Effect of Sulphur-Based Amino Acids with or without Formic Acid on Performance and Microbial Load of Broiler Chickens

The aim of the study was to investigate the effect of sulphur-based amino acids with or without formic acid on performance and microbial load of broiler chickens in a 56-day feeding trial. One hundred and ninety-two one-day old unsexed Arbor Acre broilers were used. The birds were brooded for 7 days after which they were randomly allotted to 4 dietary treatments with 4 replicates of 12 birds each. The experimental treatments were: Diet 1: Basal diet + DL-methionine without formic acid, diet 2: Basal diet + DL-methionine with 0.8% formic acid, diet 3: Basal diet + methionine hydroxyl analogue without formic acid, diet 4: Basal diet + methionine hydroxyl analogue with formic acid. The design of the experiment was a completely randomised design in a 2X2 factorial arrangement. Dietary treatments had no significant influence on the feed intake (FI) pattern of the birds. However, the inclusion of formic acid and the sulphur amino acid sources significantly affected body weight gain (WG) and feed conversion (FCR). Birds fed with diet 2 had significantly (P<0.05) improved WG (3.16kg/bird) and FCR (1.42) compared with birds fed with the other diets with values ranging from 2.28 to 2.64kg/bird. The microbial load of the digesta from selected segments of the gastrointestinal tract (i.e. duodenum and ileum) were also significantly (P<0.05) affected by the dietary treatments. The total bacteria count and coliform count were significantly (P<0.05) reduced with formic acid supplementation (1.60 to 6.26 logCFU/ml digesta) relative to the total bacteria and coliform count observed in the digesta of birds fed diets without formic acid supplementation (12.60 to 33.20 logCFU/ml digesta). Formic acid supplementation had positive effect on body weight gain and microbial population of the experimental birds.