MEAT QUALITY AND MICROBIAL STUDIES OF BROILER CHICKEN FED DIETS SUPPLEMENTED WITH VITAMIN E AND SOYA BEAN OIL

Abstract

The experiment was designed to determine the effect of dietary vitamin E and soya oil supplementation on quality and microbial count of broiler chicken meat. Two hundred and twenty-five (225) day-old unsexed chicks were purchased from a reputable hatchery and randomly assigned into 5 treatments of 3 replicates per treatments with 15 birds in each replicate. They were assigned five dietary treatments; T1 - Basal diet + 0 % Soya oil and Vitamin E; T2 – Basal diet + 100 g/kg+100 mg/kg of soya oil and vitamin E respectively; T3 - Basal Diet + 100 g/kg + 200 mg/kg of Soya oil and vitamin E respectively, T4 (Basal diet + 100 g/kg + 300 mg/kg of soya oil and vitamin E respectively and T5 - Basal diet + 100 g/kg + 400 mg/kg of soya oil and vitamin E respectively in a completely randomized design. At the end of the 8th week of experimental feeding, one bird from each replicate was slaughtered and meat samples (breast muscle) were collected aseptically to determine meat microbial, technological, proximate and sensory parameters. Dietary supplements had significant effect (p>0.05) on meat Lipoprotein profile. The group had the highest (p<0.05) value for HDL, while the lowest value was observed in T4, T3, T2 and T1 (26.98 mg/dl, 28.80 mg/dl, 29.17 mg/dl and 29.30 mg/dl) respectively. Moreso, chickens fed with the basal diet had the best (p<0.05) meat lipid profile. T4 group had the highest vale for triglyceride (347.67 mg/dl), with T1 having the least value (193.67 mg/dl). T4 and T5 (147.60 and 125.17 mg/dl) groups had the highest value for cholesterol, while the lowest values for cholesterol was observed in T1 – T3 groups with values ranging from 92.90 – 115.10 mg/dl. All treatment diets influenced (p>0.05) proximate parameters of meat obtained from chickens fed dietary supplements. Results show that the dietary treatment had significant effect (p<0.05) on taste, tenderness, overall acceptability and meaty but there was no significant effect on the colour. Overall meat acceptability of sensory parameters was adjudged best for birds fed T5 (Basal diet + 100 g/kg + 400 mg/kg of soya oil and vitamin E respectively) diet, while meat lipid profile was best (p<0.05) in groups fed basal diet. For microbial analysis, data generated from this study were subjected to a 5 by 3 factorial arrangement in a completely randomized design. Escherichia coli amongst all other parameters measured were not found on the meat samples. Salmonella spp. Was significantly (P<0.05) different except in meat obtained from T3 (2.95 log10cfu/ml) and T4 (2.98 log10cfu/ml) groups on day 14 of refrigeration, which was not significantly (P>0.05) different. Though, all the treatments were capable of reducing microbial load on broiler meat if refrigerated, T2 effectively reduced microbial population on refrigerated broiler meat more than T1, T3, T4 and T5 groups with the consideration of shelf life.