Utilização de extrato de Aspergillus oryzae contendo alfa - amilase em dietas de confinamento para bovinos nelore
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Data
2018-02-23
Autores
Nascimento, Cleisy Ferreira do
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Universidade Estadual Paulista (Unesp)
Resumo
Em dietas com teores elevados teores de amido, fornecidas a ruminantes podem apresentar subaproveitamento em relação ao tempo de permanência da digesta no rúmen, assim, considerando que a digestão é mediada por enzimas presentes na composição dos microorganismos ruminais, a adição de isoenzimas exógenas pode potencializar o aproveitamento da dieta. Desta forma, o objetivo do trabalhofoi avaliar os efeitos da adição de extrato de Aspergillus oryzae contendo alfa - amilase em dietas com elevada inclusão de concentrado no metabolismo e desempenho de bovinos Nelore. O experimento foi conduzido no confinamento individual da estação experimental APTA - Colina / SP / Brasil. Foram utilizados dois delineamentos distintos para avaliar o metabolismo (Exp. 1), e o desempenho (Exp. 2). No Exp. 1 (Metabolismo) foram utilizados dez bovinos Nelore, (5 animais por tratamento), canulados no rúmen, com peso corporal inicial (PCI) 400 ± 25 kg e idade média 24 meses, em um delineamento em esquema crossover e distribuídos em dois tratamentos: Controle (ausência de alfa-amilase) e adição de Amilase (5g/animal/dia de extrato de Aspergillus oryzae alfa-amilase – Amaize®, Alltech, Inc). A dieta foi isoprotéica fornecida ad libitum foi formulada para conter 2,96 Mcal/kg de Energia Metabolizáve (EM)l. A fermentação ruminal foi mensurada a partir de amostras de flúido ruminal coletadas ao final de cada período de 25 dias do total de 125 dias de período experimental. Enquanto que as amostras de sangue foram coletadas no início e final deste mesmo período. A digestibilidade e balanço de compostos nitrogenados foram mensurados concomitantemente, por meio de coleta total de fezes e urina, respectivamente (3 dias consecutivos). No Exp. 2 (desempenho) foram utilizados quarenta e dois bovinos Nelore, não castrados, com PCI de 353 ± 13 kg e idade média de 24 meses, alocados em baias individuais, em um delineamento experimental em blocos casualizados (PCI foi considerado o critério de blocagem). Os tratamentos e a dieta foram os mesmos descritos para o metabolismo, com 21 animais por tratamento. Os dados foram analisados utilizando o procedimento MIXED do SAS, as diferenças entre as médias foram comparadas pelo teste t com 5% de probabilidade e tendências discutidas entre 5 e 10% de probabilidade. A concentração de propionato foi 8,72% maior para animais recebendo Amilase (P = 0,027), apresentando tendências de diminuição na concentração de acetato e consequentemente na relação acetato:propionato (P = 0,088). A concentração de insulina plasmática nos animais que receberam Amilase tendeu a ser menor (P = 0,062). A digestibilidade da PB tendeu a ser maior (P = 0,064), assim como para a digestibilidade da FDN em animais que receberam Amilase (P = 0,066). O balanço de compostos nitrogenados não sofreu efeito do uso da Amilase (P = 0,904). Entre as características de desempenho, o PC final, peso de carcaça quente (PCQ) e os ganhos tanto em PC quanto em peso de carcaça tenderam a ser maior para animais que receberam Amilase (P = 0,092), o que corresponderia a quase 9 kg a mais de peso de carcaça em comparação com animais do grupo controle. Para as características de qualidade da carne, houve diferenças para a cor L * (luminosidade) (P = 0,041) e tendências para a cor b * (amarelada) (P = 0,074). A cor L * (37,80 vs. 40,01) e b * (13,98 vs. 15,33) apresentaram valores mais baixos em animais que receberam Amilase, comparados com o controle, respectivamente. O teor de ácidos graxos hipocolesterolêmicos foi maior para animais alimentados com Amilase (P = 0,049), correspondendo a 5,92% superior em comparação ao grupo controle. O uso de extrato de Aspergillus oryzae contendo alfa - amilase aumenta a utilização da dieta por meio da melhor digestibilidade da PB e fibra, assim como pela maior concentração de propionato no rúmen que implicará em melhor desempenho tanto pelo ganho em peso, quanto pelas características de qualidade de carne.
In diets with high levels of starch supplied to ruminants, the strategy to improve reduce underutilization of the concentrate is to optimize the digestibility. The digestion is enzyme-mediated by the rumen microorganisms, the addition of exogenous isoenzymes can enhance the use of diet. The objective of this study was to evaluate the effects use of Aspergillus oryzae extract containing alpha-amylase in feedlot diets on metabolism and performance of Nellore cattle. The study was in feedlot at the APTA experimental facility - Colina / SP / Brazil. Two distinct designs were used to evaluate metabolism (Exp. 1) and performance (Exp. 2). Exp. 1: Ten Nellore bulls, rumen cannulated (initial body weight between 400 ± 25 kg and age of 24 months) were housed in individual pens. The experimental design was crossover, in which the animals were randomized between two treatments 1: Control - absence of amylase and 2: Amylase -Aspergillus oryzae extract containing alpha amylase activity (Amaize®, Alltech, Inc,), 5 g/animal daily. The diet was isoprotein provided ad libitum, formulated to contain 2,96 Mcal/kg ME. Ruminal fermentation was measured from rumen fluid samples collected at the end of a 25 day period, while blood samples were collected at the beginning and end of this period. The digestibility and nitrogen balance were measured concomitantly, through total collection of feces and urine, respectively (3 consecutive days). Exp. 2 (performance): Forty-two bulls Nellore (initial body weight of 353 ± 13 kg and 24 months) were used in individual pens. The experimental design was a randomized blocks (blocked by initial BW) with the same treatments and diet as on metabolism design. The data were analyzed using the MIXED procedure of SAS. The differences between means were compared by the t-test with 5% probability and trends were discussed between 5 and 10% probability. The concentration of propionate was 8.72% greater for animals receiving Amylase (P = 0.027), showing decreasing trends in acetate concentration and consequently acetate: propionate ratio (P = 0.088). Plasma insulin concentration in animals receiving Amylase tended to be lower (P = 0.062). The digestibility of CP tended to be higher (P = 0.064), as well as for the digestibility of NDF in animals receiving Amylase (P = 0.066). The balance of nitrogen compounds was not affected using Amylase (P = 0.904). Among the performance characteristics, the final BW, hot carcass weight (HCW) and gains in BW and carcass weight tended to be greater for animals receiving Amylase (P = 0.092), which would correspond to almost 9 kg more carcass weight compared to control animals. For the meat quality characteristics, there were differences for the color L * (luminosity) (P = 0.041) and tendencies for the color b * (yellow) (P = 0.074). The color L * (37.80 vs 40.01) and b * (13.98 vs. 15.33) had lower values in animals receiving Amylase, compared to control, respectively. The content of hypocholesterolemic fatty acids was greater for Amilase (P = 0.049), corresponding to 5.92% higher in compared to the control group. The use of Aspergillus oryzae contanning alpha - amylase extract increases dietary utilization through better digestibility of CP and fiber, as well as greater concentration of propionate in the rumen which will imply in better performance both by gain in weight and by the characteristics of meat quality.
In diets with high levels of starch supplied to ruminants, the strategy to improve reduce underutilization of the concentrate is to optimize the digestibility. The digestion is enzyme-mediated by the rumen microorganisms, the addition of exogenous isoenzymes can enhance the use of diet. The objective of this study was to evaluate the effects use of Aspergillus oryzae extract containing alpha-amylase in feedlot diets on metabolism and performance of Nellore cattle. The study was in feedlot at the APTA experimental facility - Colina / SP / Brazil. Two distinct designs were used to evaluate metabolism (Exp. 1) and performance (Exp. 2). Exp. 1: Ten Nellore bulls, rumen cannulated (initial body weight between 400 ± 25 kg and age of 24 months) were housed in individual pens. The experimental design was crossover, in which the animals were randomized between two treatments 1: Control - absence of amylase and 2: Amylase -Aspergillus oryzae extract containing alpha amylase activity (Amaize®, Alltech, Inc,), 5 g/animal daily. The diet was isoprotein provided ad libitum, formulated to contain 2,96 Mcal/kg ME. Ruminal fermentation was measured from rumen fluid samples collected at the end of a 25 day period, while blood samples were collected at the beginning and end of this period. The digestibility and nitrogen balance were measured concomitantly, through total collection of feces and urine, respectively (3 consecutive days). Exp. 2 (performance): Forty-two bulls Nellore (initial body weight of 353 ± 13 kg and 24 months) were used in individual pens. The experimental design was a randomized blocks (blocked by initial BW) with the same treatments and diet as on metabolism design. The data were analyzed using the MIXED procedure of SAS. The differences between means were compared by the t-test with 5% probability and trends were discussed between 5 and 10% probability. The concentration of propionate was 8.72% greater for animals receiving Amylase (P = 0.027), showing decreasing trends in acetate concentration and consequently acetate: propionate ratio (P = 0.088). Plasma insulin concentration in animals receiving Amylase tended to be lower (P = 0.062). The digestibility of CP tended to be higher (P = 0.064), as well as for the digestibility of NDF in animals receiving Amylase (P = 0.066). The balance of nitrogen compounds was not affected using Amylase (P = 0.904). Among the performance characteristics, the final BW, hot carcass weight (HCW) and gains in BW and carcass weight tended to be greater for animals receiving Amylase (P = 0.092), which would correspond to almost 9 kg more carcass weight compared to control animals. For the meat quality characteristics, there were differences for the color L * (luminosity) (P = 0.041) and tendencies for the color b * (yellow) (P = 0.074). The color L * (37.80 vs 40.01) and b * (13.98 vs. 15.33) had lower values in animals receiving Amylase, compared to control, respectively. The content of hypocholesterolemic fatty acids was greater for Amilase (P = 0.049), corresponding to 5.92% higher in compared to the control group. The use of Aspergillus oryzae contanning alpha - amylase extract increases dietary utilization through better digestibility of CP and fiber, as well as greater concentration of propionate in the rumen which will imply in better performance both by gain in weight and by the characteristics of meat quality.
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Palavras-chave
Aditivos, Amido, Desempenho, Enzimas, Metabolismo, Additives, Enzyme, Metabolism, Performance, Starch