Open AccessPrincipal component analysis of pre-weaning growth traits in Santa Inês lambs
Author(s) -
Natália Albieri Koritiaki,
Edson Luís de Azambuja Ribeiro,
Carolina Amália Souza Dantas Muniz,
Bruna Silva Marestone,
Francisco Fernandes
Publication year - 2019
Publication title -
semina. ciências agrárias
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.268
H-Index - 25
eISSN - 1679-0359
pISSN - 1676-546X
DOI - 10.5433/1679-0359.2019v40n6supl2p3269
Subject(s) - weaning , principal component analysis , zoology , birth weight , perimeter , body weight , domestic sheep reproduction , biology , mathematics , demography , veterinary medicine , medicine , statistics , pregnancy , endocrinology , genetics , geometry , sociology
The aim of this study was to evaluate the interrelation among growth traits in Santa Inês lambs using principal component analysis. Data on 270 lambs born between 2008 and 2013 were used. The variables studied were weight at birth,adjusted weight from birth to weaning, and average daily gains at 14, 28, 52, and 70 days of age. The wither height, thoracic perimeter, and length at birth and adjusted at 28 and 70 days of age (weaning), were also used. The statistical model comprised the fixed effects of the contemporary group, the linear effect of julian date at birth, and the linear and quadratic effects of lambing weight. The first principal component explained approximately 89% and 85% of the total variation for body weight at different ages and average daily gains, respectively. The second principal component compared heavier animals or those that gained more weight at 14 days with lighter lambs or those that gained less weight at 14 days of age and explains the variation of approximately 5% and 10%, respectively, among the animals. The first principal component accounted for 77%, 91%, and 77% of the variation for weight, thoracic perimeter, wither height, and length at birth, 28 days, and 70 days of age, respectively, and compared large animals or animals with greater body volume. The second component, with values of 16%, 6%, and 14% of the total variation at the three ages, respectively, compared animals with distinct conformation to discriminate animals of different shapes and verified that the weights at the different ages and the thoracic perimeter are important sources of variability among the animals.