Study On The Growth Traits Of New Strain Of Mutton Purpose Sheep In Penfeed And Analysis Of Genetic Effect Of The GH Gene

Intensive production of mutton sheep in recent decades has become a mainstream of agricultural area.At present,penfeed lacks specific mutton sheep breed,mainly contain traditional grazing sheep,but their growth rate is more slow,economic efficiency isn't high.Therefore,it's more significant to cultivate new strain of mutton purpose sheep by upgrading in penfeed.The study designed five cross combination,German merino(♂)×Small-tail han sheep(♀)(DH),Poll Dorset(♂)×Small-tail han sheep(♀)(TH),Borderdale(♂)×Small-tail han sheep(♀)(BH),German merino(♂)×DH(♀)(DH₂),Small-tail han sheep(♂)×German merino(♀)(HD),and compared with different cross combination on the growth performance and fattening performance(3～6months);and the associations between genetic effect of the GH gene and growth traits were analyzed by PCR-SSCP.The results were as followed:1 With regard to birth weight,average daily gain and economic benefits on fattening stage.Hybrid progenies were significantly higher than HH.2 Birth weight and average daily gain of DH₂ were higher than first filial generation,chest girth and cannon circumference of DH₂ improved obviously,and DH₂ had appeared parts of mutton characteristics.3 DH₂ can be considered as new strain of mutton purpose sheep in penfeed.4 There was only one SNPs in the exon 4 of GH gene,six SNPs were found in the intron 3.Genotype frequencies,there were different significantly between sheep group with fast growing rate and better mutton performance and Small-tail han sheep.5 In the exon 4 of GH gene,different genotypes have some effect on some growth traits involving body weight and body measurement by GLM.especially,the LSM values of genotype BB were higher than genotype AA and genetype AB in three-month-old(P＜0.05),it's significant and important in the sheep production. Therefore,the GH gene which can be considered as candidate gene can be applied to evaluate the effects of genotypes on growth traits in the sheep group.