Question
I own a pregnant 12-year-old Thoroughbred broodmare, about 15.2 hands (157 cm) and 1,060 lb (480 kg). She has difficulty maintaining weight at times, fluctuating between a body condition score of 4.5 and 5.5 on the 1-9 Henneke scale. As far as her diet, she gets 12 lb (5.5 kg) of feed, one cup of alfalfa (lucerne) pellets (about 0.25 lb or 0.1 kg), one cup of beet pulp pellets (about 0.25 lb or 0.1 kg), 2-3 flakes of hay each day, and some flaxseed. She also gets some low-quality pasture for 7-8 hours a day. She is eight months pregnant now, and I want to make sure she maintains her weight through late pregnancy and early lactation. Can you review her diet, please?
Answer
Based on the information provided, I have a few suggestions that should help your mare maintain her weight.
First, to make sure she is able to sustain her weight throughout pregnancy and lactation, I recommend increasing her forage intake. Ideally, you would want to provide free-choice hay (while she’s stalled, especially) to help meet her feed requirements of 1.5-2.5% of her body weight per day. Estimating a flake of hay at approximately 3 lb (1.4 kg), this would mean about 5-8 flakes of hay per day would meet her needs. To get an exact weight of each flake, and to be sure you’re feeding enough forage, I propose weighing the hay with a kitchen or multipurpose scale.
In growing seasons, pasture would also contribute to her overall forage intake, but because the pasture is poor at this time, it’s likely not adding much to her diet, both in terms of intake and nutrients. The forage pellets she’s receiving, about 0.25 lb (0.1 kg), do not provide many calories. Therefore, in an effort to increase calories from fiber sources, you can also increase the amount of alfalfa (lucerne) and beet pulp pellets without having to add more feed.
Second, if you find more calories are needed during lactation on top of the extra forage, you may consider adding vegetable oil (soybean, canola, coconut) to her grain meals to add a dense source of calories from fat. This is a better option than adding more grain since she is already getting 12 lb (5.5 kg) of feed daily.
If possible, split her grain into three meals a day to decrease the risk of hindgut acidosis, a condition characterized by a drop in the pH caused by the microbial fermentation of starches and sugars, and resulting in accumulation of excessive lactic acid in the hindgut. Large grain meals cannot be completely digested by the stomach and small intestine, and therefore enter the hindgut, which is not designed to handle starch and sugar digestion.
To ensure hindgut acidosis does not inhibit her nutrient absorption or digestion, consider adding 4 oz of EquiShure to the ration, split among meals. EquiShure is a time-released hindgut buffer that balances the pH in the hindgut.
Another supplement suggested for pregnant mares is EO•3, an oil rich in omega-3 fatty acids. EO•3 is a source of DHA and EPA omega-3 fatty acids that are more efficiently used as precursors of local hormones than plant-based sources of omegas such as flaxseed.
