Effects Of Microbial Fermentation Of Straw On Production Performance And Nutrients Apparent Digestibility For Mutton Sheep

In straw microbial fermentation process, the degradation crude fiber material turn into animal easy digestion and absorption of small subclass compounds, and use the NPN protein synthesis of bacteria, improve the protein content of the straw. At the same time, the straw also can produce digestive enzymes, promoting the growth factors and other unknown microbial metabolic product, improve the palatability and the nutritional value, so as to promote the growth of mutton sheep. So far, about fermented corn straw application in mutton sheep is very much, but about improving palatability, increasing protein content to more than 12% after fermentation, and can replace part of protein feed, in order to reduce its usage is rarely reported.This test researched the production performance and nutrients apparent digestibility of mutton sheep by adding the different ratio of microbial fermentation of straw, compared with feeding silage straw, to explore microbial fermentation of straw can replace part of protein feed in lamb mutton sheep breeding process, so as to save feed and reduce feed cost, provide scientific theory basis for solving the problem of food shortages.In order to better study the fermented straw optimum adding proportion, the test set up four treatment group and one control group( the proportion of microbial fermentation of straw is respectively 25%, 50%, 75%, 100% and 0%), divided 80 sheep into 5 groups randomly,using randomized design, each group had 16 sheep, breeding is divided 3 period and each period has 20 days. After feeding, we would choose four sheep for digestion and metabolism, research the effects on production performance and nutrients apparent digestibility of the mutton sheep.The results showed as follows: The differences were not significant in 5 groups on initial weight,final weight, average daily gain,F/G,dressing percentage and pure meat percentage(P > 0.05).Analysis for nutrient digestion and metabolism rate, compared with the control group,the total energy and fecal energy levels in 75%, 100% add group had no significant difference(P > 0.05); the urinary energy,digestible energy,metabolic energy,gross energy digestibility and metabolic rate among different groups were not significant(P > 0.05). The nitrogen level in 25% and 50% treatment group was 28.18%(P > 0.05), 30.86%(P > 0.05) lower than the control group; however,the nitrogen level in 75%, 100% treatment group had no significant difference(P > 0.05)with the control group(P > 0.05); In addition to the 75% add group, the fecal nitrogen levels of each group, respectively, compared with the control group was reduced by 20.74%(P > 0.05), 41.48%(P < 0.05) and 11.82%(P > 0.05); 75% and 100% treatment group of sediment nitrogen level slightly increased compared with control group, but there were no significant difference(P > 0.05), there were no significant difference among each group of urine nitrogen, nitrogen digestibility compared with the control group(P >0.05).Compared with the control group,the apparent digestibility of dry matter,crude fat,NDF,ADF of each treatment group had no significant difference(P > 0.05), but calcium and phosphorus levels in 25% add group was significantly lower than the control group and 100% add group(P < 0.05), and other groups had no significant difference compared with control group(P > 0.05). Overall, adding 75% of microbial fermentation of straw had the appropriate level of energy metabolism and nitrogen metabolism, increased the net weight,slaughter rate and net meat percentage, and produce the highest economic benefit.