Management of shrinkage in calves coming out of wheat pastures

Many of the calves that grazed on wheat this winter were removed earlier in March so that a crop of wheat could be harvested. However, some of the calves have just come out of pasture wheat and other cool season cover or forage crops in preparation for planting cotton or summer grains like milo or soybeans. Price adjustments to compensate for different shrinkage conditions are common in the beef industry. Ranchers, cattle feeders and cattle dealers are constantly seeking more information about declining cattle numbers through marketing channels.

Generally, the amount of shrinkage varies with the type of feed before penning and transportation.

Cattle consuming moisture-rich diets, such as wheat pasture, tend to shrink more when removed from the diet than cattle fed drier diets. Wheat pasture often contains 25% or less dry matter, or over 75% water, one of the wettest diets, making it notorious for a high rate of shrinkage when cattle are removed from the pasture and transported to markets or feedlots. In addition to diet, there are many other management factors that influence body weight loss and shrinkage rate, including time without food and water, weather conditions, and weighing conditions (such as handling, the distance between the pasture and the paddocks and the disposition of the livestock).

Calves on wheat at Oklahoma State University were pulled from pasture and weighed, then either herded into facilities next to the pasture or walked on an adjacent dirt road for a total of 1.6 miles. The calves were then mixed and kept in the pens in a dry pen for 24 hours. After the 24 hour reduction, the cattle were reweighed and returned to pasture for 25 hours to determine the extent of weight recovery. When the cattle were weighed again after 24 hours, they decreased by more than 8%. Driving cattle on foot for 1.6 miles did not increase the amount of shrinkage compared to simply removing them from pasture and holding them for 24 hours without food or water. The shrinkage rate is quite high, linked to the very high moisture content of the wheat forage, but the cattle regained all the lost weight after 6 hours after being put back on pasture.

Two weeks later, this same group of steers were transported on trailers for 4 hours, either directly out of wheat pastures or after having access to hay and water for 24 hours. After 4 hours in transit, steers straight out of wheat lost 37 pounds (5.1% shrinkage). Steers given access to hay prior to transport lost 28 pounds (3.85% shrinkage) during the same transport. This shows that shrinkage losses were approximately 1.18% per hour of transport, but access to dry hay prior to transport decreases shrinkage, possibly due to a slower rate of passage of food in the digestive tract and less water loss.

Source: Paul Beck, Oklahoma State University, which is solely responsible for the information provided and is wholly owned by the source. Informa Business Media and all of its affiliates are not responsible for any content contained in this information asset.