PSV-9 Effect of ensiling period and treatment on the composition and digestibility of olive pomace in beef cattle.

摘要

The objective was to examine ensiling as a preservation technique and the effect of adding urea and SiloSolve MC (LAB) on fermentation, nutritive value, and digestibility of olive pomace (OP) for cattle. Fresh OP (Olivas de Oro, Creston, CA) was treated with either: no additives (control; CONT); urea at 5% of DM (UREA; Agrium U.S. Inc); or SiloSolve MC (LAB; a mixture of Enterococcus faecium M74, Lactococcus lactis SR3.54, and Lactobacillus plantarum CH6072 applied at 1.5 x 105 cfu/g; Chr. Hansen). Treated OP was ensiled into 20-L vented silos and analyzed for nutritional composition, in situ disappearance, fermentation, and microbial profile at d0 and d120 in a completely randomized design with quintuplicate treatments. At d0, DM was 2% higher for UREA, while NDF and ADF did not differ. Fat was significantly lower for CONT (12.87%) and DMR was higher in LAB (98.72%, P < 0.0001). NDF and ADF were lower for LAB and UREA (P < 0.0001). CP was highest for UREA (21.04%) and fat content decreased by 1.71% and 2.68% for LAB and UREA, respectively by d120. At 24h in situ, DMD was greatest for UREA (P < 0.01), but this advantage diminished by 48h. Ensiling did not influence NDFD (P < 0.01), however, at 24h in situ NDFD was significantly highest in LAB and UREA. Lactic acid significantly increased due to ensiling across all treatments with UREA having the highest content (0.72%) and most NH3N (0.39%) at d120, while LAB contained the most lactic acid bacteria (7.078 log cfu/g). Yeast, molds, and sugars significantly decreased with ensiling. In conclusion, OP was determined as a viable nutritional source for ruminants given its nutrient profile, effective preservation after 120d of ensiling, and increased CP by adding UREA, while LAB improved portions of fermentation and microbial profiles.