Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/17/1997
Publication Date: N/A
Citation: N/A Interpretive Summary: Recombinant porcine somatotropin (PST) administration shifts the priority of nutrient partitioning favoring lean tissue growth and greatly reduces fat accretion in growing pigs. The young pig grows extremely efficiently and does not respond to PST administration. This study examined if nutrient supply could limit the response of young pigs to PST administration. Artificially reared pigs treated between 10 and 25 kg did not respond to PST assessed by daily gain, feed intake and feed efficiency. Several blood parameters of metabolism were beneficially affected by PST. Approaching significance, whole body protein deposition was increased and fat deposition was decreased by PST administration. Nutrient intake is not a factor explaining the diminished beneficial effects of PST administration anabolic in the very young pig.
Technical Abstract: A porcine somatotropin (PST) dose optimized study was conducted with 10 kg pigs artificially reared on a high energy and protein diet containing supplemental lysine. The study was conducted for a 20 d period. Blood urea nitrogen was dcreased and glucose and nonesterified fatty acids were increased by PST. Body composition changes approached significance suggesting PST shifted nutrient partitioning. Plasma concentrations of insulin and insulin-like growth factor 1 increased, while insulin-like-growth factor ll decreased. No significant increase in the insulin-like binding protein 3 was observed. The latter suggests that the growth hormone-insulin-like growth factor axis and its components are not matured permitting the young pig to fully respond to exogenous PST.