How Interactive are Nutritionists and Veterinarians?

Newsletter No. 60

The following blog, authored by Mojtaba Yegani, was published this month under the title: Poultry Nutritionists and Veterinarians – How interactive are they? on the World Poultry web site.

The poultry industry is a complex network of technical people with different educational backgrounds such as genetics, production management, nutrition, veterinary medicine and engineering. Nutritionists and veterinarians are usually considered as two dominant categories in commercial poultry production. It is a well-known fact that having a fully cooperative management team is of paramount importance in order to be able to achieve production goals and stay in this highly competitive business.

Efficient interactions of poultry nutritionists and veterinarians are essential to this accomplishment. We, as nutritionists or veterinarians, can discuss the following questions in this blog:

a. How interactive are you as a poultry nutritionist or veterinarian?
b. Blaming someone else could be a first reaction to a problem. Has this been your experience when a problem occurs in your farm?
c. Nutritionists and veterinarians can efficiently benefit from each other’s knowledge and practical experiences. Do you agree with this?

There are a number of responses and without exception all are in full agreement.

A few years ago I asked a senior ostrich vet if he believed there should be cross over between veterinary and nutritionist as the two disciplines are so interrelated. He agreed and went onto state that he had no knowledge of nutrition. We only have to look at the tables in the links below listing the clinical signs of deficiencies to understand just how these two disciplines interrelate to each other, no matter which specie – the principles are the same.

Functions, Deficiencies, Interrelationships & Toxicities of Minerals and Vitamins– Poultry including Ostrich Nutritional Deficiencies and Excesses - Pigs

Optimum Vitamin Nutrition™
Roche Vitamins, now owned by DSM, introduced the terminology Optimum Vitamin Nutrition™ (OVN). The company recognised that many of the National Research Council (NRC) nutritional recommendations are set dangerously low. The following is their explanation of OVN as it relates to production livestock. There are recommendations out for Ostrich, although not yet published by the NRC, and proving to also be set too low.

Quote: "Optimum Vitamin Nutrition" refers to providing all known vitamins in the diet at levels that permit optimum health and performance. The figure below provides a simplified visualization.

optimum nutrition

The y-axis, Average Animal Response, refers to any average productivity or health measure, such as growth rate, feed efficiency, immunity or reproductive performance, as it responds to vitamin allowances.

The x-axis, Vitamin Allowances, refers to the total level of vitamins in the diet, including feedstuffs and fortification:

  • Deficient marginal allowances (2) are below the requirements published by the National Research Council, putting the animals at risk of developing clinical deficiency signs and disorders.
  • Suboptimum marginal allowances (3) exceed the NRC requirements and thus prevent clinical signs, but they are inadequate to permit optimum health and productivity.
  • Optimum allowances (4) permit optimum animal health and productivity.

Note that there is not a single optimum vitamin allowance. Various influencing factors will affect both the animal's requirements and the ability of the diet to meet them. These factors include:

  • Stressors on the animal:
    - Disease
    - Confinement
    - Restricted feeding
    - Vitamin antagonists
    - Air quality
    - Temperature
  • Variations of vitamin levels in feedstuffs:
    - Bioavailability
    - Stability
    - Quality of feedstuffs

For instance, vitamin allowances that are optimum in a stress-free environment may become suboptimum as the heat stress of summer increases. Thus, Optimum Vitamin Nutrition remains a dynamic aspect of animal agriculture that must be regularly evaluated. END

Note that the current published recommendations for ostrich fall into Category 2 above, as we still see many clinical deficiency signs, even with this company.

The following is a quote from the first couple of paragraphs of chapter in The Poultry Site Hand Book. The whole article can be read by clicking this link.

Optimum vitamin nutrition of laying hens
The overall goal of the layer industry is to achieve the best performance, feed utilization and health of birds. All nutrients including proteins, fats, carbohydrates, vitamins, minerals and water are essential for these vital functions, but vitamins have an additional dimension. They are required in adequate levels to enable the animal to efficiently utilize all other nutrients in the feed. Therefore, optimum nutrition occurs only when the bird is offered the correct mix of macro- and micronutrients in the feed and is able to efficiently utilize those nutrients for its growth, health, reproduction and survival.

Vitamins are active substances, essential for life of man and animals. They belong to the micronutrients and are required for normal metabolism in animals. Vitamins are essential for optimum health as well as normal physiological functions such as growth, development, maintenance and reproduction. As most vitamins cannot be synthesized by poultry in sufficient amounts to meet physiological demands, they must be obtained from the diet. Vitamins are present in many feedstuffs in minute amounts and can be absorbed from the diet during the digestive process. If absent from the diet or improperly absorbed or utilized, vitamins are a cause of specific deficiency diseases or syndromes. End

As can be seen vitamins are essential to good health, but only of value when part of a correctly balanced diet, containing all the correct nutrients. We certainly agree with Mojtaba Yegani.

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