Nutritional Value and In Vitro Gas Production of Forage Cactus Varieties Harvested at Different Phenological Phases

Forage cactus is an alternative feed for ruminants in arid and semiarid environments; however, differences among species and phenological stages may alter its nutritional composition and ruminal fermentation. This study aimed to evaluate forage cactus varieties’ nutritional value and in vitro gas production in different phenological phases. The experiment was conducted in a completely randomized design in a 4 × 3 factorial arrangement, with four forage cactus varieties (F‐24, Copena F1, Redonda, and Orelha de Onça) and three phenological phases (young, intermediate, and mature). Bromatological analyses, carbohydrate fractionation, in vitro dry matter digestibility, and gas production during 48 h of ruminal fermentation were evaluated. The results indicated that the Copena F1, Orelha de Onça, and Redonda varieties maintained their nutritional value between the young and intermediate stages, while F‐24 showed nutritional stability up to the mature stage. The Orelha de Onça variety exhibited higher digestibility and greater in vitro gas production, associated with its high pectin content and nonfiber carbohydrates. It is concluded that the evaluated varieties present good nutritional value at different phenological stages; however, the Orelha de Onça cactus should preferably be supplied at the mature stage and associated with fibrous roughages to avoid excessive gas production.