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Lala Lajpat Rai University of Veterinary & Animal Sciences, Hisar

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2014 - 20172
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Subject: Animal Genetics and Breeding × Author: Kamaldeep ×
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    ThesisItemOpen Access
    Identification of SNPs in genomic sequences of MBL1 gene and its association with mastitis and performance traits in cattle and buffalo
    (LUVAS, 2017) Kamaldeep; Pander, B.L.
    The present study was conducted on randomly selected sixty Hardhenu cattle, twenty five Sahiwal cattle and sixty Murrah buffalo to identify polymorphism in mannose binding lectin (MBL1) gene and their association with incidence of mastitis, production and reproduction traits and somatic cell score. Two sets of reported primers were used to amplify targeted regions viz., exon 2 of MBL1 gene in three breeds. Two SNPs i.e. g.2686T>C and c.2534G>A of MBL1 gene were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). SNP g.2686T>C of MBL1 gene was polymorphic in Hardhenu and Sahiwal cattle (TT ,TC and CC), whereas, only one genotype (CC) was found in Murrah population under study. SNP c.2534G>A was (GG, AG and AA) in Hardhenu and Murrah animals, however it was dimorphic (AG and GG) in Sahiwal. CC and GG genotype of g.2686T>C and c.2534G>A SNPs of MBL1 gene were least susceptible to mastitis compared to other genotypes. Genetic variants of g.2686T>C SNP of MBL 1 gene in Hardhenu cattle showed significant association with Somatic Cell Score (P<0.01), total milk yield (P<0.01 and P<0.05), 300 days milk yield (P<0.01), and First Calving Interval (P<0.05). CC genotype Hardhenu cows had higher milk yields during 1st and 2nd lactation and lower SCS. SNP c.2534G>A in Murrah buffalo had significant association(P<0.01) with 2nd lactation milk yield. Age at first calving for Hardhenu and Murrah was found to be significantly associated (P<0.05) with genotypes. Somatic Cell Score was also found to be significantly associated (P<0.01 and P<0.05) with genotypes of Hardhenu cattle and Murrah buffalo. GG genotype animals had lesser clinical mastitis incidences, low SCS and AFC and higher milk yield. These observations on SNPs of MBL1 gene and their association with the incidence of mastitis, production traits, reproduction traits and somatic cell score can be utilized as an aid to selection for simultaneously improvement of both antagonistic traits (milk yield and mastitis), however, validation of results on large number of animals is warranted.
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    ThesisItemRestricted
    Genetic evaluation of MURRAH sires for different economic traits using dIfferent procedures
    (LUVAS, 2014) Kamaldeep; Yadav, A.S.
    The first lactation records pertaining to 344 Murrah buffaloes at Buffalo Resarch Center, Department of Livestock Production and Management, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar spread over a period of 20 years (1993-2012) were utilized for the present study. This investigation was conducted to estimate genetic and phenotypic parameters of economic traits and comparison of three sire evaluation procedures (OLS, RLS and BLUP) based on estimated breeding value of the various performance traits, phase traits and stayability traits in Murrah buffaloes. The overall means for various economic traits as 6.52 kg/day for MYLL; 4.20 kg/day for MYFCI; 1.06 kg/day for MYASC; 1.27 kg/day for MYAC; 5459.50 kg for LMY4; 6177.78 kg for HLMY; 280.22 kg for APY; 117.41 kg for PPY; 1634.78 kg for DPY and 1199.37 days for STAYAB, respectively. The effect of period of calving was statistically significant on all the economic traits except MYFCI, MYASC, MYAC, APY and DPY, while season effect was also significant on all the traits included in the study except MYLL, MYAC, LMY4, HLMY, DPY and STAYAB, respectively. The effect of age at first calving (linear) was significant on all the economic traits except MYFVI, LMY4, HLMY, DPY and STAYAB; however, its quadratic effect was not significant on any of the traits under study. Moderate estimates of heritability were obtained for MYASC, MYAC, LMY4, APY, PPY, DPY and STAYAB to the tune of 0.214, 0.270, 0.295, 0.358, 0.347, 0.294 and 0.205, respectively. Furthermore, higher estimate of heritability were recorded for MYFCI and HLMY as 0.473 and 0.407, respectively. The estimate of heritability was low for MYLL as 0.118. OLS procedure showed nearly perfect normal distribution as coefficient of kurtosis was nearest to three, with coefficient of skewness, BLUP method was most appropriate. When standard error of estimates were considered, RLS was found to be more accurate followed by BLUP, when coefficient of determination was considered OLS method was obtained as most accurate followed by RLS and when coefficient of variation was taken into consideration RLS was obtained most appropriate. It is suggested to use BLUP procedure in a situation where correct ratio of residual variance to sire variance is known and use of OLS is suggested in a situation where correct ratio of residual variance to sire variance is unknown.