Candidate K232A mutation of DGAT1 gene associated with production and reproduction traits in Indian Dairy cattle.

The present study was conducted on Hardhenu and Sahiwal cows to evaluate the genetic diversity and the effect of candidate K232A mutation of diacylglycerol O-acyltransferase (DGAT1) gene on performance traits. PCR product of 413 bp size targeting K232A mutation of DGAT 1 gene was genotyped by Eae1 restriction enzyme and further confirmed by sequencing. The PCR-RFLP analysis for K232A showed that the frequencies of alleles K and A were 0.80 and 0.20 in Hardhenu and 0.98 and 0.02 in Sahiwal cattle, respectively. The frequencies of genotypes for KK and KA genotype were estimated as 0.60 and 0.40 in Hardhenu and 0.96 and 0.04 in Sahiwal cattle, respectively. Chi-square test showed that K232A SNP did not meet with the Hardy-Weinberg equilibrium (p < .01) in Hardhenu cattle. Association analysis revealed that KA genotype was significantly associated with total milk yield (p < .01) and 305 days milk yield (p < .01)in Hardhenu cattle. Hardhenu cows having KA genotype comparatively revealed favorable mean values for AFS (880.31 ± 26.65), AFC (1166.36 ± 19.94), SP (157.46 ± 22.80), CI (441.41 ± 44.28) and AI/Conception (1.80 ± 0.17), indicating that KA genotype can be used as a candidate marker for simultaneous improvement of both production and reproduction traits.

Evaluation of candidate genotype of GH gene associated with growth, production and reproduction traits in Dairy Cows.

Growth hormone (GH) is a major regulator of postnatal growth and metabolism in mammals and plays a critical role in growth, production and fertility in cattle. The present study was conducted in dairy cattle to find the association of g.48769565 C > T mutation with growth, production and reproduction traits in Sahiwal and Hardhenu cattle. PCR-RFLP was performed to genotype g.48769565 C > T mutation using the MspI restriction enzyme in our resource cattle population. In Hardhenu cattle, the frequencies of C and T alleles were 0.59 and 0.41, respectively, while genotypic frequencies were 0.33, 0.53 and 0.14 for CC, CT and TT respectively. The frequencies of the C and T alleles were 0.24 and 0.76, respectively, in Sahiwal cattle and it was observed that the highest frequency was for the TT genotype (0.58) and the lowest was for the CC genotype (0.06). Chi-square analysis showed that g.48769565C>T SNP loci meet with the Hardy-Weinberg equilibrium in Sahiwal and Hardhenu cattle. From the least-squares analysis, it was observed that CC genotype was significantly associated with total milk yield (TMY), 300 days milk yield (300D MY), lactation length (LL), dry period (DP) and artificial insemination (AI)/conception (p < .05). We also observed a significant association (p < .05) of genotype CT with 3-month calves body weight. Cows with TT genotype revealed comparatively favourable service period (SP) and calving interval (CI) in our resource population. These observed differences in their allelic and genotypic frequencies in association with the traits underlying production and fertility can be utilized for genetic improvement in dairy cattle.

Evaluation of candidate genotype of immune gene MBL1 associated with udder health and performance traits in dairy cattle and buffalo of India.

An investigation was conducted to identify polymorphism in mannose-binding lectin 1 (MBL1) gene and its effect on udder health and performance traits in dairy cattle and buffalo of India. Candidate single-nucleotide polymorphism (SNP) c.2534G > A of MBL1 gene was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). All the possible genotypes for SNP c.2534G > A (GG, AG, and AA) were observed in the studied population. However, Sahiwal cows revealed dimorphic pattern (AG and GG). The effect of targeted SNP on incidence of mastitis was evaluated and found to be significant. Animals with GG genotype were less susceptible to clinical mastitis and had comparatively lower somatic cell score (SCS) in Hardhenu cattle (P < 0.01) and Murrah buffalo (P < 0.05). Animals having GG genotype also exhibited significantly (P < 0.05) lower age at first calving (AFC). AG genotyped Murrah buffalo animals revealed significantly higher second lactation milk yield (P < 0.01). GG genotype with SCS and AFC could therefore be exploited as a promising candidate marker for the genetic improvement of udder health and AFC in dairy animals.

Evaluating advanced computing techniques for predicting breeding values in Harnali sheep.

Advanced computing techniques have been used by animal researchers to understand the intricate data structures for deriving the most reliable allusions of populations in order to conserve genetically superior animals. The present attempt was made to evaluate the potential of two advanced techniques, artificial neural networks (ANN) and Bayesian technique (BT), for predicting breeding values (BV) of weaning weight (WWT) using data of 498 lambs born to 41 sires and 173 dams in Harnali sheep for the period from 2014 to 2019. The estimated BV for WWT was initially obtained using univariate animal model under restricted maximum likelihood procedure. ANN using multilayer perceptron with two hidden layers was fitted to training set (75%) of estimated BV to predict BV for test set (25%). Similarly, BT using Markov chain Monte Carlo (MCMC) method was also fitted to similar datasets. The high accuracy of prediction, i.e., correlation between BV and predicted BV, was observed as 0.89 and 0.90 under ANN and BT, respectively. Further, similar ranges of goodness of fit criteria, viz., R2, root mean square error (RMSE), mean absolute error (MAE), and bias, indicated that both ANN and BT had similar prediction ability, which was also confirmed by 10-fold cross-validation. The present study indicated high capability and analogous model adequacy for both techniques that can be exploited in selection programs.

Influence of maternal and additive genetic effects on offspring growth traits in Beetal goat.

The purpose of the present study was to obtain estimates of variance components and genetic parameters for direct and maternal effects on various growth traits in Beetal goat by fitting four animal models, attempting to separate direct genetic, maternal genetic and maternal permanent environmental effects under restricted maximum likelihood procedure. The data of 3,308 growth trait records of Beetal kids born during the period from 2004 to 2019 were used in the present study. Based on best fitted models, the direct additive h2 estimates were 0.06, 0.27, 0.37, 0.17 and 0.10 for birth weight (BWT), weight at 3 (WT3), 6 (WT6), 9 (WT9) and 12 (WT12) months of age, respectively. Maternal permanent environmental effects significantly contributed for 10% and 7% of total variance for BWT and WWT, respectively, which reduced direct heritability by 40 and 10% for respective traits from the models without these effects. For average daily gain (ADG1) and Kleiber ratios (KR1) up to weaning period (3 months) traits, maternal permanent environmental effects accounted for 7% and 8% of phenotypic variance, respectively, and resulted in a reduction of 6.6% and 5.4% in direct h2 of respective traits. For post-weaning traits, the maternal effects were non-significant (p > .05) which indicates diminishing influence of mothering ability for these traits. High and positive genetic correlations were obtained among WT3-WT6, WT6-WT9 and WT9-WT12 with correlations of 0.96 ± 0.25, 0.84 ± 0.23 and 0.90 ± 0.13, respectively. Thus, early selection at weaning age can be practised taking into consideration maternal variation for effective response to selection in Beetal goat.

Evaluation of the immunocontraceptive potential of Escherichia coli-expressed recombinant dog ZP2 and ZP3 in a homologous animal model.

Dog zona pellucida glycoprotein 2 (dZP2), excluding the N-terminal signal sequence and the C-terminal transmembrane-like domain, was cloned and expressed as a polyhistidine fusion protein in Escherichia coli to evaluate the immunocontraceptive efficacy of ZP glycoproteins. The recombinant dZP2 (rec-dZP2) revealed a 70 kDa band corresponding to the full length transcript, as well as several low molecular mass fragments in western blot analysis. In addition to rec-dZP2, E. coli expressed recombinant dog ZP glycoprotein 3 (rec-dZP3), which has also been evaluated for its efficacy to block fertility in a homologous system. Three groups of female dogs (n = 4 per group) were immunized with rec-dZP2 conjugated to diphtheria toxoid (rec-dZP2-DT), rec-dZP3 conjugated to DT (rec-dZP3-DT) and DT alone. Immunization of female dogs with rec-dZP2-DT and rec-dZP3-DT led to generation of antibodies against the respective ZP proteins as well as to DT. Subsequent to mating, the four female dogs immunized with rec-dZP2-DT all conceived, which is indicative of failure of the anti-rec-dZP2 antibodies to block fertility. In the group of dogs immunized with rec-dZP3-DT, three of four animals did not conceive when mated with males of proven fertility. The block in fertility was associated with anti-dZP3 antibody titres. Ovarian histopathology revealed that the block in fertility in the group immunized with rec-dZP3-DT is probably manifested by inhibition in the development of follicles and is due to atretic changes in the zona pellucida. These results, although preliminary, indicate that immunization with dZP3 may be a feasible proposition to control dog populations provided that adequate antibody titres are achieved.

Antigenic relationships among sheep pox, goat pox and contagious pustular dermatitis viruses.

Antigenic relationships among sheep pox, goat pox and contagious pustular dermatitis (CPD) viruses were determined by serological techniques using soluble antigens partially purified by DEAE-cellulose chromatography. Homologous antigen-antibody reactions were characterized by the presence of 7 precipitation lines with sheep pox and of 5 ones each with goat pox and CPD viruses. The nature of cross-reactions of sheep pox, goat pox and CPD virus soluble antigens with corresponding sera suggested that sheep pox virus shared 3 soluble antigenic components with goat pox and either 3 or 4 ones with CPD virus. Goat pox virus shared either 2 or 3 soluble antigenic components with CPD virus. Cross-neutralization tests revealed an one-way cross of goat pox virus with sheep pox and CPD viruses, respectively. The results showed that the 3 viruses in question share common soluble antigenic components.

Cross-neutralization tests on sheep pox, goat pox and contagious pustular dermatitis viruses.

In cross-neutralization tests in cell cultures, sheep pox and contagious pustular dermatitis (CPD) hyperimmune sera did not cross-react in the heterologous system. But goat pox hyperimmune serum neutralized both sheep pox and CPD viruses revealing a one-way serological relationship of goat pox virus with both sheep pox and CPD viruses.