Kinetics of ruminal passage rate of particles of signal grass silage, maize and intercropped / Cinética ruminal de passagem de partículas das silagens de capim-braquiaria, de milho, e do consórcio capim-braquiaria e milho

ABSTRACT

The purpose of this study was to evaluate the kinetics of ruminal passage rate of particles from the subsequent associations corn and signal grass; corn, signal grass and Calopogônio; corn, signal grass and Macrotiloma; and corn, signal grass and Estilosantes. It was used four crossbred holstein-zebu cattle with the rumen tubed in order to determine the the kinetics of ruminal passage rate of particles. The feces were collected at the times zero (immediately after addition of fibers complexed with chromium), 1, 2, 4, 6, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 56 , 64, 72, 80, 88, 96, 120, 132, 144 and 192 hours. The profile parameters of passage rate estimative were adjusted according to robust regression procedures. The average time of particles retention in the raft (ATPR1); the average time in the rumen liquid phase (ATRLP2) and the average time of total ruminal retention (ATTRR) were adjusted for the passage kinetics and estimated with the NLIN procedure of SAS. From the observed results, may be suggested that the transference rate ? has an inverse behavior to the escape rate , the average values, the average retention time and average particles retention time in the rumen liquid phase (ATRLP2) were not statistically different. The feed characteristics after the raft escape and reach to ATRLP2, were very similar; (ATTRR), related to treatments, were not statistically different (P <0,05). There were observed small TMRR numerical differences in different foods. The corn and signal grass; corn, signal grass and calopogônio; corn, signal grass and macrotiloma, corn, signal grass and estilosantes silage fibers had similar rates of ?, k, ATPR1, ATRLP2 and ATTRR. Therefore, the the kinetics of ruminal passage rate of particles is similar. Thus, the choice of the system should be based on other factors, such as viability of the management ease and silage cost.(AU)

RESUMO

Objetivou-se com este trabalho avaliar a cinética da taxa de passagem ruminal de partículas das silagens oriundas dos consórcios milho e capim-braquiária; milho, capimbraquiária e calopogônio; milho, capimbraquiária e macrotiloma; e milho, capimbraquiária e estilosantes. Foram usados quatro bovinos mestiços holandês-zebu, fistulados no rúmen. As fezes foram coletadas nos tempos zero (imediatamente após a administração da fibra complexada com cromo), 1, 2, 4, 6, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 56, 64, 72, 80, 88, 96, 120, 132, 144 e 192 horas. As estimativas dos parâmetros dos perfis de taxa de passagem foram ajustadas de acordo com procedimentos de regressão robusta. O tempo médio de retenção de partículas no raft (TMR1); o tempo médio de retenção de partículas na fase líquida ruminal (TMR2) e o tempo médio de retenção ruminal total (TMRR) foram ajustados para a cinética de passagem e estimados com o procedimento NLIN do SAS. A partir dos resultados observados, pode-se sugerir que a taxa de transferência possui comportamento inverso à taxa de escape.(AU)