ABSTRACT. This study examined the influence of the external markers chromium oxide (CO), titanium dioxide (TD), isolated, purified and enriched lignin (LIPE®) and isolated, purified, enriched lignin in nanoparticles (NANOLIPE®) as well as the internal markers indigestible dry matter (iDM), indigestible neutral detergent fiber (iNDF) and indigestible acid detergent fiber (iADF) in diets with inclusion of passion fruit by-product for dairy heifers on the estimation of fecal output and nutrient digestibility. Sixteen Holstein × Zebu crossbred heifers at an average live weight of 363 ± 28 kg were randomly distributed in a completely randomized design where they received diets in which Tifton 85 (Cynodon sp.) hay was replaced with passion fruit by-product (0, 12, 24 and 36%, as-fed basis). The CO, LIPE®, NANOLIPE® and iNDF markers did not differ from the total collection method (p > 0.05) in the estimation of fecal output and nutrient digestibility. The TD and iDM markers overestimated, while iADF underestimated fecal output. Under the presented conditions, we recommend using the CO, LIPE®, NANOLIPE® and iNDF markers to estimate fecal output and nutrient digestibility in diets with inclusion of passion fruit by-product for dairy heifers.

The objective of this study was to evaluate the effect of inclusion of lipid residue of biodiesel originated in the processing of palm oil (Elaeis guineensis) in the diet on the digestibility of feedlot lambs. Twenty-five crossbred male castrated lambs, weighing 20±1.61 kg, were distributed in randomized blocks with five treatments and five replications. The experimental period lasted 22 days; 15 for diet adaptation, 2 for the adaptation to the indicator LIPE (lignin from Eucalyptus grandis isolated, purified and enriched, UFMG, Minas Gerais) and 5 for fecal sampling. Diets were formulated with 64% concentrate based on corn and soybean meal, 31% Massai grass (Panicum maximum cv. Massai) hay and 5% lipid supplementation from increasing levels of substitution of 0, 25, 50, 75 and 100% of palm oil for biodiesel oil from palm residue. The lambs were offered two meals a day, at 7h00 and 16h00. There was linear effect of inclusion of the residue from palm oil biodiesel on dry matter intake. There was no change in digestibility of nutrients except for ether extract. The use of biodiesel from palm oil residue up to 100% replacement for the lipid supplementation of sheep positively influences the consumption without altering the digestibility of nutrients.