Spastic paresis in calves
SIR, - I wish to report the occurrence of hindlimb straightness and stiffness with inability to flex the hock in calves, in a herd of 21 pedigree Simmental cows that calved in the spring of 2003. Six of eight female calves were affected, with 13 unaffected males. The age of onset was from
Bovine spastic paresis: A review of the genetic background and perspectives for the future.
Bovine spastic paresis (BSP) is a sporadic, progressive neuromuscular disease that is thought to affect all breeds of cattle. The disease manifests as a unilateral or bilateral hyperextension of the hind limb due to increased muscle tone or permanent spasm of mainly the gastrocnemius and/or the quadriceps muscle. Clinical signs only appear in rising, standing and moving animals, which is an important diagnostic feature. Although several medical treatments have been described, surgical procedures such as neurectomy or tenectomy are generally indicated. Even though complete recovery can be achieved, BSP-affected animals should not be used for breeding, since BSP is commonly considered a hereditary disease. The condition therefore negatively affects animal welfare, economics and breeding. When first described in 1922, BSP was already assumed to be heritable, and this assumption has been perpetuated by subsequent authors who have only discussed its possible modes of inheritance, which included monogenetic and polygenetic modes and gene-environment interactions. Besides some clinical aspects and the consideration of the tarsal joint angle as a BSP-correlated trait, this review mainly focuses on the assumed genetic aspects of BSP. Evaluation of the published literature demonstrates that to date, irrevocable proof for the assumed heritability of BSP is still missing. The assumption of heredity is further contradicted by known allele frequencies and incidences of proven hereditary diseases in cattle, such as arachnomelia or bovine spinal muscular atrophy. Consequently, future research is needed to determine the cause of spastic paresis. Procedures that will help test the null-hypothesis ('BSP is not hereditary') and possible modes of inheritance are discussed in this review.
The status of FAO and codex alimentarius developments on vegetable proteins
The FAO is interested in increasing world protein supplies both by advising and assisting developing countries to increase their production of staple foods and by encouraging the development of technology to produce protein concentrates both from vegetable and animal sources to supplement diets which are low in protein content. Recent revisions of the amount of protein required in the diet in relation to total per capita energy requirements and the difficulties encountered in introducing novel foods into established dietary patterns has led FAO to concentrate on increased agricultural productions in developing countries as the primary means of combatting malnutrition. In the meantime, in North America and Europe, advances in the technology of processing vegetable proteins has given highly acceptable products simulating meats which are being used as meat extenders and meat analogues. The consequent increase in vegetable protein production has revealed a need for international, agreement on standardization, and it has been agreed that this will be undertaken by the Joint FAO/WHO Food Standards’ Programme. The program operates chiefly through the Codex Alimentarius, Commission, an international governmental body, the purpose of which is to protect consumers against health hazard in food and against fraud. The Commission, which has 116 member governments, controls an intensive program of work covering the composition, labeling, additives, contaminants, pesticide residues, hygiene, sampling and analysis aspects of foods and has established a procedure which allows member governments ample opportunity to reach agreement on food standards and to accept them for incorporation into national legislation. The Codex Commission, at its 12th session, decided to establish a Committee on Vegetable Proteins with the following terms of references: “to elaborate definitions and world-wide standards for vegetable protein products deriving from soybeams, cottonseed, groundnuts, cereals and from other vegetable sources as they come into use for human consumption, and to elaborate guidelines on utilization of such vegetable protein products in the food supply system, on nutritional requirements and safety on labeling and on other aspects as may seem appropriate.” The question of which country will host the Committee is still under discussion.