Dietary interactions between lysine and threonine in broilers

Abstract

Two experiments were conducted to evaluate the effects of two dietary levels of lysine and four dietary levels of threonine in a factorial arrangement on broiler growth, carcass traits, and immunity. In both experiments, 120 broilers were allocated to each of 56 floor pens (6,720 total broilers). In Experiment 1, two levels of lysine (1.10 and 1.20% of diet) and four levels of threonine (0.68, 0.74, 0.80, and 0.86% of diet) were fed to broilers from 1 to 18 d of age in a sorghum-peanut meal diet. Body weight gain, feed:gain, mortality, and cellular and humoral immunity were measured. In Experiment 2, all broilers received a common basal diet up to 18 d of age. Experimental diets were fed from 18 to 34, 34 to 44, and 44 to 54 d of age. Two levels of lysine [100 and 105% of NRC (1994) recommendations] and four levels of threonine [83, 92, 100, and 108% of NRC (1994) recommendations] were included in the experimental diets for each age group (seven replications per treatment). The diets consisted of wheat (soft), corn gluten meal, soybean meal, and meat and bone meal Weight gain, feed:gain, mortality, and carcass traits were measured at 54 d of age. In Experiment 1, increasing dietary lysine from 1.10 to 1.20% from 1 to 18 d in broilers improved (P < 0.001) BW gain (453 vs 488 g) and feed:gain (1.39 vs 1.33). No interactions between lysine and threonine were observed in Experiment 1. Differences in immune parameters or mortality were not observed. In Experiment 2, an interaction in 18 to 54 d weight gain occurred with the highest gain in broilers receiving dietary lysine and threonine levels equivalent to 100 and 83%, respectively, of NRC (1994) or lysine and threonine at levels of 105% and 100% of NRC (1994), respectively (P < or = 0.05). Supplemental lysine (105% of the 1994 NRC) improved (P < or = 0.01) 18 to 54 d feed:gain (2.30 vs 2.26). No differences in mortality occurred. Supplemental lysine increased preslaughter weight (P < or = 0.05), but differences in carcass yield were not observed. Breast fillet yields were the highest (P < or = 0.03) in broilers receiving 100% of NRC lysine and 83 or 92% of NRC threonine or 105% of NRC lysine and 100 or 108% of NRC threonine. In conclusion, additional lysine improved feed:gain independent of threonine from 1 to 54 d of age. However, lysine and threonine interact to increase weight gain and breast fillet yields.

Change in Growth Performance and Liver Function Enzymes of Broiler Chickens Challenged with Infectious Bursal Disease Virus to Dietary Supplementation of Methionine and Threonine

“…This level of threonine occasionally permitted maximum growth and feed utilization, but usually resulted in significantly poorer performance than the diet containing 0.72% or more threonine. However, the findings of the current study do not support the previous research by Kidd et al (1997), Smith and Waldroup (1988) that the NRC (1994) and NRC (1984) estimate on threonine, for 0-3-week-old chicks are too high.…”

Energy and lysine for broilers from 44 to 55 days of age

“…Parr & Summer (1991) did not report significant responses in performance parameters with lysine supplementation 10% above the normal requirements. Kidd et al (1997) supplemented diets with 105% of the lysine levels recommended by Skinner et al (1992) and obtained better feed conversion and weight gain. Table 3 presents carcass yield results at the end of the experimental period.…”

Níveis de lisina mantendo a relação aminoacídica para frangos de corte no período de 1 a 21 dias de idade, em diferentes ambientes térmicos

“…Portanto, ao se avaliarem níveis de lisina para frangos de corte, a manutenção da relação da lisina com os demais aminoácidos é essencial para possibilitar ao animal expressar todo o seu potencial genéti-co. Segundo KIDD et al (1997), aumentar o nível de lisina na ração, sem considerar os demais aminoácidos, pode resultar em desempenho limitado por deficiên-cia de algum outro aminoácido essencial.…”