Study On Slaughter Performance And Meat Quality Of Wanyue Black Pigs With Different Weight

Wanyue Black pig is a high-quality lean-type black pig,which is jointly bred by Anhui Agricultural University and local black pig conservation enterprises in Yuexi County,Anhui Province.At present,there are few studies and reports on Wanyue Black Pigs.To meet the needs of industrial development of Wanyue Black Pigs and to determine the appropriate slaughter weight so as to improve the breeding economic efficiency,Wanyue Black Pigs with an average weight of 95 kg,105 kg and 115 kg were selected in this experiment,and 10 pigs in each group were slaughtered.The slaughter performance,meat quality,muscle antioxidant capacity,blood biochemical indexes and muscle nutrient content（amino acid,fatty acid,inosine acid,collagen,etc.）were measured.The main results are as follows:1、Blood biochemical indexes:alanine aminotransferase（ALT）levels in the 95 kg and115 kg weight group were significantly different from the 105 kg weight group（P<0.05）.The urea（UREA）levels in blood were significantly higher in 95 kg and 105 kg weight groups than in 115 kg weight groups（P<0.05）,which were 22.5%and 18.06%higher respectively.The content of glucose（GLU）in 105 kg group was 34.59%and 35.92%higher than 115 kg group（P<0.01）.There was no significant difference in other indicators.2、Slaughter performance:With the increase in slaughter weight,carcass weight,three-point average backfat thickness,eye muscle area,carcass length and carcass straight length showed an increasing trend.The carcass weight of the 115 kg group was 17.10%higher than that the of 95 kg group（P<0.05）.The average backfat the thickness of 105 kg group and 115 kg group was significantly higher than that of 95 kg group（P<0.01）.The carcass slant length and carcass the straight length of 115 kg grou were significantly the higher than those of 95 kg group（P<0.01）.the longissimus dorsi area of 115 kg group was significantly higher the than 105 kg group and 95 kg group（P<0.05）.The lean meat rate showed a decreasing trend,95 kg body weight was significantly higher than 115 kg body weight,significantly higher than 105 kg body weight.The skin thickness of 105 kg was 8.38%higher than that of 95 kg（P<0.05）.The slaughter rate showed a decreasing trend but no significant difference.3、Meat quality:p H₂₄of the 115 kg weight group was significantly higher than 105 kg weight group（P<0.05）,The 24 h meat color value of 95 kg weight group was 69.14,which was significantly higher than 11.09%of 105 kg weight group（P<0.05）.Significantly higher than 115 kg weight group 12.28%（P<0.01）;there was no significant difference in other indicators.4、Muscle conventional substance content:with the increase of slaughter weight,intramuscular fat showed an increasing trend,115 kg weight group was significantly higher than 95 kg weight group 13.05%（P<0.05）;dry matter and crude ash content between the three groups did not show regularity,no significant difference.5、Antioxidant capacity of muscle:With the increase in slaughter weight,the total antioxidant capacity of muscle decreased,and 95 kg and 105 kg weight group were significantly higher than 115 kg weight group（P<0.01）;the MDA content of 115 kg weight group of 105 kg weight group was significantly higher than that of 95 kg weight group,which was 27.05%and 25.41%respectively（P<0.01）.There was no significant difference in the content of total superoxide dismutase among the three groups.6、The content of collagen,inosinic acid and cholesterol in muscle:Inosine content in 95kg weight group was 2.56 mg/g,significantly higher than that in 105 kg weight group and115 kg weight group（P<0.05）;with the increase of slaughter weight,collagen and cholesterol content increased slightly,but there was no significant difference（P>0.05）.7、Amino acid content:Glutamate（Glu）content in 95 kg weight group was significantly higher than 105 kg weight group（P>0.01）and 115 kg weight group（P>0.05）,glycine（Gly）content was significantly higher than 105 kg body weight group and 115 kg weight group（P<0.01）,tyrosine（Tyr）content was significantly higher than 105 kg weight group（P<0.01）and 115 kg weight group（P<0.05）;the Cys content in 95 kg and 105kg recombinants was significantly higher than that in 115 kg recombinants（P<0.01）,and the Leu content was significantly higher than that in 115 kg recombinants（P<0.05）.The contents of histidine（His）and delicious amino acid（DAA）in the 95 kg weight group were significantly higher than those in the 115 kg weight group（P<0.05）.8、Fatty acid content:A total of 8 fatty acids were detected.The linolenic acid content of the 95 kg weight group was significantly higher than that of the 115 kg weight group（P<0.05）,and there was no significant difference in other fatty acids.The unsaturated fatty acid content of 95 kg weight was significantly higher than that of 115 kg weight.The content of polyunsaturated fatty acids（PUFA）in 95 kg weight group and 105 kg weight group was significantly higher than that the in 115 kg weight group（P<0.05）.The ratio of saturated fatty acids to unsaturated fatty the acids in 115 kg group was 19%higher the than that in 95 kg group（P<0.05）.9、Correlation analysis among blood biochemical indexes,slaughter performance and meat quality performance:there was a significant aboriginal correlation among some traits,such as live weight and carcass weight,carcass length,carcass skew length,backfat thickness,eye muscle area,tenderness（shear force）were extremely significantly positively correlated（P<0.01）;it was significantly positively correlated with skin thickness（P<0.05）;total protein（TP）was significantly positively correlated with p H₂₄（P<0.01）,and significantly positively correlated with carcass weight（P<0.05）.Porcine albumin（ALB）was significantly negatively correlated with the color of meat at 24h（P<0.05）.Serum urea（UREA）was significantly negatively correlated with live weight,carcass weight,carcass length and carcass length（P<0.05）.Glucose（GLU）was significantly negatively correlated with carcass weight,carcass length,p H₂₄and intramuscular fat（P<0.05）.And lean meat rate was significantly positively correlated（P<0.05）.