Modelling interactions between farmer practices and fattening pig performances with an individual-based model

Abstract

European pig production continues to encounter economic and environmental challenges. To address these issues, methods have been developed to assess performances of pig production systems. Recent studies indicate that considering variability in performances among pigs improves the accuracy and reliability of results compared with modelling an average animal. Our objective was to develop a pig fattening unit model able to (i) simulate individual pig performances, including their variability in interaction with farmers' practices and management, and (ii) assess their effects on technical, economic and environmental performances. Farmer practices included in the model were chosen from a typology generated from on-farm surveys focused on batch management, pig allocation to pens, pig feeding practices, practices of shipping to the slaughterhouse, and management of the remaining pigs. Pigs are represented using an individual-based model adapted from the InraPorc® model. To illustrate the model's abilities, four scenarios were simulated that combine two feed rationing plans (ad libitum, restricted to 2.5 kg/day) and two feed sequence plans (two-phase, 10-phase). Analysis of variance was performed on the simulated technical, economic and environmental indicators (calculated via Life Cycle Assessment). The feed rationing plan and feed sequence plan significantly affected all indicators except for the premium per pig, for which the feed sequence plan did not have a significant effect. The 'restricted 10-phase' scenario maximised gross margin of the fattening unit (14.2 €/pig) and minimised environmental impacts per kg of pig produced. In contrast, the 'ad libitum two-phase' scenario generated the lowest margin (8.20 €/pig) and the highest environmental impacts. The model appears to be a promising tool to assess effects of farmers' practices, pig characteristics and farm infrastructure on technical, economic and environmental performances of the fattening unit, and to investigate the potential of improvement. However, further work is needed, based on virtual experiments, in order to evaluate the effects of a larger diversity of practices.

Proceedings of the 9th Workshop on Modelling Nutrient Digestion and Utilization in Farm Animals (MODNUT)

“…The model of the pig fattening unit considers individual variability in performance among pigs, farmers feeding practices and animal management, and estimates environmental impacts (through Life Cycle Assessment) and economic results of the unit (Cadero et al, 2018a). This model provides reliable estimates of the fattening unit performance (Cadero et al, 2018b).…”

“…It was written in Python language. The growth model is an individual-based model adapted from the InraPorc model, combined with a generator of the within-room pig population and additional tools dealing with management issues such as mortality rate or delivery to slaughterhouse (Cadero et al, 2018). At the room level, the bioclimatic model allows for the calculation of the rate of ventilation and the input of heat required to achieve the expected ambient temperature.…”

Microbiome composition differences among breeds impact feed efficiency in swine

“…The ASV for T1, T2, and T3 were analyzed using a negative binomial model with the "edgeR" [57] package in R including the fixed effects described in the model (1). Orthogonal contrasts were fitted as reported above to obtain ASV significance among breeds.…”

“…where y ijklmn was the phenotype (ADFI, ADG, RF1, RF2, FCR, backfat, loin depth, and IMF); µ was the overall intercept of the model; Br i and Ro j were the fixed effects described in the model (1); As k was the covariate of the kth ASV; As × Br ik was the fixed effect of the ikth As × Br ik interaction; Si(Br) l:i , Pe(Ro) m:j and e ijklmn were as in the model (1). Orthogonal contrasts among breeds were fitted as reported above.…”

“…Feed efficiency is an essential trait in pig production because feed accounts for 50 to 85% of pork producers' costs [1,2]. Feed conversion ratio and residual feed intake are two traits that have been routinely used to evaluate feed efficiency [3].…”