Genetic discrimination of Muzaffarnagri and Munjal sheep of northwestern semi arid zone of India based on microsatellite markers and morphological traits

Abstract

Muzaffarnagri and Munjal are both mutton-type and highly course-wooled sheep of north-western-semi arid zone of India. Muzaffarnagri is a descript sheep breed while Munjal is not recognized as a breed at the national level. The present study examines the genetic differentiation based on microsatellite markers and morphometric traits using multivariate analysis. A total of 194 Munjal and 294 Muzaffarnagri sheep were described for 7 body measurements for morphometric characterization. The study included animals aged between 2- To 8-teeth, raised under field conditions in semi-Arid environment. The univariate analysis revealed that Munjal sheep were larger and heavier than Muzaffarnagri sheep. The sexual dimorphism (m/f) was 1.13 (Munjal) and 1.11 (Muzaffarnagri). Munjal males were 37% heavier than females, whereas Muzaffarnagri males were 27% heavier than females. The coefficient of variation of all traits ranged from 4.14 to 33.67%. Flock and age effects established high heterogeneity among females of different flocks in both breeds/populations, whereas in males these effects showed homogeneity between flocks in Muzaffarnagri sheep and heterogeneity in Munjal sheep. Step-wise discriminant analysis revealed that paunch girth followed by tail length was more discriminating for the 2 sheep breeds/populations. The Mahalanobis distance (3.65, female; 4.56, male) between 2 sheep breeds was high and significant. Nearest Neighbour Discriminant Analysis showed that 86.31% of Muzaffarnagri females and 90.48% of Munjal males were classified into their source population. Microsatellite markers data showed high level of allelic richness (>6.0) and genetic diversity (>0.7) for both breeds/populations. Bayesian cluster analysis also indicated distinct clusters with average membership coefficient of 0.974 and 0.972 for Muzaffarnagri and Munjal sheep respectively. The results based on morphological and microsatellite data revealed that these sheep belong to genetically distinct groups. The findings emerged on genetic and phenotypic analyses would serve as important inputs for designing conservation and improvement strategy for these sheep breeds/populations.