Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/8/2006
Publication Date: 8/1/2006
Citation: Min, B.R., Pinchak, W.E., Anderson, R.C., Fulford, J.D., Puchala, R. 2006. Effects of condensed tannins supplementaion level on weight gain and in vitro and in vivo bloat precursors in steers grazing winter wheat. Journal of Animal Science. 84:2546-2554. Interpretive Summary: Frothy bloat in cattle grazing wheat pasture is a major cause of death and illness and occurs when too much gas and slime is produced during digestion of the eaten forage. The present study was conducted to determine if certain compounds, called tannins, contained in a plant called quebracho could slow the rate of gas and slime production in gut contents collected from cattle eating wheat forage. We found that the quebracho tannins decreased the rate of gas production in the cattle’s gut contents and that the cattle fed the tannins had less bloat than cattle not fed the tannins. The cattle fed the tannins also gained weight faster than cattle not fed the tannins. We conclude that quebracho tannins are potentially a value-added supplement that could be fed to cattle grazing wheat pasture to decrease the impacts of frothy bloat and increase weight gain. This research will ultimately benefit the American consumer by helping farmers and ranchers produce less expensive beef products.
Technical Abstract: Research was conducted to determine the effects of level of supplementation with quebracho condensed tannins (CT) on in vitro ruminal fluid gas production, in vivo ruminal fluid protein fractions, bloat dynamics, and ADG of steers grazing winter wheat. Two experiments were conducted to 1) enumerate the effect of ruminal fluid from steers fed quebracho CT (0, 1, and 2% CT/kg of DMI) on in vitro gas and methane production from minced fresh wheat forage; and 2) quantify the influence of CT supplementation on ruminal protein characteristics, biofilm complexes, bloat potential, and ADG of steers grazing wheat pasture. Eighteen ruminally cannulated steers (386 ± 36 kg of BW) were randomly allocated to 1 of 3 treatments that included a control (water infusion) and 2 CT treatment levels (1 or 2% CT/kg of DMI). Treatments were administered daily (63 d) through the rumen cannula as pre-mixes with warm water (approximately 30°C). Rumen contents were collected 2 h postinfusion (at 1030 to 1130) on d 0, 20, 40, 50, and 60. Bloat was visually scored daily for 5 d each wk. In Exp. 1, supplementation of CT decreased the rate of in vitro gas production in a dose-dependent response. In Exp. 2, ADG increased (P < 0.04) at both levels of CT supplementation. Mean bloat score across stage of growth and replicates decreased linearly with increasing CT supplementation; bloat scores were greater (P < 0.001) for the vegetative than for the reproductive stage of plant growth. Biofilm production and rumen fluid protein fractions varied among CT treatments and stage of growth. Addition of CT reduced the severity of bloat, principally through reducing microbial activities, biofilm production, and ruminal gas production. Quebracho CT is potentially a value-added supplement that can decrease the impacts of frothy bloat and increase BW gains in stocker cattle-wheat systems.