Study On Some Germplasm Characteristics Of Aba Tibetan Pig

The Aba Tibetan pig is a type of Tibetan pigs on the plateau in my country.This article studies some germplasm characteristics of the Aba Tibetan pig,aiming to provide a theoretical basis for the Aba Tibetan pig’s purification and rejuvenation and scientific feeding management and breeding.The test mainly measured,analyzed and studied the growth and developmentfattening performance,slaughter performance and meat quality of Aba Tibetan pigs.（1）Growth and development:388 Tibetan pigs（including 116 boars and 272 sows）were randomly selected in the main producing area of Aba Tibetan pigs in 2,4,6,8,10,12,14,16,18 months.Body weight and body size were measured for age.Three models of Gompertz,Logistic and von Bertalnffy were fitted to the body weight growth of Aba Tibetan pigs,and the cumulative growth of body weight and the regression analysis of body weight and body size were performed.The results showed that the growth and development of Aba Tibetan pigs conformed to the Gompertz,Logistic and von Bertalnffy models,but there are differences in the applicable models between different sexes.The growth and development of boars is more in line with the von Bertalnffy growth model（R²=0.9914）,with a growth inflection point of 6.77 months and a weight of 15.38 kg;the growth and development of sows is more in line with the Logistic growth model（R²=0.9928）,with a growth inflection point of 8.35 months,the inflection point weight is 24.06 kg;There are gender differences in the growth and development of Aba Tibetan pigs,and the growth inflection point of Tibetan boars is earlier than Tibetan sows.Except for 6 months and 8 months of age,the body weight of boars is lower than that of sows.There is a high correlation between body weight and body length of Aba Tibetan boars（R²=0.965）,The formula for estimating the weight of boars through body length within 18 months of age is y=21.5449x^0.3307,and the formula for estimating the weight of the bust circumference is y=20.9619x^0.3258;There is a high correlation between sow weight and body length（R²=0.979）.The formula for estimating body weight of Aba Tibetan sows within 18 months of age is y=33.5535+0.987x;The formula for bust estimation weight is y=21.9716x^0.3052.（2）In terms of fattening performance:12 Aba Tibetan pigs（including 6 boars and 6 sows）that were weaned at 3 months of age and were castrated were healthy and basically the same weight.The fattening performance was measured according to the local traditional grazing+half-house feeding method.That is,half-house feeding for 6 months（feeding-based）,then grazing for 6 months（grazing-based）,and finally half-house feeding for 3 months（feeding-based）until the slaughter.The results showed that the daily gain at 15-18 months of fattening was the highest at 184.25 g,which was extremely significantly higher than other stages（P<0.01）,followed by 6-9 months and 12-15 months（P<0.01）.They are 111.81 g and 110.66 g respectively;The material-to-weight ratio is 1.11 at the lowest of 12-15 months,which is significantly lower than 15-18 months,6-9 months,3-6 months and 9-12 months;The feed-to-weight ratio of Aba Tibetan pigs is 2.06:1,which is generally lower than other local breeds and commercial pigs.Aba Tibetan pigs are fattened through traditional grazing+half-house feeding,which has the advantages of low feed-to-weight ratio,high feed conversion rate and low feeding cost.Finishing slaughter at about 15 months of age can achieve better production efficiency and carcass quality.（3）Slaughter performance:6 Aba Tibetan pigs fattened to 18 months of age were randomly selected for slaughter and related slaughter index determination.Compared with the slaughter characteristics of other local breeds and imported breeds of pigs.The results showed that the carcass length of Aba Tibetan pig was 58.075±0.21cm,the slaughter rate was 64.97±0.51%,the leg-to-hip ratio was 28.64±0.55%,and the lean meat rate was40.05±1.12%.The eye muscle area of Aba Tibetan pigs is 19.182±0.32cm2 higher than Hezuo Tibetan pigs,Tibetan pigs（CG）and Diqing Tibetan pigs（grazing+supplementary feeding group）.They have certain meat production potential,but they are not dominant;The carcass length is 58.075±0.21cm,which is longer than Tibetan Pig（CG）and Hezuo Pig;The backfat thickness of 3.34±0.23cm is thinner than that of Tibetan Pig（CG）and Diqing Tibetan Pig,and higher than that of foreign pig breeds.Compared with some internal organ indexes of pigs of other local breeds and imported foreign breeds,The results showed that Aba Tibetan pig heart index is 0.36%,liver index is 1.25%,spleen index is 0.15%,lung index is 1.04%,kidney index is 0.28%,stomach index is 1.09%,large intestine index is3.66%,and small intestine index is 1.04%.The large intestine index of Aba Tibetan pigs is higher than that of other local breeds and foreign pigs,and it has the characteristics of tolerance to rough feeding.（4）In terms of meat quality:the longissimus dorsi of 5 Aba Tibetan pigs that have been fattened and slaughtered are selected for meat quality determination.The results showed that the L*value was 43.56,the a*value was 17.52,and the b*value was 3.6.The L*value was lower than that of local breeds and foreign breeds,and there was no PSE;The a*value is higher than that of local breeds and foreign breeds,the meat of pork is reddish,and the b*value is lower than that of other local breeds.Aba Tibetan pork is storage-stable,and the p H24 drop rate is small,drip loss（1.78%）and shear force（3.76kg）are lower than some local breeds of pigs,and the cooked meat rate（69.58%）is higher than that of local breeds and foreign breeds pig.Aba Tibetan pig pork is rich in nutrition.Except for water content（64.73%）lower than other local breeds of pigs and DLY pigs,its crude protein（23.89%）and intramuscular fat（8.94%）are higher than other local breeds of pigs and the DLY pig.The eight amino acids content in Aba Tibetan pig pork is higher than that of local breeds and foreign pigs,and the umami amino acid content is the main one.The Aba Tibetan pig pork has a delicious flavor and high nutritional value and is worthy of promotion.