Associative Effects Of Mulberry Leave With Leymus Chinensis And Affects On Rumen Fermentation,Growth Performance,Fat Deposition In Sheep Fed With The Combined Forage Diet

This research was conducted to use in vitro ruminal fermentation method to compare the associative effects of different combinations of mulberry leave(ML)and Leymus chinensis(LC)at first.On this basis,the combination of ML and LC was used to feed sheep.Determining the optimum amount of mulberry leaves in the sheep feeding by comparing the digestive and rumen fermentation,production performance,slaughter performance,meat quality and fat deposition of sheep,which provided the reference for the rational utilization of mulberry leaves in the raising of sheep.The research mainly include the following three parts:Trial 1:This experiment aimed to use in vitro ruminal fermentation method to investigate the associative effects of different combinations of mulberry leave and Leymus chinensis,and screened the optimum combination ratios of ML and LC.ML and LC were mixed at the ratios of 0:100(TO group),20:80(T20 group),40:60(T40 group),60:40(T60 group),80:20(T80 group)and 100:0(T100 group),respectively.The mixtures were used as the fermentation substrate and incubated in vitro for 72 h for an in vitro fermentation gas production test and a batched in vitro fermentation test.The results showed as follows:1)Theological maximum gas production,gas production at 72 h,microbial protein(MCP)concentration in culture fluid and in vitro digestibility of organic matter(IVDOM)had increasing trends with the increase of ML ratio in substrate;2)At 72 h,theological maximum gas production,gas production and IVDOM in T100 group were significantly higher than those in other groups(P<0.05),and MCP concentration in culture fluid in T60 and T100 groups was significantly higher than those in other groups(P<0.05);3)At 48 and 72 h,culture fluid pH in T60,T80 and T100 groups was significantly lower than that in other groups(P<0.05);4)At 72 h,total volatile fatty acid(TVFA)culture fluid in T60 group,T80 group and T100 group were all significantly higher than those in other groups(P<0.05);5)At 6,12 and 72 h,the concentration of ammonia nitrogen(NH3-N)in culture fluid in T60,T80 and T100 groups was significantly higher than that in other groups(P<0.05);6)The multiply factor associative effect index(MFAEI)in T60 group was higher than that in other groups.In conclusion,the combination of ML and LC can improve in vitro fermentation characteristics,they have associative effects,and their optimum combination ratio is 60:40.Trial 2:The experiment was to investigate the effects of different proportion of ML on nutrient digestibility and metabolism,serum biochemistry index and rumen fermentation as well as growth performance of sheep.32 small tail Han sheep(25.15±1.03kg)were randomly divided into 4 groups,the control group(Con group),the T20 group,the T60 group and the T80 group,8 lambs as replicate in each group.Diet composition and the nutrient level were on the basis of the NRC(2007),the expected to gain is 200g daily,dry matter intake is 0.83kg and the ME was 10 MJ/kg.The roughage in the Con group was only LC.The T20?T60 and T80 groups was the groups adding ML.T20?T60 and T80 groups' ratio of ML and LC is 20:80,60:40 and 80:20,that is,the ratio of ML in each group was 0%,8%,24%and 32%respectively.The test had a 10-day for pre-experiment and a 55-day for experiment.The results showed as follows:1)There was no significant difference in the productive performance of each group(P>0.05).The finad body weight(FBW)and average daily feed intake(ADFI)of the groups adding ML were higher than those of the Con group.2)The apparent digestibility of DM and OM in groups adding ML were higher than that in Con group.(P<0.05).The apparent digestibility of CP in T20 and T60 groups was significantly higher than that in Con and T80 groups(P<0.05).The apparent digestibility of NDF and ADF in T60 group was significantly higher than that in other groups(P<0.05).The apparent digestibility of EE in T60 and T80 groups was significantly higher than that in Con and T20 groups(P<0.05).3)The content of UA in the serum of the Con group was significantly higher than that.of the other groups(P<0.05),but there was no significant difference in other serum indexes.4)There was no significant difference in pH,the concentration of NH3-N,TVFA,acetic acid,propionic acid the value of acetic acid/propionic acid in each group(P>0.05).The MCP concentration in group T60 and group T80 was significantly higher than that in control group and T20 group(P<0.05).The concentration of butyric acid in group T60 was significantly higher than that in control group and T20 group(P<0.05).Trial 3:The experiment was to investigate the effects of different proportion of mulberry leaves on sheep's slaughter performance,meat quality and fat deposition.Four sheep in each group were slaughter at the end of the feeding experiment.The results showed as follows:1)There was no significant difference in slaughter performance in each group(P>0.05).The carcass weight,dressing percentage,total lean and the ratio of muscle/bone in T60 group was higher than that in other groups(P>0.05).2)The longissimus dorsi muscle's L*and the gluteus muscle's shear force and cooking loss in the groups adding ML were significantly lower than those in the Con group(P<0.05).The longissimus dorsi muscle and vastus lateralis muscle's a;*in T60 group was significantly higher than that in Con group(P<0.05).The longissimus dorsi muscle and vastus lateralis muscle's pH24h in T60 group was significantly higher than that in other groups(P<0.05).The longissimus dorsi muscle's drip loss in T60 and T80 groups was significantly lower than that in Con and T20 groups(P<0.05).The vastus lateralis muscle's drip loss in T60 group was significantly lower than that in other groups(P<0.05).3)The back fat thickness of T60 and T80 groups was significantly higher than that of Con and T20 groups(P<0.05).There was no significant difference in carcass fat weight,abdominal fat weight,visceral fat weight,subcutaneous fat weight,tail fat weight and intramuscular fat weight in each group(P>0.05).The visceral fat weight,subcutaneous fat weight and muscle fat weight in T60 group were higher than those in other groups(P>0.05).The contents of intramuscular fat in T60 and T80 groups were significantly higher than that in Con and T20 groups(P<0.05).4)The contents of C15:1,C18:3n3,MUFA and PUFA/SFA in T60 group were significantly higher than those in other groups(P<0.05),but the content of SFA was significantly lower than that of the other groups(P<0.05),and the content of C17:1 was significantly higher than that of the Con group(P<0.05).The content of C18:ln9c in T80 group was significantly higher than that in other groups(P<0.05).The contents of C16:1 in T60 and T80 groups were significantly higher than those in the other two groups(P<0.05),and the content of C16:0 was significantly lower than that of the other two groups(P<0.05).5)The expression of ACC mRNA in the longissing dorsi in the T60 and T20 groups was significantly higher than that in the control group and the T80 group(P<0.05).The expression of AGPAT1 mRNA in the T60 group and the control group was significantly higher than that in the T20 group and the T80 group(P<0.05).The expression of ATGL mRNA in T20 group was significantly higher than that in T80 group(P<0.05).