Ron Torell, Area Livestock Specialist
Willie Riggs, Eureka County Extension Educator
Ben Bruce, State Livestock Specialist
Bill Kvasnicka, Extension Veterinarian

Introduction

The Boy Scout motto, "Be Prepared" is sound advice. This should also be the motto of cattlemen sending northeastern Nevada calves long distances to wheat pasture. The stresses of shipping, acclimation and diet change can be overwhelming and devastating to young calves. Additionally, there are potential problems associated with winter grazing wheat pasture. The calf needs to "be prepared" for these challenges.

This paper discusses how to select and prepare cattle for wheat pasture grazing and discusses some of the potential problems associated with grazing wheat pasture. Companion papers discuss the following:

• Economics and Performance of Lightweight Northeastern Nevada Calves Grazing Texas Wheat Pasture.A Marketing Alternative Case Study.
• How Good is Wheat Pasture for Winter Grazing Light Weight Calves.
• How to Find and Secure Wheat Pasture for Grazing.
• Agronomic, Cultural and Livestock Management Practices of Wheat Pasture Grazing.

Selecting Cattle for Wheat Pasture

Selection of lightweight calves for wheat pasture grazing should include only healthy and thrifty animals. Oftentimes calves are light because they are young, from a first or second calf heifer or aged cow, or they have been on poor feed. These calves generally have good growth potential. Chronic, poor producing calves that have been stunted should be avoided. Producers often refer to these types of calves as "dinks," "hairballs," or "chronics." These types of calves are losers wherever they go.

Two Oklahoma trials show that early-weaned calves (2-3 months of age) must weigh a minimum of 320 pounds and be at least 160 days of age before daily gains can be expected to reach two pounds per day. Even though the rumen is fully functional in these extremely small and young calves, the lower weight gains are probably due to a lack of rumen capacity. This lower capacity makes it impossible for the light calf to consume enough wheat pasture to meet their daily dry matter requirements. Performance will be improved if 350-pound or heavier calves are placed on wheat pasture. Lightweight calves are capable of utilizing the available protein contained in wheat pasture better than heavier weight cattle. This is primarily due to the higher protein requirements for growth of the lighter and younger calves.

The type of wheat pasture grazed will dictate the most economical size of calf to initially stock pastures with. Graze-out acreage (wheat pasture grazed past March 1 and not harvested for grain) is best suited for those calves weighing less than 400 pounds at placement time. Placement usually occurs by mid November or early December. With a growth rate of two pounds per day for 150 days (December 1 to May 1) the 400-pound stocker calf will weigh approximately 700 pounds at grazing termination on May 1. The 700 pound feeder is then at an ideal weight to enter the feedlot. Placing a larger calf on graze-out wheat results in a heavier feeder calf entering the feedlot in May. These heavier feeders are often less efficient during the feedlot phase.

For grain harvest wheat pasture, a November placed calf should weigh approximately 500 pounds. This would result in a 700-pound feeder calf at grazing termination on March 1. A lighter calf will result in a feeder calf entering the feedlot in March that would require more days on feed during the more expensive feedlot phase.

Both steers and heifers are grazed successfully on wheat pasture. Steers generally out perform their heifer mates. When grazing heifers you have the problem of estrous heat cycles and bullers. The problem is compounded when steers and heifers are run in common. Steers riding cyclic heifers often do not perform as well as steers fed separately. Feeding MGA during the late grazing season when heifers have reached puberty will suppress cyclic and bulling activity. The MGA feeding information should be passed on to the next owner or manager of the cattle. Removing heifers from the MGA program would cause them to cycle simultaneously thus reducing weight gains.

* If resistance and challenge lines should cross disease and possible death would result.

Bloat

Frothy bloat can be a major cause of death in stocker calves grazing wheat pasture. Wheat pasture is a low fiber, high moisture feed. Additionally, wheat pasture is deficient in calcium. When calcium is deficient, the rumen does not contract and mix rumen contents. A static rumen may block the esophageal opening and not allow the animal to release the rumen gases. Bloat seems to be compounded in high stocking rate situations because the forage is kept at an immature height and volume. This lowers the fiber content reducing the amount of dry matter consumed by animals.

Feeding a calcium supplement, free choice, high fiber grass hay and using conservative stocking rates will all aid in the reduction and prevention of bloat. It has also been shown that the addition of rumensin in the mineral or energy supplement will not only increase weight gains but also reduce the incidence of bloat. Studies have shown that feeding poloxoalene significantly reduced the incidence of bloat. Poloxoalene is an antifoaming agent that can be added to the feed or mineral supplement.

Summary