Carcass Traits and Growth Curve Parameters in Santa Inês Sheep

The aim of this study was to evaluate carcass traits and growth curves in Santa Inês sheep. We used weight data collected from 51 developing sheep from birth to 336 days of age, from March 2012 to May 2013. The sheep belonged to the Core Conservation Team of the Federal University of Piauí and were located at two properties, one in Bom Jesus - PI and one in Cristino Castro - PI. The model used to represent the growth curve was the Gompertz model, in which the model parameters were estimated by using a Gauss-Newton algorithm modified by the NLIN procedure in SAS. The rib eye area (REA) and subcutaneous backfat thickness (SBT) of lambs were evaluated by ultrasound. These results were used to study the growth curve and the relationship between the estimated model growth curve parameters and the evaluated carcass traits. The estimated correlation between A and K was negative. The correlations between the carcass traits (REA and SBT) and the growth curve parameters (A and K) show that animals with a high adult weight and a high rate of precocity do not always yield good carcasses. Birth weight is a good indicator of animals that can achieve better weights in adulthood. The management effect influenced the growth pattern of Santa Inês sheep, indicating a need to adapt management decisions. These adaptations would mainly relate to fodder storage during periods of food scarcity, which indirectly relates to climate effects, so there would be no influence on animal growth.