Question: I have a three year old appy mare.  She has developed a bad problem. She is outside daily with my three year old quarter horse they get along great except at feeding time.  They are fed four times a day (average feedings of hay) they get grain at the morning and evening feedings.

My problem is that my appy is running my quarter horse off her food, they are fed in separate areas from one another. We tried to put her in with other horses that would not tolerate her being pushy she now has kick marks all over herself and has urinated all over herself. Today she was put in with yet another mare and my appy insisted on trying to run her off of her food and was kicked repeatedly and kept going back for more.  What am I to do about this I don’t want her getting beat up but she needs to learn that this is not going to be allowed.

She is not in heat and was been wormed twice last month (thought that was the problem). She was seen by the vet two months ago and there is nothing physically wrong with her.

Answer: When horses are placed in a situation in which there is a limited resource (in this instance, it is the feed that you provide at intervals throughout the day), they will compete for that resource. It is natural and to be expected, and as human managers who are introducing the limited resource, we need to plan for the competition. Obviously your Appaloosa mare is dominant to your Quarter Horse mare. You say that your horses are fed in separate areas from one another, but you did not specify the distance between the mares. Obviously they are still in the same paddock during feeding. It is unclear from your email whether the mares are tussling during only grain feedings or during hay feedings as well.

The top reasons for competition for forages (hay and even grass) is that there is insufficient forage in the pasture, an inadequate forage supply, or too few piles of hay. As your mare seems to be extremely “pushy” during feeding time, placing hay in a minimum of three piles when she’s in with other horses should help eliminate the problem, as long as the piles are placed far enough apart. Placing the piles a minimum of 25 feet apart should give each mare some security that the particular pile she is eating from is “hers”. If the paddock is big enough, I would suggest you put the hay in 4 or 5 piles. You may also be able to eliminate forage competition by keeping hay in front of your mares at all times. Be sure to never place hay in the corners of paddocks, as this could lead to your more submissive mare being trapped if the dominant mare attempts to drive her away from that pile of hay. Insufficient roughage in a horse’s diet can also lead to aggressiveness during feeding time. Horse are grazers, and are used to eating small amount frequently throughout the day. Obviously you are attempting to mimic this by feeding your horses four times per day. Many horses in domestic situations receive feed only twice daily.

Another thing you need to look at is how much your horses are being worked and how much grain they are receiving. If your horses are not being worked much or are being worked minimally, you may be overfeeding grain to your mares. Overfeeding grain can lead to over-excitability, boredom (from not having hay to munch on throughout the day) and even increased aggression toward you or other horses. It may be possible to eliminate grain competition by eliminating the grain from the mares’ diets and replacing it with more forage. If your mare is being worked hard for several hours each day, she likely needs grain in her diet. If she is not, she is likely better off on a diet of good quality hay. Notice I did not say “the best” quality hay. You can overfeed horses on hay as well, and feeding all very high quality alfalfa can make a horse just as “hot” as overfeeding grain. A mixed grass hay, or a mix of legume and grass hay of good quality (you don’t want any mold or mildew and don’t want too many woody stems in the legume portion or many weeds) is often sufficient as a maintenance ration for horses.

Obviously you cannot feed one mare in the pasture grain while the other receives none. Separating your mares during feeding time (for example, place one mare in a stall in the barn during feeding or put one in another paddock prior to feeding (some people will put either their aggressive or submissive horse into a round pen or small paddock away from others prior to feeding). Another option would be to put your aggressive mare back in with other horses who will not tolerate her behavior. While you don’t want her to be injured, most horses will learn their place in the herd hierarchy quickly. Some mares will urinate small amounts when showing their submissiveness, which is probably what happened when you put her in with horses who are dominant to her and you stated that she urinated on herself. The safest method would probably be for to eliminate grain from her diet if she does not actually need it or separate her from others during grain feeding. Additionally, provide more (and probably larger if you’re having to put hay out 4 times daily)  piles of hay for your two mares to help eliminate competition over forage.

If none of these management techniques reduce your mare’s aggression during feeding time, you may wish to ask your veterinarian if your mare could have some other issue, such as a thyroid hormone imbalance. Some hormonal imbalances cause increased aggression in horses. Most aggression limited to feeding time can be eliminated by ensuring horses have adequate space between hay piles and feeding buckets. If your only option is to continue feeding grain in the pasture, try dividing your mares’ grain rations into several feeders placed a minimum of 25 feet apart. Always make sure there is a minimum of one more feeder than there is horses if you are having an issue of aggression.  Good luck!