Tuesday, March 29, 2011

The Dairy Welfare Farm Tour, part 2: growing calves

(Continued from The Dairy Welfare Farm Tour, part 1.)

We pulled up at the farm where Dr. Mulain performs a weekly herd check every Tuesday morning, checking a bunch of potentially pregnant cows to determine if they are in fact knocked up. Lots of rectals! While we were sticking our arms inside of cows, Dr. Mulain pointed out that we can tell a lot about how cows are handled by how they respond to us. When you are in the middle of a herd of cows, do they panic and run away? They have probably not had great experiences with humans in the past. Do they come up to you, sniff you, lick you, follow you around, and generally make pains of themselves? It is likely they have had good experiences with humans in the past. These cows were like mosquitoes; I was literally batting them away. When I yelled “Shoo!” and waved my arms at them, they stared at me blankly. They had clearly been handled gently by the farm workers.

After the herd check was over, we visited the calves in their hutches. This farm used the conventional method of raising calves: separate them from their mothers immediately and raise them in tiny hutches that look like plastic igloos. The hutches are typically clustered together in a little village, but must be far enough apart that the calves can't touch each other. Calves typically live in individual hutches like this from birth until shortly after weaning.

Although the little village of hutches is adorable, something in me rebels at the idea of raising social animals in isolation like this, where they cannot touch another member of their species. Why do we do it? We raise them separately to keep them cleaner. Calves inevitably have diarrhea, and if you raise them together, that will be the method of transmission of all sorts of (sometimes fatal) diseases. So it is safer for them to keep them separate until their immune systems mature. Also, taking them away from their mothers leaves more milk for sale (they are most often raised on milk replacer, which costs less than the real stuff).

This method of raising calves is the conventionally accepted one in the industry, and is what we were taught about in our large animal medicine class. But Dr. Mulain told us about a new method that some farmers are trying, and took us to see it in practice on other farms. You can apparently raise healthy calves in groups if you free feed them, in other words, let them consume as much milk, or replacer, as they want. With the extra nutrition, their immune systems are more robust. The calves grow faster, too.

Dr. Mulain said wryly, “Remember, this isn't abnormally fast growth. This is normal growth.” His perspective is that the dairy industry has been feeding calves smaller amounts to cut costs, but this has resulted in weakened immune systems and smaller calves. With time, we have come to see these weakened immune systems as normal, but they are not.

We saw one farm in which calves had access to a big bucket of milk replacer. They were living in a group of just a few calves. Another farm had turned about ten calves in with three lactating cows. Cows chosen for nanny duty were the low producing cows — the ones later in their lactation cycles who produce less milk. It is amazing that we have bred cows to produce so much milk that a low producing cow can easily support three calves! The calves didn’t bond with a particular cow, but just partook of the nearest milk bar. Because these were low producing cows, they were by definition late in their lactation cycle, so it is unlikely that any of the calves were actually theirs.

This approach to raising calves feels emotionally better to me. I don’t like to see babies of social species raised out of physical contact with other social animals. So the approach to raising calves in groups is appealing. Time will tell if it works well, producing healthy calves and saving farmers money.

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