Bone Growth and Meat Quality of Quails Submitted to Different Lighting Programs

The present study was executed to evaluate the effect of lighting programs for meat quails on their bone growth and development. A total of 1500 sexed European quails (Coturnix coturnix coturnix) were distributed using a completely randomized design in a 2 × 3 factorial arrangement, with two sexes and three lighting programs (natural, intermittent, and continuous) with five replicates of 50 quails. The lighting programs were applied in the period from 7 to 49 d of age. Weekly slaughterings were performed to remove the tibiotarsus and femur and subsequently determine weight, length, dry and mineral matter content. The growth and deposition curves of dry and mineral matter in the bones were obtained using the Gompertz model. There was no significant interaction between lighting programs and sex for the estimates of the Gompertz curve parameters of all variables studied. There was an effect of the lighting programs only on the time needed to reach the maximum deposition rate of the growth curve and dry and mineral matter deposition. Females showed higher weight and deposition of mineral matter at maturity, and took longer to reach the maximum deposition rate value for these variables. There was influence of the lighting programs on resistance and bone deformity of the tibiotarsus. For quails raised in the tropical region, a natural or intermittent lighting program must be used, as it does not compromise the development of bones and assures bone quality.(AU)

Mathematical models to describe the growth curves of Vietnamese Ri chicken / Modelos matemáticos para descrever as curvas de crescimento do frango Ri vietnamita

Ri chicken is the most popular backyard chicken breed in Vietnam, but little is known about the growth curve of this breed. This study compared the performances of models with three parameters (Gompertz, Brody, and Logistic) and models containing four parameters (Richards, Bridges, and Janoschek) for describing the growth of Ri chicken. The bodyweight of Ri chicken was recorded weekly from week 1 to week 19. Growth models were fitted using minpack.lm package in R software and Akaike’s information criterion (AIC), Bayesian information criterion (BIC), and root mean square error (RMSE) were used for model comparison. Based on these criteria, the models having four parameters showed better performance than the ones with three parameters, and the Richards model was the best one for males and females. The lowest and highest value of asymmetric weights (α) were obtained by Bridges and Brody models for each of sexes, respectively. Age and weight estimated by the Richard model were 8.46 and 7.51 weeks and 696.88 and 487.58 g for males and for females, respectively. Differences in the growth curves were observed between males and female chicken. Overall, the results suggested using the Richards model for describing the growth curve of Ri chickens. Further studies on the genetics and genomics of the obtained growth parameters are required before using them for the genetic improvement of Ri chickens.

O frango Ri é a raça de frango de quintal mais popular do Vietnã, mas pouco se sabe sobre a curva de crescimento dessa raça. Este estudo comparou o desempenho de modelos com três parâmetros (Gompertz, Brody e Logistic) e modelos contendo quatro parâmetros (Richards, Bridges e Janoschek) para descrever o crescimento do frango Ri. O peso corporal do frango Ri foi registrado semanalmente da semana 1 à semana 19. Os modelos de crescimento foram ajustados usando o pacote minpack.lm no software R e o critério de informação de Akaike (AIC); critério de informação bayesiano (BIC) e erro quadrático médio (RMSE) foram usados para comparação de modelos. Com base nesses critérios, os modelos com quatro parâmetros apresentaram melhor desempenho do que os com três parâmetros, sendo o modelo de Richards o melhor para homens e mulheres. O menor e o maior valor dos pesos assimétricos (α) foram obtidos pelos modelos Bridges e Brody para cada um dos sexos, respectivamente. A idade e o peso estimados pelo modelo de Richard foram de 8,46 e 7,51 semanas e 696,88 e 487,58 g para homens e mulheres, respectivamente. Diferenças nas curvas de crescimento foram observadas entre frangos machos e fêmeas. No geral, os resultados sugeriram o uso do modelo de Richards para descrever a curva de crescimento de frangos Ri. Mais estudos sobre a genética e genômica dos parâmetros de crescimento obtidos são necessários antes de usá-los para o melhoramento genético de frangos Ri.

Mathematical models to describe the growth curves of Vietnamese Ri chicken

Abstract Ri chicken is the most popular backyard chicken breed in Vietnam, but little is known about the growth curve of this breed. This study compared the performances of models with three parameters (Gompertz, Brody, and Logistic) and models containing four parameters (Richards, Bridges, and Janoschek) for describing the growth of Ri chicken. The bodyweight of Ri chicken was recorded weekly from week 1 to week 19. Growth models were fitted using minpack.lm package in R software and Akaikes information criterion (AIC), Bayesian information criterion (BIC), and root mean square error (RMSE) were used for model comparison. Based on these criteria, the models having four parameters showed better performance than the ones with three parameters, and the Richards model was the best one for males and females. The lowest and highest value of asymmetric weights () were obtained by Bridges and Brody models for each of sexes, respectively. Age and weight estimated by the Richard model were 8.46 and 7.51 weeks and 696.88 and 487.58 g for males and for females, respectively. Differences in the growth curves were observed between males and female chicken. Overall, the results suggested using the Richards model for describing the growth curve of Ri chickens. Further studies on the genetics and genomics of the obtained growth parameters are required before using them for the genetic improvement of Ri chickens.

Resumo O frango Ri é a raça de frango de quintal mais popular do Vietnã, mas pouco se sabe sobre a curva de crescimento dessa raça. Este estudo comparou o desempenho de modelos com três parâmetros (Gompertz, Brody e Logistic) e modelos contendo quatro parâmetros (Richards, Bridges e Janoschek) para descrever o crescimento do frango Ri. O peso corporal do frango Ri foi registrado semanalmente da semana 1 à semana 19. Os modelos de crescimento foram ajustados usando o pacote minpack.lm no software R e o critério de informação de Akaike (AIC); critério de informação bayesiano (BIC) e erro quadrático médio (RMSE) foram usados para comparação de modelos. Com base nesses critérios, os modelos com quatro parâmetros apresentaram melhor desempenho do que os com três parâmetros, sendo o modelo de Richards o melhor para homens e mulheres. O menor e o maior valor dos pesos assimétricos () foram obtidos pelos modelos Bridges e Brody para cada um dos sexos, respectivamente. A idade e o peso estimados pelo modelo de Richard foram de 8,46 e 7,51 semanas e 696,88 e 487,58 g para homens e mulheres, respectivamente. Diferenças nas curvas de crescimento foram observadas entre frangos machos e fêmeas. No geral, os resultados sugeriram o uso do modelo de Richards para descrever a curva de crescimento de frangos Ri. Mais estudos sobre a genética e genômica dos parâmetros de crescimento obtidos são necessários antes de usá-los para o melhoramento genético de frangos Ri.

Mathematical models to describe the growth curves of Vietnamese Ri chicken / Modelos matemáticos para descrever as curvas de crescimento do frango Ri vietnamita

Abstract Ri chicken is the most popular backyard chicken breed in Vietnam, but little is known about the growth curve of this breed. This study compared the performances of models with three parameters (Gompertz, Brody, and Logistic) and models containing four parameters (Richards, Bridges, and Janoschek) for describing the growth of Ri chicken. The bodyweight of Ri chicken was recorded weekly from week 1 to week 19. Growth models were fitted using minpack.lm package in R software and Akaike's information criterion (AIC), Bayesian information criterion (BIC), and root mean square error (RMSE) were used for model comparison. Based on these criteria, the models having four parameters showed better performance than the ones with three parameters, and the Richards model was the best one for males and females. The lowest and highest value of asymmetric weights (α) were obtained by Bridges and Brody models for each of sexes, respectively. Age and weight estimated by the Richard model were 8.46 and 7.51 weeks and 696.88 and 487.58 g for males and for females, respectively. Differences in the growth curves were observed between males and female chicken. Overall, the results suggested using the Richards model for describing the growth curve of Ri chickens. Further studies on the genetics and genomics of the obtained growth parameters are required before using them for the genetic improvement of Ri chickens.

Resumo O frango Ri é a raça de frango de quintal mais popular do Vietnã, mas pouco se sabe sobre a curva de crescimento dessa raça. Este estudo comparou o desempenho de modelos com três parâmetros (Gompertz, Brody e Logistic) e modelos contendo quatro parâmetros (Richards, Bridges e Janoschek) para descrever o crescimento do frango Ri. O peso corporal do frango Ri foi registrado semanalmente da semana 1 à semana 19. Os modelos de crescimento foram ajustados usando o pacote minpack.lm no software R e o critério de informação de Akaike (AIC); critério de informação bayesiano (BIC) e erro quadrático médio (RMSE) foram usados ​​para comparação de modelos. Com base nesses critérios, os modelos com quatro parâmetros apresentaram melhor desempenho do que os com três parâmetros, sendo o modelo de Richards o melhor para homens e mulheres. O menor e o maior valor dos pesos assimétricos (α) foram obtidos pelos modelos Bridges e Brody para cada um dos sexos, respectivamente. A idade e o peso estimados pelo modelo de Richard foram de 8,46 e 7,51 semanas e 696,88 e 487,58 g para homens e mulheres, respectivamente. Diferenças nas curvas de crescimento foram observadas entre frangos machos e fêmeas. No geral, os resultados sugeriram o uso do modelo de Richards para descrever a curva de crescimento de frangos Ri. Mais estudos sobre a genética e genômica dos parâmetros de crescimento obtidos são necessários antes de usá-los para o melhoramento genético de frangos Ri.

Understanding the dynamics of attributes of medium and short cycle rice cultivars under nitrogen effect / Compreendendo a dinâmica de atributos de cultivares de arroz de ciclo médio e curto sob efeito do nitrogênio

ABSTRACT: Nitrogen (N) is the element supplied by the soil that limits the development of irrigated rice. The hypothesis of the present is that to meet higher demand for N by the plant due to the higher potential yield, it is not necessary to apply a higher dose of N fertilizer. This studyevaluated the efficiency of N utilization, the rate of growth and accumulations of N by plants and the grain yield of two rice cultivars, short cycle and medium cycle, with and without N fertilization. A field experiment was installed in the Rio Grande do Sul, southern Brazil. The treatment factors evaluated were cultivar, with medium and short cycles, with doses of 0 and 150 kg N ha-1. Growth curves, absorption rate, N content and leaf area index over time, root area and grain yield were analyzed. The medium cycle cultivar has a greater potential to explore the environment when compared to the short cycle rice cultivar, both for greater leaf area and root area per cultivation area, as well as for longer exploration times. Thus, the medium cycle cultivar has greater N utilization efficiency and higher grain yield.

RESUMO: O nitrogênio é o elemento fornecido pelo solo que mais limita o desenvolvimento do arroz irrigado. A hipótese do presente trabalho é que para atender a uma maior demanda de nitrogênio pela planta devido ao maior potencial de rendimento, não é necessário aplicar uma dose maior de fertilizante nitrogenado. O objetivo do estudo foi analisar o efeito do potencial produtivo de cultivares de arroz na resposta ao nitrogênio. Um experimento de campo foi instalado no Rio Grande do Sul, sul do Brasil. Os fatores de tratamento avaliados foram cultivar, com ciclos médio e curto sob doses de 0 e 150 kg N ha-1. Foram analisadas curvas de crescimento, marcha de absorção, teor de nitrogênio e índice de área foliar ao longo do tempo, área radicular e produtividade de grãos. A cultivar de ciclo médio apresenta maior potencial de exploração do ambiente quando comparada a cultivar de arroz de ciclo curto, tanto pela maior área foliar quanto pela maior área superficial da raiz por área. Assim, a cultivar de ciclo médio tem maior capacidade de exploração de recursos e maior eficiência no aproveitamento do nitrogênio, o que é de grande importância para uma agricultura mais sustentável.

Understanding the dynamics of attributes of medium and short cycle rice cultivars under nitrogen effect / Compreendendo a dinâmica de atributos de cultivares de arroz de ciclo médio e curto sob efeito do nitrogênio

Nitrogen (N) is the element supplied by the soil that limits the development of irrigated rice. The hypothesis of the present is that to meet higher demand for N by the plant due to the higher potential yield, it is not necessary to apply a higher dose of N fertilizer. This studyevaluated the efficiency of N utilization, the rate of growth and accumulations of N by plants and the grain yield of two rice cultivars, short cycle and medium cycle, with and without N fertilization. A field experiment was installed in the Rio Grande do Sul, southern Brazil. The treatment factors evaluated were cultivar, with medium and short cycles, with doses of 0 and 150 kg N ha-1. Growth curves, absorption rate, N content and leaf area index over time, root area and grain yield were analyzed. The medium cycle cultivar has a greater potential to explore the environment when compared to the short cycle rice cultivar, both for greater leaf area and root area per cultivation area, as well as for longer exploration times. Thus, the medium cycle cultivar has greater N utilization efficiency and higher grain yield.

O nitrogênio é o elemento fornecido pelo solo que mais limita o desenvolvimento do arroz irrigado. A hipótese do presente trabalho é que para atender a uma maior demanda de nitrogênio pela planta devido ao maior potencial de rendimento, não é necessário aplicar uma dose maior de fertilizante nitrogenado. O objetivo do estudo foi analisar o efeito do potencial produtivo de cultivares de arroz na resposta ao nitrogênio. Um experimento de campo foi instalado no Rio Grande do Sul, sul do Brasil. Os fatores de tratamento avaliados foram cultivar, com ciclos médio e curto sob doses de 0 e 150 kg N ha-1. Foram analisadas curvas de crescimento, marcha de absorção, teor de nitrogênio e índice de área foliar ao longo do tempo, área radicular e produtividade de grãos. A cultivar de ciclo médio apresenta maior potencial de exploração do ambiente quando comparada a cultivar de arroz de ciclo curto, tanto pela maior área foliar quanto pela maior área superficial da raiz por área. Assim, a cultivar de ciclo médio tem maior capacidade de exploração de recursos e maior eficiência no aproveitamento do nitrogênio, o que é de grande importância para uma agricultura mais sustentável.

Mathematical models to describe the growth curves of Vietnamese Ri chicken / Modelos matemáticos para descrever as curvas de crescimento do frango Ri vietnamita

Ri chicken is the most popular backyard chicken breed in Vietnam, but little is known about the growth curve of this breed. This study compared the performances of models with three parameters (Gompertz, Brody, and Logistic) and models containing four parameters (Richards, Bridges, and Janoschek) for describing the growth of Ri chicken. The bodyweight of Ri chicken was recorded weekly from week 1 to week 19. Growth models were fitted using minpack.lm package in R software and Akaikes information criterion (AIC), Bayesian information criterion (BIC), and root mean square error (RMSE) were used for model comparison. Based on these criteria, the models having four parameters showed better performance than the ones with three parameters, and the Richards model was the best one for males and females. The lowest and highest value of asymmetric weights (α) were obtained by Bridges and Brody models for each of sexes, respectively. Age and weight estimated by the Richard model were 8.46 and 7.51 weeks and 696.88 and 487.58 g for males and for females, respectively. Differences in the growth curves were observed between males and female chicken. Overall, the results suggested using the Richards model for describing the growth curve of Ri chickens. Further studies on the genetics and genomics of the obtained growth parameters are required before using them for the genetic improvement of Ri chickens.(AU)

O frango Ri é a raça de frango de quintal mais popular do Vietnã, mas pouco se sabe sobre a curva de crescimento dessa raça. Este estudo comparou o desempenho de modelos com três parâmetros (Gompertz, Brody e Logistic) e modelos contendo quatro parâmetros (Richards, Bridges e Janoschek) para descrever o crescimento do frango Ri. O peso corporal do frango Ri foi registrado semanalmente da semana 1 à semana 19. Os modelos de crescimento foram ajustados usando o pacote minpack.lm no software R e o critério de informação de Akaike (AIC); critério de informação bayesiano (BIC) e erro quadrático médio (RMSE) foram usados para comparação de modelos. Com base nesses critérios, os modelos com quatro parâmetros apresentaram melhor desempenho do que os com três parâmetros, sendo o modelo de Richards o melhor para homens e mulheres. O menor e o maior valor dos pesos assimétricos (α) foram obtidos pelos modelos Bridges e Brody para cada um dos sexos, respectivamente. A idade e o peso estimados pelo modelo de Richard foram de 8,46 e 7,51 semanas e 696,88 e 487,58 g para homens e mulheres, respectivamente. Diferenças nas curvas de crescimento foram observadas entre frangos machos e fêmeas. No geral, os resultados sugeriram o uso do modelo de Richards para descrever a curva de crescimento de frangos Ri. Mais estudos sobre a genética e genômica dos parâmetros de crescimento obtidos são necessários antes de usá-los para o melhoramento genético de frangos Ri.(AU)

Nonlinear models in the height description of the Rhino sunflower cultivar / Modelos não lineares na descrição de altura da cultivar de girassol Rhino

Sunflower produces achenes and oil of good quality, besides serving for production of silage, forage and biodiesel. Growth modeling allows knowing the growth pattern of the crop and optimizing the management. The research characterized the growth of the Rhino sunflower cultivar using the Logistic and Gompertz models and to make considerations regarding management based on critical points. The data used come from three uniformity trials with the Rhino confectionery sunflower cultivar carried out in the experimental area of the Federal University of Santa Maria - Campus Frederico Westphalen in the 2019/2020 agricultural harvest. In the first, second and third trials 14, 12 and 10 weekly height evaluations were performed on 10 plants, respectively. The data were adjusted for the thermal time accumulated. The parameters were estimated by ordinary least square's method using the Gauss-Newton algorithm. The fitting quality of the models to the data was measured by the adjusted coefficient of determination, Akaike information criterion, Bayesian information criterion, and through intrinsic and parametric nonlinearity. The inflection points (IP), maximum acceleration (MAP), maximum deceleration (MDP) and asymptotic deceleration (ADP) were determined. Statistical analyses were performed with Microsoft Office Excel® and R software. The models satisfactorily described the height growth curve of sunflower, providing parameters with practical interpretations. The Logistics model has the best fitting quality, being the most suitable for characterizing the growth curve. The estimated critical points provide important information for crop management. Weeds must be controlled until the MAP. Covered fertilizer applications must be carried out between the MAP and IP range. ADP is an indicator of maturity, after reaching this point, the plants can be harvested for the production of silage without loss of volume and quality.

O girassol produz aquênios e óleo de qualidade, além de servir para produção de silagem, forragem e biodiesel. A modelagem de crescimento permite conhecer o padrão de crescimento da cultura e otimizar o manejo. O objetivo deste trabalho foi caracterizar o crescimento da cultivar de girassol Rhino por meio dos modelos Logístico e Gompertz e fazer considerações a respeito do manejo com base em pontos críticos. Os dados utilizados são oriundos de três ensaios de uniformidade com a cultivar de girassol confeiteiro Rhino, conduzidos na área experimental da Universidade Federal de Santa Maria, Campus Frederico Westphalen, na safra 2019/2020. Foram realizadas 14, 12 e 10 avaliações semanais de altura em 10 plantas, respectivamente, no primeiro, segundo e terceiro ensaio. Os dados foram ajustados em função da soma térmica acumulada. Os parâmetros foram estimados por meio do método dos mínimos quadrados ordinários, usando o algoritmo de Gauss-Newton. A qualidade de ajuste dos modelos aos dados foi medida pelo coeficiente de determinação ajustado, critério de determinação de Akaike, critério bayesiano de informação, e por meio da não linearidade intrínseca e paramétrica. Foram determinados os pontos de inflexão (IP), máxima aceleração (MAP), máxima desaceleração (MDP) e desaceleração assintótica (ADP). As análises estatísticas foram realizadas com Microsoft Office Excel® e o software R. Os modelos descreveram de forma satisfatória a curva de crescimento da altura do girassol, fornecendo parâmetros com interpretações práticas. O modelo Logístico apresenta melhor qualidade de ajuste, sendo o mais adequado para caracterização da curva de crescimento. Os pontos críticos estimados fornecem informações importantes para o manejo da cultura. As plantas daninhas devem ser controladas até o MAP. As aplicações de fertilizantes em cobertura devem ser realizadas entre MAP e IP. O ADP é um indicador de maturidade, após atingir este ponto, as plantas podem ser colhidas para a produção de silagem sem perda de volume e qualidade.

Comparative growth and performance of two generations of tilapia (Oreochromis niloticus)

The growth of generations of the Genomar Supreme Tilapia (GST) strain, specifically G20 and G25, was evaluated. Tilapias 8 g were reared in a recirculating aquaculture system with 0.25 m³ tanks, 80 fish m-³, with four replicates. During growth, eight fish from each tank were weighed and measured at day 1, 30, 60, 90, 120, 150, 180 and 210. Survival, weight gain, feed conversion and batch homogeneity were determined. Weight-age data were fit to Gompertz model. In addition, absolute and relative growth rates and weight and age at inflection were determined. Final weight showed 26.7% higher in G25 when compared to G20 (920.05 and 725.87 g, respectively). The feed conversion and homogeneity indexes were better in G25 than G20. The estimate of asymptotic weight was higher in G25 (1202.0 g) when compared to G20 (912.7 g). G20 presented smaller weight (335.76 g), age (108.87 days) and absolute growth rate (4.87 g day-1) when compared with G25 (442.19 g, 113.77 days and 6.41 g day-1). Carcass characteristics were similar, but G25 presented about 25% higher fillet weight than G20. After five years in the GST breeding program, results indicated that a sustained improvement of harvest weight was achieved, as well as 6 to 10% gain in performance by generation.(AU)

Evaluation of mathematical models to describe lamb growth during the pre-weaning phase / Avaliação de modelos matemáticos para descrever o crescimento de cordeiros durante a fase de cria

The aim of this study was to evaluate the use of different mathematical models to describe the growth of lambs during the pre-weaning phase and the effect of sex on their growth curve. Data from 51 lambs (26 males and 25 females) with a genetic constitution of at least 50% Santa Inês breed were used. Lamb weight was monitored during the entire pre-weaning phase (91 days) by weighing the animals weekly on a scale suitable for sheep, to draw the body-weight growth curve. The adequacy of the models was evaluated by the coefficient of determination, simultaneous F-test for parameter identity, concordance correlation coefficient, root mean square error of prediction and decomposition of the mean square error of prediction. Pairwise mean square error of prediction analysis and delta Akaike information criterion were used to compare the models in terms of accuracy and precision. The evaluation of the adequacy of the tested models showed that the data predicted by the linear, quadratic and exponential models were similar (P > 0.05) to the observed data. In contrast, the monomolecular model generated predictions that could not be accepted as true. The linear and quadratic models showed better accuracy and precision. The first-degree linear model should be preferred over the other studied models to describe growth of sheep in the pre weaning phase. Males and females exhibited distinct growth patterns.

Os objetivos foram avaliar o uso de diferentes modelos matemáticos para descrever o crescimento de cordeiros durante a fase de cria e também avaliar o efeito do gênero sobre o curva de crescimento destes cordeiros. Foram utilizados dados de 51 cordeiros, 26 machos e 25 fêmeas, com composição genética de pelo menos 50% da raça Santa Inês. O peso dos animais foi acompanhado durante toda fase de cria (91 dias) por meio de pesagens semanais em balança própria para ovinos para desenhar a curva de crescimento do peso corporal. A avaliação da adequação dos modelos foi realizada por meio do coeficiente de determinação, teste F simultâneo para identidade dos parâmetros, coeficiente de correlação de concordância, raiz quadrada do quadrado médio do erro da predição e a decomposição do quadrado médio do erro da predição. A análise do quadrático médio da predição pareada e o critério de informação delta de Akaike foram utilizados para comparar os modelos quanto à acurácia e precisão. A avaliação da adequação dos modelos testados mostrou que os dados preditos pelos modelos linear, quadrático e exponencial são semelhantes (P>0,05) aos dados observados. Já o modelo monomolecular gerou predições que não puderam ser aceitas como verdadeiras. Os modelos linear e quadrático apresentaram melhor acurácia e precisão. O modelo linear de primeiro grau deve ser preferido aos demais modelos estudados para descrever crescimento de ovinos na fase de cria. Machos e fêmeas apresentaram padrão de crescimento distinto.

Evaluation of mathematical models to describe lamb growth during the pre-weaning phase / Avaliação de modelos matemáticos para descrever o crescimento de cordeiros durante a fase de cria

The aim of this study was to evaluate the use of different mathematical models to describe the growth of lambs during the pre-weaning phase and the effect of sex on their growth curve. Data from 51 lambs (26 males and 25 females) with a genetic constitution of at least 50% Santa Inês breed were used. Lamb weight was monitored during the entire pre-weaning phase (91 days) by weighing the animals weekly on a scale suitable for sheep, to draw the body-weight growth curve. The adequacy of the models was evaluated by the coefficient of determination, simultaneous F-test for parameter identity, concordance correlation coefficient, root mean square error of prediction and decomposition of the mean square error of prediction. Pairwise mean square error of prediction analysis and delta Akaike information criterion were used to compare the models in terms of accuracy and precision. The evaluation of the adequacy of the tested models showed that the data predicted by the linear, quadratic and exponential models were similar (P > 0.05) to the observed data. In contrast, the monomolecular model generated predictions that could not be accepted as true. The linear and quadratic models showed better accuracy and precision. The first-degree linear model should be preferred over the other studied models to describe growth of sheep in the pre weaning phase. Males and females exhibited distinct growth patterns.(AU)

Os objetivos foram avaliar o uso de diferentes modelos matemáticos para descrever o crescimento de cordeiros durante a fase de cria e também avaliar o efeito do gênero sobre o curva de crescimento destes cordeiros. Foram utilizados dados de 51 cordeiros, 26 machos e 25 fêmeas, com composição genética de pelo menos 50% da raça Santa Inês. O peso dos animais foi acompanhado durante toda fase de cria (91 dias) por meio de pesagens semanais em balança própria para ovinos para desenhar a curva de crescimento do peso corporal. A avaliação da adequação dos modelos foi realizada por meio do coeficiente de determinação, teste F simultâneo para identidade dos parâmetros, coeficiente de correlação de concordância, raiz quadrada do quadrado médio do erro da predição e a decomposição do quadrado médio do erro da predição. A análise do quadrático médio da predição pareada e o critério de informação delta de Akaike foram utilizados para comparar os modelos quanto à acurácia e precisão. A avaliação da adequação dos modelos testados mostrou que os dados preditos pelos modelos linear, quadrático e exponencial são semelhantes (P>0,05) aos dados observados. Já o modelo monomolecular gerou predições que não puderam ser aceitas como verdadeiras. Os modelos linear e quadrático apresentaram melhor acurácia e precisão. O modelo linear de primeiro grau deve ser preferido aos demais modelos estudados para descrever crescimento de ovinos na fase de cria. Machos e fêmeas apresentaram padrão de crescimento distinto.(AU)

Growth parameters of the invasive gastropod Melanoides tuberculata (Müller, 1774) (Gastropoda, Thiaridae) in a semiarid region, Northeastern Brazil

Melanoides tuberculata has invaded several aquatic ecosystems in the Neotropical region. This species shows high adaptive capacity and plasticity, establishing itself in several basins, promoting negative impacts on environments and native species. Here, we determine the growth parameters and the population structure of this species, in a semi-arid environment, in Northeast Brazil (Pernambuco state). Monthly captures were conducted at three types of substrate: site 1: soft bottom with macrophytes, site 2: soft bottom without macrophytes, and site 3: gravel and rocks. Shells were classified as occupied or empty, and their shell length (SL) and opening width (SW) were measured. The growth parameters of the von Bertalanffy’s model were estimated from the size-length frequency distribution using the ELEFAN I. Also, the maturity was verified, through the size at onset of maturity (SOM - 14.85 mm SL) proposed in the literature. A total of 1,013 individuals were collected, with shells varying from 7 to 39 mm SL and mean density of 84.42 (± 3.86) individuals m-2. The substrate with the largest number of mollusks was the site 1. Largest amount of empty shells was detected at site 3. Growth of M. tuberculata indicates rapid increment, with k = 0.56, L∞ = 42 mm and t0 = -0.26 years. The mean estimated age for the species was 0.95 years. According to the SOM, 86% of individuals sampled were considered mature.

Growth parameters of the invasive gastropod Melanoides tuberculata (Müller, 1774) (Gastropoda, Thiaridae) in a semiarid region, Northeastern Brazil

Melanoides tuberculata has invaded several aquatic ecosystems in the Neotropical region. This species shows high adaptive capacity and plasticity, establishing itself in several basins, promoting negative impacts on environments and native species. Here, we determine the growth parameters and the population structure of this species, in a semi-arid environment, in Northeast Brazil (Pernambuco state). Monthly captures were conducted at three types of substrate: site 1: soft bottom with macrophytes, site 2: soft bottom without macrophytes, and site 3: gravel and rocks. Shells were classified as occupied or empty, and their shell length (SL) and opening width (SW) were measured. The growth parameters of the von Bertalanffys model were estimated from the size-length frequency distribution using the ELEFAN I. Also, the maturity was verified, through the size at onset of maturity (SOM - 14.85 mm SL) proposed in the literature. A total of 1,013 individuals were collected, with shells varying from 7 to 39 mm SL and mean density of 84.42 (± 3.86) individuals m-2. The substrate with the largest number of mollusks was the site 1. Largest amount of empty shells was detected at site 3. Growth of M. tuberculata indicates rapid increment, with k = 0.56, L∞ = 42 mm and t0 = -0.26 years. The mean estimated age for the species was 0.95 years. According to the SOM, 86% of individuals sampled were considered mature.(AU)

Method to generate growth and degrowth models obtained from differential equations applied to agrarian sciences / Método gerador de modelos de crescimento e decrescimento obtidos a partir de equações diferenciais aplicado as ciências agrárias

This study aims to propose a method to generate growth and degrowth models using differential equations as well as to present a model based on the method proposed, compare it with the classic linear mathematical models Logistic, Von Bertalanffy, Brody, Gompertz, and Richards, and identify the one that best represents the mean growth curve. To that end, data on Undefined Breed (UB) goats and Santa Inês sheep from the works of Cavalcante et al. (2013) and Sarmento et al. (2006a), respectively, were used. Goodness-of-fit was measured using residual mean squares (RMS), Akaike information criterion (AIC), Bayesian information criterion (BIC), mean absolute deviation (MAD), and adjusted coefficient of determination . The models parameters (?, weight at adulthood; ?, an integration constant; ?, shape parameter with no biological interpretation; k, maturation rate; and m, inflection point) were estimated by the least squares method using Levenberg-Marquardt algorithm on the software IBM SPSS Statistics 1.0. It was observed that the proposed model was superior to the others to study the growth curves of goats and sheep according to the methodology and conditions under which the present study was carried out.(AU)

O objetivo deste trabalho é propor um método gerador de modelos de crescimento e decrescimento por meio de equações diferenciais, bem como apresentar um modelo a partir do método proposto, compará-lo entre os modelos matemáticos não lineares clássicos seguintes, Logístico, Von Bertalanffy, Brody, Gompertz, e Richards e identificar aquele que representa melhor a curva média de crescimento. Para isso, foram utilizados dados de caprino (SRD - Sem Raça Definida) e de ovinos da raça Santa Inês oriundos, respectivamente, dos trabalhos de Cavalcante et al. (2013) e Sarmento et al. (2006a). A qualidade de ajuste foi medida por meio do quadrado médio do resíduo (QMR), critério de informação de Akaike (AIC), critério de informação Bayesiano (BIC), desvio médio absoluto (DMA) e coeficiente de determinação ajustado . Os parâmetros dos modelos (?, peso à idade adulta; ?, uma constante de integração; ?, parâmetro de forma sem interpretação biológica; k, taxa de maturação; e m, ponto de inflexão) foram estimados pelo método de mínimos quadrados utilizando o algoritmo de Levenberg-Marquardt por meio do Software IBM SPSS Statistics 1.0. Observou-se que o modelo Proposto foi superior aos outros modelos para o estudo das curvas de crescimento de caprinos e ovinos de acordo com a metodologia e condições em que foi desenvolvido o presente estudo.(AU)

Weight and morphometric growth of Pacu (Piaractus mesopotamicus), Tambaqui (Colossoma macropumum) and their hybrids from spring to winter / Peso e crescimento morfométrico de pacu (Piaractus mesopotamicus), tambaqui (Colossoma macropumum) e seus híbridos da primavera ao inverno

This study aimed to evaluate weight and morphometric growth of the products of the complete diallel cross-breeding between pacu and tambaqui during the period from the end of spring to the beginning of winter. Was used 400 pacu, tambaqui, tambacu and paqui. 20 fish from each group were collected, weighed and submitted to morphometric evaluation every 28 days. The Logistic function adjusted better to describe the growth in body weight and the morphometric measures for age on all the genetic groups. The studied groups presented similar behavior of growth for body weight and morphometric measures. There were significant differences between the genetic groups regarding parameters A (asymptotic value) and B (integration constant) for body weight and for all the morphometric measures evaluated. For the parameter K (maturity rate), there were significant difference between groups for body weight, head length and body height. The groups possibly were affected the decrease of temperature. The Tambacu was superior to the Paqui in all the variables evaluated for the parameter A, and was also superior to the pure breed, except for head length and body width.(AU)

Este estudo teve como objetivo avaliar o peso e crescimento morfométrico dos produtos do cruzamento dialélico completo entre pacu e tambaqui. 20 peixes de cada grupo foram coletados, pesados e submetidos à análise morfométrica a cada 28 dias. O modelo que obteve o maior coeficiente de determinação e que melhor se ajuste ao método de Akaike foi verificado. A função logística foi ajustada para melhor descrever o crescimento do peso corporal e as medidas morfométricas para a idade em todos os grupos genéticos. Os quatro grupos estudados apresentaram comportamento semelhante para o peso corporal, bem como para as medidas morfométricas. Houve diferenças significativas entre os grupos genéticos sobre os parâmetros A (valor assintótico) e B (constante de integração) para o peso corporal e para todas as medidas morfométricas avaliadas. Para o parâmetro K (taxa de maturação), houve diferença significativa entre os grupos para o peso corporal, comprimento da cabeça e altura do corpo. Os grupos possivelmente foram afetados pela diminuição da temperatura. O tambacu foi superior ao Paqui em todas as variáveis avaliadas para o parâmetro A, e também foi superior para a raça pura, exceto para o comprimento e largura do corpo de cabeça.(AU)

Weight and morphometric growth of Pacu (Piaractus mesopotamicus), Tambaqui (Colossoma macropumum) and their hybrids from spring to winter / Peso e crescimento morfométrico de pacu (Piaractus mesopotamicus), tambaqui (Colossoma macropumum) e seus híbridos da primavera ao inverno

This study aimed to evaluate weight and morphometric growth of the products of the complete diallel cross-breeding between pacu and tambaqui during the period from the end of spring to the beginning of winter. Was used 400 pacu, tambaqui, tambacu and paqui. 20 fish from each group were collected, weighed and submitted to morphometric evaluation every 28 days. The Logistic function adjusted better to describe the growth in body weight and the morphometric measures for age on all the genetic groups. The studied groups presented similar behavior of growth for body weight and morphometric measures. There were significant differences between the genetic groups regarding parameters A (asymptotic value) and B (integration constant) for body weight and for all the morphometric measures evaluated. For the parameter K (maturity rate), there were significant difference between groups for body weight, head length and body height. The groups possibly were affected the decrease of temperature. The Tambacu was superior to the Paqui in all the variables evaluated for the parameter A, and was also superior to the pure breed, except for head length and body width.(AU)

Este estudo teve como objetivo avaliar o peso e crescimento morfométrico dos produtos do cruzamento dialélico completo entre pacu e tambaqui. 20 peixes de cada grupo foram coletados, pesados e submetidos à análise morfométrica a cada 28 dias. O modelo que obteve o maior coeficiente de determinação e que melhor se ajuste ao método de Akaike foi verificado. A função logística foi ajustada para melhor descrever o crescimento do peso corporal e as medidas morfométricas para a idade em todos os grupos genéticos. Os quatro grupos estudados apresentaram comportamento semelhante para o peso corporal, bem como para as medidas morfométricas. Houve diferenças significativas entre os grupos genéticos sobre os parâmetros A (valor assintótico) e B (constante de integração) para o peso corporal e para todas as medidas morfométricas avaliadas. Para o parâmetro K (taxa de maturação), houve diferença significativa entre os grupos para o peso corporal, comprimento da cabeça e altura do corpo. Os grupos possivelmente foram afetados pela diminuição da temperatura. O tambacu foi superior ao Paqui em todas as variáveis avaliadas para o parâmetro A, e também foi superior para a raça pura, exceto para o comprimento e largura do corpo de cabeça.(AU)

Growth Curve of Crioulo Foals from Birth until 24 Months of Age

Background: Breeding of Crioulo horses in the southern region of Brazil is very significant. Notwithstanding, not all animals meet the standards defined for the breed, raising concern among breeders, owners and veterinarians, driving them to an effort to know and understand the development of Crioulo foals. In order to get a registry at Brazilian Association of Crioulo Horse Breeders (ABCCC), the foals must be presented to a certified technician as of 24 months of age and show the breed standards and measurements required. To date, there are no data concerning development of this breed available. Therefore, this study aims to describe the growth curve of Crioulo foals in the south region of Rio Grande do Sul.Materials, Methods & Results: The study was conducted in three Crioulo horse breeding farms in the cities of Santa Vitória do Palmar, Bagé and Aceguá, in the state of Rio Grande do Sul, Brazil, for a period of two years (2013-2015). We followed up on 267 Crioulo foals from birth up to 24 months of age. Biometric evaluation was divided in 26 periods, with 40 animals in each and random repetition of individuals. Period one: birth to seven days; period two: seven to 21 days; monthly from 1st to 24th month. The three breeding farms presented similar environmental conditions and the horses were submitted to similar management. Measurements were taken on a monthly basis, usin

Growth Patterns of Two Chinese Native Goose Breeds

To study the development rules of Chinese native geese, two breeds, Shitou and Sichuan White geese were analyzed from 0 to 12 weeks of age. The growth curves were fitted with commonly used four kinds of nonlinear models (Logistic, Gompertz, Von Bertalanffy and Richards). The results showed that the growth curves were appropriately fitted with all four models but the Logistic and Richards both had the best fitting with growth curve (R2>0.99). Analyzing the fitting parameters of the Logistic and Richards, we found that male Shitou had the highest adult body weight while Sichuan White female had the lowest weight. In Shitou breed, Shape parameter Predicted with Richards model was corresponded with Gompertz curve, while in Sichuan breed it was in between Gompertz and Bertalanffy. Growth parameters predicted with Logistic model was much more closed to observed value as compared others. So overall logistic was the best model to analyze the growth curve in Chinese native goose and Shitou goose had excellent growth performance when compared to Sichuan White.(AU)

Growth Patterns of Two Chinese Native Goose Breeds

To study the development rules of Chinese native geese, two breeds, Shitou and Sichuan White geese were analyzed from 0 to 12 weeks of age. The growth curves were fitted with commonly used four kinds of nonlinear models (Logistic, Gompertz, Von Bertalanffy and Richards). The results showed that the growth curves were appropriately fitted with all four models but the Logistic and Richards both had the best fitting with growth curve (R2>0.99). Analyzing the fitting parameters of the Logistic and Richards, we found that male Shitou had the highest adult body weight while Sichuan White female had the lowest weight. In Shitou breed, Shape parameter Predicted with Richards model was corresponded with Gompertz curve, while in Sichuan breed it was in between Gompertz and Bertalanffy. Growth parameters predicted with Logistic model was much more closed to observed value as compared others. So overall logistic was the best model to analyze the growth curve in Chinese native goose and Shitou goose had excellent growth performance when compared to Sichuan White.

Curva de crescimento em potros da raça Crioula do nascimento aos 24 meses de idade / Growth curve of Crioulo foals from birth until 24 months of age

Background: Breeding of Crioulo horses in the southern region of Brazil is very significant. Notwithstanding, not all animals meet the standards defined for the breed, raising concern among breeders, owners and veterinarians, driving them to an effort to know and understand the development of Crioulo foals. In order to get a registry at Brazilian Association of Crioulo Horse Breeders (ABCCC), the foals must be presented to a certified technician as of 24 months of age and show the breed standards and measurements required. To date, there are no data concerning development of this breed available. Therefore, this study aims to describe the growth curve of Crioulo foals in the south region of Rio Grande do Sul.Materials, Methods & Results: The study was conducted in three Crioulo horse breeding farms in the cities of Santa Vitória do Palmar, Bagé and Aceguá, in the state of Rio Grande do Sul, Brazil, for a period of two years (2013-2015). We followed up on 267 Crioulo foals from birth up to 24 months of age. Biometric evaluation was divided in 26 periods, with 40 animals in each and random repetition of individuals. Period one: birth to seven days; period two: seven to 21 days; monthly from 1st to 24th month. The three breeding farms presented similar environmental conditions and the horses were submitted to similar management. Measurements were taken on a monthly basis, using a mechanical scale for weight and a hippometer for height. The analysis were conducted on SAS/ETS® version 9.2. Logistic non-linear regression model was used to obtain growth curves for height and minimum, medium and maximum weight of the foals on their respective ages, by this way six growth curves were produced. Results show an increase in weight and height at 24 months of age compared to the moment of birth. This increase was accentuated during the first months of life, both in weight and height.[...]