Genetic Evaluation of Dual-Purpose Buffaloes (Bubalus bubalis) in Colombia Using Principal Component Analysis

Abstract

Genealogy and productive information of 48621 dual-purpose buffaloes born in Colombia between years 1996 and 2014 was used. The following traits were assessed using one-trait models: milk yield at 270 days (MY270), age at first calving (AFC), weaning weight (WW), and weights at the following ages: first year (W12), 18 months (W18), and 2 years (W24). Direct additive genetic and residual random effects were included in all the traits. Maternal permanent environmental and maternal additive genetic effects were included for WW and W12. The fixed effects were: contemporary group (for all traits), sex (for WW, W12, W18, and W24), parity (for WW, W12, and MY270). Age was included as covariate for WW, W12, W18 and W24. Principal component analysis (PCA) was conducted using the genetic values of 133 breeding males whose breeding-value reliability was higher than 50% for all the traits in order to define the number of principal components (PC) which would explain most of the variation. The highest heritabilities were for W18 and MY270, and the lowest for AFC; with 0.53, 0.23, and 0.17, respectively. The first three PCs represented 66% of the total variance. Correlation of the first PC with meat production traits was higher than 0.73, and it was -0.38 with AFC. Correlations of the second PC with maternal genetic component traits for WW and W12 were above 0.75. The third PC had 0.84 correlation with MY270. PCA is an alternative approach for analyzing traits in dual-purpose buffaloes and reduces the dimension of the traits.

Genotype–environment interaction for age at first calving in buffaloes, using the reaction norm model

“…The AFC heritability estimate using the standard animal model was 0.196. This value is close to those found by other authors, which ranged from 0.170 to 0.260 for buffaloes (Agudelo‐Gomez, Pineda‐Sierra, & Cerón‐Muñoz, ; Catillo, Moioli, & Napolitano, ; Thiruvenkadan, Panneerselvam, & Murali, ). On the other hand, the heritability in the reaction norm increased considerably with the improvement of environmental conditions (Figure ), ranged from 0.178 to 0.364 for the GAFC and 0.131 to 0.394 for the GMY, respectively.…”

Multivariate analysis of milk yield, lactation length and calving interval in female buffaloes

“…Oliveira et al (2014) applied the PCA technique to the genetic evaluation of 9 traits in Murrah Buffaloes finding that only the first 4 PCs were necessary to explain the covariance structure of the features. Furthermore, Agudelo-Gómez et al (2015) reported that the first three PCs from eight reproductive features in dual purpose buffaloes in Colombia presented eigenvalues higher than one, which explained 65.8% of the total variation. Vohra et al (2015) concluded that the first four components from 13 different body measurements of Gojri Buffaloes were sufficient to explain 70.9% of the total variation.…”

Body morphometric measurements in Murrah crossbred buffaloes (Bubalus bubalis)

“…It is possible to find some body traits about buffaloes in literature (Espinosa-Núnês et al 2011;Johari et al 2009;Vohra et al 2015;Mirza et al 2015;Dhillod et al (2017), but studies about the correlation between them are scarce, although they are very important to genetic improvement programmes. As reported by Agudelo-Gómez et al (2015), the body measurements of female buffaloes and their correlations can aid in predicting the potential and aptitudes of these animals. There is some association between the body measurements, the productive and reproductive traits in buffaloes (Thomas and Chakravarty 2000;Espinosa-Núnês et al 2011;Kern et al 2014) and in cattle (Wenceslau et al 2000;Rennó et al 2003;Lagrotta et al 2010;Silva et al 2011).…”