feeding beer to cows
Any ruminant (sheep, cows, goats) can digest alcohol. It actually breaks down in their first stomach, before it hits the bloodstream. We have fed spent beer to cows and sheep, and while they will drink it, they do not seem to derive any positive affects from it - either in terms of health or perceived quality of their singing. Pigs, on the other hand, not being ruminants, get right drunk and hang around shouting obscenities and falling over. If you want to get a ruminant drunk, feed them apples, which will ferment in their stomach (which is exactly that, a fermentation vessel) and create alcohol.
So, there is no urban myth involved in feeding beer to cattle, but there's no benefit. I would suggest using the beer to water the garden or to moisten compost - try a local vegetable or fruit grower. That way, the nutrients in the beer can be added back to the soil.
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