What’s the cost of a lame cow?
Let’s work it out. An average adult cow that goes lame in mid-October once she has started bulling. Let’s say she gets a grade one lameness that goes unnoticed and untreated. She’s less likely to graze as hard. Less likely to be a first-row cow and return to the paddock for the most grass. Maybe it costs her 10% of her milk production at peak so that’s 0.2 kg ms/day. Say she’s lame for 20 days. That’s 4 kg MS lost at $6.30 = $25.20.
She’s more reluctant to join the sexually active group and is 20% less likely to detected on heat. That’s 4 days lost production next season at early production. Say 4 x 1.5 kg ms x $6.30= $37.80.
There is an increased risk that she will be empty because she has a higher risk of not being detected on heat and she is more likely to return to anoestrus. Say a 10% increased risk of being empty. If the herd empty rate is 13% then the increased risk of empty is .1 x .13 = .013 or 1.3 %. If the price difference between an in-calf cow and an empty cow is $1000 then that’s $13.
Say she has a 30% chance of getting more lame. Grade 2. Now her risks of lost milk, anoestrus, and being empty treble. 3 x $76 x 0.30 = $68.40.
So, we are at $144.00 per grade 1 lame cow without even trying. If you are looking at a grade 2 lame-cow then treble the risks which trebles the cost which is $433.20.
So, lame cows cost money. There are also the less tangible costs like the stress of having lame cows, and the animal welfare concerns that the farming community and the general-public are increasingly aware of. It’s hard to put a $$$ value on those.
