Fermentability coefficient of tropical forages and fermentative profile and in vitro degradability of silages

Our objective was to determine the fermentability coefficient (FC) of different tropical forages and the fermentative profile, chemical composition, and in vitro degradability of their silages. A randomised block design was used, with five treatments and four repetitions. The forage species studied were whole-plant maize (Zea mays), Cenchrus purpureus cv. BRS Capiaçu, Urochloa brizantha cv. BRS Piatã, U. decumbens cv. Basilisk, and Megathyrsus maximus cv. BRS Zuri. The FC was highest (P < 0.001) in whole-plant maize, followed by BRS Capiaçu, and lowest for BRS Piatã, Basilisk, and BRS Zuri. The fibrous fraction of the plant was higher (P < 0.001) for BRS Capiaçu and lower for whole-plant maize. The pH and ammonia content were lower (P < 0.001) for maize and BRS Capiaçu silages, and higher for BRS Zuri silage. Maize silage showed the highest effective DM digestibility (P < 0.001). The BRS Capiaçu silage exhibited a higher (P = 0.009) indigestible NDF fraction. In conclusion, if whole-plant maize cannot be produced for silage, ensiling perennial grasses, such as BRS Capiaçu, BRS Piatã, and Basilisk, is recommended due to their higher ensilability compared to BRS Zuri.