Cross Combinations For Lamb Production And Polymorphism Of ANGPTL4 Gene In Tibet Sheep

In order to investigate the growth and meat production performance of F1 lambs at 6-month-old ages with different cross combinations in the plateau pastoral areas of Qilian mountain. There are three types of cross combination experiments were conducted in this study. The crossing sire sheep breeds were Texel, Poll-Dorset, Black Suffolk, and the dam was Gansu Alpine Merino. The results showed that F1 generation lambs birth weight of each hybrid combination had no significant difference(P>0.05); The F1 generation rams weaning weight and average daily gain before weaning of TG and HSG were extremely higher than Gansu Alpine Merino increased by 42.91%, 35.45% and 49.66%, 63.64%,(P<0.01); F1 generation rams 6-month-old body weight and average daily gain after weaning of TG were 40.90 kg and 156.22 g, higher than 33.53% and 43.96% compared with Gansu Alpine Merino(P<0.01); The body weight before slaughter and carcass weight of TG F1 generation rams were 38.67 kg and 17.45 kg, and higher than that of Gansu Alpine Merino by 26.25% and 41.18%(P<0.01); There was no significant difference in dressing percentage of each combination rams(P>0.05), while F1 generation ewes dressing percentage of TG and DG reached to 46.89% and 47.30%, which extremely significant higher than 42.39% of Gansu Alpine Merino(P<0.01). These results suggest that the growth and meat production performance of Gansu Alpine Merino can be improved by introducing foreign sheep, and “Texel × Gansu Alpine Merino” is the optimal hybrid combination for manufacturing 6-month-old mutton in Qilian mountain alpine pastoral areas compared with other combinations.In order to study polymorphism of ANGPTL4 gene in Tibetan sheep, we selected 391 Tibetan sheep blood samples and extracted genomic DNA. Specific primers were designed and named as P1 and P2 of ANGPTL4 gene intron-3 and exon- 6 of Tibetan sheep. And PCR-SSCP technique along with DNA sequencing were used to detect variations. By designing these primers, we get 280 bp and 289 bp of the two fragments of Tibetan sheep ANGPTL4 gene. Three kinds of genotype AA, BB and AB of intron-3 of ANGPTL4 were discovered and the frequency were 0.6488, 0.3130 and 0.0382, respectively. Polymorphism information content was 0.2656 with moderate polymorphism. Sequencing results showed that intron-3 had one variation c.400+90G/T. Two kinds of genotype AA and AB of exon-6 of ANGPTL4 were detected and the frequency were 0.9618 and 0.0382, respectively. Polymorphism information content was 0.0369 with low polymorphism. Sequencing results showed that exon-6 of ANGPTL4 gene had one variation c.837C/T, which lead to the corresponding amino acid change at p.279. Two variations observed in intron-3 and exon-6 of ANGPTL4 gene would influence the production performance of Tibetan sheep, and can be used as molecular marker to improve and protect germplasm resources.