Standardized ileal digestible lysine requirements of 21-28 days old male broilers

The objective of this study was to estimate the standardized ileal digestible (SID) lysine (Lys) requirement for male broiler chickens at the age of 21-28 days. A total of 240 (21 days old) Ross 308 broilers (842 +/- 43.9 g; mean +/- SD) were allocated to six different dietary treatments in a randomized complete block design with eight replicate cages per treatment. The six experimental diets were formulated based on corn, soybean meal, and synthetic amino acids to contain dietary SID Lys equally increased from 7.5 g/kg to 12.5 g/kg, with a consistent concentration of all amino acids except for Lys. As the SID Lys increased in the experimental diet, the weight gain, feed intake, and G:F increased linearly (P < 0.05) and quadratically (P < 0.05). The Lys intake linearly (P < 0.01) increased as the SID Lys concentration increased. The SID Lys requirements for weight gain and G:F were 10.6 g/kg and 10.9 g/kg for the one-slope broken-line, 11.6 g/kg and 12.1 g/kg for the quadratic line, and 11.0 g/kg and 11.5 g/kg for 95 % of the upper asymptote of the quadratic model, respectively. In summary, the dietary SID Lys for optimum body weight gain and G:F of 21-28 days old male broilers were 10.7 g/kg and 10.9 g/kg, respectively. In addition, the SID Lys for maximum body weight gain and G:F were 11.6 g/kg and 12.1 g/kg, respectively.

Automated summary

This study aimed to estimate the dietary requirement of standardized ileal digestible lysine for male broiler chickens aged 21-28 days. The results showed that as the lysine concentration in the diet increased, there was a linear and quadratic increase in weight gain, feed intake, and feed conversion ratio. The lysine intake also linearly increased with the lysine concentration. The dietary lysine requirement for optimal body weight gain and feed conversion ratio for 21-28 days old male broilers was estimated to be 10.7 g/kg and 10.9 g/kg, respectively.