I have been asked quite a few times in the last month about alfalfa (lucerne) and its non-structural carbohydrate (NSC) content. It seems that alfalfa has gained itself a reputation of being a high NSC (with NSC = water soluble carbohydrates + starch) forage when in fact it contains one of the most consistent AND lowest NSC contents of all forages.

Dairy One (Ithaca NY, USA) give us an average water soluble carbohydrate (WSC) content of 7.5 % (based on 334 samples) and an average starch content of 1.5% (based on 411 samples) giving it a total NSC content of 9% on an as fed basis. So total NSC content is below 10% which is perfect for those of you who may be looking for a suitable low NSC forage.

The NSC content of alfalfa is also consistent with the WSC minimum and maximum for those 334 samples being 5.8% and 9.2% respectively while the minimum and maximum for starch is given as 0.3% and 2.7% respectively. So, compared to something like oaten hay or chaff that can vary (according to the data from Dairy One again) from 8.1% to a huge 21.9% WSC and from 1.5% to 7.5% starch there is very little variation in the amount of sugar and starch alfalfa contains which means you can more confidently change from batch to batch of alfalfa hay without worrying too much about variation in NSC content (which is not something you can do with most grassy or cereal hays).

It is because of alfalfa's low and consistent NSC content (and its high quality protein) that I am regularly recommending it for horses that need low NSC diets including horses with laminitis or Cushing's disease. That recommendation does come with a caution or two however. As with all new feeds for these horses, introduce it slowly as it can have high levels of nitrates and potassium that may exacerbate the condition (alfalfa isn't alone in this respect, all forages can have high levels of these nutrients if grown under the right conditions). Good quality alfalfa is also high in digestible energy and protein, so it does need to be fed in moderation to ponies and horses that have problems with being overweight.

For more on alfalfa, read our newsletter Alfalfa Hay: Friend or Foe or listen to the podcast about alfalfa on the Horse Radio Networks Horse Tip Daily Show.