By Gary Sliworsky, Ag rep, Emo
This article continues the discussion on selenium from last week, although many of the ideas apply to all minerals.
Force-feeding is important in reducing individual animal variation in mineral intake. Many producers, however, choose to provide mineral supplements to their cattle “free choice.”
This may be the only practical alternative for supplementing cattle on summer pasture. However, field studies have demonstrated that the free-choice intake can be highly variable within a group of pastured cattle.
Some animals will not eat any while other individual animals may consume near toxic amounts.
If free-choice feeding is the only practical method of supplementing cattle, consider some of the following ideas for improving intake.
Intake usually is better with loose rather than block supplements. Mixing loose mineral with salt, dried molasses, or protein supplements can increase intake.
Put small amounts out frequently to keep the supplements fresh.
Locate the mineral feeders in heavily-used areas of the pasture. And make sure there are enough for all cattle to have sufficient access (one feeder for every 50 animals has been suggested).
Finally, read the label. Calculate how long it should take your cattle to go through a bag when they are eating the recommended amount the product each day.
Variation in individual animal behaviour, and problems in estimating mineral wastage, can make an accurate determination of dietary intake very difficult.
If after considering the above suggestions you are concerned that selenium deficiency might be a problem in you herd, talk to your veterinarian.
The selenium requirement may be influenced by other factors in the environment and the diet of the herd. Vitamin E performs many similar functions to selenium in the diet.
When a problem with selenium is suspected, you also should evaluate the amount of vitamin E available to the cattle.
Vitamin E deteriorates in stored feedstuffs and, unlike many of the other fat soluble vitamins, it is not stored in substantial quantities by the cow.
Also, unlike selenium, vitamin E is not efficiently passed through the placenta to the developing fetus.
Colostrum is a very important source of vitamin E for the newborn calf.
If injectable selenium products are used in calves at birth, choose products that provide the most vitamin E for the recommended dose.
Talk with your veterinarian to determine whether supplementation is necessary in your herd.