http://lattes.cnpq.br/7701952618244899; MACÊDO, Alberto Jefferson da Silva.
Abstract:
This dissertation was composed by two experiments. In the first experiment, the objective was to evaluate the agronomic potential and morphological characteristics of 34 cactus pear genotypes destined for forage production. The genotypes were implanted in a randomized complete block design, with 34 treatments and three replications. After 330 days of cultivation, biometric measurements of the morphological characteristics, mortality check, pest and disease occurrence, and crop cutting were performed for agronomic production. Green mass production correlated with dry mass production, water accumulation, water use efficiency, water accumulation and cladode number per plant. The genotypes indicated for cultivation are Negro Michoacan (V07), Tamazunchale (V12), Califórnia (V14), Orelha de Elefante Mexicana (V17) e Amarillo 2289 (T32) for having presented higher yields of dry and green mass, as well as greater accumulation of water, water use efficiency and carrying capacity. In the second experiment, the objective was to evaluate the fermentation pattern and the in situ degradability of dry matter of silages in the form of diet. Five diets were formulated based on spineless cactus (Opuntia ficus-indica Mill cv. Gigante) and buffelgrass (Cenchrus ciliaris). The experimental design was completely randomized, with five treatments and three replications in which the diets differed in the proportion of buffelgrass (0, 15, 25, 30 and 35%, based on natural matter). Effect was observed for the chemical composition of the diets, with all dry matter (DM) contents were within the ideal range for adequate fermentation. There was no effect on ammonia nitrogen concentration. There was effect for dry matter recovery (RMD), which ranged from 96.3 to 99.9%. The pH values decreased as the opening time (days) was prolonged. The levels of organic acids differed in all diets. However, in general, all diets had satisfactory lactic acid content. As the proportion of buffelgrass increased in diets, the degradation of DM decreased. Based on the profile of fermentation, losses and chemical composition, the diet with higher a proportion of spineless cactus can be recommended for silage production.