
%0 Journal Article
%A Ma, L. 
%A Dunshea, F. R. 
%A Brockwell, Y. M. 
%A Inglis, R. L. 
%A Kingston, D. J. 
%A Sillence, M. N. 
%T IGF-I is not a useful marker for nutritional status in the growing pig under commercial conditions
%J Australian Journal of Agricultural Research
%D 2001/04/23
%V 52
%N 5
%P 603-608
%K pigs, diet, fasting, growth, insulin, glucagon.
%R https://doi.org/10.1071/AR00096
%U https://www.publish.csiro.au/paper/AR00096 
%X Plasma hormone concentrations were measured in gilts after fasting, long-term protein restriction, or supplementation. In 11-week-old pigs fasted overnight, plasma insulin, glucagon, gastrin, urea, and glucose were increased 30 min after re-feeding (P &#60; 0.05), whereas IGF-I did not change. In 16-week-old gilts fed a standard commercial diet &#91;14.6% crude protein (CP)&#93;, or a high-protein diet (16.7% CP) for 4 weeks, the high-protein diet increased weight gain (13%; P &#60; 0.05) and carcass weight (4%; P &#60; 0.05), but did not alter plasma IGF-I, insulin, or glucagon. In 10-week-old gilts fed high-protein diets (19.4% and 18.3% CP), or low-protein diets (15.5% and 13.3% CP) for 12 weeks during the grower and finisher phases, respectively, the low-protein diet decreased weight gain (18%; P &#60; 0.001) and carcass weight (11%; P &#60; 0.01), with a marked increase in plasma glucagon (P &#60; 0.05), no change in insulin, and only a trend towards decreased IGF-I (P = 0.1). The pigs were more sensitive to altered dietary protein at 10 weeks of age than at 16 weeks. Plasma IGF-I was not responsive to the short-term effects of feeding or the long-term effects of dietary protein. Glucagon could provide a useful marker for nutritional status in young pigs, provided that time of feeding is taken into account. 
