Effects of probiotics supplementation on growth performance, nutrient digestibiliry, carcass characteristics, meat quality, intestinal microflora and fecal noxious gas emission in broilers
A total of 765 broilers (BW 36.77± 0.33 g ; 1 d old) were used in a 35-d feeding trial to evaluate the effect of fermented plants on performance, carcass traits, blood profiles, nutrient digestibility, intestine microbial population and fecal noxious gas emission of broiler chicks. Broilers were randomly distributed into 1 of 5 treatments on the basis of BW (9 replicate pens per treatment with 17 broilers per pen). Dietary treatments were: 1) NC (basal diet); 2) PC (NC + 5ppm enramycin); 3) P1 (NC with 0.5% of CP reduced + 150ppm phytogenics; 4) P2 (NC + 0.1% probiotics); 5) P3 (NC + 0.2% probiotics). All nutrients in diets were formulated to meet or exceed the recommendation of NRC (1994) for broilers. The broilers were weighed and feed intake were recorded on d 1, 14, 28 and 35 for calculating BW gain (BWG), feed intake (FI), and feed conversion ratio (FCR). At d 35, fresh excreta samples were collected from each pen for the measurement of nutrient digestibility according to the procedures of AOAC (2003). All data were subjected to GLM procedures of SAS (1996) as a randomized complete block design, with pen as the experimental unit. Differences among treatments were separated by Duncan's multiple range test ; P < 0.05 was considered statistically significant. Overall, broilers fed P3 diet had greater (1770 vs. 1681 g; P<0.05) body weight gain (BWG), and lower (1.555 vs. 1.625; P<0.05) feed conversion ratio (FCR) than those fed NC diet. The nutrient digestibility of dry matter (DM) and nitrogen (N) was increased (76.30 vs. 73.26 %; 65.32 vs. 62.71 %; P<0.05) in P3 compared with NC. There was no difference (P>0.05) in meat quality, relative organ weight and blood profiles. Addition of 0.2% probiotic enhanced the growth of Lactobacillus, but inhibited Escherichia coli in the small intestinal and large intestinal. Also, addition of 0.1% probiotic showed same result with P3 on the large intestinal microflora but no change in the number of Lactobacillus and Escherichia coli in small intestine. A signiﬁcant increase in the rate of ammonia was observed in 1.0 g/kg and 2.0 g/kg probiotic-treated birds versus controls.
broilers, growth performance, gas emission, nutrient digestibility, probiotic