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ARS Home » Plains Area » Bushland, Texas » Conservation and Production Research Laboratory » Livestock Nutrient Management Research » Research » Publications at this Location » Publication #325650
Title: Post-extraction algal residue in steam-flaked corn-based diets for beef cattle

Author
item SARTURI, JHONES - Texas Tech University
item MACDONALD, JIM - University Of Nebraska
item WICKERSHAM, TRYON - Texas A&M University
item Cole, Noel
item MCCOLLUM, TED - Texas Agrilife Extension
item PINDEO, PABLO - Texas A&M Agrilife
item Meyer, Beverly

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/24/2015
Publication Date: N/A
Citation: N/A

Interpretive Summary: By-products of various biofuel industry are high in nitrogen and thus maybe suitable feed ingredients for finishing beef cattle. The effects of post-extraction algal residue (PEAR) as N source in steam-flaked corn-based (SFC) beef cattle finishing diets were studied by scientists from ARS (Bushland, Texas), Texas Tech University, University of Nebraska-Lincoln and Texas A&M AgriLife Research and Extension Service. Results indicated that feeding the post-extraction algal residue can be used as nitrogen source for beef cattle diets and residue coupled with other ingredients supplying high levels of degradable intake protein may improve ruminal fermentation. These results are of interest to beef feedyard operators that are in proximity of plants using algal sources as a means of producing biofuels.

Technical Abstract: The effects of post-extraction algal residue (PEAR) as N source 23 in steam-flaked corn-based (SFC) beef cattle finishing diets on intake, duodenal flow, digestion, ruminal microbial efficiency, ruminal parameters, and blood constituents were evaluated. Ruminally and duodenally cannulated steers (BW = 441 ± 37 kg) were randomly assigned to a 6 x 6 Latin square design. Control diet (CTL) contained 79.5% SFC, 10.0% alfalfa hay, 5.0% sugar cane molasses, 3.0% yellow grease, and 2.5% supplement. In the remaining treatments, PEAR and/or urea replaced the original SFC inclusion at the rate of: PEAR-1: 10% PEAR; PEAR-2: 15% PEAR; PEAR-3: 15% PEAR + 0.6% urea; Urea-1: 0.75% urea; Urea-2: 1.5%. The experimental periods were 21 d (15 d for diet adaptation and 6 d for data collection). Data were analyzed with Glimmix procedure of SAS using repeated measures for daily observations. Steers fed PEAR-2, PEAR-3 and CTL had 24% less (P = 0.02) DMI compared to steers fed Urea-1. The maximum N intake was observed for steers fed Urea-1 and Urea-2, which was 31% greater (P < 0.01) compared to the average steers fed PEAR-2, PEAR-3 and CTL. Total tract DM digestibility was 36 6% greater (P < 0.01) for the average of PEAR-3, Urea-1 and Urea-2 compared to PEAR-2 and CTL. Steers fed PEAR-1 and PEAR-3, had similar OM digestibility coefficients compared to Urea-1 and Urea-2. Total DM and OM duodenal flow was not affected (P = 0.45). However, steers fed PEAR-3 showed 31% greater (P = 0.03) microbial OM duodenal flow compared to the average of steers fed PEAR-1, PEAR-2 and CTL. Dietary treatments did not (P = 0.24) affect total duodenal N flow. Though, microbial duodenal N flow was reduced by 36% (P = 0.04), when steers were fed CTL compared to the average of Urea1, Urea-2 and PEAR-3. Ruminal microbial N efficiency for steers fed PEAR-3 was 28% greater compared to the average of CTL, Urea-1 and PEAR-1. The blood of steers fed Urea-2 diet showed the highest values of BUN and P serum concentrations (P = 0.03), recording 8.81 and 6.54 mg/dL, respectively. PEAR-1 showed the greatest Ca serum concentration (P = 0.02). Total tract and ruminal starch digestibility indicates that PEAR can be used as an N source for beef cattle finishing diets. Combination 47 of PEAR and N source with high DIP characteristic may improve ruminal fermentation pattern.