The Origin And Evolution Of Zaosheng Cattle And The Analysis Of Meat Quality

Zaosheng cattle are a good local breed in GanSu province. Zaosheng cattle microsatellite and mtDNA D-loop sequences were studied by using PCR and DNA sequencing analysis. The relationship of origin and evolution of Zaosheng cattle was explored by establishing the phylogenetic tree. Texture parameters of Zaosheng cattle such as hardness H1, hardness H2, adhesion, flexibility, cohesiveness, adhesiveness and chewiness were analysed by Texture Profile Analysis method and then the standardized evaluation criterion of Zaosheng cattle muscle was proposed. The extraction and purification process of taurine in beef were optimized by response surface analysis, which contribute to the exploration of development in Zaosheng cattle high value-added production. These results were as follows:1 There was a higher polymorphism in microsatellite loci IDVGA27 whose difference between effective alleles and allele could reach 2.4443 from seven microsatellite loci and a total of 25 alleles were found in 112 Zaosheng catties. PIC in seven microsatellite loci ranged from 0.4724 to 0.9453, and the average was 0.6526. Expected heterozygosity was between 0.5 and 0.9513 and the average was 0.6996. Zaosheng cattle microsatellite seat in EDVGA27 exists high polymorphism..2 Zaosheng cattle and Qinchuan cattle were originated from Bos taurus. The genetic distance was 0.0953 between Zaosheng and Bohai Black cattle, was 0.0918 between Zaosheng with Mongolian cattle and was 0.1194 between Zaosheng and Jinnan cattle. The genetic distance was 0.0944 beween Qinchuan and Luxi cattle, was 0.1060 between Qinchuan and Jiaxian cattle and was 0.1064 betweem Qinchuan and Nanyang cattle. This means Zaosheng cattle was more close to Bohai Black, Jinnan and Mongolian cattle, however Qinchuan cattle was more close to Luxi, Jiaxian and Nanyang cattle. There was a difference in formation order and evolutionary time between Zaosheng and Qinchuan cattle. The genetic distance of the Mongolian cattle and Zaosheng cattle is lower than that of Qinchuan cattle and Mongolian cattle. Based on this, it was concluded that the origin evolution of cattle in the north of China was European cattle followed by Mongolian cattle and by Zaosheng cattle and Qinchuan cattle at last. Therefore, the formation of Zaosheng cattle was earlier than Qinchuan cattle.3 The texture characteristics of tenderloin in Zaosheng cattle were determined for the first time. When the starting force conditions is UN,55% deformation,10mm diameter and 1×1×1cm in length and breadth of beef meat, the comprehensive assessment of Zaosheng cattle was best. The seven textural indicators were as follows. Hardness 1 is 25.54±4.34N. Hardness 2 is 19.66±1.40N. The cohesive value of 0.49±0.02Ratio. The value of elasticity is 0.33±0.034N. The value of Adhesion is 0.45±0.05N.mm. The value of tackiness of 12.57±2.07N and the chewiness value is 4.16±.86mJ.4 A pre-column derivatization and high performance liquid detecting taurine content in Zaosheng cattle beef has been established and the extraction process of beef taurine also has been optimized. When hydrolysis time was 20.50h, extraction temperature was maintaind at 85℃, extraction time was 55min and solid-liquid ratio was 0.21, the taurine extraction rates reached the maximize value of 3.76g/kg.