不同葡萄籽酿酒残渣水平全混合日粮在育肥羊瘤胃内的有效降解率

摘要

本试验旨在评定不同葡萄籽酿酒残渣水平全混合日粮(TMR)在育肥羊瘤胃内的有效降解率.选取3只安装永久性瘤胃瘘管、平均体重为(35.0 ± 3.7)kg的哈萨克去势公羊作为试验动物,共进行5期试验,各期分别以5种不同葡萄籽酿酒残渣水平[0(TMR1)、4.17%(TMR2)、8.33%(TMR3)、12.50%(TMR4)、16.67%(TMR5)]的TMR进行瘤胃灌注试验,按葡萄籽酿酒残渣水平由低到高依次进行.每期15 d,其中第1~7天为预试期,第8~12天为连续灌注期,第13~15天为采样期.同时在每期的第13~15天进行尼龙袋试验.采用醋酸镱(Yb?ac)作为食糜标记物,绘制浓度衰减曲线并利用非线性回归法来拟合外流速度;评定干物质(DM)、有机物(OM)及粗蛋白质(CP)的降解动力学参数,计算瘤胃有效降解率.结果表明,葡萄籽酿酒残渣水平与瘤胃食糜外流速度之间呈显著正相关的直线关系(r=0.6070,P<0.05);DM、OM和CP的有效降解率均随着TMR葡萄籽酿酒残渣水平的增加而先下降后趋于稳定或略有上升,TMR4组和TMR5组均显著低于TMR1组(P<0.05);5种TMR均为瘤胃能氮负平衡型,瘤胃能氮平衡(RENB)值均随葡萄籽酿酒残渣水平的增加呈线性下降趋势(P=0.0055).总之,育肥羊TMR中葡萄籽酿酒残渣的适宜水平为8.33%~12.50%.%The purpose of this experiment was to evaluate the effective degradability of total mixed ration (TMR)with different levels of brewing residue of grape seed(GSBR)in rumen of fattening sheep. Three Ka?zakh wethers weighed(35.0±3.7)kg with permanent rumen cannulas were used as experimental animals. The test consists of five periods, rumen perfusion tests were conducted using TMRs with different GSBR levels[0 (TMR1),4.17%(TMR2),8.33%(TMR3),12.50%(TMR4)and 16.67%(TMR5)],respectively. The tests were carried out from low to high GSBR levels. Each period lasted for 15 d, day 1 to 7 was for pre?test period, day 8 to 12 was for continuous perfusion period, and day 13 to 15 was for sampling period. At the same time, the nylon bag test was carried out on day 13 to 15 of each period. Ytterbium?acetate(Yb?ac)was used as the marker for digesta,and its decay curve was mapped to calculate outflow rate(Kp)using nonlinear regression; degradation kinetic parameters of dry matter(DM), organic matter(OM)and crude protein (CP)were evaluated,and ruminal effective degradability was calculated. The results showed as follows:rumi?nal digesta Kp had significantly linearly positive relationship with GSBR level(r=0.607 0, P<0.05); effec?tive degradability of DM, OM and CP showed then tendency of firstly decrease and then stable or slightly in?crease with the increase of GSBR level in TMR,TMR4 and TMR5 groups were significantly lower than TMR1 group(P<0.05); the five TMRs were all ruminal energy and nitrogen negative balance type,and ruminal en?ergy nitrogen balance value was linearly decreased with the increase of the GSBR level(P=0.005 5). In con?clusion, the optimal level of GSBR in TMR for fattening sheep is 8.33% to 12.50%.