Application of non-linear mixed models for modelling the quail growth curve for meat and laying

Abstract

The objective of the current paper was to apply mixed models to adjust the growth curve of quail lines for meat and laying hens and present the rates of instantaneous, relative and absolute growth. A database was used with birth weight records up to the 148th day of female quail of the lines for meat and posture. The models evaluated were Brody, Von Bertalanffy, Logistic and Gompertz and the types of residues were constant, combined, proportional and exponential. The Gompertz model with the combined residue presented the best fit. Both strains present a high correlation between the parameters asymptotic weight (A) and average growth rate (k). The two strains presented a different growth profile. However, growth rates allow greater discernment of growth profiles. The meat line presented a higher growth rate (6.95 g/day) than the lineage for laying (3.65 g/day). The relative growth rate was higher for lineage for laying (0.15%) in relation to the lineage for meat (0.13%). The inflection point of both lines is on the first third of the growth curve (up to 15 days). All results suggest that changes in management or nutrition could optimize quail production.

Quail growth curve model identity

“…In contrast, weight gain does not appear to have been a focus of selection for these lines, as we detected no significant differences with respect to the maturation rate parameter. Previously, Santos et al (2018) have shown that European quail lines specifically bred for meat production have a higher adult weight range than that of Japanese quail lines, whereas Sezer and Tarhan (2005) have observed distinct growth behavior in the first and second growth phases of three quail lines, which indicates that different sets of genes can determine differences in the early and late growth of lines. Additionally, a difference in the growth curve with respect later weights was considered to reflect a significant effect of the adult weight parameter for the different lines evaluated.…”

“…Some authors have studied the effect of selection or the nutritional levels of diets (Zancanela et al, 2015;Santos et al, 2018) on the growth curves of quails, and have inferred that further studies should investigate the effects of diet on the quail growth curve. Furthermore, using standard and reaction models, Mota et al (2015) examined the effects of genotype × environment interactions with respect to different diets on the body weight of quails, and accordingly observed that nutritional levels affected body weight only under less favorable environmental conditions.…”

“…Moreover, in a comparison of the growth of two generations of Japanese quails using the Gompertz model, Santos et al (2018) performed a parameter equality test of the model and concluded that a common equation should not be used to describe the growth of the two generations.…”

“…In addition to facilitating verification of differences in the growth of different lines used in the production of animal protein, growth curve determinations make it possible to identify the ideal time to change diets, based on a knowledge of the parameters of nonlinear models (Grieser et al, 2015). According to Santos et al (2018), lines that reach adult weight at an earlier age have a higher nutritional demand than slower growing lines.…”

Multiphasic nonlinear mixed growth models for laying hens

“…The objective of growth in meat-type poultry, lean-tissue production, differs widely from the growth objective in egg-type poultry, which focuses on establishment of critical skeleton mass to support Ca metabolism and proper development of the reproductive tract ( Bain et al., 2016 ). In addition, Santos et al. (2018) concluded that meat- and laying-type female quail differed in the growth profile as modeled by a mixed Gompertz function, where the relative growth rate was higher and the mature weight was lower in laying-type than meat-type females (0.15 vs. 0.13% and 159 vs. 305 g, respectively).…”