1341 Application of Pediococcus pentosaceusand chitinase to high moisture alfalfa hay at baling: effects on nutrient digestion and on growth performance of beef cattle

The objective of this study was to assess the effect of applying a Pediococcus pentosaceusand chitinase mixture (PED+CH) at baling on nutrient digestion and on growth performance of beef cattle. Pure alfalfa was harvested and sun-cured to either 23 to 30% (HMH) or 10 to 13% (NMH) moisture. The HMH (Treatment) was baled with application of PED (6.5 × 1011cfu/tonne)+CH (1.5 g/tonne) and NMH was baled without additives (Control). A crossover experiment (Exp 1) used eight cannulated heifers that were divided into two groups and fed diets containing 77% of control or treated alfalfa hay and 33% concentrate (DM basis). Each period consisted of a 10-d adaption, 2-d for measuring rumen fermentation products and 7-d for measuring total tract digestibility using chromium oxide (Cr2O3) as an indigestible marker. In Exp 2, fifty Angus×Hereford crossed-bred steers (270 ± 1.12 kg) were stratified by BW and allocated randomly to two groups in 10 pens, and fed diets containing 57% (DM basis) of treated or control alfalfa hay for 112 d and DMI, ADG and feed efficiency (FE) were measured. Data were analyzed as a completely randomized design using PROC MIXED procedure of SAS with cattle (Exp 1) or pen (Exp 2) as the statistical unit. Differences among means were identified using LSMEANS with the PDIFF in SAS. Cattle fed both diets had similar (P> 0.05) DM, NDF and ADF digestibility. However, HMH alfalfa treated with PED+CH had lower (P< 0.05) CP digestibility as compared with NMH alfalfa hay. Both groups of cattle had similar rumen pH, VFA and ammonia concentrations and cellulolytic enzyme activity. The two groups of cattle also had similar (P> 0.05) DMI, ADG and FE over the 112-d backgrounding period. The similar rumen fermentation characteristics, nutrient total tract digestibility and growth performance between the 2 groups of cattle indicate that alfalfa HMH preserved with PED+CH exhibited similar ruminal and total tract digestibility and feed value to NMH alfalfa. The PED+CH additive has the potential to conserve high-moisture alfalfa hay so that its nutritive and feeding value is similar to that of sun-dried alfalfa hay.