Assessment of final body weight and feed conversion ratio in batches of growing pigs with statistical modeling

Abstract

This study was conducted to assess prediction models for production indexes in batches of growing pigs using performance regressors (period of the year and farm size).A database containing 663 records on the performance of pig batches (18.83 ± 4.37 to 111.26 ± 10.59 kg body weight (BW) at housing and finisher, respectively) from a private company was used to assess the following average animal characteristics: initial number of animals (INA), initial BW (IBW), initial age (IA), final BW (FBW), final age (FA), daily feed intake (DFI) and feed conversion ratio (FCR). Data were categorized by period (P) of the year (P 1 = Nov to Apr and P 2 = May to Oct), and farm size (FS): 0 ≤ INA ≤ 1,000, FS 1 ; 1,001 ≤ INA ≤ 2,000, FS 2 ; 2,001 ≤ INA ≤ 3,000, FS 3 ; and INA > 3,000, FS 4 . The analysis resulted in representing 58 % of the variance of FCR data. The INA impaired FCR, and having larger pig batches improves FCR and profitability. The FBW prediction errors ranged from 2.47 to 3.38 %. Feed conversion ratio prediction errors ranged from 3.27 to 4.47 %. Based on the joint criteria of non-bias and accuracy, the models for predicting the FBW of growing pig batches have practical value in animal science on account of their accuracy. In addition, increasing the initial number of housed pigs in batches affects the FCR regardless of the period of the year.