Studies on Influence of Certain Blood Adipokines and their Genetic Polymorphism on Lactation of Sahiwal Cows

Abstract

newline Adiponectin and resistin are very vital adipokines which influence the energy newlinehomeostasis, insulin sensitivity and mobilization of body fat stores. The present investigation newlinewas performed to elucidate the influence of periparturient period (-30 to +90 days), stage of newlinelactation (early, mid and late lactation) and parity (first, second and third) of animals on newlinecirculating levels of adipokines and other biochemical indices (hormones and metabolites) newlineand genetic polymorphism in adiponectin (ADIPOQ) and resistin (RETN) genes and their newlineassociation with production and reproduction traits in Sahiwal cows. newlineBlood samples were collected from 6 pregnant Sahiwal cows from -30 days newlineprepartum to +90 days postpartum at 15 days interval and from six animals each of first, newlinesecond and third parity in their early (30th day), mid (90th day) and late (200th day) lactation newlinefor biochemical study while from gt70 lactating cows for studying genetic polymorphism in newlineADIPOQ and RETN genes. Biochemical study in periparturient cows revealed sharp decrease newlinein plasma levels of ADIPOQ, LEP, progesterone, TG, cholesterol, HDL, proteins and Ca from newlinepregnancy to parturition and thereafter gradual increased to prepartum levels. The circulating newlinelevels of RETN, estrogen, urea and NEFA increased from pregnancy to parturition and newlinesubsequently reduced to prepartum levels. During periparturient period, ADIPOQ levels newlineshowed positive association with LEP and lipid profile while negative association with newlineestrogen, NEFA and creatinine while levels of RETN revealed positive association with newlineestrogen, NEFA and creatinine while negative association with LEP and lipid profile. newlineAssociation studies of ADIPOQ-I/TsaI PCR-RFLP assay revealed significant newlineinfluence of genotypes on CI, LP, TMY and DRPY. ADIPOQ-II/RsaI PCR-RFLP assay newlineshowed monomorphic pattern in Sahiwal cattle due to absence of restriction site for RsaI newlinerestriction enzyme at specific location in ADIPOQ-II gene. Association studies of RETN-I newline/SSCP assay revealed significant influence of genotypes on LP, AMY, MY300 and PY. newlineAssociation studies of RETN-II /SSCP assay revealed significant influence of genotypes on newlineBW, DP and LP. In conclusion, SNP identified in ADIPOQ and RETN genes suggests that newlinethese genes might serve as candidate genetic marker for selection of Sahiwal cattle with better newlinemilk yield. However further studies are needed to explore SNPs in other regions of these newlinegenes, and validation of these markers in another breed and population and their association newlinewith other production traits required to be verified.