Study On The Stability Of Chaetomium Thermophile Fiber Enzyme And Mechanism Of Growth Promotion In Broilers

The experiments were conducted to study the mechanism of growth promotion in broilers in vivo, and the stability of C. thermophile fiber enzyme with different temperatures, pH, feed types, storing time and the processing of feed granulate in vitro. The results showed that C. thermophile xylanase activity was not reduced seriously within 100℃in the lab and had higher activity between 40℃and 60℃.The optimum pH lied in the range of 3.2-4.4.Xylanase activity was affected by different feed types and the storing time (P <0.01), reduced to 15.41%, 23.22% and 26.97% after 24h in premix, concentrate and complete feed, respectively, and cut down by 42.83%, 31.93% and 19.85% again after stored for 45d. Xylanase activity was affected by the processing notably (P <0.01), and reduced to 56.68%, 32.48%, 24.00% and 27.42% after mixed, modulated, granulated and cooled.Thirty-six broilers (42d) were used to determine the nutrient metabolic rate of individual feed with precision-feeding method. The results showed that C. thermophile fiber enzyme added 0.15% in diet improved the apparent metabolic rate of crude protein in cotton meal and wheat (P <0.05), ether extract, energy and apparent metabolizable energy in corn, wheat and wheat middling (P <0.05). The enzyme didn't elevate the apparent metabolizable energy, the apparent metabolic rate of ether extract in cotton meal and crude protein in corn. All nutrient metabolic rates in soybean meal and peanut meal hadn't notable change (P >0.05).One hundred and twenty broilers were distributed randomly into 4 treatments with 3 replicates of 10 birds. Two birds of each replicate were slaughtered in 14, 35 and 49-day-old respectively to study the allelotaxis and enzyme activity in digestive tract. The results showed that C. thermophile fiber enzyme reduced the relative weight of large intestine and pancreas (P <0.05), didn't affect the relative weight of stomach and small intestine,the length of small intestine (P >0.05). C. thermophile fiber enzyme added 0.15% and 0.25% in diets improved the villous height and radio of villous height and crypt...