I had a discussion the other day with one of my clients about overstocking his facility. He is currently about 30% overcrowded. Everyone tells him that this will limit his production and compromise health and reproduction. So, assuming that permitting is not an issue, is overstocking a facility always a bad idea?
Rick Grant at the Minor Research Institute has studied dairy cattle behavior for many years, and his work may help to answer this question. Here are some of his findings. As stocking density increases within a pen:
1. Cows are more aggressive at the feed bunk.
2. Cows spend less time lying down.
3. Cows eat faster (up to 25% faster).
4. Rumination may be suppressed.
5. Fat test can be reduced and somatic cell count (SCC) increased.
Limited feeding time does not necessarily result in less feed intake. Cows with limited feeding time consume feed faster and eat more often, so total intake may not change. But timid cows and first-calf heifers do suffer more under these conditions.
If a facility is overstocked, headlocks may be an advantage over post and rail feeders. Timid animals in headlocks aren’t displaced as much by aggressive animals.
If a facility is overstocked, more frequent feeding may help increase intake. Fresh feed stimulates eating more than just pushing feed up. One caveat is that more frequent eating can reduce resting time. Grant states that a cow’s innate need for rest trumps her eating behavior when these activities are limited. If a cow does not get adequate rest and lying time, overall health and production can suffer. Research has shown that a minimum of 12 to 13 hours of rest are required.
Now the flip side is how much total milk production do you gain by overstocking a facility? Fixed costs and labor are big expenses on a dairy. Producing more milk per stall spreads these costs out. I think the first consideration should be whether overstocking negatively affects resting time and cow health. If health parameters, reproduction and milk quality can be maintained within accepted benchmarks, the next question is, “How much milk per cow am I giving up by overstocking?” Grant is working on a “decision-support tool” integrating data that affect eating behavior, resting time and rumen health that may help answer this question.
My client has very intense management protocols in place. Cow health is excellent, reproduction is outstanding and SCC is less than 100,000. Milk per cow is also very good. We don’t know how much more milk per cow he would be getting if his barns weren’t overstocked. But it’s hard to argue that the milk from 30% more cows help cash flow more than a few pounds of milk per cow as long as the cows remain healthy. I wouldn’t recommend this for everyone, but this particular dairy is managing it well.