Ruminal digestion of protein from seven shrubs native to northeastern Mexico

In leaves from the shrubs Acacia farnesiana, Porlieria angustifolia, Celtis pallida, Leucophyllum texanum, Cordia boissieri, Condalia obovata y Prosop is glandulosa the effective degradability of crude protein (EDCP) was estim ated, and compared to Medicago sativa hay. Rumen cannulated sheep (Pelibuey x Rambouillet) were used to incubate nylon bags (5x10 cm and 53 mum pore s ize) with ground (1 mm screen) samples (4 g) of each shrub in each season. Bags were suspended in the ventral part of the rumen at 0, 4, 8, 12, 24, 36 and 48 h. Shrubs such as C. pallida (72%), C. obovata (64%) and P. glandul osa (66%) showed higher EDCP values than alfalfa hay (62%). Acacia farnesia na (62%) and P. angustifolia had similar values to M sativa, but L. texanum (60%) and C. boissieri (57%) were lower. It seems that cell wall and ligni n content negatively affected the EDCP. Because of high values of CP and ED CP in C, pallida, C. obovata, P. glandulosa, Acacia farnesiana, and P. angu stifolia these plants may be good protein supplements for grazing ruminants , especially during winter and spring.