Horses grazing naturally eat to maintain a high level of gut fill, feeding consists of bouts of uninterrupted feeding separated by non-feeding intervals. Feeding doesn’t occur randomly but is divided into ‘meals’. During meal times horses take short (less than 10-minute breaks) to look around, stand guard, or to walk over to see what their neighbour is eating. There are longer periods between meal times for sleeping and resting, the feeding habits are similar to deer. Meal lengths are affected by the time of day and they prefer to eat during the day rather than the night.
Meal times in April are around 3 hours and 20 mins long, dropping to just 1 hour and 10 mins in October, the change in the length of the meal time is due to the increase in the fibre content of the grass as the season goes on, suggesting that horses eat to fill their gut and to maintain a high gut fill level. In April though the nutritive value (glucose/starch/protein) of the green shoots are high whilst the biomass is low meaning they have to consume a greater quantity before the gut is full. Perhaps this partially explains why horses appear to gorge in spring and why grazing masks worn for long periods may cause a level of stress in the horse is turned out hungry. Might be better to feed a hay net of low-quality fodder before turning out?
During times when flies are a nuisance, meal times are much shorter, horses stop feeding to rub themselves on each other and to groom each other, intervals between meals are longer and horses no longer feed until full and have longer periods of walking in between. The average feeding bout in between grooming and rubbing is around 25-45 seconds, literally snatching a bite to eat!
This change in routine coincides with mid- season when glucose/nutritive is still high and fibre content is also high enough to allow less time eating before gut fill level is achieved. Flies become a nuisance in the UK from the beginning to mid-June onwards, and in the fly season feral horses graze for much longer periods between the hours of 4am and 8am.
Some native grass species contain more fibre even in the spring, consider the difference between the old unimproved grasses compared to the improved varieties of which Perenenial Rye is the most common.
Five reasons to include Bull Grass (Bromus hordeaceus) also known as soft brome in your pasture.
1. Low sugar content from 2.pm is 40% glucose in comparison to an old variety Perennial Rye 62% (not the modern species Aber Magic, Aber Dart which will be much higher), Common Bent 57%, Yorkshire Fog 40%.
2. Glucose levels of Bull Grass continue to Fall to 36% by 4.30 pm until the last measurement at 10.pm in comparison to PR 65% rising to 70% and Common Bent 57% rising to 63%
3. Bull grass is higher in lignin, inulin and oligosaccharides which are natural prebiotics., which when included in a pasture mix will offset the effects of the higher sugar grasses.
4. Horses eat until gut fill in reached, this happens quicker in high fibre grasses like Bull Grass reducing the need to gorge.
5. Bull grass is higher in the beneficial anti- oxidants known as phenolic acids, the type found in bull grass are anti- inflammatory, anti- obesity, anti arthritic and good for the G.I. tract.