Effects of increasing crystalline amino acids in sorghum- or corn-based diets on nursery pig growth performance

A total of 300 pigs (PIC 1050; initially 23.3 lb BW) were used in a 21-d study to compare the effects of increasing crystalline amino acids in sorghumand corn-based diets on nursery pig growth performance. Treatments with 5 pigs per pen and 10 pens per treatment were arranged in a 2 Ã— 3 factorial with main effects of grain source (sorghum vs. corn) and crystalline amino acid supplementation (low, medium, or high). Amino acid ratios to lysine as well as standardized ileal digestibility coefficients used were set by NRC (20123). Because replacing increasing amounts of soybean meal with crystalline amino acids changes the NE of the diet, all diets were formulated to the same Lys:NE ratio. The lysine concentration in the diets was formulated at 95% of the pigâ€TMs estimated requirement to ensure that the other amino acids, on a ratio to lysine, would not be underestimated. The grain sources and soybean meal were analyzed for amino acid profile and diets formulated from these concentrations. The low amino acid fortification contained L-lysine HCl and DL-methionine. The medium amino acid fortification contained L-lysine HCl, DL-methionine, and Lthreonine, and the high amino acid fortification contained L-lysine HCl, DL-methionine, L-threonine, and Lvaline. Overall, no main or interactive effects (P > 0.05) of grain source or added amino acids were detected for any response criteria. This suggests that balancing to the third, fourth, or fifth limiting amino acids is possible in both sorghumand corn-based diets with the use of crystalline amino acids without detrimental effects on growth performance.; Swine Day, Manhattan, KS, November 20, 2014


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Effects of Increasing Crystalline Amino Acids in Sorghum-or Corn-Based Diets on Nursery Pig Growth Performance1 K.E.Jordan, J.E. Nemechek, M.A.D. Goncalves2 , R.D. Goodband, M.D. Tokach, S.S. Dritz 2 , J.M. DeRouchey, and J.C. Woodworth Summary A total of 300 pigs (PIC 1050; initially 23.3 lb BW) were used in a 21-d study to compare the effects of increasing crystalline amino acids in sorghum-and corn-based diets on nursery pig growth performance.Treatments with 5 pigs per pen and 10 pens per treatment were arranged in a 2 × 3 factorial with main effects of grain source (sorghum vs. corn) and crystalline amino acid supplementation (low, medium, or high).Amino acid ratios to lysine as well as standardized ileal digestibility coefficients used were set by NRC (20123 ).Because replacing increasing amounts of soybean meal with crystalline amino acids changes the NE of the diet, all diets were formulated to the same Lys:NE ratio.The lysine concentration in the diets was formulated at 95% of the pig's estimated requirement to ensure that the other amino acids, on a ratio to lysine, would not be underestimated.The grain sources and soybean meal were analyzed for amino acid profile and diets formulated from these concentrations.The low amino acid fortification contained L-lysine HCl and DL-methionine.The medium amino acid fortification contained L-lysine HCl, DL-methionine, and L-threonine, and the high amino acid fortification contained L-lysine HCl, DL-methionine, L-threonine, and L-valine.

Introduction
To lower feed costs, crystalline amino acids are used routinely in swine diets to replace a portion of the soybean meal.The amino acids that are currently economical to add to swine diets include lysine, threonine, methionine, tryptophan, and valine.The increased availability of economical sources of crystalline amino acids has created the opportunity to formulate either sorghum-or corn-based diets to the fifth or sixth limiting amino acids.If this can be accomplished without negatively affecting pig growth performance, it will result in greater economic return; however, in some cases, low-protein, amino

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acid-fortified diets have not provided growth performance similar to grain-soybean meal-based diets.
The objective of this study was to determine the effects of feeding high levels of crystalline amino acids in sorghum-or corn-based diets on growth performance of nursery pigs.

Procedures
The protocol for this experiment was approved by the Kansas State University Institutional Animal Care and Use Committee.The study was conducted at the Kansas State University Segregated Early Weaning Facility in Manhattan, KS.The facility is a totally enclosed, environmentally controlled, mechanically ventilated barn.Each pen was equipped with a 4-hole stainless steel dry self-feeder and a cup waterer for ad libitum access to feed and water.Pens (4 ft × 4 ft) had wire-mesh floors and deep pits for manure storage.
A total of 300 pigs (PIC 1050; initially 23.3 lb BW) were used in a 21-d study.The experimental treatments with 5 pigs per pen and 10 replications per treatment were arranged in a 2 × 3 factorial with main effects of grain source (grain sorghum vs. corn) and crystalline amino acid level (low, medium, or high).Amino acid to lysine ratios, as well as standardized ileal digestibility coefficients used, were set by NRC (2012).The lysine concentration in the diets was formulated at 95% of the pig's estimated requirement to ensure that the other amino acids, in ratio with lysine, would not be underestimated.Furthermore, because replacing soybean meal with crystalline amino acids increases the NE of the diet, all diets were formulated to a constant lysine:NE ratio.The grain sources and soybean meal were analyzed for amino acid profile and diets formulated from these concentrations (Table 1).The low amino acid fortification contained L-lysine HCl and DL-methionine.The medium amino acid fortification contained L-lysine HCl, DL-methionine, and L-threonine, and the high amino acid fortification contained L-lysine HCl, DL-methionine, L-threonine, and L-valine (Table 2).Pig weight and feed disappearance were measured on day 0, 7, 14, and 21 of the trial to determine ADG, ADFI, and F/G.Experimental diets were fed in meal form and were manufactured at the K-State O.H. Kruse Feed Technology Innovation Center.
Multiple samples of each diet were collected from feeders, blended and subsampled, and submitted to Ward Laboratories, Inc. (Kearney, NE) for analysis of DM, CP, Ca, and P. Amino acid analysis was conducted by Ajinomoto Heartland, Inc. (Chicago IL; Table 3).

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amino acids were lysine, methionine and cysteine, threonine, and valine.The diets were then co-limiting on tryptophan and isoleucine.The variation of these amino acid profiles for these grain sources confirms the need to evaluate sources routinely and update amino acid profiles when formulating and manufacturing diets.As expected, the analyzed CP content of the experimental diets decreased as soybean meal was replaced by the crystalline amino acids (Table 3).
Overall, no main or interactive effects (P > 0.05) of grain source or added crystalline amino acid level were detected for any response criteria measured (Tables 4 and 5).Pigs fed sorghum-based diets had similar growth performance and feed efficiency to those fed corn-based diets.Sorghum is typically thought to have approximately 96% the energy value of corn, resulting in slightly poorer feed efficiency than pigs fed corn-based diets, but this was not the case in our study.Furthermore, we saw no negative responses to increasing crystalline amino acid concentrations in place of soybean meal in the diets.This suggests that balancing to the third, fourth, or fifth limiting amino acid is possible in both sorghum-or corn-based diets with the use of crystalline amino acids without detrimental effects on growth performance.

Table 3 .
Chemical analysis of experimental diets (as-fed basis) 1