Using Bur Clover and Managing for Frothy Bloat

In a previous post I talked about the advantages of using bur medic as part of a pasture mix in South Texas. In this current post I would like to discuss some advantages and managing for the biggest disadvantage of using cool season annual legumes in your pasture rotation.

In my scouting the fields and pastures of Karnes County I am seeing all kinds of bur medic species flourishing in many pastures. I am seeing entire fields that were severely impacted by drought conditions being dominated by bur medic species. I have even been seeing common bur medic which I have not seen in years. In the picture at right, common bur medic is the species in foreground with dark red spot at the base of the leaf. Spot can also be orange. 

This is a good thing for several reasons:

1.      Lessen our dependence on hay and feed resources allowing cows and calves nutritious and plentiful forage.  Bur medic will average 14% protein and 80-90% TDN.

2.      Increase fertility as we go into summer as bur medic is capable of adding up to 50 units on Nitrogen back to the soil after it has finished its lifecycle and through nutrient recycling through cattle.

However, one of the main disadvantages is that it can cause frothy bloat in cattle that eat too much of this legume or other lush grasses. It is a big concern for cattle coming off of drought stressed pastures.

What is frothy bloat?

Frothy bloat is the most common form of bloat, and is where gas builds up in a foam or froth above the liquid/semi-liquid fraction of the rumen content and the normal belching is inhibited. Observable bloat can occur after as little as 15 minutes of grazing. Often the animal bloats only mildly and stops eating. The discomfort is eventually relieved. In more severe bloat, the animal's rumen is distended by ballooning of the rumen, it urinates and defecates frequently, bellows and staggers. Death, due to restricted breathing and heart failure follows unless action is taken.

You can prevent frothy bloat numerous ways: 

1.      In cattle that exhibit early signs I have had some success moving or following them at a walk or trot with a horse or 4 wheeler. However, this does not work after the earliest stages.

2.      Consider using Bloat Guard® (Poloxalene) during periods where bloat is likely. Poloxolene can be mixed with grain supplement or drinking water, drenched, or fed as a pasture block. Effectiveness of this product depends on daily intake. Thus mixing with a daily supplement is more effective than feeding in blocks on pasture. Another useful product is Rumensin® which has also shown efficacy in reducing the incidence of bloating

3.      One of the simplest and most effective practices is to keep dry grass hay available to cattle while they are on these pastures. Keep it in a high travel area near water so they will be inclined to eat at least some hay. Remember that not all animals will eat adequate amounts of hay since they have preferences just like we do.

4.      Do not start animals grazing when the forage is wet from dew or rain. I learned this when I lived in New Mexico where we grazed stockers on alfalfa fields.

5.      Start animals on legume pastures gradually. For example, leave cattle on pasture 1 hour the first day and gradually increase grazing time to 4 hours by the third day and day-long grazing by day five. Another strategy we used in New Mexico with stockers on alfalfa.

6.      Be sure that fiber is maintained in the animal ration during initial grazing periods. As mentioned in #2 above, feed some dry hay or corn silage to grazing animals prior to turning them out to pasture. 

7.      Check animals for bloat carefully every two hours when beginning grazing.

8.      When rotating cattle or sheep among pastures, be sure that animals are moved fast enough so that they are not excessively hungry when going onto fresh pastures. In other words: keep cattle full!

9.      Animals with supplemental feed will be less likely to bloat. For example, a dairy cow, where 40 to 50 percent of the intake is pasture will be less likely to bloat than beef cattle, dairy heifers, and sheep, where pasture comprises 100 percent of the diet. Stocker cattle receiving at least a couple of pounds of supplement are also less susceptible.

10.  Some animals are chronic bloaters. If a particular animal frequently shows signs of bloat, it may be best to remove that animal from the herd and place them in areas without the lush grasses. Always keep your eyes peeled for chronics.

What do you do if cattle still bloat:

Inevitably, no matter how hard you try and how well you manage, you will still, from time to time, encounter some problems with bloating. When bloat is observed, immediately remove all animals from pasture and offer dry hay. This will reduce the bloat problem in all animals that will eat. Forcing bloated animals to walk, as mentioned above, is also helpful. Bloat can cause death in as little as 1 hour so it is important to be prepared to render emergency treatment. When handling an effected animal remember to move them calmly and quietly. As noted, the walking may improve the physical conditions in the rumen causing the animal to eructate, thus releasing some of the gas. If the bloating has not been lessened once you get the animal to the pen then several options are possible. They include:

1.      Stomach tubing – this involves restraining the animal and passing a rubber hose down it's esophagus (taking care to avoid passing it into the animal's trachea) and into the rumen providing a mechanical release of the gas. 

2.      Administration of oil – using a vegetable oil drench will reduce the surface tension and allow the gas to escape.

3.      If neither of these work call your veterinarian.

Conclusion

It is much more effective to take a proactive stance in the prevention of bloat than have to treat it after it occurs. In most cases this involves planning and understanding that some isolated incidences may very well occur. Good management is crucial to prevention.