Teores de proteína bruta para bovinos alimentados com feno de capim-tifton 85: parâmetros ruminais, eficiência de síntese microbiana e degradabilidade in situ
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Data
2007-02-01
Autores
Silva, Edilane Aparecida da
Berchielli, Telma Teresinha [UNESP]
Reis, Ricardo Andrade [UNESP]
Pires, Alexandre Vaz
Sato, Kátia Junko [UNESP]
Paes, José Mauro Valente
Lopes, André Dias [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira de Zootecnia
Resumo
Avaliou-se o efeito da deficiência de PB na dieta sobre a eficiência de síntese microbiana e a degradabilidade in situ da MS e FDN em novilhos mestiços. Os tratamentos consistiram de dietas compostas de feno de tifton 85 (FN) suplementadas com uréia (FNUR), farelo de soja (FNFS) e farelo de glúten de milho- 60 (FNGL). Foram utilizados oito novilhos canulados no rúmen e no duodeno, distribuídos em dois quadrados latinos 4 x 4. O pH e a concentração de nitrogênio não-amoniacal (N-NH3) foram mensurados no fluido ruminal antes e 2, 4, 6 e 8 horas após o fornecimento da ração, utilizando-se a fibra em detergente ácido indigestível (FDAi) como indicador do fluxo duodenal. A eficiência microbiana foi determinada por meio das bases purinas. em todas as dietas, o pH e a concentração de N-NH3 foram adequados para o crescimento dos microrganismos ruminais. Não houve efeito da deficiência de PB na dieta sobre a ingestão de MS, a eficiência de síntese microbiana e a cinética de degradação da MS e FDN do feno de tifton 85. O teor de PB das dietas não alterou o crescimento microbiano, a eficiência de síntese microbiana e a cinética de degradação ruminal.
Eight crossbred steers fitted with ruminal and duodenal cannulas were randomly assigned to two replicated 4 x 4 Latin squares to evaluate the effects of crude protein (CP) levels on microbial protein synthesis efficiency and in situ degradability of nutrients. Animals received a control diet containing Tifton 85 bermudagrass hay or the control diet supplemented with urea, soybean meal or corn gluten meal-60. Ruminal pH and concentration of ruminal ammonia (NH3-N) were determined in the ruminal fluid at 0 (pre-feeding), 2, 4, 6 and 8 hours after feeding. Indigestible acid detergent fiber was used as the internal marker for measuring duodenal flow of nutrients while total purines were used as the direct microbial marker to measure microbial protein synthesis and microbial efficiency. Ruminal pH and NH3-N were within expected ranges indicating a stable ruminal environment. There were no effects of different dietary CP levels on intakes of DM and N as well as on microbial efficiency and degradability kinetics of DM and NDF. It can be concluded that different CP levels had no effect on microbial protein synthesis and efficiency and kinetics of ruminal degradability.
Eight crossbred steers fitted with ruminal and duodenal cannulas were randomly assigned to two replicated 4 x 4 Latin squares to evaluate the effects of crude protein (CP) levels on microbial protein synthesis efficiency and in situ degradability of nutrients. Animals received a control diet containing Tifton 85 bermudagrass hay or the control diet supplemented with urea, soybean meal or corn gluten meal-60. Ruminal pH and concentration of ruminal ammonia (NH3-N) were determined in the ruminal fluid at 0 (pre-feeding), 2, 4, 6 and 8 hours after feeding. Indigestible acid detergent fiber was used as the internal marker for measuring duodenal flow of nutrients while total purines were used as the direct microbial marker to measure microbial protein synthesis and microbial efficiency. Ruminal pH and NH3-N were within expected ranges indicating a stable ruminal environment. There were no effects of different dietary CP levels on intakes of DM and N as well as on microbial efficiency and degradability kinetics of DM and NDF. It can be concluded that different CP levels had no effect on microbial protein synthesis and efficiency and kinetics of ruminal degradability.
Descrição
Palavras-chave
corn gluten meal 60, pH, ruminal ammonia, purines, Soybean meal, Urea, concentração de amônia, Farelo de glúten de milho - 60, farelo de soja, pH, purina, Uréia
Como citar
Revista Brasileira de Zootecnia. Sociedade Brasileira de Zootecnia, v. 36, n. 1, p. 225-236, 2007.