11/20/2025
Some really great information about lysine!
If you’re considering adding lysine, here are two simple example diets, using as-fed values based on average-quality hay fed at 2% of body weight, plus a little feed, for perspective.
An 1,100lb horse in heavy work needs at least 37 g of lysine per day.
Lysine contributions:
Diet 1
• Feed: 5 lb/day at 0.70% lysine → 15.9 g
• Alfalfa: 5 lb/day at 1% lysine → 22.7 g
• Coastal hay: 17 lb/day at 0.30% lysine → 23.2g
Total lysine: ~62 g/day
Diet 2
• Alfalfa hay: 22lbs/day at .9% lysine → ~90g
Every horse is different, and forages do vary. While meeting the minimum isn’t always the goal, this does show how a common performance-horse diet can easily surpass basic lysine needs.
Extra lysine is considered safe, but fixating on lysine alone can overlook the bigger picture and ignores other essential amino acids and important nutrients that influence performance and health.
Hopefully this helps put things in perspective, eases your mind, or encourages you to chat with a nutrition professional. ❤️
