Won't eat alfalfa?

I have an elderly pony who does best if he gets just a little alfalfa hay every day. I feed him approximately 3 lbs of grass and 1 lb. Of alfalfa twice a day with 1lb senior 1lb omelene 300 once daily. He maintains very nicely on this diet.

BUT every now and then(about every 6 months or so) he decides he doesn't want to eat the alfalfa any more. He picks out all of the grass and leaves the alfalfa. I will nearly double his grass portions but he will still start dropping weight when he doesn't eat that little bit of alfalfa. I used to have to put him on free-choice grass and double the pelleted feed he was on and he would still get almost skeletally thin in a matter of weeks, but then I started him on the omelene which has helped tremendously in maintaining his weight.

3 weeks ago he went off his alfalfa again, I am just now beginning to see that he is dropping a few pounds. I am completely baffled. He has done this for all of the 12 years I've had him, so I'm not too worried, now that he isn't losing as much weight as he used to(thanks to the omelene) and I'm pretty certain he will suddenly decide he loves to eat alfalfa again in another week or two.

My questions are: Why does that little bit of alfalfa make so much difference in his weight? I've never known another horse to need alfalfa like that. And Why does he quit eating it every now and then? I haven't been able to figure out a rhyme or reason to his quitting.

Have you tried opening another bale of alfalfa when he starts refusing? Feeding at one pound per feed it would take some time to get through an entire bale - so am wondering if you have tried a new bale to eliminate a "bad" bale as the cause.
Have you ever tried soaked cubes/pellets in place of actual baled alfalfa?

Those are great suggestions, I don't usually switch bales for him, I may try that in the future. In the past when I have tried to substitute pellets for hay he will refuse the alfalfa pellets too. I've found that the quickest way to get him eating his alf. Again is to take it away from him completely for 5-7 days and then reintroduce it slowly one handful at a time, until he will eat a full lb again. He ate a handful of alf. For the first time in 3 weeks this morning. I just wish I knew why he does this!

He may be having trouble with the alfalfa stems. Any sharp teeth? Any missing? Horses do have a definite preference for the less stemmy hay.

In addition to MackPack's suggestion, consider that alfalfa is very high in protein, calcium, etc, which may be causing imbalances - particularly high protein with older horses. They tend to 'know' what they need or not & will take it if it's there, avoid it if they're getting too much IME. You might want to check out something like feedxl.com to analyse whether he's getting well balanced nutrition.

The other thing is, feeding the senior & omolene only once daily may well be upsetting his system a bit. It's important for horses to be fed little & often and I'd divide his grain into at least 2 meals, pref more.

I had his teeth checked in Oct. And they were fine then, the alf. He is on is very leafy, he is actually more inclined to eat the stems than the leaves.

Loosie you could be very right about some kind of imbalance in his diet, before I got him he had been starved and neglected, then was fed on really hot straight alfalfa and 4-way for two years by the person I got him from. He was thin and and colicky for a long time after I bought him, I think his past may have messed up his system some, he has been a really hard keeper for a POA.

I am intrigued with feedxl, I hadn't heard of it before it's a cool site, I will be looking in to that some more, thank you. I agree totally about dividing his grain into smaller meals, but my schedule doesn't allow for that:(

Beware, there's so much great stuff on FeedXL, you can lose track of time! If you can't manage more than 1 feed daily, I'd be avoiding grain all together, in favour of something like beet pulp or soy hulls or such.