Effects Of Different Proportions Of Protein Grass Hay Replacing Alfalfa Hay On Growth Performance,Rumen Fermentation,Slaughter Performance And Meat Quality Of Fattening Sheep

Protein grass(Rumexpatientia L.×Rumextianshanicus A.Los),scientific name "protein oxalate",is a new variety of the genus of rumex that has been cultivated through the hybrid breeding technique in our country.It has the advantages of high protein content,rich nutrients,good palatability,high yield and strong stress resistance,and has the potential to be developed into a new forage feed material.At the present,domestic alfalfa hay can not meet the development needs of domestic animal husbandry,and it is urgent to develop and use new forage resources to solve the problem of insufficient supply of alfalfa hay.The purpose of this experiment was to study the effects of different proportions of protein grass hay replacing alfalfa hay on growth performance,apparent digestibility of nutrients,rumen fermentation parameters,enzyme activity,slaughter performance and meat quality of fattening sheep,and to provide theoretical basis and data support for the application of protein grass in livestock production and the expansion of new feed resources in animal husbandry.The test mainly includes the following contents:The first part was to study the effects of different proportions of protein grass hay replacing alfalfa hay on growth performance of fattening sheep.Fifty-six male Australian white sheep ♂ ×Hu sheep ♀ with initial body weight of 19.80±2.59kg and 3 months old were randomly divided into 4 treatment groups with 14 sheep in each group.Piglets in control group(CON group)were fed a basal diet(roughaag was alfalfa hay).The experimental groups were given protein grass hay replacing 33%(33%group),66%(66%group)and 99%(99%group)alfalfa hay in the diet,respectively,and the concentrate to forage ratio in each group was 6:4.The results showed as follows:when protein grass hay replaced 33%and 66%alfalfa hay,there was no significant effect on the growth performance of fattening sheep(P>0.05).When protein grass hay replaced 99%alfalfa hay,the average daily gain in 4 to 8 weeks was significantly decreased(P<0.05),and FCR was significantly increased(P<0.05).The results showed that the replacement of 33%and 66%alfalfa hay in the diet with protein grass hay did not significantly affect the growth performance of fattening sheep(P>0.05),and alfalfa hay could be replaced with 33%and 66%protein grass hay.The second part was to study the effects of different proportions of protein grass hay replacing alfalfa hay on nutrients apparent digestibility of fattening sheep.In this study,digestion and metabolism tests were conducted on the basis of animal experiments,and nutrient apparent digestibility was determined by total feces and urine collection method.The results showed that the replacement of alfalfa hay with protein grass hay had no significant effect on the apparent digestibility of nutrients(P>0.05).It indicates that alfalfa hay in the diet can be replaced with protein grass hay.The third part was to study the effects of different proportions of protein grass hay replacing alfalfa hay on rumen fermentation parameters and digestive enzyme activities of fattening sheep.The results showed that rumen fermentation parameters and digestive enzyme activities of experimental groups were not significantly different with the CON group(P>0.05).Dietary replacement of 33%,66%and 99%alfalfa hay with protein grass hay did not significantly affect rumen fermentation parameters and digestive enzyme activities of fattening sheep(P>0.05).The fourth part was to study the effects of different proportions of protein grass hay replacing alfalfa hay on slaughter performance and meat quality of fattening sheep.The slaughter performance indexes of fattening sheep were determined at slaughter,and the longissimus dorsi muscle was taken to determine the meat quality,amino acid and fatty acid composition.The results showed that the replacement of 66%and 99%alfalfa hay with protein grass hay significantly increased liver weight(P<0.01),but had no significant effects on other slaughter indexes(P>0.05).In terms of meat quality,the effect of 66%protein grass group was similar to CON group(P>0.05).There were no differences in amino acids and fatty acids composition and content among all groups(P>0.05).The content of cis-11,14-eicosadienoic acid(C20:2)in 66%and 99%groups were significantly higher than that in CON group and 33%group(P<0.05).There were no significant differences in the contents of saturated fatty acids(SFA),polyunsaturated fatty acids(PUFA)and monounsaturated fatty acids(MUFA)among all groups(P>0.05).In conclusion,it is feasible to replace alfalfa hay with protein grass hay,and protein grass hay has excellent feeding value to replace alfalfa hay.The 33%and 66%protein grass hay can be used to replace alfalfa hay,and the best effect is 66%protein grass hay.