Curvas de crescimento de cordeiros da raça Ile de France criados em confinamento

Falcão, Paula Fernanda; Pedrosa, Victor Breno; Moreira, Raphael Patrick; Sieklicki, Michelli de Fátima; Rocha, Caroline Gomes; Santos, Izaltino Cordeiro dos; Ferreira, Evandro Maia; Martins, Adriana de Souza

doi:10.1590/s1519-99402015000200012

Cited by 5 publications

(6 citation statements)

References 9 publications

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“…The average weaning weight (60 days old) of Ile de France sheep in confinement, was 22.90 kg [4], similar to the weights observed in this study. This result demonstrates that the animals and the system adopted in this study had a good performance, which can be observed from the weaning, despite the higher birthweight and the characteristic larger size of Ile de France compared to Texel.…”

Section: Discussionsupporting

confidence: 86%

“…Over the past few years, growth curves were used to analyze the growth rate of animals in the farm to improve their production systems [18]. Nonlinear methods are interesting alternatives because they allow the farmer to determine the model that best fits the growth behavior and development of the animals in the herd, so it becomes possible to predict or anticipate the most appropriate management system [4]. A growth curve study [13] has shown that non-linear models cannot solve the system of equations directly, as in the case of linear systems, since the resolution of the system depends on the estimation of the parameters themselves.…”

Section: Discussionmentioning

confidence: 99%

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Growth Curves of Texel Male Lambs

Sieklicki

Pedrosa

Rocha

et al. 2016

Acta Scientiae. Vet.

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Background: The consumption of lamb meat is growing due to improved farming methods. However, to be economically feasible, the animal should stand out for its precocity, fast finishing and muscular force, such as seen in Texel breed. Besides, knowledge about weight gain and development can facilitate the selection of the best animals, and allow a better fitting to farming systems. Growth curves are an effective method that describes animal development, modeling the relationship between weight and age and help to predict the growth rate. Thus, this study aimed to analyze which nonlinear model, including Brody, Gompertz, Von Bertalanffy and Logistic best describe the growth curve of Texel sheep.Materials, Methods & Results: In this experiment, the lambs were kept in confined system while the ewes, in a semi-extensive system. This study followed 42 Texel male lambs, which were confined from birth to slaughter, and fed concentrated feed (3% of body weight) and corn silage (average 1.5 kg/animal/day), 4 times a day. The lambs were weighed fortnightly, in different classes considered as follows, weight at birth (BW), 15 days (P15), 30 days (P30), 45 days (P45), 60 days (P60), 75 days (P75), 90 days (P90), 105 days (P105), and 120 days (P120), which was defined as the slaughtering weight. The growth curves were determined using the nonlinear models of Brody, Von Bertalanffy, Gompertz and Logistic. The following parameters were used in the curves, Y, slaughtering weight; A, asymptotic weight; k, growth rate, t, animal age; B, constant related to the initial weight; and, m, constant of the curve shape. The criteria used for selecting the model that best described the curve were the mean square error (MSE), which was calculated by dividing the sum of squared error by the number of observations, and also the coefficient of determination (R²), calculated as the square of the correlation between the observed and estimated weights. The average weights observed were as follows, 4.02 kg at birth, 21.68 kg at weaning (P60) and 32.55 kg at slaughtering (P120). The solution of the nonlinear models allows, thru the parameters, establish specific feeding programs and define the optimal slaughtering age. Furthermore, the coefficients of determination, with values close to 97.3%, showed good fits for all models. Still, considering the mean square error, where the lower value indicates the best fit to the data evaluated, the results were 13.1564 (Brody), 13.3421 (Von Bertalanffy), 13.4876 (Gompertz) and 13.6717 (Logistic). The results showed that Brody could be considered the model that best describes the growth rate up to 120 days old of Texel lambs.Discussion: Compared to other studies, the average weights obtained in the experiment varied widely. This large variation can be explained by the used rearing system that might favor or not the performance of lambs. However, the average weaning weight obtained was similar to several studies in the literature, confirming the potential of Texel breed. This breed demonstrated to be capable to provide a precocious animal, with good growth results from the early developmental stage until the slaughtering age. Regarding the growth curves, the Brody model was the best fit for the estimated and observed weights. Moreover, the coefficient of determination indicated good fits for all models. However, an important aspect is the negative correlation between the A and k parameters, demonstrating that the higher the animal growth rate, the lower its asymptotic size.

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Section: Discussionsupporting

confidence: 86%

Section: Discussionmentioning

confidence: 99%

Growth Curves of Texel Male Lambs

Sieklicki

Pedrosa

Rocha

et al. 2016

Acta Scientiae. Vet.

Self Cite

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“…The parameter β 2 is an integration constant related to the proportion of growth after the birth of the animal (Falcão et al, 2015). Based on the results, the highest β 2 values were observed in the Gompertz (2.788) and Logistic (2.069) models, which had lower weights at maturity (158.80 g and 156.20 g, respectively), indicating a negative correlation between β 1 and β 2 .…”

Section: Resultsmentioning

confidence: 91%

Adjustment of four growth models through Bayesian inference on weight and body nutrient depositions in laying quail

et al. 2016

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-An experiment was conducted to estimate the parameters of the Gompertz, Brody, Logistic, and Von Bertalanffy equations through Bayesian inference and evaluate the potential for growth in terms of weight and body composition of laying female quail (Coturnix coturnix japonica). The weights and body compositions of the birds were obtained weekly (1-119 days), allowing the adjustment of the four equations by Bayesian inference. The parameters mature weight (β1), integration constant (β2), maturity rate (β3), and their credibility intervals in four models on body weight and body components were properly estimated by Bayesian inference to describe the body growth in laying quail. The inflection point was determined by the 1st and 2nd derivatives of the Gompertz equation for body weight and body components (fat, protein, ash, and water). Based on Deviance Information Criterion (DIC) for the studied and analyzed variables, there is a model that fits best as a result of its better performance to achieve the DIC value. The Von Bertalanffy model proved to be very versatile, not obtaining good fit of data only for fat. The study shows that other models can also be used in several data sets as an alternative to Gompertz, which, due to its adequate biological interpretation and desirable characteristics in a curve growth, is generally the most used.

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“…Models 1 and 2 overestimated the final mass of the meat-producing mammals, as verified by in the study on cows, Falcão et al (2015) in the study on sheep, and Jacob et al (2015) in the study on rabbits, using the model of von Bertalanffy.…”

Section: Resultsmentioning

confidence: 61%

“…Sheep data on mass (kg) were collected in the report by Falcão et al (2015) on 31 males of Ile de France breed, confined from the birth to the slaughter, at 120 days of age.…”

Section: Methodsmentioning

confidence: 99%

Growth curves of meat-producing mammals by von Bertalanffy’s model

Fernandes

Pereira

et al. 2019

Pesq. agropec. bras.

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The objective of this work was to evaluate how the parameterization and the application of different allometric values affect the obtention of the most adequate fit of von Bertalanffy’s model, in the description of the growth curve of meat-producing mammals (bovine, pigs, rabbits, and sheep). Among the nonlinear models, von Bertalanffy’s has been very often applied in several areas, with different parameterizations. This model has been commonly used with an allometric value of m = 2/3; however, for mammals, it is believed that this value can be m = 3/4. The analyzed data referring to the mass of meat-producing mammals according to their age were obtained from research institutions and from the literature. The results showed that von Bertalanffy’s model, with the allometric value of m = 3/4 and the used parameterization, provided better adjustments to quality evaluators. Besides, the model softened the overestimation of parameter a, giving a direct interpretation of parameter b, with the lowest values for curvature measurements, mainly for the parametric ones, and provided more reliable adjustments. Von Bertalanffy’s model can be used in the description of the growth curves of meat-producing mammals.

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Curvas de crescimento de cordeiros da raça Ile de France criados em confinamento

Cited by 5 publications

References 9 publications

Growth Curves of Texel Male Lambs

Growth Curves of Texel Male Lambs

Adjustment of four growth models through Bayesian inference on weight and body nutrient depositions in laying quail

Growth curves of meat-producing mammals by von Bertalanffy’s model

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