Efectos de enzimas e inoculares sobre la composición del ensilaje de maíz

Treating silages with fibrolytic enzymes and bacterial inoculants has been shown to improve digestibility, fermentation and aerobic stability of a variety of forages. The objective of this experiment was to evaluate the effects of three additives on chemical composition and fermentation charac-teristics of silage from seven different hybrids: DK641�, Eagle 238W�, Golden Harvest EX313�, Golden Harvest H9403�, Pioneer 32R25�, Pioneer 31G98�, and Producers 725�. Corn plants were planted in experimental plots (1 ha each) in Chihuahua, Mexico and harvested at stage of maturity of 1/3 of milkline. Whole corn plants were cut and subsamples were chopped and ensiled in mini silos (1.3±0.1 kg) for 42 d. Treatments were control: CT: 20 ml distilled water; SA: 0.0065 g Sill All� 4x4 (L. plantarum, P. acidilactii, E. faecium, and B. salivarus); BS: 0.182 g Bio-sile� (L. plantarum and P. pentosaceus) and FB: 0.31 g Fibrozyme� (xylanases and T. viride). Silage samples were analyzed for dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), cellulose (CE), hemicellulose (HE), in vitro dry matter digestibility (IVDMD), in vitro organic matter digestibility (IVOMD), pH and lactic acid (LA). Inoculation with SA and BS increased content of NDF of silage of hybrids 31G98 and DK641 (p<0.05). Addition of SA increased CP of silages from H9403, 238W and EX313 (p<0.05). However, FB decreased NDF concentration of 31G98, H9403 and 238W, lowered pH of DK641 and EX313 and increased concentration of LA content of EX313 and increased concentration of LA content of EX313 (p<0.05). No effect on DM and OM digestibility was observed for FB, but when BS and SA were added a significant difference (p<0.05) was observed for the hybrids DK641, 32R25 and Producers 725. These show that when applied at ensiling certain inoculants and fibrolytic enzymes can improve various chemical characteristics of corn silage, however, effects vary depending of the particular corn hybrid.El tratamiento de ensilajes con enzimas fibrolíticas e inoculantes bacterianos ha mostrado aumentar digestibilidad, fermentación y estabilidad aeróbica de varios forrajes. El objetivo fue evaluar el efecto en la composición química y características de fermentación en el ensilaje con los híbridos DK641® (DK641), Eagle 238W® (238W), Golden Harvest EX313® (EX313), Golden Harvest H9403® (H9403), Pioneer 32R25® (32R25), Pioneer 31G98® (31G98) y Producers 725® (725) tratados con tres aditivos. Los híbridos se sembraron en parcelas experimentales de 1 ha en Chihuahua, México. La cosecha se realizó en la etapa de madurez con 1/3 de llenado del grano tomándose muestras representativas para la elaboración de microsilos (1,3±0,1 kg) por 42 d. Se evaluaron cuatro tratamientos de microsilos: el control (CT) con 20 ml de agua destilada y tres tratamientos con aditivo; SA con 0,0065 g de Sill All 4x4® (L. plantarum, P. acidilactii, E. faecium y B. salivarus), BS con 0,182 g de Bio-sile® (L. plantarum y P. pentosaceus) y FB con 0,31 g de Fibrozyme® (xylanases y T. viride). Se determinó materia seca (MS), proteína bruta (PB), fibra detergente neutro (FDN), fibra detergente ácido (FDA), celulosa (CE), hemicelulosa (HEM), digestibilidad in vitro de la materia seca (DIVMS) digestibilidad in vitro de la materia orgánica (DIVMO), pH y ácido láctico (AL). La inoculación (SA y BS) incrementó los contenidos de FDN en los ensilajes de los materiales 31G98 y DK641 (p<0,05). Asimismo, la adición de SA incrementó el contenido de PB en H9403, 238W y EX313 (p<0,05). La adición de FB disminuyó el contenido de FDN en 31G98, H9403 y 238W; pero disminuyó el pH en DK641 y EX313 e incrementó la concentración de AL en 32R25 (p