| With the development of consumer living standard,people's demand for pork quality is getting higher and higher.Recently,the study found that increasing the content of MyHC? can improve pork quality.Sox6,a member of the Sox family,is an important regulatory factor for the transformation of muscle fiber type,affecting the content of type I muscle fibers in the muscle.This study was conducted to investigate the effect of active immunization against porcine Sox6(pSox6)on growth performance,carcass quality,meat quality traits,muscle index,viscera index,skeletal muscle related metabolic enzyme activity,muscle fiber morphology,and myosin heavy chain(MyHC)isoform expression in growing-finishing pigs,providing a theoretical basis for the application of pSox6 in improving meat quality.Twenty-four castrated Duroc×Landrance×Yorkshire(DLY)pigs with average weigh of 22.3 kg were randomly divided into three groups of the following:(1)Control group(0 mg/head group);(2)1 mg/head pSox6 active immunity group(1 mg/head group);(3)4 mg/head pSox6 active immunity group(4 mg/head group).The pigs were housed individually in pens.The trial period was 91 days.Basic immunization was performed on the first day of the experiment,and immunization was strengthened on days 15,29 and 43.After the feeding experiment,the slaughtering and indexes were carried out.The results were as follows:(1)There was no significant difference on ADFI,ADG and F/G of active immunization against pSox6.Active immunization against pSox6 could significantly improve muscles a*(red)value and marble content(P< 0.05)in 4 mg/head group,while no significant change was observed in L*(Lightness)value,b*(Yellowness)value,intramuscular fat,loin eye area,backfat thickness and cooking loss.(2)Active immunization against pSox6 had no significant effect on the cardiac index,liver index and kidney index.(3)Active immunization against pSox6 significantly improves the activities of succinic dehydrogenase and malic acid dehydrogenase in muscle,and significantly reduces the activity of muscle lactate dehydrogenase(P< 0.05).In addition,the activity of lactate dehydrogenase in serum of 4 mg/ head group also decreased significantly(P< 0.05).(4)Active immunization against pSox6 significantly reduced the diameter and area of muscle fibers(P< 0.05).(5)Active immunization against pSox6 significantly upregulated the mRNA expression of MyHC? in Longissimus dorsi muscle(LM)(P< 0.05),while no effect was observed on the mRNA expressions of MyHC?a,MyHC?x and MyHC?b.At the same time,pigs in the 4 mg/head immunized group exhibited higher MyHC? protein level(P< 0.05),while no significant influence was observed on MyHC?b protein level.In addition,pigs in the 4 mg/head immunized group exhibited lower Sox6 mRNA level(P< 0.05).In conclusion,4 mg/head active immunization against porcine Sox6 significantly increased a*(red)value,marble content,the activities of succinic dehydrogenase and malic acid dehydrogenase and the MyHC? mRNA and protein expression in Longissimus dorsi muscle.Four mg/head active immunization against porcine Sox6 significantly decreased the activity of lactate dehydrogenase,the diameter and area of muscle fibers and the mRNA level of Sox6 in Longissimus dorsi muscle.Together,our data imply that active immunization against pSox6 could improve the pork quality and promote the MyHC? expression in growing-finishing pigs. |
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