Ruminal digestion characteristics and effective degradability of cell wall of browse species from northeastern Mexico

Abstract

Foliage from 15 shrub species was used to estimate the extent and rate of cell wall (CW) degradation in the rumen of fistulated Pelibuey sheep. Branches from the browse species: Acacia berlandieri, Acacia farnesiana, Acacia greggii, Acacia rigidula, Celtis pallida, Cercidium macrum, Condalia obovata, Cordia boisieri, Desmanthus virgathus, Leucaena leucocephala, Leucophyllum texanum, Opuntia lindehimieri, Porlieria angustifolia, Prosopis glandulosa, and Ziziphus obtusifolia, were collected during the spring of 1993 in Marı́n, County, Nuevo León, México. Medicago sativa hay was used for comparison. Twelve ruminally cannulated male sheep (45 kg BW) were used (four sheep per plant) to incubate nylon bags (5 × 10 cm and 53 μm pore size); containing 4 g of ground material (1 mm screen) of each plant. Bags were incubated at 0, 4, 8, 12, 24 and 48 h. The rate of CW degradation ( c, %) was highest ( P < 0.001) in O. lindehimieri (9.8) and lowest in A. rigidula (2.8). Only O. lindehimieri and C. pallida (8.5) had higher CW degradation rates than M. sativa (7.1). Effective degradability of CW (EDCW), at outflow rates of 2%, 5% and 8% h −1 values were higher in C. pallida (74.3, 62.9 and 56.6), C. obovata (54.5, 45.8 and 39.7), L. leucocephala (54.7, 45.1 and 39.8) and O. lindehimieri (67.8, 56.6 and 50.6) than in M. sativa (54.1, 44.9 and 39.5). High levels of lignin and condensed tannins affected the EDCW in some plants. Species such as C. pallida, C. obovata, L. Leucocephala and O. lindehimieri may be considered as good available forages for grazing ruminants in northern Mexico.