Commercial dairy cows in Cumbria – should they be “retired” before slaughter?
Good grief. Just when I think I’ve heard it all, another food pundit comes up with an idea so daft that you could bottle it and sell it as vegan, gluten-free, dairy-free, humanely-reared organic water. The latest brainwave from Jamie Oliver is to “retire” old dairy cows onto pasture, where they can graze for four years before producing highly-marbled beef. Contrary to most of the breed-related marketing, Holstein beef is pretty good, so it’s a mouth-watering concept until we take a step back and think about the actual sustainability impacts.
Producing beef from cull dairy cattle? Excellent idea. I once had a heated argument with an activist protestor outside the Smithsonian Museum in Washington DC who seemed surprised that, when he told me that most cull dairy cows end up as burgers, I didn’t renounce my heathen ways and immediately seek out the nearest tofu burrito. It makes perfect sense – where would be the logic in discarding an entire cow’s worth (~301 kg) of nutritious, delicious beef simply to bury, burn or use the meat for non-food purposes? Indeed, ~50% of the UK (and ~24% of the US) beef supply comes either from cull dairy cows or dairy calves reared for beef.
Is there an argument for giving extra feed to cows that are going to be culled so that they get a little fatter and produce tastier beef? Yes indeed, adding value to cull dairy cows is a great idea, especially when the beef price is high. But here’s the rub. The average dairy cow in the U.K. is culled at 6.4 years of age. By that time she should have reached her mature weight, which means that the majority of extra weight she puts on in “retirement” is fat. Although we love the streaks of intramuscular fat that we see in a steak (marbling) and enjoy the depth of flavour that gives to the meat, the vast majority of fat on a carcass isn’t particularly edible. So we’re feeding a cow for four years of retirement in order to discard (or rather render into tallow – perhaps to make some £5 notes?) a significant proportion of the weight that she gains.
A cow will eat 2-2.5% of her body weight in dry matter every single day. Four years of feeding a 700 kg cow = 4 x 365 days x 700 kg x 0.025 = 25,550 kg of feed dry matter, or 106,458 kg of fresh grass given that it’s only ~24% dry matter. Plus 4-years worth of drinking water, manure and greenhouse gas (GHG) emissions. A hefty environmental impact compared, for example, to rearing two beef steers on the same amount of pasture over a 4-year period, in addition to culling the dairy cow when she leaves the herd (sans retirement). That scenario would provide 200% more beef (~900 kg total, even allowing for the lighter weight for grass-finished vs. grain-fed steers) from the same amount of pasture and with a smaller total quantity of manure and GHG emissions because the growing animals are lighter in weight throughout, therefore excrete and emit less*.
I can’t decide whether the increasingly asinine proposals for sustainable food production propounded by Jamie Oliver’s “Friday Night Feast” programme, which recently left the casual viewer with the impression that welfare of housed dairy cows is equivalent to that of battery hens are serious, or simply a way to court fame through controversy. However, the number of tweets lauding the programme’s food philosophy is alarming given the amount of time devoted to non-sustainable ideology. Time for TV programmers to redress the balance with some Friday Night Facts vs. Fiction?
*Note that I have not accounted for the beef cows needed to produce the steers, nor for the cost of rearing the dairy cow or the heifer needed to replace her in dairy herd. This is not a full system assessment, but simply about the best use of a unit of pasture area – adding fat to a mature cow (less efficient) or adding muscle and fat to growing animals (more efficient)