- North America
- Latin America
Yes, there are! The history of vitamin discovery is based on the presence or absence of an organic (non-mineral) compound required in small quantities in the diet essential for normal growth and nutrition. Since vitamins can’t be synthesized in the body, the discovery of vitamin functions were often based on specific deficiency symptoms, such as night blindness (Vitamin A), scurvy (vitamin C), or rickets (vitamin D). Although classical vitamin deficiency symptoms today are rare, simple vitamin deficiencies can occur. Several years ago researchers at University of Wisconsin noted kyphosis (hump-backs) in growing pigs consuming a standard research ration. On further inspection, they noted that vitamin D3 was inadvertently left out of the vitamin premix, and that the kyphosis observed was associated with a simple D3 deficiency. Similarly, fast-growing chicks can exhibit rickets (vitamin D deficiency, coupled with mineral imbalances). Other deficiency diseases such as perosis (biotin) or encephalomalacia (vitamin E) can occur because of low dietary input or because of dietary antagonists or lack of the vitamin in the feed or premix).
In the famous “single grain experiments” of McCollum and Hart, dairy heifers were fed diets comprised of solely corn (stover, grain, corn gluten) or wheat (straw, wheat meal, wheat gluten). Diets were identical in terms of carbohydrate, fat, and protein content, based on “known chemistry at the time.” Although the heifers consuming corn-based diets grew, conceived, and nursed their healthy calves; calves from the wheat-based dams were either stillborn or born weak and died shortly thereafter, even though at the time the rations were considered chemically identical. Years later, factors (vitamins) were identified in milk and other supplements which corrected these symptoms. Although it was never completely elucidated, the “Single grain” calves on the wheat diet were probably vitamin A deficient, since neither diet contained the leaves of the plants, which might have provided enough beta-carotene to supply adequate vitamin A.
From the McCollum and Hart experiments and from field experience, vitamin deficiencies are rarely clear-cut and often exacerbated by co-deficiencies, and symptoms are not specific—in poultry for example these symptoms might be noted:
(ref Ward, ANC, 2022)
Rarely will a nutritionist or DVM encounter “star-gazer” chicks exhibiting a clearcut B1 deficiency, but multiple deficiencies can combine to reduce growth, inhibit feed conversion, or otherwise depress normal performance.
In the above modern-day example from the University of Wisconsin, kyphosis in growing pigs could be associated with vitamin D, calcium/phosphorus imbalance, or unsaturated fat sources in the diet: multiple causes which combine to cause a disease. Mulberry heart disease in fast-growing pigs is often associated with both vitamin E and selenium issues, possibly compounded by diet and genetics. Vitamin E deficiency is a risk factor for mastitis (udder infection) in dairy cows, but is almost always compounded with selenium deficiency and a myriad of other causes, including infectious agents, poor bedding, housing, and milking procedures.
Start by calculating vitamin amounts being offered in the diet. In the case of the kyphosis example, assure that the diet provides the correct amount of D3 and or HyD® for the species segment and production class, and that mineral contributions are also correct. The best place to start with vitamin supplementation guidelines is OVNTM because these represent the state of the art in terms of industrial and academic progress, knowledge of genetic differences, and production goals. Make sure feeds are mixed and stored properly, and that animals are receiving the recommended amounts of vitamins via their daily feed intake. Although animal status can be measured for most vitamins, most of the time vitamin deficiencies can be avoided through careful ration adjustments.
17 October 2022
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