Question
I have a Miniature Horse mare that weighs about 240 lb (110 kg). She is just shy of being in moderate body condition; certainly, you can see a hint of rib at all times. She’s not in work right now and spends her time in a drylot. Her diet consists of 6.5 lb (3 kg) of timothy/orchardgrass hay, fed in a slow feeder, and about 0.25 (100 g) of a preserved grass forage. In terms of supplements, she gets coat conditioner, gastric and hindgut buffer, and Himalayan salt. She continues to be a hard keeper. She is sensitive to certain grains and has a predisposition to gas colic and perhaps insulin resistance. I’d rather not feed her alfalfa (lucerne), either. I’d appreciate some general suggestions about what else I can try to help her put on some weight.
Answer
From the information you have provided about your mare, adding a concentrated fat source would be the most effective way to increase calories for weight gain. Because she has some sensitivities to certain feedstuffs (corn, rice, wheat), adding vegetable oil (canola or soybean oil) will provide a source of highly digestible energy without significantly increasing the amount of feed offered.
An alternative to alfalfa would be beet pulp, as it lower in protein but jam-packed with fermentable fiber. Soaked beet pulp is a great vehicle for delivering vegetable oil and supplements. Another high-fat supplement that is great for weight gain and conditioning is stabilized rice bran, but you have indicated the removal of rice from her diet was necessary previously.
In regard to the overall protein content of the mare’s diet, the majority of the dietary protein is coming from the grass hay. Mature horses and ponies can easily meet their crude protein requirement even when offered a mid-quality hay with a protein content of 8-9%. However, in most instances of diet formulation, particularly for horses that are hard keepers, meeting their dietary energy needs can cause the diet to provide more protein and other nutrients then they require.
Through the extensive efforts of Kentucky Equine Research (KER), including investigations into nutrient requirements and digestibility, as well as conducting nutrition consultations and evaluations, the company developed a nutritional program referred to as daily recommended allowances. KER has determined an acceptable range of nutrient intakes for each individual nutrient and horse classification to assess nutrient adequacy in the diet.
According to KER, protein is one nutrient that can be safely fed to healthy horses at higher levels than its requirement; the amount of dietary protein in your mare’s diet falls within the higher acceptable level for a maintenance horse of her size. In the healthy horse without a medical condition such as chronic kidney failure, excess dietary protein is eliminated from the body by the kidneys through urine. One downside to high-protein diets can be excessive urine production and this can be a management issue for stalled horses.
Because the mare has a tendency to produce excess gas and has had recurrent colic episodes, you may want to consider switching to EquiShure (15 g/d) to provide a more concentrated amount of the hindgut buffer.
