Ensilagem de partes da planta de milho em cultivo solteiro ou consorciado com capim-ruziziensis

Abstract

– Maize is the standard crop for ensiling since it presents ideal attributes for silage of high nutritional value. An alternative in ruminant nutrition is silage production using different maize plant parts, besides the possibility of intercropping with grasses in crop-livestock integration systems, aiming at the renewal of degraded pastures or the intercropping for the straw production in a no-tillage system. Thus, the aim was to evaluate the nutritive value and the fermentative characteristics in the ensiling of maize plant parts in a single crop and with intercropped ruziziensis grass. The field experiment was implemented in the rural property Nossa Senhora Aparecida, in the municipality of Colorado do Oeste – RO, and laboratory analyzes were performed at the Federal University of Mato Grosso, Campus Cuiabá. A randomized block design with five repetitions was used. The treatments were arranged in a double factorial scheme (2x4), with the first factor being the cultivation modality (single and intercropped) and the second factor as the maize parts (whole plant, half plant, plant without ear and ear with straw). Dry matter losses in silage and dry matter recovery; forage and silage characteristics: dry matter (DM), the insoluble fiber in neutral detergent (NDF) and acid (ADF), total digestible nutrients (TDN), dry matter (DMS), and organic (DMO) digestibility and mineral matter (MM) contents; and silage fermentation pattern were evaluated. The pH values of forages and silages did not change due to the cultivation modality and/or maize parts, with a mean value of 5.65 and 3.85, respectively. The crude protein (CP) content of forages showed a mean value of 7.73% and silages of 7.32%. Higher buffering capacity values were observed for forage of whole maize plant in a single crop, plant without ear in a single crop, and whole maize plant with intercropped ruziziensis grass. Higher values were observed for the contents of NDF and ADF in maize plants without ear in a single crop (64.11% and 35.27%, respectively); in silage, the values found were 30.60 and 13.88%, respectively. Low gas losses in silage fermentation were quantified, with a mean of 1.07% of DM. The mean value obtained for effluent losses was 33.03 kg t-1 of green mass. The recovery of dry matter from the silage was higher in the ensilage of the whole plant and the ear with straw, indicating lower losses during the fermentation process of this silage. The NH3-N contents were higher for silages of the whole plant in a single crop, half-plant in a single crop, and ear with straw in intercropped. Ensiling of the whole plant, half plant, plant without ear and ear with straw in single or intercropped modality may be recommended.