Here is the full list of all 43 Horse Farm achievements.
You have reached level 10.
You have reached level 30.
You have reached level 50.
You have reached level 60.
You have reached level 90.
You have participated in 500 events.
You have won 20 endurance races.
You won an event with a success chance of less than 10%.
You have won 100 events.
You have won 50 races.
You have won 100 show events.
You have watered your flowers 10 times.
You have watered your flowers 1,000 times.
You have watered your flowers 5,000 times.
You can house 3 guests.
You can house 25 guests.
200 Level 2 guests have left happy.
You have assigned your guests to the activity center 500 times.
1,000 guests have left the ranch happy!
You have trained horses 10 times.
You sold a horse for over 2,000 Dollars!
You now own 10 horses.
You have leveled up horses 100 times.
You have fulfilled 5,000 horse wishes.
You now own 20 horses.
You have trained horses 1,000 times.
You have bred your first foal!
You have bred 500 foals.
You have started 5,000 productions.
You have cooked 50 servings of french fries.
You have started 20,000 productions.
You have expanded your farm property 3 times.
You have expanded your ranch 10 times.
You have completed 1,000 quests.
You have earned 20,000 dollars through quest rewards.
You have earned 100,000 experience points through quest rewards.
You have 500,000 dollars in your coffers.
You have 5,000,000 dollars in your coffers.
You have earned 200,000 Horse Dollars with the swimming hole.
You have earned over 100,000 Dollars with snack shacks.
You have removed 100 pieces of trash from your ranch.
You have completed the tutorial.
Your ranch now has a prestige rating of 5,000.