Body condition score and age do not affect the physiological responses, thyroid hormones, hematological or serum biochemical parameters for tropical ewes

Abstract

ABSTRACT Tropical ewes of the Morada Nova breed were used to evaluate concordance on the effects of body condition score (BCS) and age classification using canonical discriminant analysis (CDA) as the classification method. The dependent variables in this study were: physiological responses, thyroid hormones, hematological and biochemical parameters. The hypothesis of this study was that the effect of BCS and age classification of the ewes might explain changes in physiological responses, thyroid hormones, hematological and serum biochemical parameters; however, very little effect was observed. Only the physiological responses and the thyroid hormones presented a subtle change using the BCS classification effect. An elevated error rate with both effects was observed, especially for age. However, the lowest total error rate was detected when all variables for BCS and for the thyroid hormones according to chronological age were used in the analyses. Therefore, the results do not support the recommendation of using BCS and age as classification effects, and therefore other effects should be used to improve reference ranges.