Beef Cattle Health Traits

3.9 Health traits

General

Healthiness of the animals is an essential prerequisite for any production system. Animal health is an increasingly important subject for beef recording schemes. Diseases may affect level of production, shorten length of productive life of animals and be the cause of confiscation of parts or of the whole carcass. Confiscation may be based on the risk to consumers’ health and/or on the effect on the quality of carcass or meat. In all cases, profitability of the beef production system is affected because of veterinary treatment, loss of value of carcasses or of the value of the final meat product, increasing costs of slaughtering animals and the potential impact on consumers’ demand.

Compilation of health data provides a mechanism of control of health status that may affect the profit of the beef enterprise, animal welfare and public health. Recording of animal health data is a tool for monitoring and controlling animals’ diseases. It is also a useful tool for national and international trade in animals and their products as well as for the control of the epidemiology of diseases with special interest for zoonoses.

Disease resistance traits are among the most difficult to include in genetic improvement programs. They require good field measurements of the disease status of the animals under selection. In particular, infectious diseases depend very much upon environmental factors such as the degree of exposure to pathogen agent. In this context, molecular information may be a key tool for breeding purposes. Another approach in considering animal health as a whole is to include functional longevity in the set of breeding goals. Molecular information could provide and important tool for selection of genetic resistance to diseases.

Condition for data recording

Immunizations and screening tests are an important part of preventive veterinary services. Prevention has an strong impact diminishing morbidity and mortality in animal population. Most health service systems create population immunity from vaccination campaign or seasonal treatments. However, there is a number of diseases with a high prevalence in the beef cattle populations whose impact may be reduced through selection for diseases resistance. Recording of health traits allows for improvement in disease resistance. In countries where veterinary services are directly linked to performance recording schemes, there is an ideal environment to obtain information on health traits for breeding or/and epidemiological purposes. In other situations, it will be necessary to generate the need of systematic recording of animals health status among those professionals responsible for animals health and farmers. It is required at least a compromise solution of systematic recording of diseases which are obliged to be declared. The International Office of Epizooties (www.oie.int/eng/normes/mcode/a_summry.htm) provides information each year on the most significant epidemiological events with particular attention to contagious and economically significant diseases. OIE publishes two lists of disease, A and B. Diseases on list A are assumed to be either highly contagious and/or with significant economic effect (OIE list A). Diseases on list B (OIE list B) are less contagious than those on List A, but pose a significant threat to national economies or public health.

A systematic recording and storing of data at slaughter as a regular practices in abattoirs may be an important source of information for diseases at post mortem meat inspection. It is of particular interest for cases when non visible clinical signs has been detected. It is also of great interest when data is linked to on farm recording systems to identify risk factors. Data recording need to be done on individual basis. It is also necessary to compile information that allows the establishment of the ‘environmental conditions’, timing, transmission factors etc.

Data recording

1. Animal Identification: this will link the animal to its invariable animal data such as sex, birth date pedigree and herd of birth or/and changes of location.
2. Code for disease.
3. Clinical signs or not: False or True. If true:
   • Date of visual appraisal of clinical signs.
   • Person responsible.
4. Type of diagnostic:
   • Clinical: symptoms.
   • Patognomonic lesions.
   • Laboratory Techniques: T or F. If true:
   • Technique: Direct (detection of the agent): Faecal counts (eggs or larvae counts), Inmunohistochemistry, PCR, Antigens, Culture and Isolation.Indirect: Delaged hypersensitivity: Antibodies, Others.
   • Lab.
   • Specificity or sensitivity of the technique.
5. Sample.
6. Date of sample.
7. Vaccination: T or F. If true:
   • Vaccine
   • Date of vaccination.
8. Treatment: T or F. If true:
   • Treatment.
   • Date of treatment.
9. Relapse.
10. Date of relapse.

Classification of diseases and injuries

For data recording and storing is necessary to establish a systematic classification of diseases. As a first approach, there is an international classification of diseases from the World Health Organization (WHO). Thus, firstly, disease could be grouped as in the following list which is based on that classification (www.who.int):

1. Infectious and parasitic diseases.
2. Systemic diseases.
3. Endocrine, metabolic and nutritional diseases and immunity disorders.
4. Diseases of the nervous system or neurological diseases.
5. Diseases of respiratory system.
6. Diseases of circulatory system.
7. Diseases of digestive system.
8. Diseases of genitourinary system.
9. Diseases of skin and subcutaneus tissue.
10. Diseases of the musculoskeletal system and connective tissue.
11. Traumatism, injury and poisoning.
12. Genetic disorders.
13. Disease of blood and blood forming organs.
14. Complication of pregnancy and delivery.

Annex I - Diseases included in list A and B of the OIE

The following diseases are included in List A:

1. Foot and mouth disease.
2. Bluetongue.
3. Vesicular stomatitis.
4. Rinderpest.
5. Contagious bovine pleuropneumonia.
6. Rift Valley fever.

The following diseases are included in List B, within the category of multiple species diseases:

1. Anthrax.
2. Aujeszky’s diseases.
3. Echinococcosis/hydatidosis.
4. Leptospirosis.
5. Q fever.
6. Rabies.
7. Paratuberculosis.
8. Trichinellosis.
9. New world screwworm (Cochliomyia hominivorax ).
10. Old world screwworm (Chrysomya bezziana ).

The following diseases are included in List B, within the category of cattle diseases:

1. Bovine anaplasmosis.
2. Bovine babesiosis.
3. Bovine brucellosis.
4. Bovine genital campylobacteriosis.
5. Bovine tuberculosis.
6. Bovine cysticercosis.
7. Dermatophilosis.
8. Enzootic bovine leukosis.
9. Haemorrhagic septicaemia.
10. Infectious bovine rhinotracheitis(IBR)/infectious pustular vulvovaginitis.
11. Theileriosis.
12. Trichomonosis.
13. Trypanosomosis (tsetse-transmitted).
14. Malignant catarrhal fever.
15. Bovine spongiform encephalopathy (BSE).

Annex II - Single –Locus genetic diseases

Single –Locus genetic diseases, refer to OMIA database for all species here and specifically for cattle here. The following is a partial list of known defects: http://www.angis.org/Databases/BIRX/omia:

• Anhidrotic ectodermal dysplasia.
• Cardiomyopathy.
• Cardiomyopathy, dilated.
• Ceroid lipofuscinosis.
• Chediak-higashi syndrome.
• Chondrodysplasia.
• Chronic interstitial nephritis with diffuse zonal fibrosis.
• Citrullinaemia.
• Coat colour, albinism.
• Complex vertebral malformation.
• Deficiency of uridine monophosphate synthase.
• Dwarfism, dexter.
• Dwarfism, growth-hormone-receptor deficiency.
• Dwarfism, snorter.
• Dyserythropoiesis.
• Ehlers-danlos syndrome.
• Ehlers-danlos syndrome, type vii.
• Epitheliogenesis imperfecta.
• Factor xi deficiency.
• Gangliosidosis, gm1.
• Glycogen storage disease ii.
• Glycogen storage disease v.
• Goitre, familial.
• Hyperbilirubinaemia, unclassified.
• Hypotrichosis.
• Lethal trait a46.
• Leukocyte adhesion deficiency.
• Mannosidosis, alpha.
• Mannosidosis, beta.
• Maple syrup urine disease.
• Mucopolysaccharidosis i.
• Muscular hypertrophy.
• Myoclonus.
• Porphyria, congenital erythropoietic.
• Progressive degenerative myeloencephalopathy.
• Protamine-2 deficiency.
• Protoporphyria.
• Renal dysplasia.
• Sex reversal: xy female.
• Spastic lethal.
• Spherocytosis.
• Spinal dysmyelination.
• Spinal muscular atrophy.
• Syndactyly.
• Testicular feminization.
• Testicular hypoplasia.
• Tibial hemimelia.
• Trimethylaminuria.
• Vertical fibre hide defect.
• There are also a number of non-heritable genetic defects including: Turner Syndrome (XO) and Klinefelter (XXY) both are non-heritable genetic defects that result in sterile animals.