Vikas Vohra

Genetic variants of beta-lactoglobulin gene and its association with milk composition traits in riverine buffalo.

A study was carried out to determine genetic variants of beta-lactoglobulin gene and to explore associations between these and milk composition traits in riverine buffalo. Single strand conformation polymorphism was employed to detect the genetic variants of the gene. Two fragments of this gene i.e. 119 bp of exon I and 400 bp spanning exon IV and intron IV were included in the study. For 119 bp fragment, three alleles namely, A, B and C were observed in all the buffalo breeds whereas four alleles (A, B, C and D) were detected for 400 bp fragment. The frequency distribution of alleles was different in different breeds of buffaloes for both the fragments. For exon I fragment, the milk composition traits such as total SNF, protein, solid, fat and whey protein yield were found to be significantly (P<0.05) associated with genotypes in Murrah and Bhadawari buffalo whereas in Mehsana breed genotypes were significantly (P<0.05) co-related with total SNF, solid and fat yield. Genotypes of 400 bp fragment, only total fat yield in Mehsana buffalo was found to be significantly (P<0.05) associated with genotypes.

Phenotypic Characterization and Multivariate Analysis to Explain Body Conformation in Lesser Known Buffalo ( Bubalus bubalis ) from North India

Phenotypic characterization and body biometric in 13 traits (height at withers, body length, chest girth, paunch girth, ear length, tail length, length of tail up to switch, face length, face width, horn length, circumference of horn at base, distances between pin bone and hip bone) were recorded in 233 adult Gojri buffaloes from Punjab and Himachal Pradesh states of India. Traits were analysed by using varimax rotated principal component analysis (PCA) with Kaiser Normalization to explain body conformation. PCA revealed four components which explained about 70.9% of the total variation. First component described the general body conformation and explained 31.5% of total variation. It was represented by significant positive high loading of height at wither, body length, heart girth, face length and face width. The communality ranged from 0.83 (hip bone distance) to 0.45 (horn length) and unique factors ranged from 0.16 to 0.55 for all these 13 different biometric traits. Present study suggests that first principal component can be used in the evaluation and comparison of body conformation in buffaloes and thus provides an opportunity to distinguish between early and late maturing to adult, based on a small group of biometric traits to explain body conformation in adult buffaloes.

Genetic polymorphism of alpha-lactalbumin gene in riverine buffalo

Alpha-lactalbumin (α-LA) is a major whey protein found in milk. Polymorphs of α-LA gene are reported to be significantly associated with milk production and constituent traits. Therefore, the present study was undertaken to detect polymorphism in α-LA at the genic level and to explore allelic variability at this locus. A total of 196 animals, belonging to four breeds of riverine buffalo viz. Bhadwari, Mehsana, Surti and Murrah were included under the present investigation. Two fragments i.e. 133 bp (Exon 1) and 159 bp (Exon 2) of α-LA gene were amplified by polymerase chain reaction and subsequently, single strand confirmation polymorphism (SSCP) study was carried out to identify different allelic pattern and genotypes of the animal included in the study. Both fragment of α-LA gene was found to be polymorphic in all the four breeds of riverine buffalo. Number of genotypes and allele varied breed to breed for both the fragments. In case of 133 bp fragment, four alleles A, B, C and D were found among different breeds of buffalo whereas in 159 bp fragment, five alleles namely A, B, C, D and E was found in different breeds. Nucleotide sequence data of different alleles showed the presence of both silent as well as functional mutation leading to variability in polypeptide chain.

Variability of Milk Fat Globule Membrane Protein Gene between Cattle and Riverine Buffalo

A study on butyrophilin (BTN) gene was conducted to detect variability at nucleotide level between cattle and buffalo. Hae III PCR-RFLP was carried out in crossbred cattle and it revealed polymorphism at this locus. Three genotypes namely, AA, BB and AB and two alleles were observed with frequencies 0.78, 0.17, 0.04 and 0.87, 0.13, respectively. The sequences of different cattle, buffalo and sheep breeds have been reported in the EMBL gene bank with accession numbers: AY491468 to AY491475. The nucleotides, which have been substituted from allele A to B, were found to be C to G (71st nucleotide), C to T (86th nucleotide), A to T (217th nucleotide), G to A (258th nucleotide), A to C (371st nucleotide) and C to T (377th nucleotide). The nucleotide substitution at 71st, 86th and 377th position of the fragment were expected to be a silent mutation where as nucleotide changes at 217th, 258th and 371st positions were expected to be substituted by lysine with arginine, valine with isoleucine and leucine with proline in allele B. The differences of nucleotides and amino acids between cattle, buffalo and sheep breeds have been revealed and on the basis of nucleotide as well as protein variability the phylogenetic diagram have been developed indicating closeness between cattle and buffalo.

Characterization of rare migratory cattle and evaluation of its phylogeny using short-tandem-repeat-based markers

ABSTRACT Bovine-specific microsatellite markers were used to assess the genetic variation in Belahi cattle. Both within-breed (Belahi) and between-breed (Sahiwal, Gir, Tharparkar, Rathi, Nagori, Mewati, Kankrej and Belahi breeds) diversity indices were estimated. Sixteen microsatellite loci were polymorphic with more than five alleles per locus. Mean allelic diversity was 9.31, with a total of 149 alleles. Polymorphism information content varied from 0.31 (TGLA227) to 0.87 (CSSM33) with an average of 0.71. Estimate of Nei’s gene diversity was 0.72 ± 0.15. The observed and expected heterozygosity at different loci were 0.69 ± 0.17 and 0.71 ± 0.15 and varied from 0.30 (TGLA227) to 0.88 (TGLA122) and 0.32 (TGLA227) to 0.88 (CSSM33), respectively. Within-population inbreeding estimates (FIS) for Belahi cattle was 0.0337, indicating an average deficiency of 3.37%. Belahi cattle revealed the presence of genetic diversity within population and there was no significant heterozygosity excess indicating the absence of genetic bottleneck in the recent past. Global FST estimates demonstrated that 85% of the total variation was contributed by within-breed genetic differentiation, while 15% genetic variation was present across different breeds. Nei’s standard genetic distance estimates among the studied milch breeds varied from 0.27 (Tharparkar and Rathi) to 0.51 (Tharparkar and Sahiwal), whereas in studied dual-purpose breeds, it varied from 0.07 (Kankrej and Mewati) to 0.90 (Belahi and Mewati). Unweighted Pair Group Method with Arithmetic Mean based phylogenetic tree constructed from the Nei’s genetic distances revealed that Sahiwal and Belahi cattle were grouped together in one cluster. However, Kankrej and Mewati were found to be closely related breeds.

Estimates of genetic parameters for fat yield in Murrah buffaloes.

Aim: The present study was performed to investigate the effect of genetic and non-genetic factors affecting milk fat yield and to estimate genetic parameters of monthly test day fat yields (MTDFY) and lactation 305-day fat yield (L305FY) in Murrah buffaloes. Materials and Methods: The data on total of 10381 MTDFY records comprising the first four lactations of 470 Murrah buffaloes calved from 1993 to 2014 were assessed. These buffaloes were sired by 75 bulls maintained in an organized farm at ICAR-National Dairy Research Institute, Karnal. Least squares maximum likelihood program was used to estimate genetic and non-genetic parameters. Heritability estimates were obtained using paternal half-sib correlation method. Genetic and phenotypic correlations among MTDFY, and 305-day fat yield were calculated from the analysis of variance and covariance matrix among sire groups. Results: The overall least squares mean of L305FY was found to be 175.74±4.12 kg. The least squares mean of overall MTDFY ranged from 3.33±0.14 kg (TD-11) to 7.06±0.17 kg (TD-3). The h2 estimate of L305FY was found to be 0.33±0.16 in this study. The estimates of phenotypic and genetic correlations between 305-day fat yield and different MTDFY ranged from 0.32 to 0.48 and 0.51 to 0.99, respectively. Conclusions: In this study, all the genetic and non-genetic factors except age at the first calving group, significantly affected the traits under study. The estimates of phenotypic and genetic correlations of MTDFY with 305-day fat yield was generally higher in the MTDFY-5 of lactation suggesting that this TD yields could be used as the selection criteria for early evaluation and selection of Murrah buffaloes.