Effects Of Tea Premix Feed On The Production Performance And Fat Deposition In Finishing Pigs

Green tea is rich in polyphenols and other components.Utilization of tea resources have become research hotspot in green health care products and animal feed additives.Because of the complex composition of green tea,the effect mechanisms on the growth,metabolism and immune function of the animal were not clear.In this paper,the effect of diets with different Tea Premix Feeds(TPF)on backfat thickness,meat quality,fat deposition and their gene-related expressions have been explored.Sixteen hybrid pigs(DD)from Duroc × Dingyuan pig were selected,dividing randomly into 2 groups,8 of each group with 4 males and 4 females,in which the one group(DDA)fed basic diet,and the another group(DDB)fed the basic diets with 3% TPF.Twenty-four hybrid pigs(DL)from Duroc×(Landrance×Yorkshare)were selected,dividing randomly into 3 groups,8 of each group with 4 males and 4 females,in which three groups fed the basic diets with 3% TPF(DLC),4% TPF(DLD)and 5% TPF(DLE),respectively.Trial period was 90 days,with weighing and recording feed consumption at begin and end trial stages.All pigs were slaughtered at the end of the test,with determination of the backfat thickness,meat quality traits,and blood index.The effects of TPF on the gene expression and its pathway associated with digestion and absorption of fat were investigated by using RNA-seq in liver tissue.The influences of TPF on fat deposition of pig were explored.The results showed that:(1)In DD,the backfat thickness of DDB fell 23.4% than that of DDA(P < 0.05);the backfat thicknesses of DLD and DLE decreased respectively 14.8% and 20.9%(P< 0.05)than that of DLC in DL.Loin eye area,pork color,marbling and water-holding capacity didn't differ with the ratio of TPF in the diet(P > 0.05).(2)The muscle fat content of DDB significantly decreased 16.20% than that of DDA in DD(P<0.05),and the differences between groups showed a downward trend in DL,but was not significant(P>0.05).There were no significant difference in the contents of water,Ca,P,crude ash and inorganic salt in pig muscle(P>0.05).With the increase of TPF in the diet,the cholesterol in muscle and fat showed a downward trend,but they did not reach a significant level(P>0.05).(3)The blood triglyceride and total cholesterol decreased with the increase of TPF,and the correlation coefficient were-0.9820 and-0.9673(P<0.01),respectively,but the difference between the groups was not significant(P>0.05).In DL,the albumin increase for DLD vs DLC was 10.9%(P < 0.05),15.4% for DLE vs DLC(P < 0.01);alpha-1globulin decrease for DLE vs DLC was 31.8%(P < 0.01);and the total content of blood globulin decrease for DLE vs DLC was 8.66%(P < 0.01).(4)Comparing the pigs fed TPF diet group and basic diet group,the gene expression levels of Scavenger receptor(CD36),Phosphatidatephosphatase(PAP),Microsomal triglyceride transfer protein large subunit(MTP),ApoB-48,ATP-binding cassette subfamily A(ABC1,member 1),and ApoA-I were significantly down-regulation in TPF diet group.It was shown that the TPF could decrease the expression level of the related enzymes genes in fat digestion and absorption.