Title: Use of crude glycerin in steam-flaked corn-based growing diets Authors
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: February 15, 2012
Publication Date: March 19, 2012
Citation: Bondurant, R.G., Luebbe, M.K., Hales, K.E., Cole, N.A., Macdonald, J.C. 2012. Use of crude glycerin in steam-flaked corn-based growing diets. Journal of Animal Science Supplement. 90: 45-46. Technical Abstract: Three experiments were conducted to evaluate the use of crude glycerin in steam-flaked corn (SFC) based beef cattle growing diets. Experiment 1 utilized 50 crossbred steers (initial body weight (BW) = 282 +/- 2 kg) to determine the effects glycerin concentration (0.0, 2.5, 5.0, 7.5, and 10.0% dry matter (DM) inclusion) on steer performance. In experiment 2, 54 crossbred steers (initial BW = 283 +/- 1 kg) were used to determine the effects of replace SFC or alfalfa hay (ALF) with crude glycerin on animal performance. Dietary treatments consisted of 0.0% crude glycerin (CON) or 7.5% crude glycerin which replaced either ALF (REPALF) or SFC (REPSFC). In experiment 3, in-vitro volatile fatty acid (VFA) concentrations were determined after 48-h of fermentation comparing crude glycerin, SFC, and ALF as substrates. In experiment 1, increasing dietary crude glycerin concentration resulted in a linear decrease in BW gain: feed DM intake (P = 0.05). Steer average daily gain and final BW tended (P = 0.08) to increase in a quadratic manner with 7.5% crude glycerin resulting in the greatest responses among treatments. No difference was found for final BW and dry matter intake (P > 0.11). In experiment 2, final BW increased 12 kg (P =0.04) for steers fed REPALF vs. CON. Steers fed REPALF also had a greater average daily gain of 0.17 kg/day (P= 0.03) vs. CON. Final BW and daily gain were similar for CON and REPSFC (P > 0.51). No differences in dry matter intake or gain: Feed intakes were found among treatments (P > 0.25). In experiment 3, using glycerin as a fermentation substrate resulted in an 83% increase in total volatile fatty acid concentration compared to ALF (P < 0.01), and similar total volatile fatty acid concentration compared to SFC (P = 0.42). The acetate to propionate ratio was reduced 12-fold for glycerin vs. SFC (P < 0.01), and reduced 25-fold for glycerin vs. ALF (P < 0.01). Crude glycerin appears to have a minimal impact on animal performance when replacing SFC, although the weight gain: feed intake ratio may be reduced by up to 4.5% when including glycerin at 7.5% of the diet dry matter, where average daily gain appears to be maximized. The energy value of crude glycerin is greater than ALF but appears to be less than SFC.