| dc.description.abstract | The aim of this review was to evaluate the fecal dry matter production (FDMP) from three different breed groups of heifers submitted to a different feeding levels; using the method of total collection and estimated with external markers chromium oxide, titanium dioxide and LIPE®, and indigestible dry matter markers (iDM), indigestible neutral detergent fiber (iNDF) and indigestible acid detergent fiber (iADF) support. Two experiments were conducted. On the first one we used 18 heifers from three genetic groups: Holstein, ½ Holstein / Gir (F1) and Gir, fed with 70:30 forage x concentrate diet, under ad libitum consumption. On the second experiment, we used 12 animals from Gir and F1 groups, fed on a restricted diet, only with forage, on maintence levels. Two different protocols were also compared: fecal collection (at 8:00 and 16:00 h during 5 days collection and six times with 6 hour intervals on a 3-day period).In all comparisons, internal markers MSi, and iADF iNDFoverestimated the FDMP. The external markers chromium oxide, titanium dioxide, can be used in ruminant nutrition studies in specific conditions. Whereas the LIPE®, can be used in all conditions. There was no difference between protocols.The protocol choice will be according to the researcher and the research conditions. | |
