Modelos matemáticos aplicados para análise da curva de crescimento e eficiência energética na produção de frangos de corte
Carregando...
Data
2021-04-20
Autores
Carvalho, Patrícia Martiniano de Oliveira
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
A avicultura é uma atividade que apresenta um alto consumo energético, o que gera externalidades negativas. Diante do crescimento populacional e a necessidade crescente de aumentar a produção, sem que isso implique em prejuízos ambientais, medidas que garantam a obtenção de melhores índices de eficiência energética são primordiais, como a mensuração da relação output/input, ferramenta econômica útil que avalia o sistema produtivo a longo prazo. O objetivo deste estudo foi aplicar o Programa Prático de Modelagem de Forças (PPFM), o qual trabalha com a força ontogênica do crescimento e avaliação da eficiência energética através da energia cinética, cuja soma culmina no princípio da ação, na análise das curvas de crescimento de frangos de corte e também na avaliação da energia retida na carcaça em função da idade, através do modelo de Richards, no contexto da análise da eficiência energética para o sistema produtivo de carcaças evisceradas, como também expressar, em modelo matemático, a eficiência no uso de energia relacionando os inputs e outputs envolvidos na produção de frangos de corte. Foram utilizados dados dos padrões de crescimento de 384 frangos de corte (128 aves/linhgem), de ambos os sexos, segundo as linhagens Cobb 500, Hubbard Flex e Ross 380 para a modelagem das curvas de crescimento, e para estimar a eficiência energética foram empregados dados dos padrões de crescimento de 560 frangos de corte machos, da linhagem Cobb 500, de 1 a 56 dias de idade, alimentados com rações de diferentes níveis de energia metabolizável (EM) (2850, 3000, 3150 e 3300 kcal kg-1 de ração). Pintainhos e ração foram considerados como inputs, e a carcaça eviscerada como output. Para avaliar a energia depositada na carcaça (ERcarc) calculou-se a energia retida como gordura (ERgord) e na forma de proteína (ERprot). A determinação dos inputs obteve-se mediante o conhecimento das energias retidas no pintainho (ERpint) e no alimento (ERalim). A eficiência no uso de energia (EUE), produtividade energética (PEn) e energia líquida (EL) foram calculados. Os dados foram submetidos à análise de variância e ajustaram-se as regressões polinomiais significativas. A análise de superfície de resposta foi empregada para verificar e quantificar os efeitos sinérgicos e antagônicos. Através da análise energética do sistema produtivo, os índices EUE, PEn, EL encontrados foram 30%, 0,024 kg MJ-1 e -72,53 MJ, respectivamente. Os resultados revelaram que a produção de frangos de corte avaliada possui baixa eficiência energética. Portanto, medidas são necessárias para melhorar os índices energéticos, como utilizar menos energia input através de dietas que atendam precisamente às necessidades energéticas das aves, já que a ração é o insumo que mais demanda energia, e/ou melhorar o rendimento de carne, através da utilização de outras partes da ave, como pescoço, pés e cabeça.
Aviculture is an activity that presents a high consumption of energy, which generates negative externalities. Due to population growth and the growing need of increasing production, without this implicating in environmental harms, measures which ensure the achievement of better indexes of energy efficiency are paramount, as the measurement of the output/input ratio, a useful economic tool that assesses, in the long term, the productive system. This study has aimed to apply the Practical Program for Forces Modeling (PPFM), which works with the ontogenetic growth force and energy efficiency assessment through kinetic energy, whose sum culminates in the action principle, in the analysis of broiler chickens growth curves and also in the assessment of energy retained in the carcass in function of age, through the Richards model, in the context of energy efficiency analysis for the productive system of the eviscerated carcass, as well as expressing, in a mathematical model, energy use efficiency relating the inputs and outputs involved in broiler chicken production. Data from the growth patterns of 384 broiler chickens (128 poultry/strain), from both sexes, according to the Cobb 500, Hubbard Flex, and Ross 380 strains were used to model the growth curves and, in order to estimate energy efficiency, data from the growth patterns of 560 male broiler chickens from the Cobb 500 strain, from 1 to 56 days of age, fed with feeds of different metabolizable energy (ME) levels (2850, 3000, 3150, and 3300 kcal kg-1 of feed) were employed. Chicks and feed were considered inputs, and the eviscerated carcass, outputs. For the assessment of the energy deposited in the carcass (ERcarc), the energy retained as fat (ERfat) and in the form of protein (ERprot) was calculated. The determination of the inputs was obtained through the knowledge of the energies retained in the chicken (ERchick) and in the feed (ERfeed). The energy use efficiency (EUE), energy productivity (EP), and net energy (NE) were calculated. Data was submitted to analysis of variance and significant polynomial regressions were adjusted. Response surface analysis was employed to verify and quantify the synergetic and antagonistic effects. EUE, Pen, and EL indexes of 30%, 0,024 kg MJ-1, and -72,53 MJ, respectively, were found through productive system energy analysis. The results revealed that the broiler chicken production assessed has low energy efficiency. Therefore, measures are needed to improve the energy indicators, as using less energy input through diets with precise energy requeriments, since the feed is the highest energy input, and/or improving meat yield, through the use of others parts of birds, such as neck, feet and head.
Aviculture is an activity that presents a high consumption of energy, which generates negative externalities. Due to population growth and the growing need of increasing production, without this implicating in environmental harms, measures which ensure the achievement of better indexes of energy efficiency are paramount, as the measurement of the output/input ratio, a useful economic tool that assesses, in the long term, the productive system. This study has aimed to apply the Practical Program for Forces Modeling (PPFM), which works with the ontogenetic growth force and energy efficiency assessment through kinetic energy, whose sum culminates in the action principle, in the analysis of broiler chickens growth curves and also in the assessment of energy retained in the carcass in function of age, through the Richards model, in the context of energy efficiency analysis for the productive system of the eviscerated carcass, as well as expressing, in a mathematical model, energy use efficiency relating the inputs and outputs involved in broiler chicken production. Data from the growth patterns of 384 broiler chickens (128 poultry/strain), from both sexes, according to the Cobb 500, Hubbard Flex, and Ross 380 strains were used to model the growth curves and, in order to estimate energy efficiency, data from the growth patterns of 560 male broiler chickens from the Cobb 500 strain, from 1 to 56 days of age, fed with feeds of different metabolizable energy (ME) levels (2850, 3000, 3150, and 3300 kcal kg-1 of feed) were employed. Chicks and feed were considered inputs, and the eviscerated carcass, outputs. For the assessment of the energy deposited in the carcass (ERcarc), the energy retained as fat (ERfat) and in the form of protein (ERprot) was calculated. The determination of the inputs was obtained through the knowledge of the energies retained in the chicken (ERchick) and in the feed (ERfeed). The energy use efficiency (EUE), energy productivity (EP), and net energy (NE) were calculated. Data was submitted to analysis of variance and significant polynomial regressions were adjusted. Response surface analysis was employed to verify and quantify the synergetic and antagonistic effects. EUE, Pen, and EL indexes of 30%, 0,024 kg MJ-1, and -72,53 MJ, respectively, were found through productive system energy analysis. The results revealed that the broiler chicken production assessed has low energy efficiency. Therefore, measures are needed to improve the energy indicators, as using less energy input through diets with precise energy requeriments, since the feed is the highest energy input, and/or improving meat yield, through the use of others parts of birds, such as neck, feet and head.
Descrição
Palavras-chave
Avaliação energética, Energia cinética, Força ontogênica do crescimento, Programa prático de modelagem de forças, Relação input-output, Energy analysis, Kinetic energy, Input-output ratio, Ontogenetic growth force, Practical program for forces modeling