Intensificação do manejo do pasto e uso da suplementação nos parâmetros produtivos na recria e terminação de bovinos de corte
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Data
2016-12-15
Autores
Koscheck, Jefferson Fabiano Werner [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Objetivou-se avaliar a massa de forragem, estrutura do dossel, composição química, consumo e digestibilidade, desempenho, conteúdo do trato gastrointestinal e metano entérico de touros jovens Nelore recriados em pastos de Brachiaria brizantha cv. Marandu submetido a diferentes alturas de pastejo e níveis de suplementos durante o período de águas e transição águas seca sob lotação contínua com taxa de lotação variável, assim como, o efeito da recria sobre a terminação no confinamento ou no pasto. Os tratamentos no período das águas consistiram de altura baixa do pasto (15 cm) (AB) e suplementação a 0,3% do peso corporal (PC) (AB-0,3%), AB e suplementação a 0,6% do PC (AB-0,6%), altura moderada do pasto (25 cm) (AM) e suplementação a 0,1% do PC (AM-0,1%), AM e suplementação a 0,3% do PC (AM-0,3%), altura alta do pasto (35 cm) (AA) e suplementação mineral (AA-SM), AA e suplementação a 0,1% do PC (AA-0,1%). Na transição os tratamentos consistiram de AM e suplementação a 0,3% do PC (AM-0,3%), AM e suplementação a 0,6% do PC (AM-0,6%), AA e suplementação 0,1% (AA-0,1%), AA e suplementação a 0,3% do PC (AA-0,3%). Na fase de terminação os animais foram divididos em dois experimentos, no experimento 1, 24 animais foram terminados em sistema de pastejo, recebendo 2% do PC, enquanto os do experimento 2, 24 animais foram terminados em sistema de confinamento em baias individuais. A dieta de terminação no confinamento foi constituída por bagaço de cana-de-açúcar como volumoso (13% com base na MS) e concentrado (87% com base na MS). No período das águas foram utilizados 126 touros jovens da raça Nelore, sendo adotado o delineamento experimental inteiramente casualizado, com seis tratamentos e três repetições (piquetes) por tratamento (n = 18). Na transição foi utilizado 68 animais, sendo utilizado o delineamento experimental inteiramente casualizado, com quatro tratamentos e três repetições (piquetes) por tratamento (n = 12). Na terminação foi utilizado o delineamento inteiramente casualizado com quatro tratamentos e três repetições (lote de 2 animais cada) por tratamento (n = 12). Como todas as variáveis avaliadas apresentaram efeito antes do início do experimento, as mesmas foram testadas como covariáveis no final do experimento. No período das águas, a massa de forragem dos pastos de AA, assim como a massa de folha verde, colmo verde e material morto foram maiores (P<0,01) que os valores observados nos pastos de AB em todos os períodos experimentais (P<0,01). O consumo de matéria seca (CMS) de pasto dos animais nos pastos de AA foi maior que o consumo na AB (P<0,01), porém, o CMS total foi igual nas três alturas estudadas. O tratamento AB-0,6% proporcionou maior ganho em carcaça, quando comparado com AB-0,3%, AM-0,1% e AA-SM (P<0,01), e menor ganho diário em carcaça foi observado no tratamento AM-0,1% e AA-SM (P<0,01). No período de transição águas seca, os tratamentos AM-0,3% e AM-0,6% proporciona menor massa de forragem total, de folha verde e de colmo verde, maior taxa de lotação e menor CMS de pasto pelos animais. Animais no tratamento AM-0,6% do PC apresentam maior consumo de energia bruta e energia metabolizável, e maior ganho de PC e de carcaça por hectare. No presente estudo, apesar dos planos nutricionais terem proporcionado peso de carcaça diferente ao final da fase de recria, ao mensurar o peso de carcaça no final da fase de terminação não foram observadas diferenças estatísticas entre os sistemas avaliados.
It was aimed in this work to evaluate the forage mass, sward structure, chemical composition, intake and digestibility, performance, gastrointestinal tract content and enteric methane of young Nelore bulls reared in Brachiaria brizantha cv. Marandu submitted to different grazing heights and supplement levels during the rainy season and rainy-dry season transition under continuous stocking with variable stocking rate, as well as the effect of rearing on finishing in feedlot or pasture. The treatments in the rainy season consisted of low grass height (15 cm) (AB) and supplementation at 0.3% of body weight (PC) (AB-0.3%), AB and supplementation at 0.6% of PC (AB-0.6%), medium pasture height (AM) and 0.1% PC supplementation (AM-0.1%), AM and PC supplementation 0.3% (AM-0.3%), high grass height (35 cm) (AA) and mineral supplementation (AA-SM), AA and 0.1% PC supplementation (AA-0.1%). At the transition, treatments consisted of AM and 0.3% PC supplementation (AM-0.3%), AM and 0.6% PC supplementation (AM-0.6%), AA and 0.1 % PC supplementation (AA-0.1%), AA and 0.3% PC supplementation (AA-0.3%). In the finishing phase the animals were divided in two experiments, in the experiment 1, 24 animals were finished in grazing system, receiving 2% of the PC, while those of experiment 2, 24 animals were finished in feedlot in individual stalls. The feedlot finishing diet consisted of sugarcane bagasse as bulky (13% based on DM) and concentrated (87% based on DM). In the rainy season, 126 young Nellore bulls were used, with a completely randomized design with six treatments and three replicates (stalls) per treatment (n = 18). In the transition, 68 animals were used, and the experimental design was completely randomized, with four treatments and three replicates (stalls) per treatment (n = 12). At the finishing phase, a completely randomized design with four treatments and three replications (batch of 2 animals each) was used per treatment (n = 12). As all variables evaluated had an effect before the beginning of the experiment, they were tested as co-variables at the end of the experiment. In the rainy season, the forage grass mass of AA, as well as the mass of green leaf, green stem and dead material were higher (P <0.01) than the values observed in grass of AB in all experimental periods (P <0.01). The dry matter intake (CMS) of pasture of the animals in the pastures of AA was higher than the intake in the AB (P <0.01), however, the total CMS was equal in the three heights studied. The AB-0.6% treatment provided higher carcass gain, when compared to AB-0.3%, AM-0.1% and AA-SM (P <0.01), and lower daily gain in carcass was observed in the treatment AM-0.1% and AA-SM (P <0.01). In the rainy-dry transition season, the AM-0.3% and AM-0.6% treatments provided lower total forage mass, green leaf and green stem, higher stocking rate and lower CMS of pasture by animals. The animals in the treatment AM-0.6% of the PC present higher crude energy intake and metabolizable energy, and higher PC and carcass gain per hectare. In the present study, although the nutritional plans provided different carcass weight at the end of the rearing phase, when measuring the carcass weight at the end of the finishing phase, no statistical differences were observed between the evaluated systems.
It was aimed in this work to evaluate the forage mass, sward structure, chemical composition, intake and digestibility, performance, gastrointestinal tract content and enteric methane of young Nelore bulls reared in Brachiaria brizantha cv. Marandu submitted to different grazing heights and supplement levels during the rainy season and rainy-dry season transition under continuous stocking with variable stocking rate, as well as the effect of rearing on finishing in feedlot or pasture. The treatments in the rainy season consisted of low grass height (15 cm) (AB) and supplementation at 0.3% of body weight (PC) (AB-0.3%), AB and supplementation at 0.6% of PC (AB-0.6%), medium pasture height (AM) and 0.1% PC supplementation (AM-0.1%), AM and PC supplementation 0.3% (AM-0.3%), high grass height (35 cm) (AA) and mineral supplementation (AA-SM), AA and 0.1% PC supplementation (AA-0.1%). At the transition, treatments consisted of AM and 0.3% PC supplementation (AM-0.3%), AM and 0.6% PC supplementation (AM-0.6%), AA and 0.1 % PC supplementation (AA-0.1%), AA and 0.3% PC supplementation (AA-0.3%). In the finishing phase the animals were divided in two experiments, in the experiment 1, 24 animals were finished in grazing system, receiving 2% of the PC, while those of experiment 2, 24 animals were finished in feedlot in individual stalls. The feedlot finishing diet consisted of sugarcane bagasse as bulky (13% based on DM) and concentrated (87% based on DM). In the rainy season, 126 young Nellore bulls were used, with a completely randomized design with six treatments and three replicates (stalls) per treatment (n = 18). In the transition, 68 animals were used, and the experimental design was completely randomized, with four treatments and three replicates (stalls) per treatment (n = 12). At the finishing phase, a completely randomized design with four treatments and three replications (batch of 2 animals each) was used per treatment (n = 12). As all variables evaluated had an effect before the beginning of the experiment, they were tested as co-variables at the end of the experiment. In the rainy season, the forage grass mass of AA, as well as the mass of green leaf, green stem and dead material were higher (P <0.01) than the values observed in grass of AB in all experimental periods (P <0.01). The dry matter intake (CMS) of pasture of the animals in the pastures of AA was higher than the intake in the AB (P <0.01), however, the total CMS was equal in the three heights studied. The AB-0.6% treatment provided higher carcass gain, when compared to AB-0.3%, AM-0.1% and AA-SM (P <0.01), and lower daily gain in carcass was observed in the treatment AM-0.1% and AA-SM (P <0.01). In the rainy-dry transition season, the AM-0.3% and AM-0.6% treatments provided lower total forage mass, green leaf and green stem, higher stocking rate and lower CMS of pasture by animals. The animals in the treatment AM-0.6% of the PC present higher crude energy intake and metabolizable energy, and higher PC and carcass gain per hectare. In the present study, although the nutritional plans provided different carcass weight at the end of the rearing phase, when measuring the carcass weight at the end of the finishing phase, no statistical differences were observed between the evaluated systems.
Descrição
Palavras-chave
Altura do pastejo, Carcaça, Comportamento ingestivo, Ganho de peso, Metano, Suplemento, Carcass, Grazing height, Ingestive behavior, Methane, Supplement, Weight gain