Development of a mobile phone application to predict live body weight in Ugandan village pigs without the use of a scale using various body measurements

Abstract Text:

In Uganda very few pig producers own scales, thereby making fair sale of pigs based on weight quite difficult. To remedy this situation, a study to develop pig body weight prediction equations based on various body measurements was conducted in the rural Kamuli district, Uganda. Body weight (kg) and body measurement data (cm) were collected from 411 pigs between 15 kg and 127 kg from both local and exotic (mainly crossbred) pigs. Five body measurements; body length, heart girth, height, body width (over the shoulders), and flank-to-flank were taken from each pig. Prediction models were developed by regression analysis where body weight was the dependent variable and the various body measures were the independent variables. The data were organized into three categories for modeling: pigs categorized as < 40 kg, ≥ 40 kg and all pigs. Mean weights in the < 40 kg and ≥ 40 kg categories were 27 ± 6.5 kg and 63 ± 19.6 kg, respectively. Body length and heart girth were used to predict (R² = 0.89) weight for the < 40 kg pigs with the prediction equation: Weight = -41.814 + 0.296 (body length) + 0.654 (heart girth). Four body measurements; body length, heart girth, height, and body width were strongly predictive (R² = 0.92) of live body weight for the ≥ 40 kg pigs with the prediction equation: Weight = -108.198 + 0.228 (body length) + 1.094 (heart girth) + 0.267 (height) + 0.922 (body width). The flank-to-flank measurement did not affect model prediction (P > 0.05) and quadratic terms also did not improve accuracy. Because local Ugandan farmers are not likely to use prediction equations to compute pig weights, an android-based mobile app was developed using the appropriate body measurements.  The app is designed to be used with English or Luganda, a Uganda native language spoken by most of the people in the country. We concluded that this weight estimation tool would empower Ugandan small scale pig farmers by providing them with an accurate estimate for the animal’s live weight and giving them better bargaining power when selling their pigs.

Keywords: body measurements , weight prediction model, mobile app