Much of the vitamin A cattle consume comes from lush, green forages such as alfalfa and clover, but with winter in full swing and less and less green grass available, it is appropriate for producers to consider their cattle’s vitamin A stores and decide whether or not to provide a supplement.
Eldon Cole, a livestock specialist with the University of Missouri Extension, said vitamin A is essential to cattle’s bone development, skin and tissue maintenance and vision. Cattle consume carotene in sources such as yellow corn, hay and green forages and then convert the carotene to vitamin A.
Because green forage is rare this time of year, the winter months can be the hardest to keep vitamin A levels consistent in cattle. Most producers feed hay during the winter months, and that can help keep their cattle healthy; however, Cole warns that hay that has been stored outside has less active vitamin A than barn-kept hay.
“Vitamin A becomes less stable when exposed to the elements,” Cole said. “The vitamin will leach out of hay if not properly protected. Producers should try to keep hay fresh and out of the harsh winter weather to preserve as much of the vitamin as possible.”
Cole said vitamin A can be stored in the liver for up to three months, but depending on the weather conditions during the fall, that might not be enough to make it to spring.
“Missouri had a pretty good fall this year, so I am thinking that most cattle will have adequate stores,” he said. “However, producers in areas that suffered droughts or experienced early winters should consider using a supplement to prevent illnesses such as pink eye and foot rot.”
Supplements are available in several forms including mineral and feed additives. Cole said when green forage is not available for an extended period of time, injections are often the least expensive method of increasing vitamin A levels in cattle.
Most vitamin A injections are combined with other essential vitamins such as D and E. The injections contain enough vitamin A to be stored for 60-90 days and usually cost 35-40 cents per head. Cole said producers are often vaccinating cows or pouring for lice during the winter months, so administering the injection could be done at that time.
Supplements are not always necessary, but producers should not be worried about their cattle getting too much vitamin A.
“Cattle have a high tolerance for vitamin A,” Cole said. “Even if producers give a supplement when it is not really needed, they are not going to poison their cattle.”
While there are not any hard and fast symptoms that indicate a vitamin A deficiency, Cole said producers should consider using a supplement if their cattle are suffering from foot soreness, poor vision or are all together unthrifty.
“Vitamin A is a powerful nutrient and should not be overlooked,” Cole said. “Even in a depressed cattle market, it is never a good idea to short your cattle on the things they need to be healthy.”
