Nutritive value of Kochia scoparia L and ammoniated barley straw for goats

Chemical composition, in vivo digestibility and usable energy value of kochia (Kochia scoparia L.) were determined using goats of Murciano-Granadina breed. Fifteen mature goats were fed fresh kochia substituting ammoniated barley straw at 0, 25, 50, 75 or 100% of their complete diets in a completely randomized experimental condition. There were no differences (P>0.05) in DMI or DMD or OMD among the five diets containing kochia and treated straw. Kochia substitution resulted in a quadratic increase (P<0.001) in N digestibility as rising levels of kochia replaced treated straw. In contrast, the substitution of treated straw with kochia in increasing amounts resulted in a decline (P<0.001) in NDF, ADF and cellulose digestibilities. ME content of kochia (5.7 MJ kg(-1) DM) was significantly (P<0.001) lower than treated straw (8.1 MJ kg(-1) DM). However, four kochia diets had a low ME content. This result suggests the possible role of kochia in a grazing system for goats, during periods, such as the hot season, in which pasture availability in the Mediterranean regions is reduced.