Composting barns raise hopes for dairy's future


The following is a snippet from an article by Keith Woodford

It is being increasingly recognised that paddock wintering of cows around the clock is not the way forward for New Zealand dairy. The challenge is to find solutions. These solutions need to achieve good environmental management, they need to be animal-friendly, and they also need to make economic sense.

Over recent months I have been on a personal journey of learning about composting barns. That journey is ongoing and I have more to learn. But I am now at a point where I am confident composting barns can be a major part of the strategic solution for New Zealand dairy.  They can be win-win-win for the environment, for animals, for profitability. 

One important qualification: None of us yet have all of the answers for New Zealand conditions. Also, there is evidence that some farmers are going into composting barns with a poor understanding of the critical factors for success.

With a composting barn, if things go wrong they can go really wrong. This is when what should be sweet-smelling, dry and warm compost which cows love to lie in turns to smelly sludge. At that point, it is out with the sludge and back to square one.  But if the basic design of the shed is wrong, things will go wrong again.

If working well, the compost stays in the barn for 12 months. It then gets taken out, left for some further decomposition, and used as valuable fertiliser.

For success, the key requirement is to first get the infrastructure right, and then manage the barn so as to maintain an environment that favours aerobic bacteria (the good fellows) rather than anaerobic bacteria (the bad fellows).  

The distinguishing concept of a composting barn is that composting occurs in situ. The cows roam freely in the barn and lie on a mix of wood chips and straw, with the wood-chip component being critical. 

Read the full article on Stuff.co.nz here

Alternatively talk to us about our dairy barn systems - Calder Stewart specialise in rural buildings and we can design the correct solution for you.