Authors : R.E. Alfonso, H.J. Herrera, F.C. Lemus, C.M.E. Ortega, R.C. Cortez and P.J. Perez
Abstract: In order to characterize morphometrically the breed, under tropical conditions, a study was done in the Frailesca region of Chiapas, Mexico. Five herds of 272 lactating cows, four were selected from the Mexican Association of Brown Swiss Breeders. Each cow was measured for 29 type traits, milk production and body weight. Milk production per lactation was estimated through monthly sampling with a fixed date and adjusted to 305 day. The information was analyzed using a fixed effects model with covariance in the SAS software and Least Square Means (LSM) were estimated. A multivariate Analysis of Principals Components (ACP) was then done to reduce the dimensional spaces of the variables. A Cluster analysis was calculated with the selected subset defining four well-defined morphotypes. A Pearson correlation analysis was done and type traits were related with milk production and body weight. Six type traits accounted for 70% of the total variation. The estimated LSM were: body weight (PC) 519.23±4.0 kg, Heart Girth (HG) 187.3±0.6 cm Withers Height (WH) 137.4±0.3, Abdominal Perimeter (AP) 203.4±0.8 cm, Body Depth (BD) 231.8±0.9 cm and Front Legs Perimeter (FLP) 19.5±0.1. The Pearson correlations coefficient among type traits and milk production were low (r<0.23) and significant (p>0.05) but the relationship between type traits with body weight were high (0.70, p<0.01). The Cluster analysis grouped the cows in three morphotypes with little variation among them. It is concluded that the 6 traits selected though the ACP can be used to define type groups of Brown Swiss cows under Mexican tropical environment.
R.E. Alfonso, H.J. Herrera, F.C. Lemus, C.M.E. Ortega, R.C. Cortez and P.J. Perez, 2011. Morphometric Characterization of American Brown Swiss Cows in a Tropical Region of Chiapas, Mexico. Journal of Animal and Veterinary Advances, 10: 454-459.