The act of giving monetary reward to cows that have provided good service.
This is particularly common in rural societies, where cows are routinely employed in the service industry. Cows are not entitled to the minimum wage and rely heavily on tips.
'since organising her neighbours to lobby the city council to spend £1m to clean up their area, renovate houses, planttrees and stop fly-tipping...' (Tim Bouquet interviewing Sameen Ali in the Times magazine, 08.03.08)