The grass is beginning to grow here in the southeast. Grass fever is beginning to push feeder calf prices up as folks begin the hunt for stocker calves. These high feeder calf prices dictate diligence with respect to management to ensure animals remain healthy and have good performance this grazing season.
It is not uncommon for a high percentage of light weight calves to develop bovine respiratory disease as a result of stress associated with weaning, commingling with other cattle, and shipping. This transition can also result in an increased risk to coccidiosis robbing performance and profits from stocker operations. Ionophores are feed-grade antibiotics that have been proven to aid in the control of coccidiosis. They inhibit coccidia at various stages of development breaking the life cycle and lowering the shedding of oocytes reducing the risk of spreading the organism.
Common ionophores used for stocker cattle include monensin and lasalocid. Manufacturer’s information for the use of monensin in the control of coccidiosis indicates that 0.14 to 0.42 mg per pound of body weight up to 200 mg per head per day should be fed to stocker cattle. Lasalocid is listed to be fed at a rate of 1 mg per 2.2 lbs of body weight to calves up to 800 lbs with an upper limit of 360 mg per head per day. The targeted feeding rates for a 400 lb stocker calf would be 56 to 142 mg of monensin or 181 mg of lasalocid to aid in the control of coccidiosis.
Both products are approved to be fed free-choice to stocker cattle via mineral. However, it is important to recognize that a great degree of variability exists in the consumption of free-choice mineral products. In order to ensure adequate consumption of mineral, management of the mineral feeder is important. Provide adequate feeder space. Time to access feeders may be manipulated by placing them near shade or water sources to encourage intakes. Do not let the feeder run empty and prevent rain from saturating the mineral.
Lastly, provide fresh mineral about every 7-10 days which will allow you to more closely monitor intake levels.
In areas where conditions are not conducive to handling loose mineral, one might consider a new product to the market. A salt-based mineral block containing lasalocid was introduced early this year with a low targeted intake. Those desiring to use a block containing an ionophore might consider this product. For ionophores to be effective it is important that consumption is near the targeted intake levels. When using blocks similar to this product, ensure adequate numbers of blocks are distributed in the pasture for the number of cattle in the pasture. Too often too few blocks are placed in the pastures limiting intake. Follow the product label and when using the product other sources of salt should be removed from pastures. This new block contains copper oxide which will not provide sufficient levels of available copper for fescue-based pastures and will not fulfill CPH-45 requirements.