Journal of Animal Science, Vol 72, Issue 2 367-379, Copyright © 1994 by American Society of Animal Science

JOURNAL ARTICLE

The effects of diets formulated on an ideal protein basis on growth performance, carcass characteristics, and thermal balance of finishing gilts housed in a hot, diurnal environment

J. Lopez, R. D. Goodband, G. L. Allee, G. W. Jesse, J. L. Nelssen, M. D. Tokach, D. Spiers and B. A. Becker
Department of Animal Science, University of Missouri, Columbia 65211.

Forty-eight finishing gilts (initial BW = 70.6 +/- .95 kg) were randomly assigned to one of eight experimental treatments in a 2 x 2 x 2 factorial arrangement with main effects including dietary lysine (.60 vs 1.00%), source of amino acid fortification (intact protein vs synthetic amino acids formulated on an ideal protein basis), and environmental temperature (thermoneutral [TN]: 20 degrees C vs hot, diurnal [HD]: 27.7 to 35 degrees C). The ideal protein diets were formulated by using corn and soybean meal to meet the fifth-limiting amino acid; synthetic lysine, threonine, tryptophan, methionine, or isoleucine were added to meet the gilts' estimated requirements. The ratios of other total amino acids relative to lysine were as follows: threonine, 66%; tryptophan, 17%; methionine and cystine, 56%; and isoleucine, 63%. Average daily gain, ADFI, and feed efficiency (G/F) were similar for gilts fed the intact and those fed the ideal proteins diets (P > .10). Increasing dietary lysine improved d 0 to 14 ADG (P < .01), but no differences were observed for the overall experiment. Gilts in the HD environment ate less feed and had lower ADG than gilts in the TN environment (P < .01). A temperature x lysine interaction was observed (P < .02) for G/F. Increasing dietary lysine had no effect on G/F of gilts in the TN environment but improved G/F of gilts in the HD environment. Gilts fed the intact protein diets had higher (P < .01) N intake and plasma urea concentrations. Gilts fed the ideal protein diets had lower (P < .05) plasma essential amino acids, with the exception of lysine. Carcass protein and lipid contents were improved (P < .01) for gilts in the HD environment and for those fed 1.00% lysine. Backfat thickness and longissimus muscle area (P < .01) were improved and lipid accretion rate tended to decrease (P < .08) in gilts fed 1.00% lysine. The source of amino acid fortification did not influence carcass characteristics (P > .10). Rectal, skin, and ear temperatures were higher for gilts in the HD environment (P < .05). Metabolic heat production was elevated by feeding gilts the ideal protein diets (P < .03). In conclusion, increased dietary lysine improved G/F and carcass leanness in gilts to a greater extent in HD than in TN environments. However, no improvements in growth performance or carcass traits resulted from feeding ideal protein diets.

This article has been cited by other articles:

				F. Guay and N. L. Trottier Muscle growth and plasma concentrations of amino acids, insulin-like growth factor-I, and insulin in growing pigs fed reduced-protein diets J Anim Sci, November 1, 2006; 84(11): 3010 - 3019. [Abstract] [Full Text] [PDF]

				B. J. Kerr, C. J. Ziemer, S. L. Trabue, J. D. Crouse, and T. B. Parkin Manure composition of swine as affected by dietary protein and cellulose concentrations J Anim Sci, June 1, 2006; 84(6): 1584 - 1592. [Abstract] [Full Text] [PDF]

				E. A. Jablonski, R. D. Jones, and M. J. Azain Evaluation of pet food by-product as an alternative feedstuff in weanling pig diets J Anim Sci, January 1, 2006; 84(1): 221 - 228. [Abstract] [Full Text] [PDF]

				B. J. Kerr, L. L. Southern, T. D. Bidner, K. G. Friesen, and R. A. Easter Influence of dietary protein level, amino acid supplementation, and dietary energy levels on growing-finishing pig performance and carcass composition J Anim Sci, December 1, 2003; 81(12): 3075 - 3087. [Abstract] [Full Text] [PDF]

				B. J. Kerr, J. T. Yen, J. A. Nienaber, and R. A. Easter Influences of dietary protein level, amino acid supplementation and environmental temperature on performance, body composition, organ weights and total heat production of growing pigs J Anim Sci, August 1, 2003; 81(8): 1998 - 2007. [Abstract] [Full Text] [PDF]

				E. R. Otto, M. Yokoyama, P. K. Ku, N. K. Ames, and N. L. Trottier Nitrogen balance and ileal amino acid digestibility in growing pigs fed diets reduced in protein concentration J Anim Sci, July 1, 2003; 81(7): 1743 - 1753. [Abstract] [Full Text] [PDF]

				J. A. Shriver, S. D. Carter, A. L. Sutton, B. T. Richert, B. W. Senne, and L. A. Pettey Effects of adding fiber sources to reduced-crude protein, amino acid-supplemented diets on nitrogen excretion, growth performance, and carcass traits of finishing pigs J Anim Sci, February 1, 2003; 81(2): 492 - 502. [Abstract] [Full Text] [PDF]

				S. Zervas and R. T. Zijlstra Effects of dietary protein and oathull fiber on nitrogen excretion patterns and postprandial plasma urea profiles in grower pigs J Anim Sci, December 1, 2002; 80(12): 3238 - 3246. [Abstract] [Full Text] [PDF]

				S. Zervas and R. T. Zijlstra Effects of dietary protein and fermentable fiber on nitrogen excretion patterns and plasma urea in grower pigs J Anim Sci, December 1, 2002; 80(12): 3247 - 3256. [Abstract] [Full Text] [PDF]

				J. L. Figueroa, A. J. Lewis, P. S. Miller, R. L. Fischer, R. S. Gomez, and R. M. Diedrichsen Nitrogen metabolism and growth performance of gilts fed standard corn-soybean meal diets or low-crude protein, amino acid-supplemented diets J Anim Sci, November 1, 2002; 80(11): 2911 - 2919. [Abstract] [Full Text] [PDF]

				P. B Mikkelsen, S. Toubro, and A. Astrup Effect of fat-reduced diets on 24-h energy expenditure: comparisons between animal protein, vegetable protein, and carbohydrate Am. J. Clinical Nutrition, November 1, 2000; 72(5): 1135 - 1141. [Abstract] [Full Text] [PDF]