Nottle M B, Kleemann D O, Seamark R F
Department of Obstetrics and Gynaecology, Medical School University of Adelaide, Australia.
Anim Reprod Sci. 1997 Sep;49(1):29-36. doi: 10.1016/s0378-4320(97)00066-3.
The effect of undernutrition on the ovulation rate of Merino ewes supplemented with lupins was examined in two experiments using a 2 x 2 factorial (low vs high nutritional plane x none vs supplemented) design. In both experiments, ewes were assigned at random to two equal-sized groups and differentially grazed for 8 weeks (low and high). In Experiment 1, flocks were recombined and managed as one group for 18 weeks and then divided into their original nutritional treatments 17 days prior to ovulation. Each of these groups was divided at random into equal-sized subgroups and one subgroup fed lupins for 10 days prior to ovulation. Restricting nutrition 6 months prior to ovulation resulted in a difference in mean liveweight between the low and high groups of 9.3 kg at the end of the 8-week period (P < 0.001). Ovulation rates per ewe were 1.06 +/- 0.07 (low, no supplement), 1.63 +/- 0.09 (low, lupin-supplemented), 1.28 +/- 0.09 (high, no supplement) and 1.57 +/- 0.08 (high, lupin-supplemented). The increase of 0.22 ovulations per ewe for the low vs high plane of nutrition without supplement was significant (P < 0.05). There was a significant interaction (P < 0.05) between previous nutrition imposed 6 months prior to ovulation and lupin supplementation, indicating that the ovulatory response to lupins was greater at the low compared with the high plane of nutrition (0.57 vs 0.29 extra ovulations per 100 ewes). In Experiment 2, the previous nutritional treatments were imposed for 8 weeks immediately before ovulation. Restricting feed intake in the low group resulted in a difference in mean liveweights between the two groups of 6.2 kg (P < 0.001) 6 weeks after the start of the nutritional treatments. Ovulation rates were 1.22 +/- 0.06 (low, no lupin supplement), 1.38 +/- 0.09 (low, lupin-supplemented), 1.67 +/- 0.08 (high, no lupin supplement) and 1.64 +/- 0.09 (high, lupin-supplemented). The effect of previous nutrition on ovulation rate was significant (P < 0.001) with 0.35 extra ovulations per ewe fed the high plane. Ewes in the low group responded to lupin supplementation with 0.16 extra ovulations per ewe (P = 0.06), whereas ewes previously fed on a high plane did not respond to the lupin treatment.
在两项实验中，采用2×2析因设计（低营养水平与高营养水平×不补充与补充），研究了营养不良对补饲羽扇豆的美利奴母羊排卵率的影响。在两项实验中，母羊被随机分为两个大小相等的组，并分别进行8周的不同强度放牧（低强度和高强度）。在实验1中，羊群重新组合并作为一组管理18周，然后在排卵前17天分为原来的营养处理组。这些组中的每一组又被随机分为大小相等的亚组，其中一个亚组在排卵前10天补饲羽扇豆。排卵前6个月限制营养，导致8周期末低营养组和高营养组的平均活重相差9.3千克（P<0.001）。每只母羊的排卵率分别为1.06±0.07（低营养水平，不补充）、1.63±0.09（低营养水平，补饲羽扇豆）、1.28±0.09（高营养水平，不补充）和1.57±0.08（高营养水平，补饲羽扇豆）。低营养水平与高营养水平且不补充时，每只母羊排卵数增加0.22个，差异显著（P<0.05）。排卵前6个月施加的先前营养与羽扇豆补饲之间存在显著交互作用（P<0.05），表明与高营养水平相比，低营养水平下母羊对羽扇豆的排卵反应更大（每100只母羊额外排卵数分别为0.57个和0.29个）。在实验2中，先前的营养处理在排卵前立即进行8周。低营养组限制采食量，导致营养处理开始6周后两组平均活重相差6.2千克（P<0.001）。排卵率分别为1.22±0.06（低营养水平，不补饲羽扇豆）、1.38±0.09（低营养水平，补饲羽扇豆）、1.67±0.08（高营养水平，不补饲羽扇豆）和1.64±0.09（高营养水平，补饲羽扇豆）。先前营养对排卵率的影响显著（P<0.001），高营养水平组每只母羊额外排卵0.35个。低营养组母羊对羽扇豆补饲有反应，每只母羊额外排卵0.16个（P = 0.06），而先前处于高营养水平的母羊对羽扇豆处理无反应。
