Maternal Nutrition, Developmental Programming, and the Small Intestine
Resumen
Small intestinal growth and function are critical for optimal animal growth and health, playing a major role in nutrient digestion and absorption, energy and nutrient expenditure, and immunological competence. Small intestinal growth and development are often overlooked but essential processes driving metabolism, immunology, survival, and growth. The small intestine not only serves as the main site for digestion and absorption of nutrients, but it is also a major energy and nutrient sink due to its high metabolic activity and rapid turnover. Changes in small intestinal mass, cellularity, and oxygen consumption have been demonstrated during feed restriction and in response to specific nutrients. The effects of in utero environment have become a major area of study in animal and human nutrition, physiology, and epidemiology research, as evidenced by the hundreds of reviews on the subject. In livestock, intrauterine growth restriction (IUGR) results in impaired fetal development, low birth weight offspring, and decreased long-term production. Programming of growth and development in livestock may be driven by many factors, but often occurs in response to compromised nutrient supply to developing offspring. Because the small intestine is critical to animal growth, health, and production and is responsive to its luminal and extraluminal environment, early life effects on small intestinal development likely play a significant role in observed programming of later animal health and performance, including in the acquisition of nutrients during the pre- and postnatal periods. Additionally, impacts of gestational nutrition on the maternal small intestine may change nutrient delivery to offspring, both in utero and during lactation. This review will focus on impacts of nutrition during pregnancy on maternal and offspring small intestines and focus on data from ruminant livestock models.