The objective of this study was to evaluate "in situ" degradability of ground cob corn and corn (maize) bran in goats and wooless sheep kept in natural and artificial shade environments in the semi-arid region of Paraíba. Four goats and four sheep were used, being distributed in two environments, one natural and the other artificial. Nylon sacks were incubated containing samples of ground cob corn and corn (maize) bran in intervals of 6, 12, 24, 48, and 72 hours for the bulk food, and 6, 12, 24, and 48 hours for the concentrate. The effects of the environments and of the species in fractions b and c of dry matter in the cob corn were independent. In the artificial environment, the average of the degradability of fraction b (55,36%) was higher than the average obtained in the natural environment (50,97%); and fraction c presented a higher value in the natural environment (40,90%) than in the artificial (36,51). With respect to fractions b and c of the dry matter of the corn bran, there was no interaction between species and environments; and the degradability of fraction b of dry matter for the goats was higher than for the sheep, with 60,77% and 56,47%, respectively. With respect to fraction c, the inverse was verified. The sheep presented a higher average than the goats (31,93 and 27,63%). There was environmental effect for potential degradability of dry matter of the cob corn. The values of fraction b in the natural and artificial environments were 50,97 and 55,36%, respectively. The potential degradability of corn bran for the goats was higher than for the sheep (72,37 and 68,07%, respectively). The effective degradability to 5% of the dry matter was higher for the goats (31,17%) than for the sheep (28,48%). The effective degradability of the dry matter (calculated with passage rate of 2 and 5%/h) of the corn bran for the goats was superior (60,34 and 49,18%) as compared to the sheep (56,88 and 46,51%, respectively). It can be concluded that animal species and environment have an influence on food degradability. The sheep and goats in this study presented similar characteristics with respect to the degradability of dry matter, crude protein, and neutral detergent fiber of the cob corn. However, with respect to the corn bran, the sheep were more efficient in degradability of crude protein, as the goats were in degradability of dry matter.
thermal comfort; Moxotó; Santa Inês; degradation rate; temperature
