Postnatal adaptation of the gastrointestinal tract in neonatal pigs: a possible role of milk-borne growth factors

During the postnatal period the gastrointestinal (GI) tract of the neonatal pig encounters numerous challenges and severe stress, particularly at the time of birth and weaning. In response to such challenges, the GI tract undergoes marked changes, including accelerated tissue growth and functional maturation during the immediate postnatal period, and intestinal villus atrophy and damage following weaning. The changes are apparently related to the onset of colostrum ingestion at the time of birth and the withdrawal of milk ingestion at the time of weaning. Porcine colostrum and milk contain not only highly digestible nutrients but also numerous bioactive compounds, including various types of growth factors, including epidermal growth factor, insulin-like growth factor-I (IGF-I), IGF-II, insulin and transforming growth factor-p. Experimental evidence summarized in the review indicates a regulatory role of these milli-borne growth factors in stimulating GI tissue growth and function maturation, and in enhancing repair of damaged GI mucosa in the suckling young. The findings imply that milk-borne growth factors may be used to enhance GI maturation in neonatal animals and be used to treat GI mucosal damages. Potential therapeutic applications of milk-borne growth factors in both agricultural animals and human infants warrant further investigation. (C) 2000 Elsevier Science B.V. All rights reserved.