The major difference between feeds suggested for use in broodmares and those for other classes of horses is a higher protein level. For broodmares, 14 to 16% is the usual, while 10 to 12% protein is the norm for other feeds. Pregnant and lactating mares do need a lot more protein but, frankly, even this level might not get the job done well enough.
The difference between a 10% and 16% feed in terms of protein is only 27.2 grams/lb., while an 1,100-lb. mare in heavy lactation needs about 770 grams more protein in her daily diet. Look at what happens with a 1,100-lb. mare on a hay, then hay and grain pregnancy diet, when switched to a broodmare feed after she foals.
Pregnancy: 22 lbs./day of 8% protein hay = 800 grams of protein/day (adequate through the ninth month of pregnancy); 20 lbs./day of 8% protein hay + 2.2 lbs./day of 10% protein feed = 871 grams of protein/day (adequate up to foaling)
Lactating: 25 lbs./day of 8% protein hay + 6 lbs. 16% protein feed = 1,345 grams of protein/day (about 80 grams short). Since many of the grass hays fall below 8% protein, this could be even worse.
Put It To Use
- Even 16% protein in feeds may leave the mare short of protein during lactation. Adding 1 lb./day of 50:50 alfalfa pellets and soybean meal to her diet will bridge the gap. Other options are ½ lb./day of soybean meal or sunflower meal.
Fortunately, nature provides a natural protein boost in the form of young pastures, where 20% protein is common. However, for the mare with little or no pasture access, you'll need to feed more protein.
Since the grains have a calorie value at least twice as high as most hays, it won't do any good to feed more grain because you would have to cut back the hay and 2 lbs. of an 8% protein hay has the same protein content as 1 lb. of a 16% protein grain.
Possible solutions:
- Provide 1 to 2 lbs./day of a 30% protein supplement. This will cover the protein needs, but since these products are highly mineral-supplemented you'll end up overdoing it on the mineral front.
- You could solve the problem by adding a ½ lb./day of soybean (Calcium:phosphorus = 1:2.46) or sunflower (Ca:P = 1:2.24) seed meal, or Uckele's Amino Fac 41 (Ca:P = 1:2.25), but this could upset your mineral balances.
- Another option would be a 50:50 mix of alfalfa pellets and soybean meal. This will have 31.5 to 35% protein on the average and about 50% more calories than average grass hays, so you can feed more and will provide more energy in the form of digestible fiber than with high-starch grains. 1 lb./day of the 50:50 soybean meal and alfalfa pellets has a balanced calcium:phophorus ratio, makes up the protein deficit without overdoing other minerals and costs considerably less.
Next to consider is lysine intake. Lysine is an essential amino acid that is the most essential for normal growth and development, and the only one for which precise requirements are known. A mare in the last trimester of pregnancy, who was on an adequately balanced maintenance diet before pregnancy with at least 0.3% lysine has a relatively small requirement for additional lysine. This can be easily met by feeding her 1 to 1.5 lbs./day minimum of any commercial feed with a guaranteed lysine content of at least 0.6%.
As our feed chart on page 16 shows, even "regular" feeds like Triple Crown 10 or Nutrena Compete have sufficient lysine so there's no point in switching to a mare feed.
The lactating mare has a more sizeable deficit, even when increasing her feed by 70% and starting from a good base maintenance diet as just described. If you feed this mare 6 lbs./day of a 0.6% lysine mare feed, she'll still be a little short. You'll need a feed with 0.7 to 0.75% lysine to provide enough. The 50:50 soybean meal and alfalfa mixture is also rich in lysine, about 1.8%.
