181 Effect of Application Rate of Sodium Lignosulfonate and Propionic Acid on DM Losses, Nutritional Composition, and Fungal Counts of High Moisture Alfalfa Hay Mini Bales

Abstract

Our objective was to evaluate the effects of application rate (AR) of sodium lignosulfonate and propionic acid on high moisture alfalfa hay spoilage during storage. Treatments (TRT) were sodium lignosulfonate (NaL) and Propionic Acid (PRP), which were applied at four AR: 0 (CON), 0.25, 0.5 and 1% (w/w fresh basis) to 20% bloom alfalfa hay (second cut) at 68.5% DM and packed into mini bales (10.3x10.8x13cm; 346kg fresh/m3). The treated bales were stored for 33 days in open-top insulation boxes in a room kept at 22°C. Data were analyzed as a randomized complete block design (5 blocks) with a 2 (TRT) x 4 (AR) factorial arrangement, and differences were declared at P ≤ 0.05. At day 0, no differences were observed for DM (68.5 ± 0.61 %), CP (23.2 ± 0.31% DM), and NDF (42.6 ± 0.66% DM), but NaL had more sugars than PRP (0.99 vs. 0.87 ± 0.66% DM) and PRP at 1% reduced mold counts vs. CON (4.71 vs. 4.97 ± 0.05 log cfu/fresh g). At day 33, DM losses were decreased by PRP at 0.5 and 1% (0.9), relative to CON (6.92) and to NaL (6.63 ± 1.13%). Both TRT decreased NDF at 0.25% (46.3) and furthermore at 1% (44.2) relative to CON (49.4), but overall PRP had lower NDF (45.2) than NaL (47.2± 0.81% DM). No differences were observed for sugars and CP. Visual moldiness (0–10) and mold counts were also decreased by PRP at 0.5% (2.4 and 5.30) and 1% (0 and 2.7) relative to CON (6.0 and 7.13) and NaL (5.85 ± 0.67 and 7.21 ± 0.31 log cfu/fresh g, respectively). In conclusion, NaL failed to prevent spoilage of high moisture hay while PRP was effective at doses >0.5%.