Adaptação a dietas de alta energia para bovinos Nelore submetidos previamente à restrição nutricional ou consumo de concentrados e efeitos nas características ruminais
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Data
2017-12-20
Autores
Pinto, Ana Carolina Janssen
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Universidade Estadual Paulista (Unesp)
Resumo
O objetivo deste estudo foi avaliar o efeito da restrição alimentar prévia ou exposição anterior a ingredientes concentrados sobre o tempo para adaptação à dietas de alto concentrado, sob os parâmetros da fermentação ruminal e o perfil de microrganismos ruminais de bovinos Nelore canulados confinados. Foram utilizados 6 bovinos da raça Nelore, castrados, com peso vivo inicial aproximado de 236 ± 23 kg, 15 meses de idade e canulados no rúmen, os quais foram divididos em dois quadrados latinos 3 x 3. Os tratamentos diferiram somente sobre o tipo de alimentação estabelecida previamente ao período de adaptação: Controle (forragem ad libitum + suplemento mineral); Restrição (forragem restrita a 1,4% do peso vivo + suplemento mineral) e Concentrado (forragem ad libitum + 0,5% do peso vivo de ingredientes concentrados e suplemento mineral). A duração deste estudo foi de 119 dias, sendo compostos por 3 períodos experimentais (33 dias cada período) e dois intervalos de washout (10 dias) entre os períodos 1 e 2, e 2 e 3. Os períodos foram divididos em: 14 dias de pré- adaptação, 6 dias de adaptação 1 (72% de concentrado), 6 dias de adaptação 2 (79% de concentrado) e 7 dias de dieta de terminação (86% de concentrado). O pH ruminal foi monitorado por meio da utilização de data loggers a cada 10 minutos. Foram avaliados a concentração de ácidos graxos de cadeia curta e amônia ruminal; a quantificação relativa das bactérias celulolíticas e utilizadoras de lactato por meio da técnica de PCR e a contabilidade total e diferencial de protozoários (0,4,8 e 12 horas após o trato). Os animais restritos, na fase de adaptação, tiveram maior concentração de AGCC (P< 0,01), maior duração de pH abaixo de 6,2 (P<0,01) e menor pH máximo nos dias 15 e 16 (P≤ 0,10) em relação ao tratamento controle. Na fase de terminação, esses animais tiveram menor CMS (P=0,02), maior pH médio e menor área de pH abaixo de 6,2 (P≤0,10) em relação ao tratamento controle. Os animais expostos previamente ao concentrado, na fase de adaptação, tiveram menor concentração de butirato e NH3 ruminal (P≤0,10) em relação ao tratamento controle. Apresentaram também menor quantidade relativa de Fibrobacter succinogenes (P=0,10) e maior CMS (P<0,01) em relação ao controle. Já na fase de terminação o CMS não teve diferença significativa em relação ao tratamento controle. Os animais que passaram por restrição alimentar ou por exposição de concentrado na fase de pré-adaptação apresentam características ruminais semelhantes durante a fase a terminação aos animais em forragem ad libitum.
The objective of this study was to evaluate the effect of diet restriction or prior exposure to concentrate ingredientes prior to the adaption period to high concentrate diet on parameters ruminal fermentation patterns and ruminal microorganisms profile of cannulated Nellore cattle. Six Nelore steers was used, with initial body weight about 350 kg, 20 months and cannulated in the rumen, which will be divided into two Latin squares 3 x 3. The treatments differed only with respect to the type of diets prior to the adaptation period: Control (forage ad libitum + mineral supplement); Restriction (forage restricted to 1.4% of body weight + mineral supplement) and concentrate (forage ad libitum + 0.5% of the body weight of concentrated ingredients + mineral supplement). The study was last 119 days, in which animals was submitted to three experimental periods (33 days each one) and two washout intervals (10 days) between the periods 1 and 2, 2 and 3; each period was divided as follows: 14 days of pre-adaptation, 6 days of adaptation 1 (72% concentrate), 6 days of adaptation 2 (79% concentrate) and 7 days of finishing diet (88% concentrate). The rumen pH and temperature was be monitored through the use of data loggers it was evaluated the rumen production of short chain fatty acids and ammonia concentration; the relative quantification of cellulolytic, amylolytic and lactate bacteria utilizing PCR and total and differential quantification of protozoa. Thus, the hypothesis is to test if Nelore cattle exposed to feed restriction or comsuption of concentrate ingredientes prior to the adaptation period present same rumen fermentation patters and microrganism profile when compared to animals of control treatment in the finish diet. Restricted animals, in the adaptation phase, had a higher concentration of SCFA (P<0.01), a higher duration of pH below 6.2 (P <0.01) and lower maximum pH on days 15 and 16 (P≤ 0.10) in relation to the control treatment. In the finish diet, these animals had lower DMI (P = 0.02), higher mean pH and lower pH area below 6.2 (P≤0.10) in relation to the control treatment. The animals previously exposed to the concentrate in the adaptation diet had a lower concentration of butyrate and ruminal NH3 (P≤0.10) in relation to the control treatment. They also presented lower amount of Fibrobacter succinogenes (P = 0.10) and higher DMI (P <0.01) in relation to the control. In the termination diet the DMI did not affect in relation to the control treatment. Cattle previously submitted to either nutricional restriction or intake of concentrate have similar ruminal characteristics during the finishing diet of the animals in control treatment.
The objective of this study was to evaluate the effect of diet restriction or prior exposure to concentrate ingredientes prior to the adaption period to high concentrate diet on parameters ruminal fermentation patterns and ruminal microorganisms profile of cannulated Nellore cattle. Six Nelore steers was used, with initial body weight about 350 kg, 20 months and cannulated in the rumen, which will be divided into two Latin squares 3 x 3. The treatments differed only with respect to the type of diets prior to the adaptation period: Control (forage ad libitum + mineral supplement); Restriction (forage restricted to 1.4% of body weight + mineral supplement) and concentrate (forage ad libitum + 0.5% of the body weight of concentrated ingredients + mineral supplement). The study was last 119 days, in which animals was submitted to three experimental periods (33 days each one) and two washout intervals (10 days) between the periods 1 and 2, 2 and 3; each period was divided as follows: 14 days of pre-adaptation, 6 days of adaptation 1 (72% concentrate), 6 days of adaptation 2 (79% concentrate) and 7 days of finishing diet (88% concentrate). The rumen pH and temperature was be monitored through the use of data loggers it was evaluated the rumen production of short chain fatty acids and ammonia concentration; the relative quantification of cellulolytic, amylolytic and lactate bacteria utilizing PCR and total and differential quantification of protozoa. Thus, the hypothesis is to test if Nelore cattle exposed to feed restriction or comsuption of concentrate ingredientes prior to the adaptation period present same rumen fermentation patters and microrganism profile when compared to animals of control treatment in the finish diet. Restricted animals, in the adaptation phase, had a higher concentration of SCFA (P<0.01), a higher duration of pH below 6.2 (P <0.01) and lower maximum pH on days 15 and 16 (P≤ 0.10) in relation to the control treatment. In the finish diet, these animals had lower DMI (P = 0.02), higher mean pH and lower pH area below 6.2 (P≤0.10) in relation to the control treatment. The animals previously exposed to the concentrate in the adaptation diet had a lower concentration of butyrate and ruminal NH3 (P≤0.10) in relation to the control treatment. They also presented lower amount of Fibrobacter succinogenes (P = 0.10) and higher DMI (P <0.01) in relation to the control. In the termination diet the DMI did not affect in relation to the control treatment. Cattle previously submitted to either nutricional restriction or intake of concentrate have similar ruminal characteristics during the finishing diet of the animals in control treatment.
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Palavras-chave
acidose, confinamento, metabolismo, Nelore, rúmen, acidosis, feedlot, metabolism, rumen