Four experiments were conducted to evaluate the influence of eight shrub
leaves on digestion, nitrogen retention and ruminal digestion
characteristics by sheep. In general, in all experiments, only few
variations in nutrient intake, nutrient digestion coefficients and N
retention were observed between sheep fed diets containing M. sativa hay
and sheep fed diets with different levels of shrubs. The same responses
were detected in sheep rumen fermentation parameters and data for
digestibility values: a, b and c values and effective degradability of
dry matter, crude protein and neutral detergent fiber of individual
forages. Even though, all shrub species contained high levels of crude
protein, it seemed that plant secondary compounds in browse species
affected their nutritional quality, reducing the nutrition of sheep fed
diets with different levels of browse plants. However, native shrubs
growing in semiarid regions of northeastern Mexico may have potential as
an economical supplementary feed for sheep fed diets based on roughages
of low nutritional quality.