Nutrient-Independent and Nutrient-Dependent Factors Stimulate Protein Synthesis in Colostrum-Fed Newborn Pigs

The neonatal period is characterized by rapid growth and elevated rates of synthesis and accretion of skeletal muscle proteins. The fractional rate of muscle protein synthesis is very high at birth and declines rapidly with age. The elevated capacity for muscle protein synthesis in the neonatal pig is driven by the high ribosome content and, together with an increased efficiency of the translation process, promotes accelerated protein synthesis rates. Feeding profoundly stimulates muscle protein synthesis in neonatal pigs and the response decreases with age. The feeding-induced stimulation of muscle protein synthesis is modulated by an enhanced sensitivity to the postprandial increase in insulin and amino acids. The developmental decline in the response to insulin and amino acids parallels a marked decrease in the feeding-induced activation of translation initiation factors that regulate the binding of mRNA to the 40S ribosomal complex. The abundance and activation of many known positive regulators of the nutrient-and insulin-signaling pathways that are involved in translation initiation are high, whereas those of many negative regulators are low in skeletal muscle of younger pigs. Thus, the activation and(or) abundance of the positive regulators, such as the insulin receptor, insulin receptor-substrate-1, phosphoinositide-3 kinase, phosphoinositide-dependent kinase-1, protein kinase B, mammalian target of rapamycin, raptor, ribosomal protein S6 kinase-1, eukaryotic initiation factor (eIF) 4E-binding protein 1, and eIF4E associated with eIF4G, are greater in 7-d-old pigs than in 26-d-old pigs. The activation of negative regulators, including protein tyrosine phosphatase-1B, phosphatase and tensin homologue deleted on chromosome 10, protein phosphatase 2A, and tuberous sclerosis complex 1/2, are lower in 7-d-old pigs than in 26-d-old pigs. Thus, the developmental decline in the stimulation of skeletal muscle protein synthesis by insulin and amino acids is due in part to the developmentally related decrease in the activation of the signaling pathways that lead to translation initiation.

Section: Postnatal Ontogeny Of the Feeding-induced Stimulation Of Musmentioning

confidence: 99%

Postnatal ontogeny of skeletal muscle protein synthesis in pigs1,2

Davis

Suryawan

Orellana

et al. 2008

“…They also observed a 33% increase in ileal protein synthesis rate in colostrum-fed pigs compared to those fed milk; however, this may have been due in part to the greater amounts of protein and energy in the colostrum (150% and 50% more, respectively) compared to that provided by the mature milk. In a second experiment (Burrin et al, 1995a) in which nutrient intake from colostrum and a cow-milk-based formula were comparable, colostrum accentuated skeletal muscle and jejunal protein synthesis, suggesting a role for non-nutritive component(s) in colostrum.…”

Section: Early Postnatal Development Of the Intestinementioning

confidence: 99%

Intestinal effects of milkborne growth factors in neonates of agricultural importance.

Odle

Zijlstra

Donovan

1996

138

Reduction of postnatal morbidity and mortality of mammalian neonates poses a significant challenge to agricultural and medical sciences. Because nutritional insufficiency and diarrhea represent major stressors, an understanding of factors mediating postnatal growth and development of the gastrointestinal tract is essential. This review explores the role that milkborne growth factors may play in stimulating functional development of the neonatal intestine, with emphasis on the porcine, bovine, and ovine species. Studies reporting milk concentrations and intestinal effects are reviewed, with emphasis on epidermal growth factor, insulin, and the insulin-like growth factors. Collectively, these studies suggest that milkborne growth factors may provide important regulatory signals to the neonatal intestine under both normal and pathophysiological states.

“…Colostrum and milk, but especially colostrum, are also rich sources of a suite of compounds such as growth factors, hormones, cells, and antimicrobial factors, including lactoferrin, lysozyme, lactoperoxidase, and cytokines (e.g., IL-1β, IL-6, TNF-α, IFN-γ, and IL-1ra), which in one way or another are involved in the stimulation and regulation of the growth and development of the GIT in this period (e.g., Burrin et al, 1995;Donovan and Odle, 1994;Xu, 1996;Sangild et al, 2000;Xu et al, 2000;Odle et al, 1996;Gauthier et al, 2006;Boudry et al, 2008). It is outside the scope of this review to discuss each (isolated) growth factor/ compound and its effects on the structure and function of the GIT for young pigs; however, interest has focused particularly on the properties and roles of epidermal growth factor (EGF), the insulin-like growth factors, insulin, and other compounds such as transforming growth factor.…”

Section: Growth Factors In Colostrum and Milkmentioning

confidence: 99%

Invited review: Aspects of gastrointestinal tract growth and maturation in the pre- and postweaning period of pigs

Pluske

2016

ABSTRACT:The growth and development of the gastrointestinal tract (GIT) of the young pig, both before and after parturition, is critical for the animal's future growth and development, efficiency of feed conversion to body depots, and, ultimately, its survival. The perinatal development of the GIT encompasses a prenatal phase, a neonatal phase, and the postweaning phase, which is associated with the adaptation of the GIT to utilize solid feed after the piglet is weaned. The consumption of colostrum, initially, and then milk after birth provides nutrients and compounds for piglets that are critically important as stimuli and substrates to the GIT that in turn evoke a suite of anatomical, immunological, biochemical, physiological, and regulatory processes that advance the overall maturity of the GIT. However, at weaning the combined influence of the various stressors imposed causes a hiatus in the growth and development of the GIT, such that the newly weaned pig endures a "growth check" while exposing it to a greater disease and health risk. Low and variable feed intake is a major outcome of the weaning process, but nevertheless, there are numerous nutritional/management interventions producers can implement in an attempt to overcome this major issue. This review summarizes some major aspects of, and influences on, GIT growth, development, and maturation in the pre-and postweaning period of pigs, demonstrating that postnatal influences occur in utero and that evolution of the GIT continues to occur after weaning.