It is mostly worthless.
The horse industry is tough. In a few years of stall mucking, horse training, getting stepped on, thrown off etc, you body just won't hold up. Then what do you do? Go back to school for a new career if you can afford it. Get a low paying job if you can't go back to school.
If you want to go into the nutrition field you might find jobs related to animal nutrition, but definitely plan on getting a master's degree.
I got a degree in equine science because I had almost $10,000 in scholarships which were only good towards an equine degree. Only now I may need to go back so I can change careers and get into something that pays better. I must point out that this covered 100% of my tuition so I don't have student loans.
The good news is my core classes are covered, and I took a lot of science classes so those should all transfer if I decide I want a second degree. They also offer accelerated master's (basically if you have a bachelor's degree but want to change careers, they give you an intensive program combining undergrad level classes with grad level classes so you get a Master's without starting over). Still it is very intensive!
Since you are just starting out you can also try doing a double major- just plan on going to school every summer session with no breaks!
I almost think high school students should take a year or two break before college and just work. Very few people go to school and get a job in what they majored in. My cousin's majored in Music- one is a supervisor at Starbucks, and the other works at a bank. Definitely not what they envisioned!
I am starting on an entirely new career path- I just have no clue what that path might be!
Currently I am researching the job market in this area- I would rather not relocate.