Estimation of fecal production, digesta flow and digestibility in dairy heifers with different indicator - doi: 10.4025/actascianimsci.v35i2.17338

Resumo

This study evaluated fecal excretion by means of the internal indicator indigestible neutral detergent fiber (iNDF) and external indicators such as chromium complexed with ethylenediaminetetraacetic acid (Cr-EDTA) and ytterbium chloride (YbCl₃), in addition to estimating the duodenal flow of dry matter and the total, ruminal and post-ruminal apparent digestibility coefficients. Eight crossbred Holstein x Zebu heifers were distributed into a 4 x 4 Latin square. Indicators Cr-EDTA, YbCl₃ and iNDF did not efficiently estimate the fecal production (p < 0.05), with results of 1.64, 1.71 and 2.71 kg day^-1, respectively, compared with the total feces collection, which resulted in 1.39 kg day^-1. The estimated values of dry matter flow, both for the methodologies of single and double indicator, can be considered biologically acceptable. However, the value obtained by the Cr-EDTA/YbCl₃ association_, used as a double indicator, was the most reliable, due to better recovery of the external indicators (Cr-EDTA and YbCl₃), which have had averages of 89 and 85%, respectively, in comparison with the internal one (iNDF), which averaged 67%. The ruminal and post-ruminal digestibility coefficients, estimated by the Cr-EDTA/YbCl₃ association, were considered the best indicators owing the dry matter flow estimated by this association.