Effect of concentration levels of dietary lysine on growth performance and immune response to Newcastle disease (ND) vaccinations

Abstract

Ayodedji B. Christian

The effect of supplementing varying concentration levels of dietary lysine on growth performance and immune response to Newcastle disease (ND) vaccinations of broiler chickens was assessed. A total number of 180 day-old broiler chicks of mixed sex were used for the experiment. The birds were divided into 4 treatments (Treatment A, B, C and D), in which each treatment was replicated 3 times with 15 birds per replicate. Diet A was the control diet that was not supplemented with dietary lysine and diet B contained the recommended level of lysine by National Research Council (NRC) standards of 1.12%, while diets C and D both contained 1.13 and 1.14% lysine which is 10 and 15% increment of the NRC requirements, respectively. The result of the statistical analysis showed that there was significant difference (P ≤ 0.05) among the various dietary treatments for feed intake, weight gain, final body weight and feed conversion ratio. Birds fed diet C had the highest final body weight (2.16 kg), total weight gain (2.12 kg) and feed intake (3.11 kg) while birds fed diet A had the best feed conversion ratio (1.37). The immunological response to ND vaccinations showed that birds fed diet C had the highest mean antibody titre values while those fed diet A with no lysine supplemented in their diets had the lowest antibody titre values. The haematological parameter was only significantly (P ≤ 0.05) different for erythrocyte sedimentation rate (ESR), mean cell volume (MCV), mean cell haemoglobin (MCH) and mean cell haemoglobin concentration (MCHC). It was concluded that supplementing lysine above NRC requirement at the inclusion rates used in this study had significant effect on performance characteristics and immune response in broiler chickens.