The relationship between body condition score and body weight, body linear measurements and real-time ultrasound body composition measurements in Alpine does prior to breeding and kidding

Abstract Text: The objective of this study was to determine the relationships between body condition score (BCS) and body weight (BW), hip height (HH), wither height (WH) girth circumference (GC) and real-time ultrasound (RTU) measurements of body composition in Alpine does prior to breeding (n = 66) and prior to kidding (n = 34). Thirty-two animals were not included in the prior to kidding measurements due to culling or failure to give birth. The body composition traits measured by RTU were 12-13^th rib fat thickness (uBF), and rump fat thickness (uRUMP). Ultrasound measurements were taken using an Aloka 500 with a 12 cm 3.5 MHz transducer.  Hair was clipped and vegetable oil was used as a coupling agent in order to enhance image quality.  Data were analyzed using the Proc CORR and Proc REG procedures of SAS.  Body condition score was highly correlated (P < 0.01) with uBF and uRUMP prior to breeding (r = 0.45 and 0.39, respectively) and prior to kidding (r = 0.84 and 0.74, respectively). Body weight and HH were highly correlated prior to breeding (r = 0.63; P < 0.0001), but not prior to kidding (r = 0.27; P = 0.12). Girth circumference was highly correlated to BW (r = 0.78; P < 0.0001) and correlated to HH (R = 0.38; P = 0.037) prior to kidding. Wither height and HH were highly correlated only when measured prior to kidding time (r = 0.63; P < 0.001). Prediction equations were developed in order to predict BCS using a stepwise procedure. Body condition score prior to breeding can be predicted from uBF with an R² of 0.21. Prediction of BCS prior to kidding using uBF had an R² of 0.63, which was the first variable included in the model. Inclusion of three additional variables (uRUMP, HH and WH) in the full model improved the R² to 0.76. Results indicate that RTU body composition traits are highly correlated with BCS in Alpine goats and that the accuracy of prediction was improved when does were close to parturition. More research is needed in order to refine the models and improve accuracy of prediction. 

Keywords: Ultrasound, body composition, goat