Thyroid Hormones and Cortisol Concentrations in Offspring are Influenced by Maternal Supranutritional Selenium and Nutritional Plane in Sheep

Colostrum traits and newborn body weight and growth: comparison between single and twin underfed sheep pregnancies

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 (n = 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 (p < 0.05 for both). Singletons had higher glycaemia than twins at 12 h postpartum (102.2 ± 32.8 vs. 73.4 ± 29.9 mg/dL, p < 0.05). 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.

Effects of nutrition restriction of fat- and lean-line broiler breeder hens during the laying period on offspring performance, blood biochemical parameters, and hormone levels

To evaluate the effects of maternal undernutrition on the performance, blood biochemical indexes, and hormone levels of broiler chicks, two broiler breeder lines (a fat line and lean line) were given either 100% or 75% of the daily feed intake recommended by the Chinese Ministry of Agriculture from 27 to 54 wk. All hens were fed the same basal corn-soybean diet. Fertile eggs were collected and hatched. All chicks were fed the same basal diet for 56 d. Then, chick performance, blood biochemical indexes, and hormone levels were measured. The results showed that there were interactions between maternal nutrition and line for some parameters, such as the kidney index, glucose, triglyceride, insulin, glucagon, leptin, and triiodothyronine (P < 0.05). Chicks of the fat line had a lower level of serum glucose, triglyceride, albumin, glutamic-pyruvic transaminase, insulin, and thyroxin than those of the lean line (P < 0.05), but the opposite trend was seen for birth weight, heart index, leptin, and triiodothyronine (P < 0.05). Maternal undernutrition decreased the birth weight and thymus index (day 28) of offspring (P < 0.05), but these effects disappeared by day 56. Maternal undernutrition decreased glucose (day 28), urea nitrogen (day 56), creatinine (day 56), glutamic-pyruvic transaminase (day 56), creatinine kinase (day 56), and leptin (day 56) levels in the offspring's serum (P < 0.05) but increased creatinine (day 28), total protein (day 28), glutamic-pyruvic transaminase (day 28), and glucagon (day 28) levels (P < 0.05). In conclusion, different lines have different metabolic processes. Maternal nutrition restriction during the laying period did have effects on the offspring, and the compensation by offspring reduced the effect of maternal nutrition restriction.