Instituto de Ganadería de Montaña (CSIC-Universidad de León), Finca Marzanas s/n, 24346, Grulleros, León, Spain.
Department of Animal Sciences, Food and Nutrition (DIANA), Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122, Piacenza, Italy.
J Dairy Sci. 2018 Sep;101(9):8021-8031. doi: 10.3168/jds.2018-14648. Epub 2018 Jun 28.
Nutritional programming caused by feed restriction during the early life may counteract the profitability of the dairy sheep farm. However, most studies have been focused exclusively on the prenatal period, and scarce information regarding the effect of milk replacer (MR) restriction on feed efficiency [residual feed intake (RFI)] and progesterone patterns of replacement ewe lambs is available. Therefore, in the present study 40 Assaf female newborn lambs were penned individually and assigned randomly to 1 of 2 treatment groups (n = 20 per treatment). The first group of lambs was fed MR ad libitum (ADLB), whereas the second one (restricted, RES) only received approximately 62.5% of the MR intake measured in the ADLB group. All the lambs were weighed twice a week until they were 35 d old. Then 8 lambs from each group were killed and a morphological study of the gut was performed. Moreover, a piece of liver was cut to measure fat content and oxidative status. The rest of the ewe lambs (24) were weaned and offered a total mixed ration ad libitum to calculate the RFI during the replacement phase. Plasma samples were collected when ewe lambs were 8 mo old to perform a nontargeted metabolomic analysis on a hybrid quadrupole-time-of-flight mass spectrometer coupled to an ultra-high-performance liquid chromatographic system. Progesterone was also measured weekly on serum samples by sequential competitive immunoassay until the end of the experiment (9.5 mo old). The results observed indicate that moderated MR restriction promoted differences in the morphology of the gut of the 35-d-old lambs, but not in the apparent digestibility or feed efficiency traits (RFI) during the replacement phase. However, there was a trend toward reduced live body weight of the RES ewe lambs when they were 9.5 mo old. Moreover, progesterone patterns revealed that only 1 RES versus 4 ADLB ewe lambs had ovulated for the first time at the end of the experiment. This evidence suggests the existence of long-term effects caused by early feed restriction with negative consequences on live body weight and reproductive traits of replacement ewe lambs.
早期饲养限制引起的营养编程可能会降低奶绵羊养殖场的盈利能力。然而，大多数研究仅集中在产前阶段，关于代乳料（MR）限制对饲料效率[残留饲料摄入量（RFI）]和替代母羊孕酮模式的影响，相关信息很少。因此，本研究中，40 只 Assaf 初生母羔羊被单独饲养并随机分配到 2 个处理组中的 1 个（每组 20 只）。第一组羔羊自由采食 MR（ADLB），而第二组（限制组，RES）仅接受 ADBL 组中测量的 MR 摄入量的约 62.5%。所有羔羊每周称重两次，直到 35 日龄。然后，每组 8 只羔羊被宰杀，并对肠道进行形态学研究。此外，取一块肝脏测量脂肪含量和氧化状态。其余的母羔羊（24 只）断奶，并提供自由采食的全混合日粮，以在替代阶段计算 RFI。当母羔羊 8 月龄时采集血浆样品，在混合四极杆-飞行时间质谱仪与超高效液相色谱系统上进行非靶向代谢组学分析。每周在血清样品中通过顺序竞争免疫测定法测量孕酮，直到实验结束（9.5 月龄）。观察到的结果表明，适度的 MR 限制促进了 35 日龄羔羊肠道形态的差异，但在替代阶段的表观消化率或饲料效率特征（RFI）上没有差异。然而，RES 母羔羊在 9.5 月龄时的活体体重有下降的趋势。此外，孕酮模式表明，只有 1 只 RES 母羔羊和 4 只 ADBL 母羔羊在实验结束时首次排卵。这一证据表明，早期饲养限制会产生长期影响，对替代母羔羊的活体体重和繁殖性状产生负面影响。
