Jaymelynn Farney of Kansas State University recently opened an article on Drovers.com with an important question: Are vitamins necessary or just an expensive luxury that the cows can get by without?, especially given the rising prices for vitamins. Eric Bailey from University of Missouri authored a related piece detailing required vitamins, the vitamins’ function, symptoms of vitamin deficiency, and feed source amounts for beef cattle. Together these pieces will help ensure your herd gets the right vitamins at the right time while you optimize your costs.
Farney leaves little doubt to the answer of the original question:
Bottom line is yes. Vitamins, especially A and E, are important around calving.
Vitamin A is vital in cow rations in the last trimester through the first couple of months of lactation. It has been found to help manage calf scours, as colostrum is high in vitamin A, and help cows to “clean” and reduce the risk of retained placenta.
Vitamin E is important to help with selenium and vitamin A absorption, aids in immune function, and is an antioxidant important in cellular metabolism. Calves born to cows that are vitamin E-deficient can be born with white muscle disease, also a symptom of low selenium.
Once again, alfalfa is a good source of vitamin E for cattle, especially in the form of alfalfa meal, as well as other green, leafy forages. Whole grains also have vitamin E, particularly from the oil.
Vitamins A, D, E, and K are fat-soluble, thus can be stored in the animal if fed in excess of requirements. Rumen bacteria make vitamin K in quantities sufficient to meet ruminant animal requirements, except if feeding moldy sweet clover hay or silage or any moldy legume.
Vitamin D is synthesized by sunlight in both the ruminant animal and in the forages. Cattle that have direct sunlight exposure or are fed at least 3 to 4 pounds of sun-cured hay per day do not require supplementary vitamin D.
Vitamin B is a water-soluble vitamin that is synthesized by rumen microbes to meet the animal’s requirements and, therefore, does not need to be added to feed for mature animals. Baby calves do not have a functioning rumen with microbes and do not synthesize vitamin B or K.
In the past it has been recommended to feed around 100% to 150% of vitamin A, D, and E requirements in free-choice minerals year-round, thereby ignoring the amount being supplied from forages or feeds. However, to reduce costs, cows could be provided 100% of their vitamin requirement a minimum of 45 days before calving through the first couple of months of lactation to mitigate low levels in harvested, stored forages or dormant native range, without negatively impeding performance.
Eric Bailey’s analysis emphasizes the importance of vitamin A. He also notes that vitamin needs of beef cattle can be confined largely to A, D and E. This is because bacteria in the rumen of cattle are considered to have the ability to synthesize vitamin K and the B vitamins in sufficient quantities to meet the animal’s requirement.
Vitamin A needs special attention in beef cattle rations. This vitamin is found only in animals. Plants, however, are the natural source of vitamin A activity for animals. Green and yellow plants contain carotene, a pigment which animals convert to vitamin A. The wall of the small intestine is the principal site for conversion of carotene to vitamin A.
One of the first easily detected signs of vitamin A deficiency in cattle is night blindness. An easy way to check for this condition is to place an obstacle in the pathway of cattle and notice if they stumble over it at twilight. Other early signs are loss of appetite, rough hair coat, dull eyes, slowed gains and reduced feed efficiency. Diarrhea and pneumonia may be the first indicators, especially in young animals. Later developments include excessive watering of the eyes, staggering gait, lameness or stiffness in knee and hock joints, and swelling of the legs and brisket (and sometimes in the abdominal region). Feedlot cattle with advanced vitamin A deficiency often pant excessively at high temperatures and go into convulsions when excited.
Signs of vitamin A deficiency in breeding herds include lowered fertility and calving percentage. Cows abort, drop dead or weak calves, and are difficult to settle.
Vitamin E This vitamin appears to increase the efficiency of vitamin A and carotene utilization by reducing their oxidation before and after absorption from the digestive tract.
Bailey offers detailed vitamin requirements for feeders, feedlot cattle, and beef cattle based on feed rations. Bailey offers similar details for other key vitamins such as D and E.
The vitamin intake is critical to monitor for your cattle. Even in an environment of increasing prices, this investment will keep you smiling.
On a lighter note, imagine what would happen without vitamins for our cows.
Image Courtesy NatureMoms