体外产气法评价4种不同来源的桑叶对江西本地黄牛的营养价值

Assessment of Nutritional Value of Mulberry Leaf on Jiangxi Yellow Cattle by Gas Production Method in Vitro

为开发新型饲料资源,利用体外产气法估测了粤桑11-1、粤桑11-2、育71-1、普通蚕桑4种不同桑叶品种对江西本地黄牛饲用的营养价值。通过体外发酵试验并采用批次培养法,将4种参试样品培养48 h,在培养过程中分别记录0、2、4、8、12、24、36、48 h的产气量,并测定发酵24、48 h时发酵液的pH值、体外干物质降解率、菌体蛋白浓度以及氨态氮的浓度。结果表明,从各个时间段产气量来看,各种参试样品的产气量均随时间先逐渐升高再降低,最后趋于平衡,其中育71-1总产气量(230.63 m L)显著高于其他样品(P<0.05),其次为普通蚕桑和粤桑11-1;育71-1在发酵前12 h的各个时间段的产气量也是各样品中最高的。通过对24 h及48 h发酵液中pH值的测定,发现各样品培养过程中发酵液的pH值均在5.4~5.7之间,育71-1在24、48 h的pH值分别为5.41和5.51,为各样品中最低;育71-1的体外干物质消化率在24、48 h分别以67.87%和73.27%保持最高,其次为普通蚕桑(分别为54.60%,57.27%)和粤桑11-1(52.40%,53.93%)。育71-1的菌体蛋白浓度在2个时间点也最高,但各样品之间不存在显著差异(P>0.05);在2个时间点氨态氮浓度育71-1最高,其次为粤桑11-1,粤桑11-2最低。说明对江西本地黄牛而言,育71-1具有较高的营养价值,其次为普通蚕桑、粤桑11-1。

This experiment estimate the nutritive value on Jiangxi yellow cattle of 4 varietals of mulberry leaves including Yue11-1,Yue11-2,Sericulture and Yu71-1 by gas production method in vitro.With the method in vitro and implement the experiment in batch,the gas production were recorded at 0,2,4,8,12,24,36 and 48 h,respectively.The fermented fluid was collected at 24 h and 48 h to determine the p H,IVDMD,the concentration of bacillus protein and NH3-N.According to the gas production of the different test materials in each time,the gas production was increased gradually with time at first and finally tends to balance.The total gas production(230.63 m L)of Yu71-1 was significantly higher than those of other materials(P<0.05),followed by the Sericulture and Yue11-1,the gas production of them were 185.62 m L and 170.23 m L respectively;at each time point of the first 12 h fermentation,the gas production of Yu71-1 was also the highest in all samples;by measuring the p H of the fermentation broth at 24 h and 48 h,it was found that the p H of the fermentation broth was between 5.4 and 5.7;the p H of Y71-1 at 24 h and 48 h were 5.41 and 5.51,respectively,which were the lowest in all samples at that two time points.The in vitro dry matter digestibility of Yu71-1 were the highest at this two time points(67.87%,73.27% respectively),followed by Sericulture(54.60%,57.27%)and Yue 11-1(52.40%,53.93%).The bacillus protein concentration of Yu71-1 were also the highest at this two time points,followed by Yue11-1,Sericulture,Yue11-2,but there was no significant difference among these samples.The highest concentration of ammoniacal nitrogen was also found in Yu71-1,followed by Yue11-1,Sericulture and Yue11-2.Under the condition of this experiment,the statistical analysis of the data showed that Yu71-1,Sericulture and Yue11-1 could be processed to be developed and utilized as a new feed resources.