In ruminant diseases, only fat soluble vitamins A, D and K have real importance.
This is available in most green plants, and if the animals graze on well managed pastures and forage, deficiencies will not occur. However, cattle fed on poor quality roughage, such as poor quality hay and straw, require supplemention.
Clinical Signs of Vitamin A Deficiency
- Decreased appetite leading to reduced growth.
- Impaired night vision.
- Increased still births in pregnant animals due to affected reproductive function, especially in cases where dry cows are offered poor diets.
- Fainting fits in calves: the calf collapses as if in a deep sleep then gets up and walks away quite normally.
- In latter stages of deficiency, bone growth is affected and this may cause pressure on nerves to the eye, which may lead to total blindness.
Diganosis of Vitamin A Deficiency
This can be done by investigating the history of animals and their diets, and by analysis of blood and liver samples in a laboratory.
There is little vitamin D in plants. Animals obtain most of it from the sun. Vitamin D is necessary for the absorption of calcium and phosphorous from the intestines and the deposition of the minerals in bone as well as in the maintenance of normal blood levels. Vitamin D deficiency in young calves is likely to occur when they are housed in dim lights and offered poor quality diets.
Clinical Signs of Vitamin D Deficiency
- Reduced Growth Rates.
- The legs may be bent and there is abnormal swelling, with stiffness and lameness occurring in a number of animals.
- The teeth may be out of line and the jaw bone deformed.
Treatment is by injecting vitamin D and by correcting the ration, including oral supplementation with vitamin D.
This is available in plenty in leafy forages. Primary deficiency does not occur. Deficiency can be induced by dicoumarol poisoning such as warfarin rat poison and mouldy clover hay, which inhibit the action of vitamin K. Vitamin K is involved in blood-clotting mechanisms.
Clinical Signs of Vitamin K Deficiency
- Failure of blood clotting, including excessive bleeding from cuts.
- Appearance of large red hemorrhagic areas in the membranes of the mouth, eyes and nose.
- Abdominal pain and lameness.
Treatment and Prevention
- Identify and remove the source of poison.
- Give Vitamin K by mouth or through injection.
This group of vitamins is formed by micro-organisms in the rumen and any excess is absorbed by the cow. They are also present in ample quantities in milk and therefore primary dietary deficiency is never seen.
This is produced in tissues of all farm livestock (cattle, sheep and goats) and dietary supply is unnecessary.