Comportamento ingestivo de bovinos Nelore confinados adaptados com diferentes protocolos à dieta de alto concentrado
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Data
2012-04-05
Autores
Ronchesel, João Ricardo [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O objetivo deste estudo foi avaliar os efeitos de diferentes protocolos de adaptação à dieta de alta inclusão de concentrado nas variáveis do comportamento ingestivo e seletividade dos ingredientes da dieta de bovinos Nelore terminados em confinamento. Cento e vinte bovinos, machos inteiros da raça Nelore com peso vivo médio inicial de 372,19 ± 21,46 kg, com idade aproximada de 24 meses foram mantidos em 24 baias de piso de concreto com cinco animais por baia, de acordo com os tratamentos: T1 – adaptação em escadas (Step up) por 14 dias (E14), T2 – adaptação em escadas (Step up) por 21 dias (E21), T3 – protocolo de restrição por 14 dias (R14), e T4 – protocolo de restrição por 21 dias (R21), constituindo-se assim delineamento experimental de blocos inteiramente casualizados em arranjo fatorial 2 × 2 (protocolos de adaptação e tempo de adaptação). Os protocolos de Escada aumentaram (P<0,05) o tempo de alimentação e mastigação em relação aos protocolos de Restrição. Já o tempo de ócio dos animais em protocolos de restrição foi maior (P<0,05) nos dias 5, 9 e 13. Os animais nos protocolos de Escada apresentaram maiores (P<0,05) eficiências de alimentação e ingestão de matéria seca nos dias 5 e 9 comparado aos protocolos de restrição. O protocolo de restrição obteve a maior (P<0,05) eficiência de ruminação no dia 5. Na peneira de 8 mm, os protocolos de 14 dias proporcionaram (P<0,05) seleção a favor de partículas de 8 mm comparado ao de 21 dias, apenas no dia 21. Logo após adaptação, animais adaptados por 14 dias apresentaram o mesmo comportamento ingestivo que animais adaptados por 21 dias, independente do protocolo
This study, conducted at the São Paulo State University feedlot, Botucatu Campus, Brazil, was designed to determine effects of restricting intake of the final finishing diet (REST) as a means of dietary adaptation compared with diets increasing in concentrate (STEPUP) over periods of 14-d and 21-d on feeding behavior and selection of feed ingredients. The experiment was designed as a completely randomized block with a 2 x 2 factorial arrangement, replicated 6 times (5 bullocks/pen), in which 120 18-mo-old yearling Nellore bulls (372.2 ± 21.5 kg) were fed in 24 pens for 84-d according to the treatments: STEPUP for 14-d, STEPUP for 21-d, REST for 14-d, and REST for 21-d. The STEPUP program consisted of ad libitum feeding of three adaptation diets over periods of 14-d or 21-d with concentrate level increasing from 55% to 85% of diet DM. The REST program consisted of restricted intake of the final diet (85% concentrate) with programmed increases in feed offered until yearling bulls reached ad libitum access over periods of 14-d or 21-d. The STEPUP protocols increased (P<0.05) feeding and chewing times compared to REST protocols. The rest time was greater (P<0.05) to REST program at 5, 9 and 13 days compared with STEPUP program. Dry matter intake and feeding efficiency of dry matter were greater (P<0.05) at 5 and 9 days in STEP but did not differed (P>0.05) between treatments after day 13. Ruminating efficiency of DM was higher (P<0.05) on REST program at day 5. At the 8-mm Penn, the animals on protocols with 14-d chose in favor of greater particles compared with animals in 21-d only at day 21. After period of adaptation, animals in 14-d of adaptation showed same feeding behavior than cattle in 21-d, independent of protocol
This study, conducted at the São Paulo State University feedlot, Botucatu Campus, Brazil, was designed to determine effects of restricting intake of the final finishing diet (REST) as a means of dietary adaptation compared with diets increasing in concentrate (STEPUP) over periods of 14-d and 21-d on feeding behavior and selection of feed ingredients. The experiment was designed as a completely randomized block with a 2 x 2 factorial arrangement, replicated 6 times (5 bullocks/pen), in which 120 18-mo-old yearling Nellore bulls (372.2 ± 21.5 kg) were fed in 24 pens for 84-d according to the treatments: STEPUP for 14-d, STEPUP for 21-d, REST for 14-d, and REST for 21-d. The STEPUP program consisted of ad libitum feeding of three adaptation diets over periods of 14-d or 21-d with concentrate level increasing from 55% to 85% of diet DM. The REST program consisted of restricted intake of the final diet (85% concentrate) with programmed increases in feed offered until yearling bulls reached ad libitum access over periods of 14-d or 21-d. The STEPUP protocols increased (P<0.05) feeding and chewing times compared to REST protocols. The rest time was greater (P<0.05) to REST program at 5, 9 and 13 days compared with STEPUP program. Dry matter intake and feeding efficiency of dry matter were greater (P<0.05) at 5 and 9 days in STEP but did not differed (P>0.05) between treatments after day 13. Ruminating efficiency of DM was higher (P<0.05) on REST program at day 5. At the 8-mm Penn, the animals on protocols with 14-d chose in favor of greater particles compared with animals in 21-d only at day 21. After period of adaptation, animals in 14-d of adaptation showed same feeding behavior than cattle in 21-d, independent of protocol
Descrição
Palavras-chave
Confinamento (Animais), Nelore (Zebu) - Alimentação e rações
Como citar
RONCHESEL, João Ricardo. Comportamento ingestivo de bovinos Nelore confinados adaptados com diferentes protocolos à dieta de alto concentrado. 2012. vii, 59 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia de Botucatu, 2012.