The development of solid food intake in calves 4. The effect of the addition of material to the rumen, or its removal from the rumen, on voluntary food intake

Abstract

SUMMARY1. Eight British Friesian male calves were fitted with rumen cannulae at 4 weeks of age, and were given either chopped or pelleted dried grass to appetite. After weaning at 6 weeks the animals were allowed to eat to appetite, or the appropriate food material was added via the cannula, or digesta removed, at the rate of 20 % (dry-matter basis) of voluntary food intake, in alternating periods of 7 days.2. The addition of food material resulted in a depression in drymatter intake (DMI) which was greater than the increase in DMI following the removal of digesta, and the difference approached significance in the small number of comparisons possible.3. The response in voluntary food intake increased significantly with age, and reached or exceeded ‘adult’ levels within 6 weeks from weaning. It is postulated that oropharyngeal factors associated with the development of eating behaviour control the initial development of solid food intake; the influences of physical or metabolic limitations upon food intake increase with time.