Resumen
- Many rustic breeds under low levels of genetic selection maintain variations in coat colour, which local farmers link to production traits, but few quantitative analyses have been made of the effect of coat colour on several zootechnical parameters of importance. The aim of the study was to describe differences in morphology, production, behaviour and welfare of adult sheep ewes (n = 50) in a Chamarita breed flock in terms of coat colour. The wool and skin colour of Chamarita sheep are quite variable, with white, black and galana sheep. Morphological measurements (weight, body length, height at withers and thorax circumference) were not significantly different for different coat colours but white sheep tended to be larger. Average litter size (1.29 lambs per ewe) was also similar, but white coated sheep gave birth to larger lambs. White-mother lambs also had a higher average daily growth during the milking period, although final weaning weight was similar to black ones. Most (>70 percent) of all the aggressive interactions observed were performed by white sheep, while affiliative interactions (friendly interactions that promote group cohesion) were similar among coat colour. Regarding the welfare assessment, most indicators were similar among sheep with different coat colour except for glucose in blood plasma, which was higher in white sheep. Chamarita ewes are relatively small compared with other breeds, and well adapted to their environment, including the production system and harder climatic conditions. Their performance is within the average of local breeds and still has margins for improvement, which underline the importance of their conservation.