NUTRIENT DIGESTION AND NITROGEN-UTILIZATION BY GOATS FED NATIVE SHRUBS CELTIS-PALLIDA, LEUCOPHYLLUM-TEXANUM AND PORLIERIA-ANGUSTIFOLIA

An in vivo digestibility trial was conducted to evaluate the influence of shrub leaves on digestion and N retention by goats. Twelve male ca strated Spanish goats (33.1 +/- 2.4 kg BW) were randomly placed in met abolism stalls and assigned to three diets (four goats/diet): (1 contr ol) 23% alfalfa hay plus 77% bean straw (BS), (2) 22% hackberry (Celti s pallida) plus 78% BS and (3) 18% ceniso (Leucophyllum texanum) plus 18% soapbrush (Porlieria angustifolia) plus 64% BS. All diets containe d 1.5% N. Diets were offered in two equal portions daily. The DM and C P intakes of goats were similar (P > 0.05) among diets. However, NDF a nd ADF intakes were lower (P < 0.05) in goats fed diets with hackberry and ceniso plus soapbrush than goats fed alfalfa hay. Digestibilities of DM and CP were similar (P > 0.05) among goats. Cell wall and its f ractions were digested less efficiently (P < 0.05) when goats were fed the hackberry and ceniso plus soapbrush diets instead the alfalfa hay diet. Goats retained N in a manner similar (P > 0.05) among diets. Di fferences on fiber digestion between diets containing alfalfa hay and browse species may be related to the chemical or physical nature of th e cell wall. (C) 1998 Elsevier Science B.V.