The effects of poloxalene on ingestion by cattle grazing Lucerne†

Abstract

The mechanisms that terminate meals of cattle grazing lucerne {Medicago sativa L.) are not well defined. Sub-acute bloat may lead to cessation of grazing and, consequently, surface active substances used in the treatment and prevention of bloat, such as poloxalene, may extend grazing meals and increase herbage intake. Twelve mature Angus cows (Bos taurus) were offered 0, 12-5 and 25-0 g poloxalene in 0-5 kg of crushed maize (Zea mays L.) kernels each day, immediately before two consecutive 1-h measured parts of a grazing meal on 21-to 24-day-old lucerne swards with a herbage dry matter (DM) mass (>5 cm) of 2-03 t ha"' and herbage DM mass allowance of 3 • 55 kg hd " 'h "'. Total herbage DM intake was 2-52 kg hd"' during the first hour and 1-54 kg hd"' during the second hour of the 2-h gt^azing meal. Differences in herbage intake were attributable to a cessation of grazing. Mean rates of biting were 26-3 and 14-8 bites min"' and mean DM intakes per bite were 1-82 and 4-38 g during the first and second part of meals, respectively. Poloxalene treatments caused a small linear decline in grazing time during the first part of meals and a larger increase in grazing time during the second part of meals. Lower rates of Correspondence: C. T. Dougherty, Department of Agronomy, University of Kentucky, Lexington, KY 40346-0091, USA. t The investigation reported in this paper (Journal Paper 90-3-67) is in connection with a project of the Kentucky Agricultural Experiment Station and is published with the approval of the Director. 180DM intake caused by poloxalene were offset by increases in grazing time. It was concluded that poloxalene moderated ingestive behaviour within grazing meals of immature lucerne and this response may have been at least partly due to the relief of sub-acute bloat.

Effect of grazing system, stocking rate and season of use on herbage intake and grazing behaviour of stocker cattle grazing alfalfa-grass pastures

“…Increased herbage availability resulted in increased intake in pastures of similar digestibility and protein content (Dougherty et al 1988), such that animals could graze up to 0.5% (herbage DM) of their bodyweight per hour (Dougherty 1989a). Other studies by Dougherty et al (1992) showed that poloxalene, as used in the present experiment to reduce the incidence of bloat, had minimal effects on voluntary intake by cattle on alfalfa pastures.…”

Spring Lamb Production on Alfalfa, Sainfoin, and Wheatgrass Pastures

“…Bloat Guard intake was 2 g of poloxalene (bis[hydroxyethylpoly(ethyleneoxy)ethyl]polypropyleneglycol) per lamb per day. Dougherty et al (1992) showed that total herbage DM intake of alfalfa grazed by cattle was not affected by poloxalene. Lambs on the remaining treatments were fed 190 g of supplement (without Bloat Guard) per lamb per day to prevent differences among treatments being confounded with supplement feeding.…”

Enhancing pasture productivity with alfalfa: A review

“…Anti-foaming agents (e.g., poloxalene) have been widely used for controlling bloat (Dougherty et al 1992;Majak et al 1995;Popp et al 1997c ), but difficulties remain, relating to ensuring consistent dosage of animals and cost effectiveness. Providing a free-choice supply of poloxalene mixed with salt is one method, although consumption levels can be inconsistent.…”