Effect Of Rice Straw Ammoniatied For Different Time On Lamb Fattening,Rumen Fermentation And Carcass Quality

In this reseach, high-pressured fast ammoniafiation system was used to make ammoniated rice straw. The effect of rice straw ammoniated for different time on feed intake,average daily weight grain,blood biochemical indexes and carcass quality were studied First, 16 female lambs(8 Suffolk×semi-fine wool sheep,8 Texel×semi-fine wool sheep) which were ablactated at 4 month age were used to fatten. They were divided into 4 groups randomly(breed is the same, and age,weight have not significant difference among the groups), 4 lambs in each group, unammoniated rice straw,rice straw ammoniated for 2h,rice straw ammoniated for 4h and rice straw ammoniated for 6h were feed respectively. Next, 4 male Dorset×semi-fine wool sheep with permanent rumen fistula were selected. Latin square experiment design was used to study the effect of rice straw ammoniated for different time on rumen fermentation and degradation rate of DM,NDF and CP.The result showed that the feed intake of ammoniated 2h,4h,6h group was significant more than unammoniated group(P<0.01), the order is ammoniated 4h group>ammoniated 6h group>ammoniated 2h group > unammoniated group, the difference was not significant among ammoniated group(P>0.05) . Ammoniated 4h group got the most average daily weight gain, and was significant more than unammoniated group(P<0.01)and ammoniated 6h group (P<0.05). The average daily weight gain of ammoniated 2h group was significant more than unammoniated group(P<0.05). After counting the cost and meat output, it showed that ammoniated 4h group got the most economic benefit, the average profit of each lamb was 49.51, and was more than unammoniated group 3.3 times.Blood biochemical indexes of lambs in each group changed a litter, and were all in normal range. All in all, the effect of fast ammoniated rice straw on blood biochemical indexes of lambs was not significant.The dressing percentage of lamb in ammoniated 4h group was the highest and reached 49.45%, the carcass meat percentage of lamb in ammoniated 6h group was the highest and reached 87.09%. The water lossing percentage of lamb in ammoniated 4h group was the lowest(19.37%), the cooked meat percentage of lamb in ammoniated 4h group was the highest(68.51%), lamb meat quality in each group was more better than others.The change of pH of each group was similar, began to fall after feeding, rised a little at 6h after feeding. The concentration of NH3-N of unammoniated group was always degressive, it rised first then fell after feeding in ammoniated group. The change of concentration of VFA of each group was similar, it rised first then fell after feeding. All in all, the pH value and the concentration of NH3-N of ammoniated group in ruminal fluid was significant lower than unammoniated group(P<0.05), but the concentration of VFA was significant higher than unammoniated group(P<0.05).The degradation of DM,NDF and CP of rice straw ammoniated for different time became higher when the time in rumen became longer. The degradation of DM of rice straw ammoniated for 4h in rumen increased 29.68%(P<0.01), the degradation of NDF rice straw ammoniated for 6h in rumen increased 32.01%(P<0.01), the degradation of CP of rice straw ammoniated for 4h in rumen increased 1.2 times(P<0.01).