Abstract
Cactus pear is used in large proportions in diets for small ruminants in semiarid regions. However, its exclusive use is not recommended due to the low fiber and crude protein content and the high water and mineral content, leading to metabolic disorders, low dry matter intake, and weight loss. The use of mixed cactus silage associated with protein and fibrous sources seeks to overcome the deficits in dry matter, fiber and crude protein, aiming to improve the nutritional quality of the diets that will be offered to ruminants. Thus, the use of gliricidia hay in cactus pear silages could represent an important alternative to improve the nutritional and fermentative characteristics of the ensiled material. Therefore, our aim was to evaluate the fermentation dynamics, nutritional characteristics, and aerobic stability of mixed silages of cactus pear combined with different levels of gliricidia hay. This was a completely randomized experimental design with five treatments and five repetitions. The treatments consisted of different levels of inclusion of gliricidia hay (0, 10, 20, 30, and 40% on a dry matter basis) in the composition of mixed cactus pear silages. The inclusion of gliricidia hay in the composition of mixed silages of cactus pear resulted in a quadratic effect for dry matter recovery, pH, NH(3)-N, buffering capacity, aerobic stability, ether extract, P, K, Na, and Zn (p < 0.05). There was a reduction in density, effluent losses, maximum pH, mineral matter, non-fiber carbohydrates, Ca, Mg, Fe, and Mn (p < 0.05), and an increase in the time to reach maximum pH as well as an upward trend in pH, dry matter, organic matter, crude protein, neutral detergent fiber, acid detergent fiber, and B (p < 0.05). Under experimental conditions, the inclusion of gliricidia hay between 20 and 30% in cactus pear-based silage provided an improvement to the chemical composition and fermentation parameters of the silages.