Impact of humate supplementation on ruminal microorganisms grown in continuous culture fermenters

Abstract

Twelve continuous culture experiments were conducted to determine the impact of humate (H) supplementation on pH ammonia (ppm), DM,NDF, ADF and HC disappearance in the bovine run-ruminal ecology. The continuous culture system was comprised of 8 fermenters (FT) innoculated with ruminal fluid, using 2 FTs/treatment. After a 40 h adaptation period each experiment was conducted for 96 h. Four diets were used- 1) a low quality forage (Coastal hay) (CD) [Exp. 1-3], 2) a high quality forage (Alfalfa hay) (AD) [Exp. 4-6], 3) a mixed diet (GD) [Exp. 7-8], 4) a high grain diet (FD) [Exp. 10-1 2]. The 2 initial experiments for each diet used H levels of 00/o, 0. 5%, 1. 00/o, and 2.0% relative to DM input. The third experiment for each diet used H levels of 00/o, 0. 125%, 0.25%, and 0. 5% relative to DM input. DK NDF, ADF, and HC disappearance were only measured in the third experiment of each diet with the lower level H treatments (Exp. 3, 6, 9, & 12). pH of the H FTs on CD and AD were not different relative to the controls (P > .05). pH for the H FTs on GD resulted in a linear increase (P <.001) with increasing H. pH for the H FTs on FD were lower relative to the control at 5% to 1. 00/o H (P < .05). H FTs on CD demonstrated a linear decrease in ammonia with increase in H relative to control (P <-05). Ammonia in H FTs receiving 1.00/% H was lower(P<.05)relative to control on the AD. Ammonia for HFTs on GD decreased quadratically (P < . 00 1) with increasing H. H FTs on FD showed a linear increase in ammonia at 1. 0% H (P <. 05) and 2. 0% H (P < . 00 1). The H did not demonstrate differences in DM, NDF, ADF, and HC disappearance relative to control (P>.05). In conclusion, H supplementation demonstrates the capacity to elevate pH for the GD and lower ammonia levels for the CD, AD, and GD.