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Bloat Prevention Through Feeding

Bloat can turn a quiet pasture into an emergency in a matter of hours. Most of the prevention work happens before the cattle ever see the risky feed, in how you plan, transition and watch them.

What bloat actually is

Cattle produce a lot of gas as feed ferments in the rumen, and a healthy animal gets rid of it by belching. Bloat happens when gas is trapped or produced faster than the animal can release it, and the rumen swells on the left side behind the ribs.

There are two broad types. Frothy bloat comes from foam that traps the gas, and it is the type linked to lush legume pastures and some high-grain rations. Free-gas bloat comes from a blocked esophagus or an animal that cannot belch for another reason. This article is about the feeding side, but any swollen animal is a vet call.

Feeds and situations that raise the risk

Risk is highest when cattle move quickly onto something rich that their rumen is not ready for. Hungry cattle that gorge make it worse, because they eat fast and eat a lot before the rumen adjusts.

Pay extra attention in these situations:

• Turning hungry cattle onto lush, young legume pasture
• Sudden changes in grain or concentrate level
• Wet, frosty or rapidly growing forage that is very high in moisture
• Finely ground feed with little long-stem fiber in the diet
• Cattle that have been held off feed during gathering, shipping or weather

Transition cattle slowly and on a full stomach

The simplest tool you have is the order of events. Before turning cattle onto a risky pasture, let them fill up on dry hay or a mature, grassy pasture so they are not ravenous when they arrive. Then limit the first sessions on the new forage and build time gradually, watching the herd each day.

Do the same with grain. Step feed up in small increments and give the rumen time to adapt, following the plan your nutritionist writes for your cattle and your feed. Do not guess at amounts, and do not make big jumps because the weather turned or a truck showed up early.

Managing legume and mixed pastures

Mixed stands that carry a healthy share of grass are generally safer than pure legume stands, because the grass dilutes the bloat-causing material. Your local extension specialist can tell you which legumes in your region carry the most risk and which do not.

Plan grazing so cattle are not put on the highest-risk pasture when it is wet, frosty or at its most rapid growth stage. Rotational systems let you control timing, but they also move cattle onto fresh forage often, so each move needs the same full-stomach routine. Ask about management practices and feed additives that fit your herd and follow label directions and your vet's guidance exactly.

Daily checks and records

Look at the cattle every day, and look at them a few hours after any change in feed or pasture. A left side that looks fuller than usual, an animal standing apart, reluctance to move, discomfort or labored breathing are all reasons to act fast.

Keep a simple log of pasture moves, feed changes, weather and any animals that looked off. Over a few seasons that record will show you the patterns on your own ground, which is worth more than any general rule.

What to ask your vet and nutritionist

Bring your actual pasture species, your usual transition plan and your handling setup to the conversation. Ask what an emergency plan should look like for your operation, who to call after hours, and what you should and should not do while you wait. Any treated animal must be held for the withdrawal time on the label or set by your vet before it enters the beef supply, and that protects the whole industry.

A feeding-day routine that lowers risk

On days when cattle move to a new pasture or get a new feed, set aside time to be there. Move them in the morning rather than late in the day so you have daylight to watch them afterward, and avoid moves right before bad weather or a holiday when help is short.

Keep the handling facilities and a headgate ready, and make sure everyone on the crew knows the plan and the phone number for your vet. Practicing the plan once costs nothing and saves minutes when they count.

Weather matters as well. Forage wet from rain or dew, or stressed by frost, behaves differently in the rumen than the same forage on a dry afternoon, and cattle eat fast when weather is changing. On those days, offer dry hay first, hold off on the highest-risk fields and check the herd more often.

More in Nutrition, Forage & Grazing

• Feeding Cull Cows
• Nutrition for Calving Cows
• Postpartum Nutrition in Beef Cows
• Nutrition and Rebreeding
• Grazing Behavior of Beef Cattle
• Pasture Weighing and Monitoring