Keeping a rabbit could be a decade-long commitment and a responsible rabbit owner should prepare a diet that is suitable for their pet rabbit’s nutritional needs. In the Consumer Council’s test on 12 rabbit feed models for adult rabbits which claimed to be “complete feed” or “complementary feed”, various nutritional problems were found amongst all models, failing to completely comply with the relevant recommendations of the European Union’s (EU) guidelines for complete pet foods. If these models were used as a long-term staple diet, it would pose health risks to rabbits. While reminding rabbit owners to pay heed to the nutritional contents and feeding instruction of the rabbit feed, the Council also urges pet food manufacturers to improve the content of various nutrients in pet food, so as to safeguard the health of small animals.
The test covered 12 rabbit feed models for adult rabbits, including 9 in pellet form, 2 with mixed ingredients, and 1 “mixed pellets” that comprised pellets of different shapes and colours. Amongst the 12 models, 8 claimed to be “complete pet food”. Most complete feed models stated that the diet must be supplemented with a large or even unlimited quantities of hay. Of the remaining 4 models, 1 stated that it was a “complementary pet food”, while the other 3 did not specify the category of the product on the labelling. The models were bought from pet supply stores and online shops at a price range from $46 to $241 per pouch, equivalent to approximately $4.2 to $30.1 per 100g, a huge disparity in the retail price.
5 Complete Feed Models Found with Insufficient or Excessive Amounts of 1 to 3 Types of Macronutrients
The nutrient composition and their contents of rabbit feed are significant for the health of rabbits. The test was conducted with reference to the recommendations for pet rabbits at different life stages established by the European Pet Food Industry Federation (FEDIAF), as well as the “Nutrient Requirements of Rabbits” by the US National Research Council (NRC).
Over 60% (5 models) of the 8 complete feed models were detected with insufficient or excessive amounts of at least 1 macronutrients (crude protein, crude fibre, crude fat or starch), including 1 model that failed to meet the EU’s FEDIAF guidelines for 3 macronutrient contents, with the amount of crude fibre detected being lower than relevant recommendation, while the amounts of crude fat and starch were both higher than recommendations. Another 2 models were found with 2 macronutrient contents that did not meet the relevant recommendations, of which 1 model was found to have relatively low amount of crude fibre but a higher amount of starch, while both the crude protein and crude fat contents of another model were found to be slightly lower than the EU nutritional guidelines, suggesting room for improvement.
The fat content of a rabbit feed attracts rabbits to consume and is an important source of energy and essential fatty acids. However, if rabbits consume a high-fat, high-calorie diet over an extended period, they may become overweight. Of the 8 complete feed models tested, based on a moisture content of 12%, the proportion of crude fat in the feed varied considerably, ranging from 2.0% to 8.8%. Amongst these, the crude fat contents of 2 models were 5.3% and 8.8% respectively, which were both higher than the crude fat content recommended by the EU’s FEDIAF for adult pet rabbits (2.5% to 5%) and growing rabbits (3% to 5%).
In addition, the starch contents in 2 models exceeded 25%, which were higher than the recommendation in the EU guidelines (less than or equal to 20% per kg of feed). Excessive starch content may cause gastrointestinal dysmicrobism and then lead to enterotoxaemia and severe diarrhoea.
A high-fibre diet helps to maintain proper gut movement and dental health in rabbits. However, the amount of crude fibre detected varied considerably amongst models, ranging from 9% to 27.3% (with a moisture content of 12%). 2 of the complete feed models had a lower crude fibre content of 9% and 13.6% respectively, lower than the FEDIAF’s recommendations for adult pet rabbits (14% to 25% per kg of feed).
In addition, 1 of the 4 complementary feed models contained 27.3% crude fibre, which was slightly higher than the FEDIAF recommendation. Excessive amount of fibre in the diet may reduce certain rabbits’ ability in energy intake, while insufficient fibre may slow down the rabbit's gut movement and even cause gut stasis. Rabbit owners are advised to pay extra attention.
Mineral Contents of All Models Need to be Improved
The test also found that all models had 1 to 3 types of mineral issues, related to calcium, phosphorus, sodium and magnesium content, or calcium to phosphorus ratio (Ca:P ratio), which failed to meet the recommendations of the FEDIAF guidelines.
Problems with the Ca:P ratio were the most prevalent amongst the models, with 8 models failing to meet the guidelines. The said ratio of 3 complete feed were above the FEDIAF’s recommended range (1.5:1 to 2:1), while 2 models were slightly below. As for the complementary rabbit feed models, the Ca:P ratios of 3 models were slightly higher than the recommended range set out in the EU guidelines. A proper Ca:P ratio helps rabbits to maintain healthy body functions, but only 3 complete feed models of and 1 complementary feed model met the relevant recommendation. With an imbalanced Ca:P ratio together with limited opportunities to chew, rabbits may develop overgrown teeth or even dental abscesses.
Besides, 2 models were found to contain 1.15% and 1.16% calcium (with a moisture content of 12%) respectively, which exceeded the recommended safe upper limit (1.0%) set by the EU guidelines. According to the US Food and Drug Administration (FDA), feeding a high-calcium diet to rabbits over a prolonged period may cause fatigue, pinkish urine and may even be fatal due to feed refusal. On the other hand, the calcium contents of 2 models were only 0.49% and 0.499% respectively, which were slightly lower than the recommended calcium content (0.50%) in the EU guidelines. If rabbits are chronically deficient in calcium, they may develop dental problems or have an increased risk of osteoporosis.
Meanwhile, 10 models were found to contain low sodium and/or phosphorus levels. The sodium content of 5 complete feed models and 2 complementary feed models in the test ranged from 0.03% to 0.19%, which were below the FEDIAF recommendation’s (0.20%). Lack of sodium ions in the body may affect digestive function and/or absorption of amino acids. Chronic deficiency of phosphorus, which is an important component in the bone structure, may increase the risk of rickets in young rabbits and osteoporosis in adult rabbits.
Furthermore, 1 complete feed model was found to contain magnesium at a level (0.38%) exceeding the recommended safe upper limit (0.35%) of the EU guidelines. If the magnesium content of the diet is too high, rabbits may suffer from osmotic diarrhoea, a significant reduction in food intake and even death due to associated complications.
Over 50% Models Did Not Meet the Recommended Vitamin D Levels
A suitable amount of vitamin D can help maintain the balance of calcium and phosphorus in the rabbit's body and maintain healthy bones. The FEDIAF recommended that the vitamin D content in the diet for adult rabbits should range from 800 IU to 1,000 IU per kg of feed. However, the vitamin D3 content of only 2 complete feed models met the recommendations of the guideline, while that of the remaining 10 models varied considerably. Out of these, 3 complete feed models were detected with comparatively higher amounts of vitamin D3, which exceeded the maximum value of 1,000 IU per kg food, though they did not exceed the safe upper limit (2,000 IU per kg food). On the other end of the spectrum, the content of another 3 complete feed models was low. It should be noted that the model detected with the highest amount was a complete feed, while another complete feed model was not found with vitamin D3 at all. Amongst the remaining 4 models of complementary feed, the detected vitamin D3 contents were all lower than the recommended range, with the lowest one being 288 IU per kg feed.
The Council reminds owners that rabbits who consume an excessive amount of vitamin D for a prolonged period are at risk of developing hypercalcaemia, with symptoms such as thirst, increased urination, weakness and loss of appetite, which could even be fatal. On the contrary, chronic vitamin D deficiency can lead to dental and bone problems.
Recommended Feeding Amount and Cost Varied Considerably
Upon examining the labelling information, it was found that some models did not specify whether the product was a complete or complementary feed. 3 complementary feed models did not state on the packaging that the product was a supplementary pet food, in which 1 model did not state that it should be fed with a large amount of grass/hay. If complementary pet foods are served as staple foods over an extended period, they cannot provide a complete and balanced nutrition to pet rabbits. Additionally, certain models only roughly specified that the feed can be fed without limit or did not come with a measuring cup, which could lead to overfeeding, increasing the risks of overweight or even obesity in rabbits. All of the above factors could lead to misfeeding by rabbit owners.
Besides, the recommended daily feeding amount varied significantly between rabbit food brands. For a 1.5kg rabbit, the recommended daily feeding amount for the 7 complete food products ranged from 26g to an average of 110g, while another model even stated that it could be fed without limit. As for complementary pet foods, the serving size ranged from 25g to an average of 45g. Excluding the cost of buying hay and vegetables, the daily cost for feeding each type of rabbit feed, making reference to the feeding instructions ranged from $1.1 to $13.6, a difference of more than 11 times.
Various studies have clearly shown that inappropriate diets are associated with diseases in rabbits. Before buying rabbit feed, consumers should pay attention to the following points:
- Refrain from selecting mixed pellets/feed containing corn, peas, grains and seeds;
- Pay attention to the macronutrient contents (such as crude fibre, crude fat and carbohydrates) to ensure the nutrition is balanced and complete. A high-fibre, low-fat and low-carb diet is ideal;
- Refer to the feeding instruction shown on the product label and feed an appropriate amount based on the rabbit’s weight. The feeding amount should also be adjusted according to the pet's age, physical condition (e.g. higher nutritional requirements during growth, pregnancy and breastfeeding), activity level, health condition, ambient temperature, etc. An unlimited amount of pellets is definitely not recommended;
- A rabbit's diet should consist of plenty of grass/hay, with an appropriate amount of different types of fresh vegetables and a suitable amount of rabbit feed, while clean water should always be provided.
Download the article (Chinese only): https://ccchoice.org/554rabbitfeed
Consumer Council reserves all its right (including copyright) in respect of CHOICE magazine and Online CHOICE.