Correlations between beef calf performance and morphological characteristics
Visual assessment, biotype, weight gain, weaning weight, Nelore.
Beef productive efficiency depends on technologies in terms of management, nutrition, health and genetics. The evaluation of morphological parameters correlated with production efficiency can guide the selection of genetically superior animals or the formation of lots depending on the production objective. The aim of the present study was to evaluate the correlation between productive parameters and the visual morphological classification of body structure, precocity and muscularity. Data were collected on a commercial farm in the municipality of Valença, State of Rio de Janeiro. A total of 598 male and 728 female Nellore breed calves were evaluated, using a method of visual assessment of body structure, precocity and muscularity, scored from one (01) to six (06). Correlations between production parameters and morphological classification were estimated using the “R” software. The average daily weight gain and weaning weight of calves was 0.78±0.11 kg/day and 203±25 kg, respectively. The average daily weight gain and body weight at weaning of the calves were 0.74±0.17 kg/day and 197±26 kg, respectively. The correlation coefficients between weight gain and body weight at weaning of calves with body structure (r=0.67 and 0.63), precocity (r=0.47 and 0.50) and muscularity (r=0, 68 and 0.64) were moderate to high. Moderate to high correlation coefficients were also observed between weight gain and body weight at weaning of calves with body structure (r=0.65 and 0.41), precocity (r=0.63 and 0.62) and muscularity (r=0.44 and 0.61). The visual morphological evaluation for characteristics of body structure, precocity and muscularity can be used for classification and selection of Nellore cattle because it presents a moderate to high correlation with productive parameters