Effects of Standardized Ileal Digestible Histidine:Lysine Ratio on Growth Performance of 15- to 25-lb Pigs

Authors

H. S. Cemin, Kansas State UniversityFollow
R. M. Karns, Kansas State UniversityFollow
C. M. Vier, Kansas State University, ManhattanFollow
M. D. Tokach, Kansas State University, ManhattanFollow
S. S. Dritz, Kansas State University, ManhattanFollow
K. J. Touchette, Ajinomoto Heartland Inc., Chicago, IL
J. C. Woodworth, Kansas State University, ManhattanFollow
J. M. DeRouchey, Kansas State University, ManhattanFollow
R. D. Goodband, Kansas State University, ManhattanFollow

Keywords

histidine, growth, modeling, swine

Abstract

Two experiments were conducted to determine the standardized ileal digestible (SID) His:Lys requirement of 15- to 25-lb nursery pigs. A total of 360 and 350 pigs (DNA 241 × 600), initially 15.6 and 14.5 lb body weight (BW), were used in Exp. 1 and 2, respectively. There were 5 pigs per pen and 12 and 10 replicates per treatment in Exp. 1 and 2, respectively. After weaning, pigs were fed a common pelleted diet for 10 d in Exp. 1 and 7 d in Exp. 2. Then, pens were assigned to treatments in a randomized complete block design with BW as the blocking factor. Dietary treatments consisted of SID His:Lys ratios of 24, 28, 32, 36, 40, and 44% in Exp. 1 and 24, 28, 30, 32, 34, 36, and 42% in Exp. 2. Experimental diets were fed in pellet form for 10 d in Exp. 1 and 14 d in Exp. 2 followed by a common mash diet for 15 d in Exp. 1 and 14 d in Exp. 2. Data were analyzed using the GLIMMIX and NLMIXED procedures of SAS. Competing statistical models were quadratic polynomial (QP), broken-line linear (BLL), and broken-line quadratic (BLQ). In Exp. 1, increasing SID His:Lys increased (quadratic,P<0.001) average daily gain (ADG), average daily feed intake (ADFI), and BW and improved (quadratic,P<0.001) feed-to-gain ratio (F/G). In Exp. 2, ADG increased (quadratic,P= 0.001) and F/G improved (quadratic,P= 0.001) and ADFI linearly increased (P= 0.001) with increasing SID His:Lys. The best-fitting model for all response variables analyzed was the BLL. In Exp. 1, requirement estimates were 29.7%, 29.1%, and 29.8% SID His:Lys for ADG, ADFI, and gain-to-feed ratio (G:F), respectively. In Exp. 2, the SID His:Lys requirements were estimated at 31.0% for ADG and 28.6% for G:F. These results suggest that the NRC may overestimate the SID His:Lys requirement for 15- to 25-lb pigs. Therefore, nursery diets can be formulated with higher inclusion of crystalline amino acids before His becomes limiting.

Recommended Citation

Cemin, H. S.; Karns, R. M.; Vier, C. M.; Tokach, M. D.; Dritz, S. S.; Touchette, K. J.; Woodworth, J. C.; DeRouchey, J. M.; and Goodband, R. D. (2018) "Effects of Standardized Ileal Digestible Histidine:Lysine Ratio on Growth Performance of 15- to 25-lb Pigs," Kansas Agricultural Experiment Station Research Reports: Vol. 4: Iss. 9. https://doi.org/10.4148/2378-5977.7669