Assessment of meat quality defect genes in indigenous pigs of Bareilly region.

This investigation was undertaken to assess the population of indigenous (Bareilly local) pigs for meat quality genes (RYR1, PRKAG3, HFABP, MYF-5, and MC4R). The results showed that indigenous pigs were monomorphic at RYR1locus (100% NN genotype), HFABP locus (100% HH genotype), and MYF-5 locus (100% DD genotype). Homozygote RR and heterozygote QR genotypes were observed at PRKAG3 (c.599 G>A) SNP locus with 89 and 11% frequency. The frequency of wild (R) and mutant (Q) allele at the said locus was 95 and 5%. The MC4R SNP had three genotypes; homozygote AA with 5% frequency, heterozygote AG with 53% frequency, and homozygote GG with 42% frequency. Corresponding frequency of A and G allele was 32 and 68%, respectively. Monomorphic status at RYR1locus for NN genotype, HFABP locus for HH genotype, and MYF-5 locus for DD genotype indicated that favorable genes for quality pork production have been fixed in the population. The higher frequency of RR genotype (89%) at PRKAG3 and GG genotype (42%) at MC4R locus further explained the existence of favorable genotypes in indigenous pigs.

Polymorphism distribution of RYR1, PRKAG3, HFABP, MYF-5 and MC4R genes in crossbred pigs.

This study was designed to screen the crossbred pigs for SNPs in five candidate genes, associated with pork quality traits and to differentiate their genotypes by PCR-RFLP. The results indicated that genotypes of crossbred pigs were NN (90%) and Nn (10%) for RYR1; RR (83%) and QR (17%) for PRKAG3; HH (98%), Hh (1%) and hh (1%) for HFABP; DD (99%) and CD (1%) for MYF-5; and AG (57%), GG (26%) and AA (17%) for MC4R SNPs, respectively. Allelic frequencies for five SNPs {RYR1 (1843C>T), PRKAG3 (c.599G>A), HFABP (c.1322C>T), MYF-5 (c.1205A>C) and MC4R (c.1426A>G)} were 0.95 and 0.05 (N/n), 0.08 and 0.92 (Q/R), 0.99 and 0.01 (H/h), 0.00 and 1.00 (C/D) and 0.45 and 0.55 (A/G), respectively. The effect of RYR1 (1843C>T) SNP was significant on pH45 (P < 0.05), pH24 (P < 0.05) and protein % (P < 0.05). The PRKAG3 (c.599G>A) and MC4R (c.1426A>G) SNP had significant association with dressing percentages. The results revealed that RYR1, PRKAG3 and MC4R SNPs may be used in marker associated selection for pork quality traits in crossbred pigs.

Optimizing age of bull at first use in relation to fertility of Murrah breeding bulls.

AIM: The aim of the present investigation was to optimize the age at first use (AAFU) of semen of Murrah breeding bulls, which will help in early selection of bulls under progeny testing program for improving the reproductive performance in the herd. MATERIALS AND METHODS: The data on AAFU, conception rate based on first A.I. (CRFAI), overall conception rate (OCR), and birth weight (B.WT) of 57 Murrah bulls during 1993-2014 at NDRI center pertaining to 14 sets of Network Project on Buffalo Improvement at ICAR-National Dairy Research Institute, Karnal, Haryana, India were adjusted for significant environmental influences and subsequently analyzed. Simple and multiple regression models were used for prediction of CRFAI and OCR of Murrah breeding bulls. Comparative evaluation of three developed models (I-III) showed that Model III, having AAFU and B.WT, fulfill the accuracy of model as revealed by high coefficient of determination, low mean sum of squares due to error, low conceptual predictive value, and low Bayesian information criterion. RESULTS: The results revealed that the average predicted CRFAI was highest (39.95%) at <3.5 years and lowest (34.87%) at >4.5 years of age at first A.I/use. Similarly, average predicted OCR was highest (41.05%) at <3.5 years and lowest (39.42%) at >4.5 years of age at first A.I/use of Murrah bulls. CONCLUSION: In organized herd under progeny testing program, Murrah bulls should be used at young age, i.e. prior to 3.5 years, which is expected to result in 5.08% better CRFAI and 1.63% better OCR in comparison to Murrah bulls used after 4.5 years of age.

Identifying factors affecting age at first semen freezing and age at first semen use in Sahiwal bulls.

AIM: The objective of the study was to evaluate the effects of non-genetic factors on reproduction traits viz. age at first semen freezing and age at first semen use of breeding bulls in Sahiwal bulls by fitting least-squares analysis. MATERIALS AND METHODS: The information on reproduction traits of 43 Sahiwal breeding bulls belonging to 8 sets of Sahiwal breeding program at Indian Council of Agricultural Research-National Dairy Research Institute (ICAR-NDRI), Karnal (Haryana), India during 27 years (1987-2013) were analyzed using fixed linear model. The information was collected from AI records, reproduction sheets, and bull AI register maintained at different sections of Institute viz. record room of Dairy Cattle Breeding Division (DCB), Cattle Yard, Artificial Breeding Research Centre, ICAR-NDRI, Karnal. RESULTS: The average age at first semen freezing and age at first semen use of Sahiwal breeding bulls was estimated as 3.17±0.01 years and 5.35±0.01 years, with the coefficient of variation 18.93% and 20%, respectively. The overall least-squares mean for age at first semen freezing and age at first semen use was estimated as 3.14±0.09 years and 5.25±0.02 years, respectively, in Sahiwal breeding bulls. Period of freezing/use had significant effects on reproductive traits (p<0.01). Season had no significant effect on any of the traits considered in this study. CONCLUSION: It can be concluded that management inputs such as nutrition, breeding, and optimum environment should be taken care of to optimize age at first semen freezing and age at first semen use for better utilization of superior germplasm.