An integral part of the immune system. How can this simple nutrient improve your herd health?

Written by Darian Livingstone | Ceres Industries
(306) 653-7258 | This email address is being protected from spambots. You need JavaScript enabled to view it.

Fresh, green grass is typically abundant with vitamin A, or at least its precursor, beta-carotene. So, livestock out on pasture in the summer months usually get plenty of vitamin A in their diets. However, in the winter months, deficiencies are more common because vitamins lose their integrity during the harvesting and storage processes. Like minerals, vitamins are essential for animals and are divided into two classes: water-soluble and fat-soluble. Vitamin A, also called retinol, is a fat-soluble vitamin. It absorbs the fats or oils in the diet and can be stored in the body's fatty tissues or liver.

Vitamin A is not readily present in plants. Cattle will use precursors, such as beta-carotene, to derive their own vitamin A. This specific carotenoid is a pigment that gives plants their vibrant colouration. Usually, plants that are high in beta-carotene will be vibrant oranges, yellows, or greens. Legumes are especially high in beta-carotene.

Several factors affect the number of precursors in forages; the recurring element is the leaf to stem ratio. Some forage species will have a greater leaf to stem ratio than others (consider alfalfa compared to bromegrass). Plant maturity will play a part in this vital ratio as well. As plants mature, the percentage of leaves drops compared to the stem content. Therefore, the beta- carotene content is inversely related to the dry matter content of forages. Aside from these natural factors, how we harvest and store forages also plays a part in the beta-carotene level.

Drying crops after cutting will significantly reduce the levels of carotenoids. In a clover hay study, as much as 80% of beta-carotene was lost during the first 24 hours of sun-drying! After four to five days, those levels were near zero. It was also found that harvested forages that were rained on before being dried had even less beta-carotene.

As you can see, harvested and stored forages are unreliable in providing livestock adequate vitamin A precursors. So in winter feeding, it is important to fortify your livestock with additional supplements to make sure they get everything they need.

Vitamin A is the most likely vitamin to be deficient in beef cattle diets. It is essential for normal growth, vision, reproduction, healthy skin, cell maintenance, and bone development. It also has a very critical role in the immune system and disease prevention. This last point is vital to note when considering colostrum.

Mature animals have the capability to store extra vitamin A in their liver for later use. Depending on the amount reserved, the excess vitamin A can last up to several months if the animal continues to consume adequate levels through its diet. Unfortunately, babies are born with meagre liver reserves of vitamin A and low vitamin A blood concentrations. Essentially they are all born vitamin A deficient.

Along with low vitamin A reserves, babies also exhibit suppressed immune systems and don't begin to develop a defence until about three weeks of age. This combination makes young animals extremely susceptible to infections and diseases.

It is common practice for farmers to inject young animals with vitamin A at birth or feed milk replacers fortified with vitamin A. This practice provides the young with a readily available vitamin A supply to help kickstart their immune system. However, the quality of the colostrum is equally as crucial as this booster.

Colostrum is full of many beneficial molecules that aid in the young's ability to survive in their new environment: immunoglobulins, proteins, and various vitamins and minerals. Studies have shown that when the dam's colostrum is higher in vitamin A, her offspring's blood vitamin A levels are also elevated. In a separate study, calves fed milk containing 87,000 IU/kg of vitamin A displayed heightened immune activity over calves fed milk containing only 7000 IU/kg of vitamin A.

Supplementing the damn with vitamin A will aid in increasing the vitamin A concentration in colostrum and subsequent milkings. Beginning to supplement during the dry period can improve their milk and their offspring's vitamin A status. Supremix Breeder is formulated with high levels of vitamins, specifically vitamin A. Feeding this supplement to cows three to four weeks before calving will ensure that their colostrum vitamin A concentration is high enough to provide calves with that immune-boosting vitamin!

To find out more, contact us at (306) 653-7258 or email This email address is being protected from spambots. You need JavaScript enabled to view it..


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