Study On The Effect And Interaction Of Four Green Additives In Broilers

In order to satisfy the need of people for green food, decreasing the use of antibiotics in Broiler's feeds, we had designed A 2×2×2×2 factorial trail to investigate the effects and the interactions of acidifier, probiotics, oligosaccharides and enzymes on growth performance, apparent digestibilites of crude protein (CP), crude fiber (CF), calcium (Ca) and phosphorus (P), microbial population in caecum, butcher index and index of immune organ of broilers. The levels of acidifier, probiotics, oligosaccharides and enzymes were 0, 0.3%; 0, 0.2%; 0, 0.1% and 0, 0.075% respectively. A total of 680 newly-hatched AA broilers were randomly allotted to 17 treatments and each treatment had 4 replicates with 10 broilers per replicate. The trail was conducted for 42 days. Feces were collected on day 30 to 35. We had slaughtered the 68 broilers which wree selected from each treatment 4 broilers in the morning of 22 d and 43 d, respectively. Fresh feces in caecum were collected and assayed immediately for Lactobacilli and Escherichia coli counts in the 22 d and 43 d. Butcher index and the index of immune organ were measured in the morning of 43 d.The main results showed : (1) During the whole trail period, the average body weight gain (ADG), were increased by 5.68% (P>0.05), 5.68% (P>0.05), -0.76% (P>0.05) and 3.39% (P>0.05), reduced feed/gain (F/G) by -7.62% (P<0.05), 0.48% (P>0.05), 3.33% (P>0.05) and 1.90% (P>0.05); improved the apparent digestibilites of CP by 3.28% (P>0.05), 8.42% (P<0.05), 3.38% (P>0.05) and 3.49% (P>0.05), and improved the apparent digestibilites of CF by 4.83% (P>0.05), 3.46% (P>0.05), 5.74% (P>0.05) and 7.51% (P<0.05); and reduced the Escherichia coli counts in caecum of 21 d and 42 d by 1.68% (P>0.05) and 26.80% (P<0.05), 1.51% (P>0.05) and 11.94%(P>0.05),11.22% (P>0.05) and 12.10% (P>0.05),2.01% (P>0.05) and 7.96% (P>0.05),increased the Lactobacillus counts by 10.00% (P>0.05) and 36.74% (P<0.05), 27.50% (P<0.05) and 41.16% (P<0.05), 9.38% (P>0.05) and 26.80% (P<0.05), 10.42% (P>0.05) and 9.53% (P>0.05); and had improved butcher index and index of immune organ in broilers supplemented solely with 0.3% acidifier, 0.2% probiotics, 0.1% oligosaccharides and 0.075% enzyme additive (chicken type); (2) The combinations of two, three or four of 0.3% acidifier, 0.2% probiotics, 0.1% oligosaccharides and 0.075% enzyme additive (chicken type) compared to basic feed had improved growth performance, apparent nutrient digestibilites, optimized the community of microorganism, and improved the butcher index and the immune function of broilers, especially the effect of the combination of 0.3% acidifier and 0.2% probiotics with 0.075% enzyme, the combination of 0.3% acidifier with 0.1% oligosaccharides, the combination of 0.3% acidifier with 0.2% probiotics were better than the others, had increased the ADG by 6.72% (P>0.05), 11.05% (P<0.05) and 7.78% (P>0.05), and reduced the F/G by 9.05% (P<0.05), 9.05% (P<0.05) and 8.57% (P<0.05), and had the significant interaction during the whole trail period, but the combination of 0.1% oligosaccharides with 0.075% enzyme had significant interaction in increasing the feed intake by 9.59% (P<0.05) compare with basic feeds. (3) The effects of acidifier and probiotics were better than oligosaccharides and enzyme additive on increasing ADG and reducing the F/G; and the effect of the combination of 0.3% acidifier and 0.2% probiotics with 0.075% enzyme on increasing ADG and reducing F/G was better than the other combination. (4) The effects of the four additives in the broilers were more obvious during 0~3 weeks than 4~6 weeks.