Importance of Weighing Your Rabbit Feed

Wellness : Nutrition

Mikelle Roeder

Ph.D. - Multi-Species Nutritionist

Meeting your rabbits’ nutrient needs is essential to keep them healthy, and that means properly feeding them the correct amount of a high-quality rabbit feed.

Manufacturers provide feeding recommendations in ounces so it’s important to measure feed by weight, not by volume.
Many people, when asked how much they feed their rabbits, will respond with something along the lines of, “Oh, I feed a half a cup daily.” The problem with this is that the customer is feeding by volume, not weight.  A half cup will always be a half cup, but it does not always weigh the same. The density of any given batch of an ingredient will usually be somewhat different from the previous batch, and when all the ingredients are added together the given density of the finished feed can vary from batch to batch. In other words, if you buy a 50 lb bag of feed, you will get 50 lbs of feed, but that feed may take up a different amount of space than the last bag you bought depending on its density.  
Below Figure A shows one bag of rabbit feed emptied into two containers. The two containers have a total of 49.98 lbs of feed and a bushel weight of 50.5 lbs. A bushel is a volume measure. Note the level to which the feed fills the containers.  
The two containers in Figure B contain a total of 49.44 lbs of feed; however the bushel weight of the feed is only 37.5 lbs, meaning it is less dense and a given weight will take up more volume. You can see how much fuller the containers are. This difference represents a variation of just over 25%.
This example is the extreme of density differences, but it does emphasize the fact that the half cup of feed you give your rabbit could have a considerably different weight, which means you are providing varying concentrations of calories, protein and all other nutrients. 
Just think if you were feeding out of the top two containers for the past 6 months, and then you feed the same amount by volume from the bottom two containers. You could be under-feeding your rabbits by as much as 25%. Or, if the normal amount by weight was 6 oz, that very same cup would only be feeding 4.5 oz, due to the reduction in bushel weight. The reverse could also happen, resulting in over-feeding and loss of body condition.
This illustrates the need to check the actual weight of the feed in the cup each time a new lot number is purchased. Always feed by weight, not by volume, to ensure your rabbits are receiving the full nutritional benefits of the feed.