Study On The Difference In Slaughter Performance And Meat Quality Of New Jilin Black Pigs With Different Weight

The new Jilin Black pig is a high quality breed with good meat quality and strong adaptability which is being cultivated by Jilin Academy of Agricultural Sciences with the modern version of Bachsia and civil pig.There are few reports on slaughter performance and meat quality of new Jilin black pigs with different weight.In order to meet the needs of large-scale breeding of new Jilin black pigs,determine the optimal slaughter weight,reduce breeding cost and improve economic benefits,three new Jilin black pigs with an average body weight of 100 kg,115 kg,130 kg and 145 kg were selected for slaughter in each group,and their serum biochemical indexes,slaughter performance and meat quality performance were determined respectively.The results were as follows:1.Slaughter performance:With the increase of slaughter weight,carcass weight,carcass straight length,carcass oblique length,eye muscle area,skin thickness at 6-7 ribs,backfat thickness at 6-7 ribs and three-point average backfat thickness showed an increasing trends.The body weight of the 145 kg group was significantly increased by 10.70%（P<0.01）,21.12% （P<0.01）and 53.18%（P<0.01）compared with the 130 kg,115 kg and 100 kg groups, respectively.The oblique carcass length of 145 kg body weight group was significantly higher than that of 100 kg body weight group and 115 kg body weight group（P<0.01）,but had no significant difference with other body weight groups.The eye muscle area and skin thickness at6-7 ribs of 145 kg body weight group were significantly higher than those of the other three groups（P<0.05）.Lean meat percentage decreased with the increase of slaughter weight.Lean meat percentage of 100 kg weight group was significantly higher than that of the other three groups（P<0.05）.2.Meat quality performance:the L*value of flesh color in 100 kg body weight group was significantly higher than that in 115 kg and 145 kg body weight groups（P<0.05）,but there were no significant difference among the other three groups（P>0.05）.The tenderness of 145 kg body weight group was significantly higher than that of 130 kg,115 kg and 100 kg body weight groups（P<0.05）,but there were no significant difference among other body weight groups （P>0.05）.pH₁,145 kg and 130 kg body weight groups were significantly higher than the other two groups（P<0.05）,115 kg body weight group was significantly higher than 100 kg body weight group（P<0.05）;p H₂₄was higher in the 145 kg group than in the other three groups,but there was no significant difference among the four groups.The water loss rate of 145 kg,130 kg and 115 kg weight groups was significantly higher than that of 100 kg weight group（P<0.05）,but had no significant difference with other weight groups.In terms of intramuscular fat,145kg body weight group was significantly higher than 115 kg body weight group and 100 kg body weight group（P<0.05）,but there was no significant difference in other groups.3.There were no significant differences in total protein（TP）and albumin（ALB）contents（P>0.05）.There were no significant differences in globulin（GLB）contents between 145 kg and130 kg groups（P>0.05）,but they were significantly higher than those between 115kg and 100kg groups（P<0.05）.The 115 kg body weight group was significantly higher than the 100 kg body weight group（P<0.05）.UREA（UREA）content,130 kg body weight group and 115 kg body weight group were significantly higher than 100 kg body weight group（P<0.05）;There was no significant difference among other weight groups（P>0.05）.4.Blood antioxidant activity:The activity of total superoxide dismutase（T-SOD）in 100 kg body weight group was significantly higher than that in the other three groups（P<0.05）; Malondialdehyde（MDA）was significantly higher in the 145 kg body weight group than in the other three groups（P<0.01）,and was significantly different among the other three groups （P<0.01）.The total antioxidant capacity（T-AOC）decreased with the increase of body weight,but there was no significant difference among the four groups（P>0.05）.In terms of catalase（CAT）,the 115 kg body weight group was significantly higher than the other three groups （P<0.05）.Glutathione peroxide（GSH-Px）,145 kg body weight group was significantly higher than the other three groups（P<0.05）.5.Correlation analysis between slaughter performance and meat quality traits:Premortem body weight was significantly positively correlated with carcass weight,three-point mean backfat thickness,skin thickness,tenderness,intramuscular fat and pH1（P<0.01）,significantly positively correlated with slaughter percentage,carcass oblique length,eye muscle area,water loss rate and cooked meat percentage（P<0.05）,and significantly negatively correlated with lean meat percentage（P<0.01）.Carcass weight was positively correlated with dressing percentage,three-point mean backfat thickness,skin thickness,tenderness and p H1（P<0.01）,and was positively correlated with carcass oblique length,eye muscle area,water loss rate,cooked meat percentage and intramuscular fat.Skin thickness was significantly positively correlated with tenderness,intramuscular fat and three-point mean backfat thickness（P<0.01）,and was significantly positively correlated with eye muscle area,drip loss and water loss rate（P<0.05）,and significantly negatively correlated with lean meat percentage（P<0.01）.6.Economic benefits:The economic benefits of different slaughter weights of new Jilin black pigs were evaluated.When the slaughter weight reached 145kg,the benefits were the highest,but the costs were also the highest.The highest economic benefit was obtained at 115kg slaughter weight.