This is from the website, this says it's a scam / ponzi / hyip, they are spelling out to you...
Welcome!
01/06/2014
To celebrate the launch of their new project Team Golden-cows.com has prepared several surprises:
1. recording When you win a green cow as a welcome gift!
2. Receive 30% bonus after your first investment.
3. Invest and earn 5% of the total investments of all players.
4. Refer your friends and earn 10% of the amount of their investment.
5. Participate in our lottery, auction and our PPC and win lots of Gold.