Dunn T G, Kaltenbach C C
J Anim Sci. 1980;51 Suppl 2:29-39.
The effects of nutrition on the length of the postpartum interval (PPI, the interval from parturition to the first postpartum estrus that is accompanied by ovulation) were reviewed for the ewe, sow and cow. Unfortunately, information on the effects of nutrition on the PPI of the mare is nonexistent. Absence of estrus following weaning is a problem in postpartum sows, especially during the summer. High feed intake (more than 3 kg daily) immediately after weaning decreases the incidence of anestrus in sows of some breeds, but not in others. The incidence of prolonged intervals between weaning and estrus and the incidence of anestrus is more frequent in primiparous than in multiparous sows. The effect of nutrition on the PPI of the ewe is more controversial than that for the sow. In mature Merino ewes, neither lactation nor undernutrition during lactation affects the duration of the PPI while both factors increase the length of the PPI in coarse-wool breeds. Undernutrition during lactation increases the incidence of anestrus in primiparous fall-lambing Merino ewes. A cow must conceive by 80 days postpartum to have a 365-day calving interval. Excessive length of the PPI in dairy cows does not appear to be one of the major detriments to fertility since most dairy cows have a PPI of considerably less than 80 days. While feeding high protein diets to high-producing dairy cows shortens the PPI; this practice also increases the interval from parturition to conception. Weight changes, both before and after calving, and body condition at calving interact to affect the PPI of suckled beef cows. The length of the PPI in cows that are in good body condition at calving is not affected by either pre- or postpartum weight changes. More cows in moderate and thin body condition showed estrus by 60 days postpartum if the cows had gained weight prior to calving compared with those that lost weight prior to calving. A high percentage of thin cows that lose weight prior to calving does not show estrus following calving unless they gain weight after calving. The length of the PPI is affected by many factors, for example: parity, breed, lactation, environment and endocrine status. Designs of future experiments must be cognizant of these factors and the possible interactions of these factors with the nutritional status of the animal.
综述了营养对母羊、母猪和母牛产后间隔期（PPI，即从分娩到首次伴有排卵的产后发情之间的间隔）时长的影响。遗憾的是，关于营养对母马PPI影响的信息并不存在。断奶后不发情是产后母猪面临的一个问题，尤其是在夏季。断奶后立即给予高采食量（每日超过3千克）可降低某些品种母猪的乏情发生率，但对其他品种则无此效果。初产母猪断奶至发情间隔延长的发生率和乏情发生率高于经产母猪。营养对母羊PPI的影响比对母猪的影响更具争议性。在成年美利奴母羊中，泌乳期或泌乳期营养不足均不影响PPI的时长，而这两个因素都会增加粗毛品种母羊的PPI时长。泌乳期营养不足会增加初产秋季产羔美利奴母羊的乏情发生率。奶牛必须在产后80天内受孕才能实现365天的产犊间隔。奶牛PPI过长似乎并非影响繁殖力的主要不利因素之一，因为大多数奶牛的PPI远少于80天。虽然给高产奶牛饲喂高蛋白日粮可缩短PPI，但这种做法也会延长从分娩到受孕的间隔。产犊前后的体重变化以及产犊时的体况相互作用，影响哺乳肉牛的PPI。产犊时体况良好的母牛，其PPI时长不受产犊前或产后体重变化的影响。与产犊前体重减轻的母牛相比，如果母牛在产犊前体重增加，那么更多体况中等和消瘦的母牛在产后60天内会发情。产犊前体重减轻的瘦母牛中，很大比例在产犊后不发情，除非它们在产后体重增加。PPI的时长受许多因素影响，例如：胎次、品种、泌乳、环境和内分泌状态。未来实验的设计必须认识到这些因素以及这些因素与动物营养状况之间可能存在的相互作用。
