The worst thing about writing these articles is the fact it emphasises what you have, or in this case haven’t, achieved in the last four weeks!
Since the last article appeared, despite having winter wheat to sow and slurry to spread we haven’t had a single tractor tyre on any of the fields – and the outlook isn’t really looking much brighter.
With the price of straw continuing to rise with its scarcity, people will clearly be looking for alternatives, so this seems like a good time to talk about our experiences in using sand for bedding, not only in cubicles but also loose-housing.
The benefits of using sand for bedding are pretty well documented. As an inert material, it doesn’t provide a substrate for bugs to grow, helping to keep down somatic cell counts. Lying times are greater with sand leading to increased milk yields.
It generally gives less hock damage to cows than mattresses as there is less chafing. Also, because it allows urine to drain away, you don’t have the wet sponge effect you can get with straw yards.
However, for all these benefits many people are discouraged from using sand because of the two main drawbacks – namely, extra wear on machinery and a build-up of settled sand. Hopefully, I can persuade you that these negatives aren’t as troublesome as they are often portrayed to be.
When we erected our original cubicle shed back in 2004, my brother was clear that sand cubicles were the way he wanted to go, and because of labour constraints the only option for scraping the passages was automatic scrapers.
Clearly this combination was a recipe for disaster! But, in fact, it wasn’t. It does work reasonably well and I think this comes down to a couple of key choices.
Firstly, rather than going for the deep bedded cubicles that seem to be ‘de rigueur’, with sand he opted for relatively shallow cubicle beds with a kerb at the back to prevent too much sand finding its way into the passage way. A few years ago we installed ‘sand saver mats’ into the beds which further reduced sand loss by stopping the cows digging into the sand as they seem to want to do.
Overall, we probably use just under two tonnes of sand per cubicle each year. The only drawback is that, relative to deep beds, cleaning is more onerous as dung needs to be removed by hand.
The second key choice was installing rope scrapers. While we do see quite a bit of wear on the scraper blades (the cubicle passage blades need replaced every 18 months as opposed to every three years for the feed passage one) the rope itself doesn’t really suffer much wear as it doesn’t drag on the concrete the way a chain would.
When the shed was originally built the slurry was all scraped to a channel at one end of the shed and this had to be well mixed weekly to re-suspend the sand before pumping to a tower.
As the sand would then settle in the tower (particularly under the discharge pipe), it was necessary every four years to dig the sand out.
This was quite a major undertaking as it required removal of a couple of panels from the tower to allow the digger access over the side, with a skidsteer lowered in to move the sand to where the digger could reach it.
In 2011, we looked to build an additional cubicle shed for cows. We wanted to stay with sand but to try and eliminate the issue of sand settling in the slurry tower. So we opted to go for a slatted shed with the cellar deep enough to allow the telehandler to access it.
This seems to have worked quite well. We’ve had to empty the settled sand out twice with it taking just over two days each time.
Three years ago we also made the move from straw to a 3-4-inch layer of sand as bedding for both the calving and fresh cow pens. Although it is a bit time consuming making sure that all the dung is removed from the pens at every milking, overall it probably doesn’t really take any longer than bedding with straw did.
From the point of view of writing SOPs, it is much easier to make sure that dung has been removed than trying to ensure that enough straw has been used without being wasteful. Not only that, it had a huge impact in reducing our mastitis rate (from 20s to low teens), particularly in cows <100DIM.
One key point with loose bedding on sand is not to make the bed too large as drainage can become an issue over larger distances.
Overall, while working with sand undoubtedly has its drawbacks, where possible it would always be our first choice of bedding material.
Finally, I just wanted to remind people that the Scottish Government consultation of the next phase of BVD eradication closes in a few weeks (November 6). I’d urge you to have your say in how we push on and hopefully get the job finished.