Nonlinear equations to determine the growth curve of immunocastrated pigs

Abstract

The objective of this work was to compare the performance of the nonlinear Gompertz, logistic, and von Bertalanffy equations, to describe the growth curve of immunocastrated male pigs from birth until reaching 140 kg body weight. Standard error, number of iterations, mean square of the error, and coefficient of determination were compared between the models. The logistic and von Bertalanffy equations do not accurately estimate the initial and slaughter weights. The Gompertz equation shows the highest reliability and is, therefore, the most suitable one to describe the growth curve of immunocastrated pigs from birth until 140 kg body weight is reached.

Many lifetime growth trajectories for a single mammal

“…We tested for differences in adult body mass, maximum growth rate, and time required to reach maximum growth across individuals. Because wild boars are rather altricial (i.e., are born in a nest and are highly restricted in their movements in their first days of age) and not as precocial as similar‐sized ungulates (Gaillard et al., 1997), and in accordance with recent growth modeling in pigs (Ceron et al., 2020), we thus expected wild boar to exhibit a Gompertz type growth trajectory. Moreover, as wild boars are strongly sexually dimorphic in size (Toïgo et al., 2008) with similar growth early in life for both sexes (Gaillard et al., 1992; Veylit et al., 2020b), we expected sex‐specific growth trajectories to follow our third scenario (i.e., males and females have the same growth rate but different growth period durations; Figure 1c).…”

“…Based on previous knowledge on the association between the shape of body growth and the state of development at birth across mammals (Gaillard et al., 1997), as well as from previous modeling of pig growth (Ceron et al., 2020), we expected wild boar to exhibit a Gompertz type growth trajectory. Indeed, wild boar are closer to the altricial end of the altricial–precocial spectrum (following the criteria of Derrickson, 1992).…”

“…Growth of domestic pigs ( Sus scrofa domesticus ) has been investigated using growth models fitted to age‐specific data of body mass change. These models showed that pig growth follows a sigmoidal function (e.g., Strathe et al., 2010; Vincek et al., 2012) and that the Gompertz model might be the most suitable (Ceron et al., 2020). Here, first, we quantified growth trajectories for each sex in each population (i.e., testing for context‐specific growth trajectories) using Gompertz, logistic, and monomolecular models, which encompass the expected range of growth shape in determinate growers.…”

Evaluation of piglet birth weight on growth performance and qualitative and quantitative characteristics of carcasses of immunocastrated pigs

“…The pigs used in this experiment had the same genetic background and, consequently, similar Gompertz equation parameters (A, B, C), so there was no reason to expect that the NP category would produce results similar to the HP category (Ceron et al, 2020). This aspect shows the need to develop nutritional and handling strategies to increase the performance of HP weight range, and not only to concentrate all the efforts of the farm to prioritize the survival and development of the LP.…”