IMPACT OF LEPTIN GENE POLYMORPHISMS ON MILK PRODUCTION TRAITS IN BARKI GOATS.

Document Type : Original Article

Authors

1 Department of Animal Breeding, Desert Research Center, 1 Matehaf AlMatariya St.,Cairo 11753, Egypt.

2 Department of Animal Production, Faculty of Agriculture, Minoufiya University, Egypt.

Abstract

The objective of this study was to test the association of variation in a 356 bp region in exon 1 of the caprine leptin gene with milk production traits (milk yield (MY), milk fat content (FAT), milk protein content (PRO), milk lactose content (LAC), milk solid not fat content (SNF), pH and somatic cell count (SCC)) in 106 Barki does using polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP). General linear model was used to test association between the variation in leptin and milk-production traits. The SSCP banding patterns for leptin revealed two variants (L1 and L2), which contained two nucleotide sequence difference (c.670528A/G and c.670639T/C). The c. 670528A/G substitution results in the substitution of valine with alanine and c.670639T/C results in the substitution of arginine with histidine. Association analysis between the variation in leptin with milk production traits revealed that leptin genotype was associated (P < 0.05) with PRO and highly (P < 0.001) associated with MY. The presence of the L1 variant in the doe genotype was significantly associated with lower MY (P < 0.01) and decreased PRO (P < 0.01), whereas, the presence of the L2 variant in the doe genotype was significantly associated with higher MY (P < 0.05). The detected leptin variants showed significant (P < 0.05) additive effect on pH and highly significant (P < 0.01) dominance effects on MY and PRO. This suggests that selection for the leptin genotypes might increase milk production and milk protein content in Barki goats.

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