High quality nuggets or pellets, where all the nutrients are present in each individual piece, are recommended for rabbits. These must never be fed in an unlimited way by constantly topping up the bowl, but fed as a small measured amount daily or used as treats or training rewards. A good general rule is to feed a maximum of 25g of pellets per kg bodyweight per day, but check the manufacturer’s instructions.
Many adult rabbits do not actually need commercial feed, especially if they are already overweight. Baby and growing rabbits require higher protein levels to that of adult rabbits and special feeds for baby rabbits are available, but the bulk of the diet should still be grass or good quality hay.
We know that when presented with mixed feeds (coarse mix or muesli), many rabbits will only eat certain components. Picking out the bits they like, and leaving the bits they don’t, means they get a very unbalanced diet, with an insufficient intake of fibre, protein, calcium and phosphorous. This can lead to many problems, the main one being dental disease. Feeding muesli has also been linked by scientific studies directly to the development of obesity, poor gastrointestinal motility, uneaten caecotrophs and messy bottoms, decreased activity levels and behavioural changes. Obesity is recognised as an increasing problem in many pets, including rabbits, and it is associated with a host of other problems such as osteoarthritis, liver and skin diseases. All this means that muesli shouldn’t be fed to rabbits.
Pelleted or extruded diets overcome the problem of selective feeding and provide a consistent ration. Extruded diets are now very popular for pet rabbits, incorporating long fibre particles without the pellet becoming crumbly. The heated extrusion process improves starch digestibility, and extruded diets are more palatable and digestible than pellets. However, even though fibre content and length may be adequate for gastrointestinal function, these diets may not provide sufficient dental wear as they are eaten with a more vertical rather than lateral chewing action of the teeth and jaws, and so should always be considered complimentary and fed in limited amounts.
Overfeeding of any concentrated diets can be a significant factor in GI disease and dental disease, and can also lead to obesity and boredom. However, they have a role in the feeding of growing, pregnant and lactating, and diseased rabbits. They can also be used to ensure nutrient requirements are fulfilled in rabbits that are unwilling to consume significant amounts of grass, hay or green vegetables, or where the quality of these is questionable.
Thankfully, greater understanding and awareness of the role of diet in disease means that the situation for rabbits is improving - for example the PDSA, through their Animal Wellbeing reports, found in 2011 that 49% of rabbits were fed muesli as the main part of their diet and 750,000 rabbits in the UK were not getting enough daily hay or grass However, since 2011 there have been significant improvements, with an estimated 300,000 fewer rabbits being fed muesli-type diets and 200,000 more rabbits being fed the recommended amount of hay.