Basic Gerbil Food Mixes
When gerbils are being kept as household pets we essentially replicate their wild diet by offering them a dried food mix, supplemented with a small amount of either fruit or vegetables. The dry feed can either be a homemade mix or a pre-packaged commercial mix sold from your local pet shop. Usually it is recommended that a single gerbil needs approximately one tablespoonful (approx 10-15 grams) of this feed per day, and that no more food should be added until the bowl is empty.
This is practiced because gerbils can have a tendency to eat what they prefer first and often avoid other foodstuffs while these are present in their bowl. Some people have adopted the practice of feeding every other day because of this. Be aware though that some seeds like whole corn and Milo may only be partially eaten, and have the hearts only bitten out; the gerbil tends to leave the larger, starchy part of the seeds, this habit of the gerbil is fine, as they will stay slimmer by avoiding the starches out of those seeds. If the intention is to breed, then smaller seeds can be added for weanling pups during this fast growing stage in their lives, also extra protein and fats during this period benefit the mother.
Always make sure their food intake is varied enough to make sure they receive adequate micronutrients, and also to prevent boredom setting in. If you feed treats on top of their staple diet, make sure the treats are always in small portions and not offered more than once per week.
Although the diet of the Mongolian gerbil has been well researched both by scientists and also by keen keepers and breeders in the rodent community, there is little definitive data on their actual dietary requirements. This is one of the reasons that any recommendations you see will not be precise, but given in a general % range. The composition of a good, proven Staple gerbil diet is set out in the table below; most authorities agree that these ratios of protein, fat, and carbohydrates, work well very well with Mongolian gerbils.
When feeding gerbils it is understood that their diet varies over their lifespan, and they cope well on a range of diets (this you would expect for a desert dwelling animal) but as a general rule of thumb, it is recognised that young active gerbils will need more fat and protein, and older gerbils need less protein and fat. As can be seen by the percentage values in the table, fats should never be completely omitted or severely reduced in their diet. Optimum values for fats vary between the 3% - 8% range. This depends on the age of the gerbil and whether it's a breeding animal or a pet. It should also be remembered that the gerbil is a highly active rodent that need fats for energy and to also help maintain their coat in an optimum condition.
However on the other hand, too much fat will lead to obesity, sterility in females due to an excess amount of fat surrounding the ovaries, also high fats in older gerbils can lead to increased cholesterol levels, the results here being heart disease and strokes. Protein contents less than 15% leads to slow growth in juvenile gerbils, and too much protein in their diet (+20%) can be detrimental to health, this can lead to liver damage, kidney stones and skin lesions. So always be wary of diets that have protein content higher than 20% especially if used for long periods.
The best way of assessing how well a gerbil is doing on a diet is to use your eyes! If you notice your gerbils getting fat on any mix, well it's a case of diluting the mix, for e.g. some extra alfalfa pellets in the mix will increase the fibre and protein and reduces the overall calorie intake. If your gerbils are looking thin, increase the protein and fats slightly (it should be noted, that in geriatric gerbils, they can often lose weight for other reasons, such as overgrown teeth, etc) this can be in the form of extra broken dog biscuits and/or cat treats. Fats are best increased using the larger nuts available, and seeds like sunflower, and Linseed can be usefully added to the diet. The fats contained in nuts are not 'bad or saturated fats' but are unsaturated fats, which are essential for correct body functions.
If you only keep one or two gerbils as a pet, this is the best way to go. Always make sure the mix is fresh and hasn't been lying on the shop shelf for a long period. Most of the nutrient values diminish over time and ingredients such as vitamins degrade very rapidly. Some brands are designed mainly for a hamsters diet and have far too many peanuts and sunflowers in them, which makes the diet too high overall in fats. In this case, the mix can either be diluted with other ingredients, such as high fibre alfalfa pellets. The sunflowers and peanuts can be removed and used as treats instead. Also now on the market are higher priced food specifically designed for gerbils. These don't usually contain sunflower seeds, but are replaced with other ingredients. Some of the brands are deficient in Calcium, and need to be supplemented accordingly with products that are high in Calcium, such as dry dog biscuits or cat treats.
The idea of a homemade mix is hopefully to better what is commercially available. It belongs mainly in the realms of the large breeder, or someone who keeps a very large colour collection of gerbils! Food is often bought in as 'straights' and mixed as needed to form the staple diet. Try to avoid using cheap ingredients whenever possible, as this negates any benefit you are hoping to achieve by making your own food. Some of the drawbacks of home made mixes is getting the ratios of fat, protein, fibre and other main ingredients just right. Storage of the 'straight' feeds may also present a problem as they take up a lot of room. Saying that, once mixing the ingredients are mastered the feed has the potential to be far superior to any commercial brands that are available. Also there are a huge variety of 'straight' feeds that you can use for this purpose.