My horses don't have pasture for grazing the whole year. I'd like to know the different nutritional values of average hay and alfalfa and the nutritional value of field grass and when they are the highest in sugars. (how to absolutely avoid laminitis) Also the difference between first cut 2nd 3rd so on.
You can find analysis of various different hays, fresh forages, and feedstuffs at Equi-analytical's website
. Things like NSC (sugar/starch) can vary significantly from batch to batch, depending even on things like what time of day it was cut. IME most hay providers don't test their hay, so you don't really know it's NSC (or other nutritional) value unless you get it tested yourself. You can lower NSC to some degree by soaking hay.
From what I understand, the cutting is less important than the maturity of the plant when it is cut. The more mature the plant, the more stems will be present. Stems contain a lot of lignin fiber, which is not digestible and will not provide energy to the horse like other types of fiber (cellulose, hemicellulose and pectin). A late 1st cutting will be very stemmy, while an early 2nd cutting could be very leafy. That same 2nd cutting could become very stemmy if left to grow a bit more before being cut.
One thing to keep in mind with hay is that it is different from pasture in that certain nutrients degrade very quickly. Vitamins A & E and omega-3 fatty acids are the big ones, and for horses that are primarily fed on hay year-round it's very important to make sure that whatever feed or supplements you're giving have these in adequate amounts to make up for it.
Can a horse get laminitis from a diet rich in alfalfa (when there is no grazing available)?
In general, alfalfa is lower in NSC than grass hay. It's more energy dense, however, so can still present a founder risk to overweight horses. If the main concern is sugars and the horse is at a healthy weight or needs to gain, then alfalfa should be safe.
Horse Nutrition Explained
Plus can anyone recommend horse nutrition websites/books that explain phosphorus calcium ratios and good safe weight gain feeds and suppliments?
is a good website to start on. "Feed Your Horse Like a Horse" by Juliet M. Getty is also a good basic resource, though to be honest I didn't find it to be as in-depth as I had hoped. When preparing a diet for your own horse, FeedXL Horse Nutrition: The D.I.Y. Equine diet planner
is a great resource. It's subscription based, but makes it very easy to put together a diet and see where holes are.
I have heard that yeast and apple cider vinegar are good for adding to feed for digestion and intestinal flora and sunflower oil a good additive to feed to improve condition. Guiness after a competition (old racehorse remedy) any others you know of?
I tend to stay away from most "old timey" remedies. Many of the good feeds out there already include probiotics, so adding things like yeast are only necessary if the horse needs more digestive support than average. The same goes for most supplements- they can get very expensive very quickly and often have no effect whatsoever, so do your research and figure out what the horse actually needs before adding stuff to a well-balanced diet.
Also treats - carrots and apples are the obvious but fennel watermelon raw potatoes sunflower seeds??
I tend to stick to easy things for treats- carrots, alfalfa cubes, etc. Watermelon is also a great treat, though my horse hasn't been lucky enough to get any from me (I'm not sure he would take it anyway... he tends to turn down most treats, including sugar cubes!)
I'd be careful with "non-traditional" things like sunflower seeds, potatoes, etc. The striped sunflower seeds, for example, have very tough hulls and can potentially cause impaction colic. Many people feed the black oil sunflower seeds to their horses for the fat content without issue, though.