Effect of incremental levels of dietary total sulfur amino acids on performance of white leghorn laying hens fed diets containing guar (Cyamopsis tetragonoloba) meal

Abstract BACKGROUND The present study evaluated the potential of increasing dietary levels of the most limiting amino acids such as total sulfur amino acids (TSAA) with respect to mitigating the adverse effects of the inclusion of guar meal (GM) in the diet of WL layers on egg production, feed efficiency and egg weight. In total, 4928 WL (Lohmann L) hens (32 week of age) were randomly allotted to eight treatments with seven replicates of 88 birds. The dietary treatments were a set of four maize–soybean meal based diets containing four graded concentrations of TSAA (5.85, 6.18, 6.51 and 6.84 g kg −1 ) and another set of four diets containing 100 g kg −1 guar meal (GM) with similar concentrations of TSAA. RESULTS The inclusion of 100 g kg −1 GM in the diet caused a 20%, 23%, 35.5% and 6.7% reduction in egg production, daily egg mass, feed efficiency and egg weight, respectively, when the diet contained 5.85 g kg −1 TSAA. Increasing TSAA levels in GM groups reduced the adverse effects on egg production and feed efficiency 50%, with no effect on egg weight. The TSAA requirement of WL birds fed 10% GM was estimated as 6.28–7.39 g kg −1 diet at different ages. CONCLUSION Increasing dietary TSAA to 7.39, 6.28, 6.53 and 6.37 g kg −1 or dTSAA (digestible TSAA) to 6.53, 5.32, 5.80 and 5.63 g kg −1 during 33–36, 37–40, 41–44 and 45–48 weeks of age, respectively, may be an effective and practical strategy for reducing the adverse effects of inclusion of 100 g kg −1 GM in the diet of WL layers. © 2018 Society of Chemical Industry