Kinetics of ruminal passage rate of particles of signal grass silage, maize and intercropped

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 λ has an inverse behavior to the escape rate κ, the τ 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

本研究旨在评估以下四种饲料组合基质颗粒的瘤胃通过率动力学：玉米与信号草；玉米、信号草与Calopogônio；玉米、信号草与Macrotiloma；玉米、信号草与Estilosantes。试验选用4头安装瘤胃瘘管的荷斯坦-瘤牛杂交肉牛，以测定上述颗粒的瘤胃通过率动力学。分别于0小时（铬结合纤维复合物添加后即刻）、1、2、4、6、8、12、16、20、24、28、32、36、40、44、48、56、64、72、80、88、96、120、132、144及192小时采集粪便样本。通过率估算的轮廓参数采用稳健回归程序进行拟合。采用SAS软件的非线性回归（NLIN）过程，对瘤胃固相筏相颗粒平均滞留时间（ATPR1）、瘤胃液相平均滞留时间（ATRLP2）及总瘤胃滞留平均时间（ATTRR）的瘤胃通过率动力学进行拟合与估算。由观测结果可知，转移速率λ与逃逸速率κ呈负相关关系；τ平均值、平均滞留时间及瘤胃液相颗粒平均滞留时间（ATRLP2）均无统计学显著性差异。经瘤胃固相筏相逃逸并进入瘤胃液相阶段（ATRLP2）的饲料特性极为相似；各处理组的总瘤胃滞留平均时间（ATTRR）均无统计学显著性差异（P