Chapingo Autonomous University, Regional Universitary Unit on Arid Lands, Bermejillo, Durango, Mexico.
Reprod Biol. 2013 Mar;13(1):51-7. doi: 10.1016/j.repbio.2013.01.171. Epub 2013 Jan 19.
This study aimed to evaluate the effects of betacarotene (BC) supplementation on ovulation rate (OR) and luteinizing hormone (LH) secretion in adult goats during the breeding season. Additionally, total ovarian activity (TOA) comprising the total number of ultrasonographically detectable antral follicles (AF) and corpora lutea (OR) was also assessed. In early October, adult goats [n=22, 3.5 years of age, 7/8 Sannen-Alpine; 26°N, 103°W at 1117m.a.s.l.] were randomly assigned to: (i) BC group (BCG), orally supplemented with 50mg of BC/goat/day [n=10; live weight (LW)=45.9±2.0kg, body condition score (BCS; range: 0-emaciated to 5-obese)=3.0±0.1], and (ii) control group (CONT) [n=12; LW=46.2±2.0kg, BCS=3.0±0.1]. All animals received a basal diet of alfalfa hay, corn silage and corn grain, with free access to water and mineral salts. The whole experimental period spanned 34 days before and 17 days after ovulation. On day 23 of the experiment, estrus was synchronized with progestin-releasing intravaginal sponges; 36h prior to estrus, an intensive blood sampling (every 15min for 6h) was performed to determine mean LH concentrations, pulsatility (LH-PULSE) and area under the curve (LH-AUC) for serial LH concentrations. Afterwards, by the end of the luteal phase (i.e., 17 days after the onset of estrus), an ultrasonographic scanning was performed to evaluate OR and TOA [AF+OR]. The average LW and BCS did not differ (p>0.05) during the experimental period. BC-supplemented goats showed an increase in OR (3.4±0.2 versus 2.8±0.2; p<0.05) and exhibited lower (p<0.05) serum LH concentrations, LH-AUC and LH-PULSE compared to CONT. A positive correlation was recorded between OR and LW (r(2)=0.42, p<0.05) and BCS (r(2)=0.47, p<0.05). In addition, AF (5.0±0.6 versus 3.4±0.6) and TOA (8.4±0.6 versus 6.2±0.6) were greater (p<0.05) in the BC-supplemented group than CONT. Supplementation with BC enhanced ovarian follicular development and ovulation rate in adult female goats under decreased photoperiods through LHRH-independant pathways or direct effects of BC on ovarian function.
本研究旨在评估β-胡萝卜素（BC）补充对繁殖季节成年山羊排卵率（OR）和促黄体生成激素（LH）分泌的影响。此外，还评估了总卵巢活性（TOA），包括超声检测到的窦卵泡（AF）和黄体总数（OR）。10 月初，将成年山羊[ n=22，3.5 岁，北纬 26°，西经 103°，海拔 1117m]随机分配到：（i）BC 组（BCG），每天口服补充 50mg BC/只[ n=10；体重（LW）=45.9±2.0kg，体况评分（BCS；范围：0-消瘦至 5-肥胖）=3.0±0.1]，和（ii）对照组（CONT）[ n=12；LW=46.2±2.0kg，BCS=3.0±0.1]。所有动物均接受紫花苜蓿干草、玉米青贮和玉米谷物的基础日粮，自由饮水和矿物质盐。整个实验期在排卵前 34 天和排卵后 17 天进行。在实验的第 23 天，通过孕激素释放阴道海绵同步发情；发情前 36 小时，进行密集采血（每 15 分钟采集 6 小时），以确定平均 LH 浓度、脉冲性（LH-PULSE）和 LH 浓度曲线下面积（LH-AUC）。之后，在黄体期结束时（即发情开始后 17 天），进行超声扫描以评估 OR 和 TOA[AF+OR]。在实验期间，BC 补充组和 CONT 组的平均 LW 和 BCS 没有差异（p>0.05）。与 CONT 相比，BC 补充组的 OR（3.4±0.2 对 2.8±0.2；p<0.05）增加，血清 LH 浓度、LH-AUC 和 LH-PULSE 降低（p<0.05）。OR 与 LW（r（2）=0.42，p<0.05）和 BCS（r（2）=0.47，p<0.05）呈正相关。此外，BC 补充组的 AF（5.0±0.6 对 3.4±0.6）和 TOA（8.4±0.6 对 6.2±0.6）均大于 CONT（p<0.05）。BC 补充通过 LHRH 独立途径或 BC 对卵巢功能的直接作用增强了成年母山羊在光照时间减少下的卵泡发育和排卵率。
