Optimal Cross Combinations For Prime Lamb Production Before Weaning And Polymorphism Of IGFBP-3Gene In Gansu Alpine Merino

Screening of cross combination is the important link for utilization of heterosis.This paper depands on Gansu Alpine Merino recourse which in Alpine Pastoral Areaof Qilian Mountain, in order to investigating the cross combination which productionof high quality suckling lambs and provide technical support for the productiveapplication in Alpine Pastoral Area of Qilian Mountain. Gansu Alpine Merino (take Gfor short) ewes sired by Texel(T), Bond(B), White Suffolk(S) and AustralianMerino(A). divided into4groups including (Texel Gansu Alpine Merino F1,Bond Gansu Alpine Merino♀F1, White Suffolk Gansu Alpine Merino F1,Australian Merino Gansu Alpine Merino♀F1)and174pure Gansu Alpine Merinobreed suckling lambs were analyzed as control group. Growth, slaughteringperformance, meat quality and visceral of853F1lambs form2008to2011years wereobserved, he results indicated that the weaning weight of T×G F1is28.27kg，higherthan B×G F1, S×G F1, A×G F1, G lambs2.46kg,3.29kg,5.76kg,4.66kg. The hotcarcass weight of T×G F1, S×G F1, B×G F1lambs increased by37.44%,11.70%,21.87%than G lambs. Additionally, Carcasses of T×G F1had larger (P<0.05)longissimus muscle areas and GR than other cross combinations, increased by16.93%and19.38%than G lambs. Whereas stomach weight and length of smallintestine were greater (P<0.05) in carcasses from T×G F1than other lambs.Conclusion:―Texel Gansu Alpine Merino‖was the ideal combination and Texel wasthe best sires for Suckling lambs production in Alpine Pastoral Area of QilianMountain. The objective of this study was to Investigate the relationship between IGFBP-3gene and sheep growth traits, search the markers correlated with sheep growth traits.The polymorphism of IGFBP-3gene were analyzed using PCR-SSCP in592GansuAlpine Merino individuals, and analyze the association of polymorphism andcombined genotypes with growth traits of Gansu Alpine Merino. There were nopolymorphism site have been found in exon2. A PCR product of249bpcorresponding to partial exon4illustrated three unique binding patterns by SSCPanalysis. Frequencies of the genotype AA,AB, BB and allele A, B in Gansu alpinemerino were0.2973,0.5405,0.1622and0.5676,0.4324. Correlation analysis showed:in Gansu Alpine Merino population, a significant effect of genotypes on birth weightand body weight (weight at weaning,6,12,18months of age) of the animals (P<0.05).Animals of BB genotype showed higher birth weight and body weight than theanimals possessing AA genotype. The average daily gain was higher for theindividuals with BB genotype than those with AA genotype. The effects of genotypesfor above traits were BB>AB>AA. These results indicate that the SNPs of IGFBP-3gene have effect on the growth traits of Gansu Alpine Merino.