Effects Of Gender On Growth Performance, Carcasstraits And Meat Quality In Guanzhong Black Pig

Guanzhong black pig is a kind of excellent breed pig in Shaanxi Province,which has the advantages of adapting rough feeding,strong resistance,tender meat,good flavor and so on.However,the growth rate of Guanzhong black pig is slow and the lean meat rate is low,which limits the production of meat.This experiment compared the differences of growth performance,carcass traits and meat quality between different gender Guanzhong black pigs,which aim to exploring the differences of production performance between different sexes of Guanzhong black pigs.The research will provide theoretical basis for feeding and management of Guanzhong black pig.In this study,5 male and 5 female pigs with similar body weight were selected,and the boars were castrated at the age of 7 days.After the weight reached 101±4.89 kg,pigs were slaughtered to analyze meat quality,histomorphology and the expression of meat related genes by real-time qPCR.Results showed:1.The weight of castrated boars was significantly higher than gilts after 5 month old(P<0.05);the body length of castrated boars was significantly higher than gilts at 2 and 8 months(P<0.05);the body height and leg hip circumference were significantly higher than those of gilts at 2 month and after 6 month old(P<0.05);the chest circumference was also significantly higher than that of gilts after 6 month(P<0.05).Therefore,the growth performance of castrated boars was significantly better than that of gilts.2.The backfat thickness of castrated boars was 34.91±5.03 mm and the fat percentage was 44.07±2.19%,which was significantly higher than that of the gilt(P<0.05);the lean meat rate was 41.04±1.53%,the skin rate was 7.47±0.44%,and the bone rate was 7.06±1.02%,which were significantly lower than those of gilts(P<0.05).3.The contents of Omega-3 polyunsaturated fatty acids in the longissimus dorsi of castrated boars were significantly higher than those in gilts(P<0.05);the content of essential fatty acid and linolenic acid was significantly higher than that of gilt(P<0.05);the proportion of essential amino acids in castrated boars was significantly higher than that in gilts(P<0.05);the percentage of flavor amino acids in the total was significantly lower than that in the gilt(P<0.05).4.The morphological differences of castrated boars and gilts was significant.The muscle fiber area of the longissimus dorsi muscle,the Semimembranous and the adductor muscle of the gilt were significantly higher than that of the castrated boar(P<0.01);the diameter and area of subcutaneous fat cells of castrated boars were significantly higher than those of gilts(P<0.01);the relative expression of PPARγ,aP2 and SCD in the longissimus dorsi of castrated black boar was significantly higher than that of the gilt(P<0.05),the relative expression of PPARγ was significantly higher than that of gilt(P<0.05);Castrated boars longissimus muscle lipolysis related gene ATGL relative expression was significantly lower than that of gilts(P<0.05);The relative expression of HSL in subcutaneous fat was significantly lower than that in gilt(P<0.05).In summary,there were a lot of differences in growth performance,carcass traits,meat quality,muscle and adipose tissue morphology and meat related gene expression between different genders of Guanzhong black pig.The results showed that the growth speed of castrated boars was faster,the fat forming ability was stronger and the meat quality was better than that of gilts,but the lean meat rate was lower than that of gilts.Therefore,this study suggested that the feeding of Guanzhong black pigs should be carried out by the male and female groups respectively,and the right amount of feeding should be appropriately limited.