Dietary branched-chain amino acid assessment in broilers from 22 to 35 days of age

Abstract

Background Valine and isoleucine are similar in chemical structure and their limitation in broiler chicken diets. To evaluate their limitation and interactive effects, multivariate assessment nutrition studies for the branched-chain amino acids (BCAA) are needed. A three level (− 1, 0, + 1), three-factor Box-Behnken design study was conducted to assess dietary BCAA ratios to lysine of 65, 75, and 85 for valine, 58, 66, and 74 for isoleucine, and 110, 130, and 150 for leucine in male and female Lohman Indian River broilers from 22 to 35 d of age. Results Live performance of male broilers was not affected by BCAA level. However, male broilers fed increasing isoleucine had improved (P = 0.07) carcass yield as leucine and valine were reduced. Female broilers had improved body weight gain (P = 0.05) and feed conversion (P = 0.003) when leucine and isoleucine were at their lowest levels, independent of valine, but increasing leucine impaired live performance and warranted concomitant increases in isoleucine to restore responses. Increasing dietary isoleucine and valine in female broilers increased breast meat yield (P = 0.05), but increasing leucine tended to diminish the response. Conclusion The female Lohman Indian River broiler is more sensitive to BCAA diet manipulation than males. Specifically, as dietary leucine is increased in female broilers, dietary isoleucine increases were needed to offset the negative effects. Both increases in dietary valine and isoleucine improved breast meat yield in female broilers, but only when birds were fed the lowest dietary leucine.

Understanding the interactive effects of dietary leucine with isoleucine and valine in the modern commercial broiler

“…This relationship is evident when evaluating ratios to optimize broiler performance. Body weight gain and FCR can be optimized at Val:Lys, Ile:Lys, and Leu:Lys ratios of 77 to 79, 64 to 66, and 110, respectively, which are in close agreement with previous research ( Baker and Han, 1994 ; Corzo et al, 2007 ; Duarte et al, 2014 ; Franco et al, 2017 ; Ospina-Rojas et al, 2017 ; Kidd et al, 2021 ). When Leu:Lys ratio increases in feed formulation, the optimum Val:Lys and Ile:Lys ratios then become higher although similar broiler performance may not be achieved compared to Leu:Lys at 110.…”

Varying isoleucine level to determine effects on performance, egg quality, serum biochemistry, and ileal protein digestibility in diets of young laying hens

“…More work is needed to unravel the digestive dynamics because protein bound amino acids (from inexpensive sources) and available synthetic ones likely will be fed to layers more often as in the present work. Other investigators suggested that due to possible imbalances, all BCAA's should be monitored when investigating any one of them in commercial avian diets [36]. Moreover, as we reported, L � W often affects many parameters.…”

Effects of L-valine in layer diets containing 0.72% isoleucine

“…Investigators (Azzam et al, 2015) reported that high levels of valine did not negatively affect the immune function in layers [ 2 ]. As noted by Kidd et al (2021), the quantity of leucine in the diet must be considered when examining the effects of valine on responses in broilers [ 35 ]. Perhaps future work on immune responses in layers should always include responses across levels of the BCAA’s simultaneously.…”