| Kele pig has strong ability to adapt to the high altitude and cold environment,resistant to rough feeding.Pork color is an important indicator for evaluating the quality of pork meat.Intramuscular myoglobin content is an important material basis for flesh color.In this experiment,Kele pig was used as the object of study in the content of myoglobin and the change of meat color in different breeding stages and different breeding modes.To explore the expression patterns of myoglobin related genes(Mb gene,MEF2 d gene)and myofibroid related genes(MyHC gene,MyHCIIb gene).qPCR and other techniques were used to detect the expression of related genes in different breeding modes and fattening stages of the Kele pig.The expression of these genes was correlated with myoglobin content and meat color.The changes of single muscle fibers were studied in the peak period of muscle growth in different culture modes.In order to reveal the change rule of pig muscle deposition and pork color in different stages and different breeding modes,In order to produce high quality pork,guide the breeding practice to provide the test basis.The results of the study are as follows:(1)In the initial stage,the content of myoglobin was extremely low in Kele pigs.During the peak period of muscle growth,the myoglobin content of Kele pigs in the grazing group was higher than that in the captive group,but there was no significant difference.The L* value(brightness)and b* value(yellowness)of the traits were all less than the captive group,and the a* value(redness)was greater than that of the Kele pigs in the captive group.At the 90 Kg stage,the myoglobin content of the Kele pigs in the grazing group was significantly higher than in the captive group(P <0.01),the a*,L* and b* values in the grazing group were significantly different from those of the Kele pigs in the captive group(P<0.05).(2)MB mRNA was at a low level in the primary period.During the peak period of muscle growth,there was more MB mRNA content in the grazing group than in the captive group,but there was no significant difference.In the best slaughter stage,the MB mRNA in the grazing group was higher than that in the captive group.And there are significant differences.(P<0.01).The level of MEF2 d mRNA was highest in the early stage of growth and development.At the peak of muscle growth,the MEF2 d mRNA content in the grazing group was slightly smaller than in the captive group,and there was no significant difference between them.There was significantly different between the grazing group and the barn feeding group at the best slaughter stage(P<0.05).The different muscle fiber subtypes had different levels in different finishing stages and different muscle tissues in different culture modes.In the muscle growth peak period of Kele pig,the MyHC gene expression levels in the muscles ofsemitendinolar muscle in the grazing group and the barn feeding group showed significant differences(P<0.05).There was a significant difference in the longissimus dorsi muscle of the expression of MyHC gene(P<0.01).In the best slaughter stage of Kele pig,the expression levels of MyHCIIb in the triceps brachii muscle tissue of grazing and barn feeding were significantly different(P<0.01),MyHCIIb gene expression in the psoas muscle tissue showed a significant difference(P <0.01),there was a significant difference between the grazing group and the barn feeding in the capsulated semitendinosus muscle(P <0.01).(3)Kele pigs have small muscle fibers in their primary stages.During the development process,single muscle fibers gradually increase in size and increase in size.In the process of increase of the thickness of single muscle fibers,the overall muscle thickening increases.After the nursery period with the group's comparative test,the muscle fiber diameter of Kele pigs was much larger than that in the barn feeding at 20 days of grazing,and there was a significant difference(P<0.01). |
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