HomePhilippine Journal of Veterinary Medicinevol. 50 no. 2 (2013)

Body Weight Prediction in Philippine-Born Adult Ostriches (Struthio camelus Linnaeus, 1758) (Aves: Struthioniformes: Struthionidae) Using External Body Measurements

Romina Gemelyn M. Castro | Conrado A. Valdez

Discipline: Veterinary Medicine



This study was conducted to examine the relationship of body weight to external body measurements in Philippine-born adult ostriches, and to formulate possible equations to predict body weight based on these measurements. A total of 43 ostriches (18 male and 23 female ostriches) were used in this study. The animals were weighed and the body measurements such as the head length, back length, thoracic girth, abdominal girth, tibio-tarsal length, tarso-metatarsal length, wing length, height to top of back, wing length, and length of neck to top of head were taken. Results in mean and standard deviation (mean ± SD) showed that there was no marked difference (mean ± SD) between males and females in the population with regards to body weight. Correlation analysis revealed that for the whole population, thoracic girth (r=0.727), abdominal girth (r=0.572), and back length (r=0.569) had the highest correlation to body weight. Predictive equations were then formulated using log-linear simple and stepwise regression analysis. The analysis of variance results for log-linear stepwise regression analysis revealed that for ostriches of both sexes, thoracic girth was the greatest single predictor. For the whole population, analysis of variance results showed that back length and thoracic girth had the highest significance as multiple predictors. The most preferred equation to predict body weight in the entire population was: log weight = -2.569 + 0.626 log (thoracic girth) + 0.259 log (back length) with R2 =0.580. It indicates that 58% of variations in body weight can be explained by the external body measurements, thoracic girth and back length. This equation can be used to estimate the body weight of Philippine-born adult ostriches if a weighing scale is not available. It is suggested however that further studies be done to investigate if a similar equation could be used for body weight determination in Philippine-born growing ostriches, and that other external body measurements be included in future studies.