The direct translation
‘The cow to the front drinks clean water.’
If one takes cows to the river, the cow to the front will get the cleanest water given that the other cows would not have muddied the river as yet. In the situation where the cows are given water out of a container or trough, the cow that gets to this container first would get the cleanest water.
My father used this proverb when he wanted to point out to me that I should try to seize opportunities as they present themselves and not wait for others to go before me.
Growing up with 9 siblings, the one to get his/her lunch first gets his/her choice of meat as compared to the one who gets his lunch last. Bèf douvan bwè dlo nèt.