RESUMEN
The objective of this study was to evaluate feed intake and digestibility and ruminal characteristics of development-stage calves fed mulatto II (Brachiaria sp.) grass hay (MGH) and a protein supplement (PS) consisting of increasing levels of the parota (Enterolobium cyclocarpum) pod (PP). We used eight Swiss-zebu calves in growth stage with an average age of 11 months and initial average weight of 157.6 ± 8.5 kg. They were distributed in a repeated 4 × 4 Latin square design with 4 treatments (period 30 days): 0% (PP0), 25% (PP25), 50% (PP50), and 75% (PP75) of the PP. Calves in the PP0 and PP25 treatments had higher intake of PS and MGH as dry matter (DM) than those in the PP50 and PP75 treatments (p < 0.05). Organic matter intake (OMI) of the PP75 calves was lower than that of PP0 and PP25 calves. Crude protein intakes (CPI) of PP0 and PP25 calves were higher than those of PP50 and PP75 calves (p < 0.05). Apparent digestibility of crude protein was higher in the PP0, PP25, and PP50 treatments compared with that in treatment PP75 (p < 0.05). The treatments did not affect total bacterial count, cellulolytic bacterial count, cellulase enzymatic activity, volatile fatty acids, or the acetate/propionate ratio (p > 0.05). Rumen pH in the PP0 calves was higher than that of the PP25 calves, whereas the protozoa count and ammonia content were higher in PP0 calves than in PP75 (p < 0.05). In conclusion, the inclusion of 25% PP in the PS for forage-fed calves is a feeding alternative.