Ref code: CAT36

Category

Teaching - 3 (Instructor : student ratio 1:3)

Research - 4

Objective

To estimate parameters of body composition such as depth of fat, content of intramuscular fat and size of muscle layers in the live animal, using ultrasound technology.

Alternatives to animal use for teaching

Procedure can be demonstrated with visual aids but must be applied to live animals.

Details of Procedure

Various types of ultrasound devices are available, using A or B-mode technology, but those using B-mode real-time equipment have been found the most accurate.

Animals are examined while restrained in a crush or race (depending on temperament and the degree of restraint required). The device (probe) is applied to the skin of the animal at a position specific to the measurement to be taken (eg. P8 or 12/13 rib site). Ample application to the skin of a good coupling agent (suitable vegetable or other oil or ultrasound scanning gel) is needed to ensure good transmission of ultrasound waves from the equipment to the animal. The output from the equipment as an image or other data can be interpreted immediately or stored for later assessment of the nature of the tissues examined.

Drugs, chemicals, or biological agents

None are generally applicable. Agents used to aid contact with the animals’ skin are harmless to the animals and operators.

Impact of procedure on wellbeing of animal(s)

Procedure has minimal impact on the animals, dependent only on their reaction to handling and confinement.

Reuse and repeated use

There is no need to restrict repetition of the procedure apart from the stress occasioned by frequent handling. This should not be a problem with animals accustomed to frequent application of the procedure.

Care of animal(s) during/ after procedure

General attention to the animals’ reactions to confinement and handling is required.

Pain relief measures

There is no pain associated with these procedures.

Qualifications, experience or training necessary to perform this procedure

People competent in handling cattle, after adequate demonstration and instruction. Users need to demonstrate proficiency by their accuracy of measurements and ability to conduct procedures within reasonable time constraints.

Demonstrator: Experience with the procedure. Thorough knowledge of the physiology and anatomy involved. Knowledge of the physics of ultrasound and associated equipment is also necessary.

Students: Students may be learning the techniques as part of certificate or degree courses, as technical assistants, or may be livestock producers or service agents to the industry. Prior experience with handling livestock and a background knowledge of anatomy, physiology and ultrasound is desirable. The extent of knowledge of the above required, will vary with the intended use of the technique by the student (eg research, commercial or other applications).

References

Brethour, J.R., (1992), Journal of Animal Science. 70:1039-1044

Perkins, T.L. et al. (1992), Journal of Animal Science. 70:1002-1010