Effect of Diet on Growth and Feed Efficiency Responses to Supplements of MD Bacitracin and 3-Nitro Phenylarsonic Acid Added Singly and In Combinations ,

Two experiments of the same design were conducted to study the effect of diet composition on chick growth response to different dosage levels of MD bacitracin, 3-nitro-4-hydroxy phenylarsonic acid or their combinations. The two experiments were conducted in sequence at the same location. Diets were mixed separately for each of the experiments, but the same drug premixes were used. The design of the experiments was a factorial comprising two diets, two drugs and four dosage levels of each drug. The two basal diets contained either corn or rye as grain components. Data on body weight, feed consumption, feces condition and leg shank color were collected up to the time the birds were three weeks of age. Results of the experiments closely parallel each other and reinforce the conclusions obtained. Diet type had a significant effect on growth and size of growth response to the different supplements. The diet containing corn elicited significantly better performance in all parameters tested, as compared with the diet containing rye. MD bacitracin improved chick growth only at levels of 27 p.p.m. or greater, while similar improvement was obtained with levels of 37 p.p.m. or more of 3-nitro-4-hydroxy phenylarsonic acid. None of the drug supplements at any level had an effect on feces condition or shank color. Growth promoting effect of drug combinations at different dosage levels varied and there was evidence of additive effects of the two drugs.