PSIV-22 Effect of dietary glycine on growth performance and skin collagen abundance of nursery pigs fed low crude protein diets

摘要

Ninety-six barrows (initial BW: 6.41 ± 0.61kg) were used to determine the effect of low crude protein (CP) diets supplemented with glycine and serine (G+S) on growth performance and skin collagen abundance. Barrows were randomly assigned to 24 pens and fed 1 of 3 dietary treatments ad-libitum in a 3-phase-feeding program: 1) corn-soybean meal diet (CON; 23.6– 20.5% CP); 2) low-CP diet (19.7–14.8% CP) supplemented with G+S to achieve the same concentration of G+S as CON; 3) similar to diet 2 but supplemented with glutamate instead of G+S to maintain the same CP concentration (GLU); diets were fed for 6 weeks. Individual BW and pen feed disappearance were measured weekly. On d 35, 1 pig/pen was sacrificed for determination of body composition and N retention, and skin samples were collected for collagen analysis. Final BW and overall ADG were greater for pigs fed CON versus GLU (P < 0.05) while G+S were intermediate; feed efficiency was not influenced by diet. Carcass weights on day 35 were greater for pigs fed CON (22.4kg) versus G+S (19.0kg) or GLU (20.4 kg; P < 0.05). Viscera weights on day 35 were greater for CON (3373g) versus G+S (2912g; P < 0.05); GLU were intermediate (3186g). Overall, whole-body N retention and N intake were greater for CON (11.98, 38.3 g/d for N retention and N intake, respectively) than G+S (9.02, 27.5 g/d) and GLU (9.52, 29.1g/d; P < 0.05). On day 35, pigs fed G+S and CON had greater skin collagen abundance (72.8%,and 72.0% for G+S and CON, respectively) versus GLU (67.2%;P < 0.05). Supplementing low-CP diets with G+S maintained BW and overall ADG (versus CON), but both G+S and GLU had reduced N retention; only G+S had skin collagen abundance not different from CON. Supplementing specific non-essential amino acids as well as measures beyond growth performance should be considered when formulating low-CP diets.