title: Long-term Bias of Internal Markers in Sheep and Goat Digestion Trials.
abstract: Two digestion trials, one with sheep and another with goats, were conducted to evaluate the long-term bias (LTB) of the indigestible dry matter (iDM), indigestible neutral detergent fiber (iNDF) and indigestible acid detergent fiber (iADF) internal markers. The study used eight Santa Inês castrated male sheep (average body weight of 16.6 kg) distributed in two 4×4 Latin squares and eight Saanen castrated male goats (average body weight of 22.6 kg) distributed in two 4×4 Latin squares. The experiments were conducted simultaneously, and the animals were housed in 1.2 m(2) individual pens with wood-battened floors equipped with individual feeders and drinkers. The animals received isonitrogenous diets that were offered ad libitum and contained 14% crude protein and 70% sugar cane (with 0, 0.75, 1.5 or 2.25% CaO, in natural matter percentage), corrected with 1% urea and 30% concentrate. The experiment consisted of four experimental periods of 14 d each, with the feed, leftovers and feces sampled on the last four days of each period. The marker concentrations in the feed, leftovers and fecal samples were estimated by an in situ ruminal incubation procedure with a duration 240 h. The relationship between the intake and excretion of the markers was obtained by adjusting a simple linear regression model, independently from the treatment (diets) fixed effects and Latin squares. For both the sheep and goats, a complete recovery of the iDM and iNDF markers was observed (p>0.05), indicating the absence of LTB for these markers. However, the iADF was not completely recovered, exhibiting an LTB of -9.12% (p<0.05) in the sheep evaluation and -3.02% (p<0.05) in the goat evaluation.
authors: Federal University of Bahia (UFBA), Animal Production Department, Salvador, BA, Brazil.
authors: Gleidson Giordano Pinto
authors: GG
authors: de Carvalho
authors: Federal University of Bahia (UFBA), Animal Production Department, Salvador, BA, Brazil.
authors: Rasmo
authors: R
authors: Garcia
authors: Federal University of Bahia (UFBA), Animal Production Department, Salvador, BA, Brazil.
authors: Aureliano José Vieira
authors: AJ
authors: Pires
authors: Federal University of Bahia (UFBA), Animal Production Department, Salvador, BA, Brazil.
authors: Robério Rodrigues
authors: RR
authors: Silva
authors: Federal University of Bahia (UFBA), Animal Production Department, Salvador, BA, Brazil.
authors: Edenio
authors: E
authors: Detmann
authors: Federal University of Bahia (UFBA), Animal Production Department, Salvador, BA, Brazil.
authors: Ronaldo Lopes
authors: RL
authors: Oliveira
authors: Federal University of Bahia (UFBA), Animal Production Department, Salvador, BA, Brazil.
authors: Leandro Sampaio Oliveira
authors: LS
authors: Ribeiro
keywords: Fecal Excretion; Intake; Marker Concentration; Ruminal Incubation