Research On The Associative Effect Of Cassava Foliage And King Grass And Its Application In The Diet Of Hainan Black Goats

This paper was divided into four research parts.We mainly studied the effect of growth height on cassava foliage feeding value and silage quality,the in vitro fermentation characteristics of cassava foliage and king grass with different proportions,the effects of different ratios of cassava foliage silage and king grass on growth performance,blood indexes,rumen parameters and rumen microorganisms of Hainan black goats.The aim was to find out the best proportion of cassava foliage silage and king grass,and to provide scientific basis for the utilization of cassava foliage in Hainan black goat production.In experiment 1,the effects of growth height on the feeding value and silage quality of cassava foliage were studied.The growth height was 0.9 m,1.2 m,1.5 m and 1.8 m.The results showed that the growth height had an effect on the contents of DM,CP and ASH in cassava foliage,but had no effect on the contents of NDF,ADF and EE.The NDF and ADF in cassava foliage increased with the increase of growth height.The RFV values of cassava foliage at four different growth heights had no significant difference,but tended to decrease with the increase of height.The contents of NDF,ADF and EE in cassava foliage silage in each group had no effect,but the ASH content in H2 cassava foliage silage was significantly higher than that in other groups,and there was no significant difference in RFV among four height cassava foliage silage.The results of silage quality showed that the 3.93 of 1.8m cassava foliage silage was lower than 4.2 of p H,and the lactic acid content was the highest,the silage score was the highest,and the silage quality was the best.In experiment 2,the in vitro fermentation characteristics of cassava foliage and king grass with different proportions were studied.Cassava foliage and king grass,cassava foliage silage and king grass were fermented in vitro according to 0:100-100:0,respectively.The results showed that the in vitro gas production of the combination of cassava foliage,cassava foliage silage and king grass decreased with the increase of the proportion of cassava foliage.The IVDMD of cassava foliage and king grass was the highest at 20: 80,and the MCP of single cassava foliage was the highest.The IVDMD of cassava foliage silage and king grass was the highest when the ratio was 0: 100,and the NH3-N content was the highest when the ratio was 30: 70.The molar ratio of propionic acid in the culture medium of cassava foliage and king grass decreased with the increase of the proportion of cassava foliage.The molar ratio of acetic acid was the highest when the ratio of cassava foliage silage and king grass was 30: 70.Experiment 3 explored the effects of different ratios of cassava foliage silage and king grass on growth performance and blood indexes of Hainan black goats.According to cassava foliage silage and king grass 0RU 100,25:75,50:50,75:25,100 Ru 0,they were divided into T1,T2,T3,T4,T5 groups.The results showed that there was no significant difference in initial weight,final weight and feed intake among the three groups.The average daily gain of group A was significantly lower than that of other groups,and the feed gain ratio of T1 was significantly higher than that of other groups.The apparent digestibility of crude protein in T1 was significantly higher than that in T2 and T3.The apparent digestibility of crude fat in group A was significantly higher than that in T3 and T5.The contents of ALT and CRE in T1 group were the highest.In T3 group,the activities of T-AOC,T-SOD,GSH-Px and the contents of Ig A,Ig G,Ig M,C3 and C4 were the highest,while the content of MDA was the lowest.Experiment 4 explored the effects of different ratios of cassava leaf silage and king grass on rumen parameters and microbial diversity of Hainan black sheep.The rumen fluid in experiment 3 was analyzed,and the results showed that the molar proportion of butyric acid in T2 was the highest,accounting for6.55%,which was significantly higher than that in T5,and there was no significant difference in p H and other VFA among the groups.Alpha diversity analysis showed that there were no significant differences in Chao,ACE,Simpson and Shannon among different groups.Bate diversity showed that with the change of addition,the microbial community changed,the distance between T1 and T2 was very close,but the distance between T3 and T4 was close,T5 was the farthest,and the community structure was different.The relative abundance of rumen microorganisms in each group had no significant difference at the genus level,and the dominant bacteria were Bacteroidetes,Firmicutes and Synergistetes,accounting for more than 90% of the total bacteria,and there was no significant difference in abundance among different groups.At the genus level,the 10 dominant genera(average relative abundance)of the five groups of rumen microorganisms were Prevotella＿1 、 Rikenellaceae＿RC9＿gut＿group 、uncultured＿bacterium＿f＿F082 、 Fretibacterium 、 Butyrivibrio＿2 、uncultured＿bacterium＿f＿Lachnospiraceae 、 Quinella 、 Christensenellaceae＿R-7＿group 、Veillonellaceae＿UCG-001、Prevotellaceae＿UCG-003,accounting for about 75% of the total rumen microorganisms.The relative abundance of Quinella in T1 group was significantly higher than that in other groups,and there was no significant difference among other dominant genera.Conclusion:(1)When the cassava foliage is directly utilized,the nutritional value of 0.9m and 1.2m cassava foliage is better,combined with the yield factor,1.2m cassava foliage better.(2)Cassava Youth is made of 1.8m growth,and the quality of silage is better.(3)When the ratio of cassava leaf and king grass is different,when the proportion of cassava leaf is less than or equal to 50%,the effect of in vitro fermentation is better,which is more beneficial to rumen fermentation;when the ratio of cassava foliage silage and king grass is 10:90-30:70,the effect of in vitro fermentation is better.(4)The proper combination of cassava foliage silage and king grass can improve the production performance,immunity and antioxidant capacity of Hainan black goat,and won’t destroy its rumen environmental homeostasis and rumen microbial diversity.Under the conditions of this study,it is suggested that the ratio is 25:75,which can effectively improve the production performance,antioxidant and immune capacity of Hainan black goats,and will not have a negative effect on the growth performance of Hainan black goats.