Morning weights, when cattle are relatively empty because they’ve been resting during the night instead of eating, are generally less than mid-day or evening weights, when the gut is full unless cattle were held off feed before weighing.

Thomas heather
Freelance Writer
Heather Smith Thomas is a freelance writer based in Idaho.

Dr. Colin Palmer, department of large-animal clinical sciences, Western College of Veterinary Medicine, University of Saskatchewan, says shrink is often misunderstood – especially the drawbacks to cattle health. Cattle always do better (staying healthier and bouncing back more quickly after transport and sale) if they are not excessively shrunk during this stressful time.

“A study done at Kansas State University and University of Arkansas reported that steers gathered at daybreak from pasture and placed in holding pens without feed or water shrank at the rate of 1.25 percent of bodyweight per hour during the first two to 2.5 hours and 1.61 percent of bodyweight during the next 2.5 to three hours,” says Palmer.

Cattle shrink a lot at first, especially if they are sorted and moved around in corrals. They defecate and urinate more when nervous, and empty out fairly quickly.

Volume lost

Mature cattle carry nearly 30 percent of their weight in the gut (and bladder), and may lose a lot of weight quickly if held off feed and water for 24 hours or if they pass a lot of manure and urine in a short time, as when exercising or excited. “You can figure loss of 8 to 10 pounds per defecation or urination; a gallon of fluid weighs about 8 pounds.


Shrink losses of up to 10 percent of bodyweight are not uncommon in cattle held off feed and water for 24 hours, and in some circumstances shrinks of up to 18 percent can occur,” says Palmer.

Julie Walker, beef specialist at South Dakota State University, and Reid McDaniel, feedlot specialist at SDSU, offer tips to producers when marketing cattle. “Shrink is generally divided into two types,” says Walker. “Gut fill is one type. For research purposes, we often hold cattle off feed and water for 12 hours, or overnight, to reduce fill in the rumen. Whenever you start moving or handling cattle and they don’t have access to feed or water, this type of shrink starts immediately,” she says.

“The other type of shrink is due to fluid loss within body tissues (tissue shrink), and this starts at the same time but is more severe when cattle are off feed or water for a long time – such as a long transport or prolonged cattle working. An example would be if the rancher gathers cattle today out of the pasture, works and sorts them, puts the calves on a truck and sends them to a sale barn – and they didn’t have feed or water or didn’t like the feed or water. They may not eat or drink for 24 hours or longer,” explains Walker.

cattle being loaded for market

If they have no way to replenish fluid loss over an extended period, they become dehydrated with fluid loss from muscles and other body tissues. “This type of shrink takes longer to resolve than fill shrink; water in the tissues is harder to replace quickly. With fill shrink, the animals can eat and drink and be right back to normal."

"Tissue shrink takes longer, and how long depends on how much shrink has occurred and how long the animals were off feed or water,” she says.

“The expected amount of shrink (gut fill) when handling or moving cattle can vary from 2 percent to 15 percent of bodyweight,” says McDaniel. “I’ve heard reports of cattle leaving Georgia and going to Iowa feedlots and losing 15 percent on the road,” he says.

Time and money

Walker says shrink is estimated in terms of hours spent on the truck, but most producers think in terms of miles rather than hours. “An Oklahoma study estimated that cattle shrink 3 percent in the first 100 miles and about 0.5 to 1 percent shrink for every additional 100 miles,” she says. It’s most dramatic at first, and then tapers off, on a long trip.

McDaniel says many things play into how much shrink cattle experience. “This varies depending on their hydration and feed status before they get on the truck. How they are handled beforehand has a huge effect,” he says. It also makes a difference whether they were on lush green pasture or dry hay just before they are worked or hauled.

Sorting cattle

Walker says most buyers do a fair job of assessing shrink and predicting how much a certain set of calves might shrink. “If a group of calves are sold at the farm, or go through a ring at the sale barn, the buyer puts a pencil shrink on those calves in his mind to adjust them back to compare with calves that have been off feed or came into the sale barn the night before and refused to eat/drink,” she says. Pencil shrink is an equalizer.

Reid says shrink has to be estimated correctly by the buyer. “If you don’t get it right, and pay weight ends up being very much off from actual weight (calves actually weigh a lot less when they show up), you essentially went down the highway throwing out money. If real-life shrink is very much more than calculated shrink, you will never regain that money.”

Newly weaned calves (and their mothers – if a person is selling open cows right after weaning their calves) suffer the most shrink because they are too upset and stressed to eat or drink. Giving them a chance to adjust to weaning and be more relaxed and back on feed can greatly reduce their stress and shrink.

“Typically, older cattle have less shrink than feeder calves because of their body composition. Cull cows typically have less shrink than finished steers, and finished steers have less shrink than weaning calves under similar conditions,” says Walker.

Cattle load factors

It also makes a difference whether you are backgrounding cattle or putting them into the feedlot for a finishing program. “There is a clear relationship regarding health and shape of the cattle,” says McDaniel. “If they leave the farm and are on a truck for 18 to 22 hours, this is quite stressful.

Loading cattle

This is not as common in our part of the country, where most cattle are fairly close to the feedyard. Shrink involves loss of hydration, and if they arrive at their destination too dehydrated, they may get sick.” They don’t bounce back, and the stress of long transport (and this much shrink) hinders their immune system.

“If cattle come in looking gaunt, and it’s been hot in the truck, we try to get water and feed into them before we do anything to them, for at least 24 to 48 hours,” he says. They need time to recuperate before being subjected to any additional stress.

Walker says the number of cattle on the truck has an impact. “If you overfill or underfill (not a full load), this puts more stress on the animals. Ideally, you want to load that truck as close to capacity as possible, without crowding, to reduce shrink,” she says. If they are overcrowded, or just a few rattling around in there, they are more stressed.

“Every time we add stress to these animals, we increase shrink. Environmental conditions such as very hot or extremely cold adds stress. Handling procedures and previous diet are also factors.” Lush green feed, being mostly water, goes through the tract rapidly, whereas hay – especially grass hay – will stay in the gut longer.

“Preconditioning calves (already weaned and not stressing over where mom is) can also make a difference – and having the calves bunk-broke. Some people try to manipulate diet to try to reduce shrink, but the main thing to do is make sure the animals have a balanced diet and their mineral/vitamin needs are being met along with their energy and protein needs.”

There’s no magic formula or silver bullet to reduce shrink, but having cattle on drier feed just before shipping can help.

McDaniel says that when you compare effects of handling cattle and shipping them, versus simply holding them off feed and water, the handling/shipping has a larger impact on the amount of shrink. Low-stress handling cattle is crucial to help reduce shrink. 27548.png end mark

PHOTO 1: Cattle such as these that are going from Georgia to Iowa, face a longer road trip and may be more subject to shrink before arrival. 

PHOTO 2: Cattle being loaded onto a trailer to haul to an auction. 

PHOTO 3: Sorting cattle in a quiet manner reduces stress for the long haul. Photos courtesy of Reid McDaniel.

PHOTO 4:    A crew member watches as cattle load up for a trip to Minnesota from Missouri. Photo by Julie Brown.