Nutritional value and kinetics of in vitro fermentation of spineless cactus of the genus Nopalea in different phenological phases.

The objective was to evaluate the chemical composition and in vitro fermentation of spineless cactus of the genus Nopalea, F-21 (Nopalea cochenillifera Dyck), IPA-Sertânia (Nopalea cochenillifera Dyck) and Miúda (Nopalea cochenillifera Salm Dyck), in different phenophases. There was no effect (P < 0.05) of the phenological phases of spineless cactus on DM, ash, OM, EE, and CP. Varieties F-21 and Miúda presented higher values of DM and OM, whereas the CP was higher for IPA-Sertânia. The contents of NDF, ADF, and ADL, as well as the fractions of carbohydrates B2 and C were higher in the mature stage, irrespective of the variety. The Miúda variety showed higher levels of NFC and fractions A + B1 and the lower levels of pectin compared to the F-21 and IPA-Sertânia varieties, but not differ of TC to F-21. The volume of gas produced via the degradation of NFC was higher for young phenological phases. The young and intermediate stages showed a higher in vitro digestibility of DM. Based on the results, varieties IPA-Sertânia and Miúda have a high potential for use in animal feed because of their high nutritional quality. Mature cladodes showed a higher fibrous fraction and lower digestibility in all varieties.