Bloat in ruminants

A direct action of flavones on smooth muscle (distinct from the potentiation of epinephrine action mentioned earlier) has been reported. Most conspicuous is the action on rabbit intestine reported by Ferguson (1948) and Ferguson et al. (1949,1950) and offered as a possible explanation of bloat in ruminants following overconsumption of herbage plants... 

It has been known for more than half a century that antifoams consisting of mixtures of PDMS and hydrophobic silica can be used to dispel excessive gas in the gastrointestinal tract. However, the first use of antifoams in this context was reported by Quin et al. [8] more than 60 years ago and concerned treatment of bloat in ruminants. That the hydrophobed silica is a necessary component of an effective PDMS-based antifoam in vivo was first demonstrated by Birtley et al. [9] using X-ray observation of the stomachs of rats in which foam had been artificially produced. 

Clinical signs include profuse salivation, incoordination, violent seizures, bloating in ruminants, and colic in horses. Early signs ace followed by hnidycaidia or tachycardia, arrhythmias, hypotension, arid hypothermia. Death may cxrcur from 1-3 days after ingestion of the milkwe. ... 

In ruminants, lecithins have also been shown to control bloat, a digestive disorder typihed by distension of the rumen. The distension is caused by the formation of a foam above the rumen hquor, which blocks the escape of gases (325). 

Saponins are present in many pasture plants (Bondi et al., 1973). Appreciable quantities accumulate in some, especially in certain forage legumes. These compounds are probably involved in the condition known as ruminant bloat. By altering the surface tension of the ruminal contents, saponins cause gas formed in the rumen by anaerobic bacterial fermentation to be entrapped as a froth. When fed to cattle, saponins elicit characteristic symptoms of bloat. In mono-gastric animals, saponins are responsible for reduced growth rate and decrease in food consumption. Poultry are particularly sensitive to alfalfa that contains saponins. Swine are less sensitive (Applebaum and Birk, 1979). 

There is no clear evidence that tannins are harmful in ruminant diets. On the contrary, many reports suggest possible beneficial effects. Condensed tannins can effectively protect dietary protein from microbial destruction in the rumen and prevent bloat in cattle (Donnelly and Anthony, 1969 Saba et al., 1972 Drledger and Hatfield, 1972 Clark and Reid, 1974 Kendall, 1966). These beneficial effects may arise due to a lower microbial competition for starch and proteins in the rumen (Hatfield, 1970). Driedger and Hatfield (1972) observed that the treatment of soybean meal with 10% tara tannic acid reduced deamination of the meal by rumen... 

In ruminants, the principal cause of bloat (a sometimes fatal condition of high rumen pressure) appears to be the formation of a stable foam in the reticulo-rumen (Reid et al., 1974). The foaming, which causes pressure retention, appears to be due to the soluble plant proteins in the rumen (Clark and Reid, 1974) and is prevented by protein precipitation with tannins (Jones et al., 1973). The production of gas by microbial fermentation is also inhibited. 

The fluids have also found a number of uses in medicine. Barrier creams based on silicone fluids have been found to be particularly useful against the cutting oils in metal machinery processes which are common industrial irritants. The serious and often fatal frothy bloat suffered by ruminants can be countered by the use of small quantities of silicone fluid acting as an antifoam. 

Lees GL. 1992. Condensed tannins in some forage legumes their Role in the prevention of ruminant pasture bloat. Basic Life Sci 59 915-934. 

Under normal conditions, rumen fermentation produces gases that, by the action of ruminal and reticular contractions, accumulate in the area known as the cardia, from which they are passed up the oesophagus in the process of emctation. Bloat occm if the gas becomes trapped and the animal is not able to clear it. Rumen stasis due to acidosis is one of the causes of free gas bloat, but on certain pastures, particularly those rich in legumes, and on high-concentrate (feedlot) diets, the fermentation process in the rumen can result in rumen gases being trapped within fluid bubbles. Therefore, the gas cannot be eructated as normal and pressure builds up in the rumen. The condition is known as... 

Tannins were primarily considered as anti-nutritional biochemicals due to then-adverse effects on feed intake and nutrient utilization (Kumar and Vaithiyanathan 1990). Nevertheless in recent years, they have been recognized as nsefnl phytochemicals for beneficially modulating the rumen microbial fermentation. The effects of tannins on ruminant production have been published in the past, which primarily focused on the adverse effects of tannins on animal systan, with some discussion on their positive effects on protein metabolism and prevention of bloat (Mangan 1988 Kumar and Vaithiyanathan 1990 Aerts et al. 1999 Barry and McNabb 1999 McSweeney et al. 2001a Min et al. 2003 Mueller-Harvey 2006 Waghom 2008). This chapter focuses on the effects of tannins on ruminal microbial populations that affect N metabolism, methanogenesis and ruminal biohydrogenation process in the mmen. 

Seizures often accompanied by excitement belligerence , tremors urination and bloat occur in cattle most commonly ects ruminants... 

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