AGRICULTURAL RESEARCH COMMUNICATION CENTRE www.arccjournals.com/www.ijaronline.in *Corresponding author’s e-mail : sankhyan@gmail.com Indian J. Anim. Res., 52 (6) 2018 : 917-922 Print ISSN:0367-6722 / Online ISSN:0976-0555 1 SMS Animal Science, Krishi Vigyan Kendra Sundernagar, Chaudhary Sarwan Kumar Himachal Pradesh Krishi Vishvavidyalaya. Morphological structuring using principal component analysis of Rampur- Bushair sheep under transhumance production in western Himalayan region, India Varun Sankhyan*, Y.P Thakur, Sanjeet Katoch, P.K Dogra and Rakesh Thakur 1 Department of Animal Genetics and Breeding, College of Veterinary and Animal Science, Chaudhary Sarwan Kumar Himachal Pradesh Krishi Vishvavidyalaya, Palampur-176 062, Himachal Pradesh, India. Received: 30-08-2016 Accepted: 28-04-2017 DOI: 10.18805/ijar.B-3296 ABSTRACT Principal component analysis (PCA) was employed on 12 biometric traits of Rampur-Bushair sheep of Himachal Pradesh. Morphological and biometrical observations were recorded on 162 young and 566 adult animals. Multivariate statistics and principal component analysis revealed that body measurements except for peripheral traits were mostly positively and significantly correlated. The correlation among conformation traits ranged from -0.08 to 0.79 and “0.18 to 0.71 in young and adult sheep respectively. Three and four factors were extracted in young and adult sheep respectively, which accounted for 57% and 61% of variation. The principal component extracted contributed effectively to explain general body conformation. The regression analysis suggested that use of principal component was more appropriate than the use of original correlated variable in estimating body weights. Therefore, factor extracted could be helpful in breeding programme with sufficient reduction in the number of biometric traits to be recorded to explain the body conformation. Key words: Biometrical traits, Phenotypic characterization, Principal component analysis, Rampur-Bushair sheep. INTRODUCTION Over the last few years greater efforts had been diverted to characterize and document indigenous breed as an important prerequisite for focusing on their conservation and sustainable utilization. FAO has recommended that a global strategy should involve identifying and understanding a unique genetic resource in a particular region and developing the proper use of associated diversity (FAO, 2012). Rampur-Bushair is an important dual purpose breed of North temperate Himalayan state of Himachal Pradesh, India predominately reared under migratory/transhumance production system (Verma, 1996). Tribes rearing this sheep breed follows Alpiwirtscaft type of strategy, associated with movement of people and animal in vertical space, community control of pastures combined with individual control of plots/ haying fields and social institution that schedule the complex movement in space and time (Bhasin, 2013). There is decline in the population of this breed due to introduction of crossbreeding program long back in the state. In spite of its connotation with tribal community and cultural heritage breed has not attracted much attention from researchers. Though breed standards and morphological evaluation do exists but lacks comprehensive evaluations compared to other breeds of region. Preliminary studies (Dixit et al., 2005) have used only few body measurements (body height, body length and heart girth) to describe this breed. Morphological conformational appraisal of livestock is probably the oldest way of information collection and it played central role in many breeding associations and has been used with great success over the years (Janssens and Vandepitte, 2004). Phenotypic characteristics are important in breed identification and classification. The first step of the characterization of local genetic resources is to assess variation of morphological traits (Delgado et al., 2001). A combination of linear body measurements along with weight of animal describes more completely an individual rather than the conventional method of weighing and grading (Riva et al., 2004; Salako, 2006). Analysis of variance and correlation are widely used to characterize phenotypic and genetic relationship among body measurements of animals (Dietl et al., 2005; Taye et al., 2010; Ogah, 2011; Patoo et al., 2016). However factor analysis using principal component analysis (PCA) is a valuable refinement statistical tool in multivariate methodology that is of use when characteristics are correlated (Yak abu and Ayodae, 2009). PCA is interdependence technique whose primary purpose is to define the underlying structure among the variables in the analysis (Yunusa et al., 2013). The purpose of present investigation is to define the biometric structure of Rampur-Bushair sheep and to develop latent factors to examine percentage contribution of various body measurements towards total dimensional variation of the breed.