Off-campus UNL users: To download campus access dissertations, please use the following link to log into our proxy server with your NU ID and password. When you are done browsing please remember to return to this page and log out.

Non-UNL users: Please talk to your librarian about requesting this dissertation through interlibrary loan.

Effects of dietary crude protein and/or crystalline amino acid concentration on serum IGF -I concentrations and IGF -I mRNA expression in growing pigs

Robert L Fischer, University of Nebraska - Lincoln

Abstract

Three experiments were conducted to investigate the effects of increasing dietary crude protein (CP) and/or crystalline amino acid (AA) intake on growth performance, serum insulin-like growth factor-I (IGF-I) concentration, and IGF-I mRNA expression in growing-finishing pigs. All three experiments utilized crossbred pigs with an initial body weight of 34 kg in 28-d (exp. 1) or 26-d (exp. 2 and 3) growth assays. Dietary treatments used in the experiments were standard corn-soybean meal diets (10, 14, 18, 22% CP) or low-protein, amino acid-supplemented diets (10% CP + AA, 14% CP + AA, and 18% +AA). Pig and feeder weights were recorded weekly during all three experiments for the determination of ADG, ADFI, and feed efficiency (ADG/ADFI). Blood samples were collected weekly and analyzed for plasma urea and serum IGF-I concentrations. On d 26 (exp. 2 and 3) and d 28 (exp. 1), real-time ultrasound backfat (BF) and longissimus muscle area (LMA) measurements were recorded and used for the calculation of fat-free lean gain (FFLG). There was no difference (P > 0.10) in ADFI among treatments throughout the growth period in all three experiments. Dietary protein concentration had linear and quadratic effects on ADG and ADG/ADFI (P < 0.01) in exp. 1 and 2. Results from experiment 3 showed that pigs fed the corn-soybean meal diets had greater ADG (P < 0.05) and ADG/ADFI (P < 0.05) than pigs fed the low-protein, amino acid-supplemented diets throughout the experiment. In exp. 2 and 3, IGF-I mRNA expression in the semitendinosus muscle increased as CP concentration increased in the diet. In all experiments, fat-free lean gain, plasma urea, and serum IGF-I concentration were increased (P < 0.01) by dietary protein concentration. Results from these experiments suggest that the consumption of a diet deficient in CP (10 and 14%) inhibits the expression in semitendinosus muscle and production of IGF-I which was associated with a reduction in growth rate and carcass protein accretion. ^

Subject Area

Biology, Animal Physiology|Agriculture, Animal Culture and Nutrition

Recommended Citation

Fischer, Robert L, "Effects of dietary crude protein and/or crystalline amino acid concentration on serum IGF -I concentrations and IGF -I mRNA expression in growing pigs" (2005). ETD collection for University of Nebraska - Lincoln. AAI3186853.
http://digitalcommons.unl.edu/dissertations/AAI3186853

Share

COinS