Use of feed additives in animal agriculture: gut response in broilers

Abstract

Feed additives such as enzymes, probiotics, prebiotics and acidifiers are few examples of suitable alternatives to in – feed antibiotics in animal agriculture due to the ban of antibiotic use. However, the Nigerian poultry industry still experiences cases of antibiotic use. The gut benefits of alternatives to antibiotics often culminate in improved growth performance but there are or may be certain gut responses that attribute to the observed performance of poultry birds. In order to ascertain this, an experiment was conducted to evaluate the effect of antibiotic administration and enzyme supplementation on gut pH and bacteria counts. One hundred and fifty day-old broiler chicks were randomly distributed to three dietary treatments having five replicates and 10 birds per replicate. The experiment lasted forty – two (42) days and was arranged as a completely randomized design. A maize- soybean meal diet not supplemented with antibiotic or enzyme served as the control. Birds fed diet II had antibiotic (Dicoxin plus ®) administered to them. Birds fed diet III had their diets supplemented with enzyme (Roxazyme G2G®). Results indicated pH of the crop to be significantly (P<0.01) reduced by feed additive. The pH of the Ileum was least (5.65) under antibiotic administration but was not significantly different (p>0.05) different that of birds fed control and enzyme supplemented diet. Gizzard pH was acidic but not significantly (P>0.05) across all the treatments. Lactobacillus and Coliform counts were significant (P<0.05) affected by feed additive addition. It can be concluded that feed additive impact on gut pH can influence the type and population of bacteria present in the gastrointestinal tract.