Choosing a great food for your pet rats is an important part of keeping them fit and healthy. But what is the best food for rats? In this article we will discuss six contenders that are easy to source in the US, to see how they measure up.
We’ll show you what to look for when selecting a feed and debunk a few myths along the way. Look out for our one special tip for improving any rat food and find out which two foods we chose as the pick of the bunch.
- What Do Rats Need – Nutrient Requirements
- Rats Have 3 Life Stages – All With Different Dietary Needs
- How to Choose the Best Rat Food
- The Myths About Rat Foods
- Top Mixed Grain Feeds for Pet Rats
- Top Rat Block Feeds
What Do Rats Need – Nutrient Requirements
The truth is that we do not know exactly. Apart from levels of fat and protein, the NCBI (an organization who report on such things) don’t even have data for an adult maintenance diet. More detailed information is available for supporting reproduction and growth.
As pet owners, we only have this data for laboratory rats, who often eat purified, uniform diets that won’t interfere with the experimental process. Real food contains anti-nutrients and fiber, which can reduce the absorption of many nutrients, including protein, minerals, and some vitamins, sometimes by as much as 50%.
This means that up to half of the nutrients contained in a real food diet may not be absorbed during digestion. Therefore, any pet rat diet would have to be at least twice as nutrient dense as the lab food data suggests – for example, instead of 5% protein a real food diet would need at least 10% protein, probably more.
In order to make an educated estimate as to how much of each nutrient is required, we have drawn on the lab data – modified to account for a real food diet – plus the nutrient density of commercial rat feeds from several countries, noting which feeds produce the best result in terms of condition and health.
We’ve also taken note of experienced rat keepers and veterinarians who have seen evidence of certain deficiencies or excesses causing health issues in rats. But before we can come up with some figures, we need to recognize that no feed could meet the needs of a rat from birth to death.
Rats Have 3 Life Stages – All With Different Dietary Needs
The best food for your rats varies with age. Rats have three main life stages:
- Reproduction and rapid growth, up to about 10 weeks.
- Adult maintenance 10 weeks through to around 18 months.
- Decline into old age 18 to 20 months onwards.
Let’s look at each stage individually.
Reproduction and Growth
Pregnant does have increasing needs for all nutrients (and calories) but deal with this by eating more as the pregnancy progresses. Their gut also changes to become more efficient at absorbing nutrients. Protein requirements increase.
Baby rats begin to eat solids at around 3 weeks. From then until 10-12 weeks they enter the rapid growth phase when protein, calcium, phosphorus, vitamin D and other nutrients are needed in abundance. The diet should approximate:
- 70% carbohydrate (both unrefined and more processed)
- 20%+ protein
- 5% fat (unsaturated)
- 5 to 6% fiber
- Enriched levels of calcium, phosphorus, vitamin D and other micronutrients.
This is a period of slower growth towards adult size, which is reached around 9 to 12 months, followed by maintenance. At this stage of life, more attention needs to be given to the amount of food offered; too much can lead to obesity.
The average rat eats approximately 15g of feed per 24 hours, but this can vary between 12 and 20g. The diet should approximate:
- 75% carbohydrate (mostly unrefined/complex, a little refined/simple carbohydrate is fine),
- 10 to 15% protein (girls may be more tolerant of higher levels than boys),
- 5% fat (unsaturated),
- 5 to 6% fiber,
- Some minerals and vitamins (minerals are recorded as ash on some feed packaging).
Decline Into Old Age
Physical decline can begin very slowly at any age between 18 months and 2 years. Most two-year-old rats show some coat changes and loss of muscle bulk, and this decline often continues until the end of the rat’s life.
Diet at this life-stage needs to consider the reduction in kidney function that occurs as rats age plus any other health issues. Protein and phosphorus should be reduced to protect kidney health, and research suggests that egg or soy protein sources could be helpful too.
The diet for an elderly rat should be approximately
- 80% carbohydrate (a little unrefined, most processed at least to a degree)
- 10 to 12% protein
- 5% fat (unsaturated)
- 3 to 4% fiber (less anti-nutrients)
- Enriched levels of micronutrients.
How to Choose the Best Rat Food
Before we go on to review some popular rat foods, we need to take a minute to think about what the best rat food might look like? Things to consider include
- what eating means to a rat,
- what their natural diet would include,
- the relationship between food and enrichment.
Rats eat to survive, but they also have similar reward and pleasure associations with food, to those we have. Because of this, smell, taste, texture, and variety are all tied up in enrichment. Rats really enjoy food!
Natural Diet and Enrichment
As an opportunistic omnivore, a wild rat would have an extremely wide natural menu to select from. It might include grain, seeds, roots, herbs, vegetables, fruits, nuts, insects, mollusks, bird eggs, small vertebrates, carrion, waste human food and even feces of other animals.
When you feed your pet rats a varied diet, you not only give them a greater spread of nutrients but also provide sensory enrichment from the smell, texture, and taste of the food. Practicing scatter feeding, also allows your rats to express natural behaviors such as digging, climbing, foraging, and problem-solving.
These are enrichments that can be given to any rat regardless of their age, history or the type of accommodation they live in. Enrichment has been shown to improve well-being and reduce stress levels in caged rats.
Reservations About Rat Blocks and Their Impact on Enrichment
Despite providing good quality nutrition, even the best pellets or rat blocks are an unnatural diet for the species, which reduce:
- taste reward and pleasure feedback,
- textural enrichment,
- enrichment from preparing a piece of food, e.g. stripping a whole oat or seed for eating,
- enrichment from the smell,
- foraging time (no small seeds and such like to find),
- the stimulation of difference (opposite of boredom).
Pelleted feeds also tend to be highly processed with ingredients being ground, extruded and then cooked to create individual biscuits. However, there are some good rat blocks available and there is a simple solution to the enrichment problem.
How to Improve Any Rat Food in One Easy Step
Any good quality pellet feed can be greatly improved (in terms of enrichment value and variety of ingredients) by mixing it 50/50 with any good quality real food mix. If each food is nutritionally balanced, then mixing them together won’t change this.
You will need to feed the amount of mix needed in 24 hours, rather than ad lib (freely available) to prevent selective feeding, but more on this soon. There are great advantages to rationing food since ad lib feeding has been noted to result in a shorter lifespan when compared to rationed feeding.
Try 15g per rat and scatter the feed around the cage. Keep a close eye on your rat’s weight and only feed a little more if your rats started at a normal weight and you see signs of weight loss. Increase the amount by 1g per rat at a time.
These small steps will make a big improvement to sensory and behavioral enrichment for your rats, as well and helping them to stay lean, fit and healthy.
Making Sense of Reviews – Key Points Explained
Wheat, oats, and rye
These grains have the highest phosphorus levels and are best kept to a minimum is the diet of an elderly rat. Look for Barley, rice, corn, buckwheat, and millet as primary ingredients if you want a kidney-friendly feed for elderly rats.
The number of main (food) ingredients
Variety is valuable when feeding pet rats in terms of overall nutrition. The more varied the ingredients list before you get to the supplements, the better. But exclude beet pulp, soy hulls, and alfalfa which are included to add fiber and are not digestible for non-ruminant animals like rats.
Protein source and percentage
Egg and soy are the proteins that are considered most protective of kidney health in rats, with fish or chicken having a slightly higher toxic load for the kidneys. Red meats are generally best avoided. Protein percentage needs to be suitable to the life stage of the rats involved.
These should be included as real food wherever possible. They are essential for optimum health. Sometimes they are included as oil, which is fine but does not give the full nutrient benefit that the food the oil is extracted from would.
If you can see individual recognizable ingredients – such as grain or seed – no (or little) processing has taken place. Biscuits and pellets are highly processed, usually ground, extruded and baked.
All feeds should include a wide range of supplemented micronutrients as nutrients like vitamin D, calcium, zinc, and copper can be naturally low in a grain-based feed. Details should be recorded on the packaging.
Some feeds use the cheapest available source of a nutrient at any given time. To allow for this they will contain ‘poultry’ rather than chicken, ‘fish’, rather than salmon or sardines and vegetables, rather than carrots, cabbage, etc. These feeds tend to have lower quality ingredients as they are determined by cost.
Unpalatable or inedible ingredients
Some ingredients such as alfalfa pellets, beet pulp, and other fibrous ingredients are generally not seen as food by rats. This is less important if they are part of an extruded pellet as other ingredients will be added to increase palatability. Most fibrous pellets will be left uneaten.
Artificial preservatives and colorants
Should be avoided as they have been linked to the occurrence of tumors and other health issues in rats.
The Myths About Rat Foods
The Internet is a really useful tool for information sharing, but it also gives a platform for erroneous ‘facts’ to spread unchecked. Over the past decades, a few myths have arisen around rat food, some of which we’d like to challenge here.
Understanding the truths behind these myths is just as important when choosing the best rat food for your situation, as is letting go of the myth itself. For instance, realizing why and when selective feeding occurs can free you to be more adventurous about what to feed your rats
The Myth of Selective Eating
Selective eating is often used as a reason not to feed a rat a natural diet, but rather to give processed rat food pellets, where each mouthful tastes, looks and feels the same. However, selective feeding is a problem caused by over-feeding and has nothing to do with the type of food offered.
Rats will eat their complete mix when they are only fed to their needs per 24 hours and not fed ad lib (with food always available). The exception to this is when unpalatable foods – such as alfalfa pellets – are added to a mix.
Understanding this allows you to make better choices for your rats. Rather than just offering pellets you may choose to feed a more natural diet with some whole grains and healthy seeds. This can easily be achieved just by mixing two different feeds together – one block feed and one-grain mix.
If you are worried about this I would encourage you to look at the experience of pet rat owners in the UK, South Africa, and across Europe.
In the UK thousands of pet rats over decades have been fed on rich and varied dry mixes – rather than pellets. These rats have thrived, maintained a good weight, reproduced, won shows (which judge condition), recovered quickly from surgery, resisted infection and had above average longevity.
The Myth That Surrounds Corn
A couple of decades ago some anonymous person wrote that corn should be avoided in rat food because the mold that can grow on it releases toxins into the food. With repeated internet repetitions, corn is now often considered “bad” for rats.
Corn can sometimes harbor mold that produces toxins, which can cause severe reactions if eaten. So can many other grains (such as oats and rice) and legumes (such as soya and peanuts). This is a recognized issue within the animal feed industry, which manufacturers take steps to overcome.
Indeed, they are required to do so by law because toxins in animal feed can pass into cows’ milk and into the human food chain. There are various ways to do this, which include methods of farming, storage, processing, in-house testing and the addition of calcium-based neutralizers.
We can assume that where a feed from a known and reputable manufacturer contain corn, oats, rice, peanuts, soya, etc., the feed has already passed rigorous testing to ensure toxins are below permissible levels (levels that we are all exposed to that do not cause health issues).
The Myth of Citric Acid Causing Kidney Issues in Males
It’s sometimes said that citric acid causes kidney issues in male rats and shouldn’t be added to rat food. This is not true. D-limonene (a chemical found in citrus oil) affects a male-specific protein in the kidneys causing protein clumps to form. Over time, these clumps can lead to tumor formation.
Citric acid is an unrelated substance to d-limonene, though both are present in citrus fruit (we think that’s where the confusion might come from). Citric acid is safe for rats to eat and is sometimes included in feeds.
Top Mixed Grain Feeds for Pet Rats
A mixed grain feed is one that contains a mixture of whole, flaked and processed grains, seeds, and legumes (soy, peas or lentils) to create a real food muesli type mix. These feeds have the value of being varied and interesting for the rats, as well as allowing for sensory and behavioral enrichment.
Tiny Friends Farm Reggie Rat & Mimi Mouse Food
Main food ingredients: Wheat, Whole Maize, Flaked Peas, Torrified Wheat, Whole Oats, Flaked Maize, Soya Bean Meal, Linseeds, Soya Oil, Extruded Locust Beans.
Nutritional Analysis: Protein 14%, Fat 4%, Fiber 4%
A minimally processed mixed rat food, which is a good all-round feed that is particularly suitable for the adult maintenance stage of life. It could also be used for growth if the protein was supplemented and in old age with the addition of some processed cereals to dilute the protein down.
Good spread of ingredients which includes grains, legumes, and seeds. Palatable for rats and encourages foraging. Alfalfa pellets will be largely ignored so some waste.
Brown’s Tropical Carnival Natural with Shrimp Mouse & Rat Food
Main food ingredients: Stripe Sunflower Seeds, Oat Groats, Peanuts, Brown Rice, Buckwheat, Wheat, Dried Lentils, Flaked Peas, Pumpkin Seeds, Flaked Corn, Dried Shrimp, Wheat Flour, Ground Corn, Ground Oats, Corn Gluten Meal, Dehulled Soybean Meal, Rice Flour, Dehydrated Ground Raspberry/Blueberry/Strawberry/Peach/Apple/Pineapple/Banana/Carrot/Sweet Potato, Soy Oil, Brewers Dried Yeast, Algae Meal
Nutritional Analysis: Protein 16%, Fat 10%, Fiber 8%
An interesting rat food, which, if you were to pick out most of the sunflower seeds and some of the peanuts (what were Brown’s thinking of?) actually has a lot to offer. Maybe you could feed the birds too!
Without the seeds, the protein fat and fiber will drop right down to a reasonable level and you are left with a nice mixed feed that contains a great range of ingredients. Super feed to add interest to other more restricted food. Best for adult maintenance unless mixed with other feed.
Kaytee Supreme Fortified Daily Rat & Mouse Food
Main food ingredients: Rolled Corn, Rolled Oat Groats, Rolled Barley, Ground Corn, Dehulled Soybean Meal, Wheat Middlings, Ground Wheat, Meat Meal, Sunflower, Peanuts, Corn Gluten Meal, Cane Molasses, Vegetable Oil, Poultry Meal, Fish Meal, Brewers Dried Yeast.
Nutritional Analysis: Protein 14%, Fat 5%, Fiber 9%
One of the only Kaytee feeds that isn’t full of artificial colorants, this is a nice mix of grains and it’s good to see Barley (low phosphorus) included there. The mix is let down only by the meat meal, which will be red meat of some kind and the unpalatable alfalfa pellets.
The fiber will be lower in practice as the alfalfa (fiber) pellets aren’t likely to be eaten. Protein and fat are particularly suitable for the adult maintenance stage of life.
Our Favorite Mixed Grain Feeds
Well, we’d really love to be able to say the Brown’s Tropical Carnival, because they have tried so hard to make it interesting, and the inclusion of less ‘commercial’ ingredients rice, buckwheat, lentils, shrimps, pumpkin seeds and algae is wonderful. But it’s unusable for rats as sold, because of the quantity sunflower seeds and peanuts – and resulting high protein, fat and fiber.
So sorry Brown’s, but the Top Pick goes to Tiny Friends Farm Reggie Rat, a good all-rounder whose main issue is the alfalfa pellets which will just become waste.
Top Rat Block Feeds
A rat block or pelleted feed is one where all the ingredients are ground together, extruded into a biscuit or pellet and cooked. Each biscuit is uniform in terms of taste, smell, texture, shape and of course nutrients.
Often called lab blocks, these diets are based on the uniform blocks needed to achieve a control diet in a laboratory setting. They can be good nutritionally but always lack in terms of enrichment for the pet rat. Many rats tire of them over time though feeding fresh food alongside can help alleviate this.
Oxbow Essentials Regal Rat Adult Rat Food
Main food ingredients: Whole Brown Rice, Oat Groats, Wheat Bran, Wheat, Soybean Meal, Menhaden Fish Meal, Flax Seed Meal.
Nutritional Analysis: Protein 15%, Fat 4%, Fiber 2-5%
A popular brand of pelleted rat food, which is a good all-round feed that is particularly suitable for the adult maintenance stage of life. It could also be used for growth if the protein was supplemented. Smells good and since being re-formulated is generally considered palatable to rats.
Some thoughtful additions, such as rice, flax seed, and soybean meal give a good nutritional balance, with great supplementation. This is one of the best rat food blocks available for adult maintenance and would also make an excellent addition to a mixed feed (see below) or homemade mix to provide for greater enrichment.
Mazuri Rat & Mouse Food
Main food ingredients: Dehulled Soybean Meal, Ground Corn, Wheat Middlings, Ground Wheat, Soybean Oil, Cane Molasses, Ground Oats, Wheat Germ, Brewers Dried Yeast.
Nutritional Analysis: Protein 23%, Fat 6.5%, Fiber 4.5%
In trying to make a feed suitable for rats and mice, Mazuri has created a feed that is too high in protein for adult rat maintenance or – particularly – in old age. However, the high protein content does lend itself for adding as the protein element to a homemade mix or to support reproduction and rapid growth. The spread of ingredients is limited, and the molasses will add sugar.
Kaytee Forti-Diet, Pro Health Mouse, Rat & Hamster Food
Main ingredients: Dehulled Soybean Meal, Ground Corn, Ground Wheat, Ground Oats, Ground Peanuts, Ground Flax Seed, Dried Cane Molasses, Brewers Dried Yeast, Wheat Middlings, Ground Rice.
Nutritional Analysis: Protein 20%, Fat 4%, Fiber 7%
Kaytee seems to have created a gimmicky, multi-species feed, marketed as providing special dental care. However, any hard food will keep a rat’s teeth worn down, as will bruxing and gnawing on wood or bones.
This feed is too high in protein for adult rat maintenance and particularly unsuitable in old age while being right at the lower edge of being useful for reproduction and growth. The spread of ingredients is good, though the molasses may add sugar. Highish fiber (more antinutrients).
Our Favorite Rat Block Feeds
Hands down Oxbow Essentials Regal Rat (Adult). This is a good all round pellet feed, which has been thoughtfully formulated. It’s good to see rice used as the main ingredient (very kidney-friendly). The only real issue is the lack of enrichment value. Mix this with the Reggie Rat and you reduce the impact of both feeds’ weaknesses.
We hope that we have encouraged you to look more closely at your rat food to determine if it’s the best rat food for your circumstances. No commercial rat food is perfect, and even without the myths, all have genuine flaws, but now you’re equipped to make good choices and your rats will benefit as a result.
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