Associação da cana-de-açúcar com palma miúda em dietas para ovinos : dinâmica da matéria seca e da fibra e parâmetros ruminais

Abstract

The aim was to evaluate the effects of partial replacement of sugarcane by small forage cactus (0; 18; 36; 54 and 72% based on dry matter (DM)) on ruminal parameters, rumen DM and fiber dynamic in sheep. Five rumen-fisted castrated male crossbred sheep with average body weight 63.38 ± 7.70 kg were distributed in 5 x 5 Latin square design. Pools of DM, neutral detergent fiber corrected for ash and protein (NDFap) and indigestible neutral detergent fiber (NDFi) reduced linearly regarding the replacement levels. DM intake (Ki) and degradation (Kd) rates increased linearly, while flow rate (Kp) developed a quadratic response with 0.035 h-1 maximum value estimated for 44% replacement. NDF intake, flow and degradation rates, and NDFi flow increased, while pH reduced linearly. Ruminal ammonia nitrogen (RAN) had a quadratic response in function of collection times with 17.89 mg/dL maximum concentration at 0.68 hours after feeding. Regarding volatile fatty acids (VFA), there was linear increment for acetate. Propionate was not influenced by replacement, and butyrate had a quadratic effect with 14.06 mmol/L maximum concentration estimated for 64.17% replacement. Replacing up to 44% of sugarcane by small forage cactus is recommended to maximize the passage rates reflecting in greater consumption of dry matter and nutrients.