Changes in the skeletal muscles volume in horses with growth.

The research article discusses changes in the muscle volume of horses and ponies during their growth. The development of muscle volume is found not to rely on the number of fibres, but on the hypertrophy of each fibre.

Research Purpose

• The focus of the study was to understand how the volume of skeletal muscles in horses and ponies changes as they age. The researchers looked specifically at eight muscles in the trunk and twelve in the extremities of the subjects.

Methodology

• A total of 24 horses (16 light horses and 8 ponies) were used in the test, both young and adult. In each, the researchers measured the area of the largest transverse section and the number of muscle fibres in a unit sectional area (1 mm2).

Findings

• It was discovered that as the horses and ponies aged, the area of the largest transverse section increased, while the number of muscle fibres in a unit area went down.
• This suggested that the increase in muscle volume in these animals does not depend on an increase in the number of muscle fibres. Instead, it depends on the hypertrophy (or growth in size) of each individual muscle fibre.