ChileanJAR

Different grain processing methods of corn, barley and sweet lupine were evaluated. Treatments were whole grain, grain treated with NaOH at 2%, dry rolled grain and ground grain. In situ digestibility was evaluated in four rumen fistulated steers. Incubation times were 1, 2, 4, 8, 12, 24, 36 and 48 h for all grains and a further 72 h treatment exclusively for corn. For each incubation time 8 replications were included per species. Degradation curves were consfructed for dry matter (DM) crude protein (CP) and acid detergent fibre (ADF). Significant effects ofthe different processing methods were observed upon the degradation of the analysed grains. The largest values of DM and PC degradation were observed in ground grains oflupine, barley and corn (99 and 98.9%,96.4 and 91%and 89.8% and 69.2%, respectively). Rolled and ground barley and corn grain treatments presented similar degradation patterns at different incubations times, although in absolute terms ground grain values were higher for DM and CP. The lowest digestibility values were observed in the whole grain and NaOH treatments for the three species. NaOH treatments were effective for barley and corn grains when compared with the whole grain treatment, and the observed digestibility values were 68.3% and 10.2% for DM and 70% and 11.3% for CP, in barley and corn, respectively. Sweet lupine grains treated with NaOH did not present significant increases of MS digestibility (37.5%) when compared to whole grains (31.7%).