Estimation of digestible sulphur amino acids requirements for growth performance and immune responses to Newcastle disease and avian influenza vaccination in broilers

Abstract

This study was conducted to determine the effects of grower diet (d11-24) digestible sulphur amino acids (SAAs) levels on performance traits, blood metabolites, and immune responses to Newcastle disease (ND) and avian influenza (AI) vaccination in the broiler chickens. Additionally, digestible SAAs requirements were determined based on nutrient dose-response data. A total of 360, 11-day-old male Ross-308 broiler chicks were randomly allocated to six dietary treatments, graded levels of supplementary DL-methionine (þ0.7 g/kg), but cystine (0.29%) was equal across groups, lead to levels of 0.59, 0.66, 0.73, 0.8, 0.87, and 0.94% dietary digestible SAAs, with six replicates and ten birds each. All birds were vaccinated with inactivated H9N2/ND and live-ND on days 5 and 11, respectively. Increasing dietary digestible SAAs level improved live body weight (LBW), weight gain (WG), feed efficiency (FE) with linear trends, and improved carcass yield, relative breast weight (RBW), and immune responses with quadratic trends. On day 24, a quadratic increase in blood serum albumin concentration was concomitant with decreasing triglyceride, whole cholesterol, low-density-lipoprotein cholesterol, creatinine, and alkaline phosphatase concentration with increasing dietary digestible SAAs levels. Based on broken-line regression models, the LBW, WG, FE, RBW, and immunity against ND and AI vaccination were optimised when dietary digestible SAAs levels were 0.73, 0.69, 0.78, 0.86, 0.73, and 0.72%, respectively. It is concluded, the digestible SAAs requirements of broilers vary according to what production parameter is taken considered for optimisation. The best grower diet digestible SAAs concentration achieved 0.86% for support performance, breast yield, and immune function. HIGHLIGHTSThe present data highlight that a better breast meat yield could be obtained by supplementing DL-Met, which raised dietary digestible sulphur amino acids level to 0.86%.

Effects of finisher diet nutrients density and slaughter age on energy and protein efficiency, productive and economic performance and meat quality of broilers

“…Depression in dietary amino acid density is another reason for weaker performance in chickens that received the low‐density diet (Mirshekar et al., 2013 ). It is reported that reducing the dietary amino acid density of broilers during 1–11 (Ghavi et al., 2020 ), 11–24 (Ghavi et al., 2021 ), 23–38 (Nikbakhtzade et al., 2020 ) and 36–59 (Dozier et al., 2006 ) days of age limited growth rate and adversely affected feed conversion.…”

Relative biological efficacy of methionine hydroxy analogue‐free acid compared to dl‐methionine in the broiler chickens

“…Methionine (Met) and cystine (Cys), known as sulphur‐containing amino acids (SAA), are the first limiting amino acids in practical poultry diets because of their limited presence in protein sources of plant origin (Ghavi et al., 2021 ; Pontin et al., 2018 ). In animal tissue, four main pathways are responsible for Met metabolism: protein synthesis, transmethylation to form S‐adenosyl Met, deamination to form oxaloacetate and trans‐sulphuration to form l ‐cysteine (Wan et al., 2017 ).…”