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Effect of chemical and biological preservatives on the dry matter loss, nutritional composition, microbial counts, and aerobic stability of ensiled wet brewer's grain.

M. Killerby

Events

06-23-2020

Abstract:

249
Effect of chemical and biological preservatives on the dry matter loss, nutritional composition, microbial counts, and aerobic stability of ensiled wet brewer's grain.
M. Killerby*1, S. T. R. Almeida2, R. Hollandsworth1, B. C. Guimar�es2, A. Y. Leon-Tinoco1, Z. Ma3, D. Coffin4, B. Perkins5, S. Annis6, C. Knight4, C. Wu7, J. Bolton4, J. J. Romero1. 1Animal and Veterinary Sciences, School of Food and Agriculture, University of Maine Orono, ME, 2Department of Animal Sciences, University of Lavras Lavras, Brazil, 3Department of Animal Sciences, University of Florida Gainesville, FL, 4University of Maine Cooperative Extension Orono, ME, 5Food Science and Human Nutrition, School of Food and Agriculture, University of Maine Orono, ME, 6School of Biology and Ecology, University of Maine Orono, ME, 7Department of Animal and Food Sciences, University of Delaware Newark, DE.

This study evaluated the effects of a wide array of preservatives on spoilage of wet brewer's grain (WBG) silage. Treatments (TRT) were sodium lignosulfonate at 1% (NaL1) and 2% (NaL2; wt/wt of fresh WBG), propionic acid (PRP; 0.5% wt/wt of fresh WBG), a combination inoculant (INO; Lactococcus lactis and Lactobacillus buchneri each at 4.9 log cfu/fresh WBG g), and untreated (CON). Five batches of unroasted WBG were collected from the same source right after lautering and cooled to room temperature for 1 d before treatments were randomly applied to each batch. Treated WBG were packed into 8.8 L mini-silos and stored for 60 d at 21�C. Data were analyzed as a randomized complete block design (5 blocks) and differences were declared at P ≤ 0.05. At d 0, no differences were observed for sugars (~28.8 � 1.88% of DM) and yeast counts (~2.89 � 0.346 log cfu/fresh g) across TRT, but NaL2 and NaL1 had a higher DM (~23.4) relative to CON (21.2 � 0.21%). PRP had a lower pH (4.63) and lactic acid bacteria counts (LAB; 4.50) relative to the other TRT (~6.13 � 0.024 and ~5.65 � 0.229 log cfu/fresh g). At opening (d 60), PRP had a lower DM loss (5.06) and a markedly better preservation of sugars (25.0) relative to all other TRT (~10.5 � 1.26% and ~13.6 � 1.36% of DM). However, PRP decreased LAB (6.74) relative to the other preservatives (~7.94), except CON (7.27 � 0.201 log cfu/fresh g). CON and INO had a higher NDF (~47.7%DM) than the other treatments (~41.2 � 0.77), and lower DM (~21.7) than PRP (23.6 � 0.33%). CP was lower for PRP, NaL1, and NaL2 (~24.5 � 0.42% of DM) compared with CON (27.4), and NH3-N (% of N) was higher for PRP and INO (~0.84) relative to other TRT (~0.50 � 0.057). No major differences were observed for yeast (~4.27 � 0.366) and mold (<2 log cfu/fresh g) counts. Aerobic stability (h) was greater for NaL2 (103.2) relative to PRP (61.9) but no differences were observed vs. CON (90.1 � 8.86). In conclusion, PRP preserved WBG nutrients during storage to the greatest extent, compared with the other preservatives tested.

Keywords: wet brewer's grain, silage, preservatives.