Impacts of gestational nutrition on maternal and offspring performance and intestinal biology.

摘要

Small intestinal development, vascularization, and function are critical for optimal animal growth and performance, playing a major role in nutrient digestion and absorption, energy and nutrient expenditure, and immunological competence. The small intestine is known to change with intake and physiological state; however, its relationship with developmental programming remains unclear. Two experiments investigated the effects of gestational nutrition on maternal and offspring performance and intestinal biology in ruminants. In Experiment 1, effects of stage of gestation and maternal nutrient restriction during early to mid-gestation were determined using mature beef cows. The maternal intestine was minimally responsive to nutrient restriction, but effects of advancing gestation give insight into possible intestinal changes to meet demands of fetal growth. Fetal weight was unaffected by maternal nutrition: however, fetal intestinal responses to nutrient restriction suggest increased efficiency potential of offspring. In Experiment 2, effects of nutritional plane and selenium supply during gestation on primiparous ewes were investigated. Maternal body weight and body composition followed nutritional plane during gestation. Additionally, ewes fed high selenium had greater body condition score change, average daily gain, gain:feed, backfat thickness, and longissimus muscle area. Lamb birth weight and neonatal average daily gain were reduced by maternal nutrient restriction, although high selenium during gestation increased birth weight for lambs born to restricted ewes. Ewe colostrum yield and nutrient content were reduced by restricted and high nutritional planes during gestation, whereas milk yield and nutrient content were decreased only by nutrient restriction. Colostrum and milk yield were greater for ewes fed high selenium compared with adequate selenium, and colostral nutrients were increased by high selenium. The maternal intestine was impacted by nutritional plane and, to a lesser extent, selenium supply during gestation both at parturition and after being fed a common diet during early lactation. Intestinal growth, vascularity, and angiogenic factor messenger ribonucleic acid expression were altered, suggesting that effects of gestational nutrition extend to early lactation and influence maternal and offspring performance. In conclusion, better understanding of gestational nutritional effects on the maternal and offspring intestine will allow for development of management and therapeutic strategies to optimize ruminant livestock performance.