control: LC: 75.4 ± 4.4 vs. SUP: LC: 64.0 ± 5.2 vs. Control: EC: 65.3 ± 4.0 vs. SUP: EC: 71.8 ± 3.7; p = .04). There was a tendency for the SUP treatment to increase pregnancy to the first TAI (64.2 ± 3.0 vs. 56.6 ± 3.1%; p = .08). A greater percentage of SUP cows was detected in oestrus at the time of the second TAI (70.1 ± 5.0 vs. 52.3 ± 4.8%; p = .01). The SUP treatment increased pregnancy to the second TAI among LC cows (SUP: LC: 75.9 ± 8.0% vs. Control: LC: 50.0 ± 8.3% vs. Control: EC: 52.0 ± 5.9% vs. SUP: EC: 41.4 ± 6.5%; p = .02). The SUP treatment increased foetal size (crown-rump; p = .04 and thoracic diameter; p < .01) at 30 days of gestation and, despite decreasing crow-rump length at 77 days after the first TAI among EC cows (p < .01), it increased the thoracic diameter at 77 days after the first TAI independent of calving season. Our results support that pregnancy establishment and foetal growth can be improved when grazing Nellore cows are supplemented with β-carotene and vitamins A + D3 + E + biotin.
摘要：
本实验的目的是评估Nellore（Bosindicus）奶牛补充β-胡萝卜素维生素AD3E生物素对身体状况评分（BCS）的影响。发情期,怀孕,和胎儿形态计量学。将来自两个牛群的泌乳母牛（n=497）在BCS和产仔期[早期产牛（EC）；后期产牛（LC）]中保持平衡，并随机分配给：对照（n=251）-补充矿物质补充剂；和SUP（n=246）-补充矿物质补充剂，以对照β-胡萝卜素（150mg/天）维生素A（300,000IU/天）维生素E（300mg/天）从第-30天至第30天补充奶牛(第0天=定时人工授精;TAI)。在TAI后30天诊断为妊娠，并在妊娠30天和77天测量胎儿冠-臀部距离和胸径。SUP治疗的奶牛在第0天更有可能出现BCS≥3.0（63.0±3.1与60.2±3.1；p<.01），并且更有可能从-30天到30天获得BCS（57.7±3.3与44.1±3.3%；p<0.01）。在第一次TAI时，在发情时检测到SUP处理中的LC奶牛较少（对照：LC：75.4±4.4vs.SUP:LC:64.0±5.2vs.控制：EC：65.3±4.0vs.SUP：EC：71.8±3.7；p=.04）。SUP治疗有增加妊娠至第一个TAI的趋势（64.2±3.0vs.56.6±3.1%；p=.08）。在第二次TAI时，发情时检测到更大百分比的SUP奶牛（70.1±5.0vs.52.3±4.8%；p=0.01）。SUP治疗将LC母牛的妊娠增加到第二个TAI（SUP：LC：75.9±8.0％vs.控制：LC：50.0±8.3％vs.对照：EC：52.0±5.9％vs.SUP：EC：41.4±6.5%；p=0.02）。SUP治疗在妊娠30天时增加了胎儿的大小（冠臀部；p=.04和胸径；p<.01），尽管在EC奶牛的第一个TAI后77天，乌鸦-臀部长度减少（p<0.01），在第一次TAI后77天，胸径增加，与产卵季节无关。我们的结果支持，当放牧Nellore母牛补充β-胡萝卜素和维生素AD3E生物素时，可以改善妊娠建立和胎儿生长。
