Turín Jesús, Sales Francisco, Peralta Oscar A, De Los Reyes Mónica, Borie Consuelo, Carrasco Albert, González-Bulnes Antonio, Parraguez Víctor H
Magister in Animal and Veterinary Sciences Program, Faculty of Veterinary Sciences, University of Chile, Santiago, Chile.
CRI-Kampenaike, INIA, Punta Arenas, Chile.
Front Vet Sci. 2023 Sep 8;10:1256989. doi: 10.3389/fvets.2023.1256989. eCollection 2023.
Maternal nutrition during gestation plays an important role in colostrum production, postnatal growth, and survival of newborn lambs, especially in twin gestations. This research aimed to investigate the effects of chronic natural undernutrition on colostrum traits and early lamb's postnatal growth born from single and twin sheep pregnancies developed in a restrictive prairie, representative of southern Patagonia. Single- and twin-bearing ewes ( = 20 per group) were maintained grazing in a natural pasture. At 140 days of gestation, ewes were placed in individual pens for lambing control. Colostrum was collected immediately after delivery and at 12, 24, and 36 h postpartum, for determination of yield and composition. Maternal blood was obtained at 140 days of gestation and at lambing for plasma glucose, progesterone, 17β-estradiol, and IgG determination. Newborn lamb blood for determining glycaemia and IgG was collected at birth and at 12, 24, 36, and 120 h after birth. Lamb mortality and growth was assessed from birth until 30 days of life. No differences were observed in progesterone and 17β-estradiol. There were no differences in colostrum yields and fat components, however single- had higher values of protein and lactose than twin-bearing ewes ( for both). Singletons had higher glycaemia than twins at 12 h postpartum (102.2 ± 32.8 vs. 73.4 ± 29.9 mg/dL, ). Colostrum IgG content was similar at delivery but higher in single ewes at 12 and 24 h, reaching a similar values at 36 h (4.7 ± 9.7 and 5.8 ± 7.7 mg/mL in single and twin pregnancies, respectively). Newborn IgG was higher in singletons compared to twins at least until 48 h of life. Lams body weight was always superior in singleton than twins from birth until 30 days of life. Mortality did not differ during the first week of life, but it increased significantly only in twins until day 30 of life. Undernourishment in pregnant ewes affected colostrum quantity and quality, resulting in a lower postnatal growth and a higher mortality in twins. Alternative managements favoring fetal growth, birth weight and neonatal viability in twin sheep pregnancies are needed, when flocks are breed under harsh environments.
孕期母体营养对初乳分泌、新生羔羊出生后的生长及存活起着重要作用，尤其是在双胎妊娠中。本研究旨在调查长期自然营养不足对来自单胎和双胎绵羊妊娠的初乳特性以及在巴塔哥尼亚南部典型的限制性草原环境中出生的羔羊早期产后生长的影响。单胎和双胎母羊（每组20只）在天然牧场放牧。妊娠140天时，将母羊放入个体围栏中以便控制产羔。分娩后及产后12、24和36小时立即采集初乳，用于测定产量和成分。在妊娠140天和产羔时采集母羊血液，用于测定血浆葡萄糖、孕酮、17β - 雌二醇和IgG。出生时及出生后12、24、36和120小时采集新生羔羊血液用于测定血糖和IgG。评估羔羊从出生到30日龄的死亡率和生长情况。孕酮和17β - 雌二醇未观察到差异。初乳产量和脂肪成分无差异，然而单胎母羊的蛋白质和乳糖含量高于双胎母羊（两者均如此）。产后12小时单胎羔羊血糖高于双胎羔羊（102.2±32.8对73.4±29.9毫克/分升）。分娩时初乳IgG含量相似，但单胎母羊在产后12和24小时更高，在36小时达到相似值（单胎和双胎妊娠分别为4.7±9.7和5.8±7.7毫克/毫升）。至少在出生后48小时内，单胎新生羔羊的IgG高于双胎。从出生到30日龄，单胎羔羊的体重始终高于双胎。出生后第一周死亡率无差异，但仅双胎羔羊在30日龄前死亡率显著增加。当羊群在恶劣环境下繁殖时，怀孕母羊的营养不足会影响初乳的数量和质量，导致双胎羔羊出生后生长较慢且死亡率较高。需要采取有利于双胎绵羊妊娠中胎儿生长、出生体重和新生儿活力的替代管理措施。
