By Hannah Cargill, contract broiler manager, Avara Foods
You’d think that after more than a year of lower stocking densities across much of the UK broiler industry, we’d have most things figured out by now. As it turns out, the birds still have a habit of teaching us something new.
One area I’ve found particularly interesting is what happens after thinning.
The stocking density always reduces after thinning, but now the reduction can be far more dramatic. It’s not uncommon for a shed to go from around 30 kg/m² down to 16 kg/m² within a few hours.
The obvious response is to reduce ventilation. Fewer birds mean less heat, less moisture and less carbon dioxide to remove. On paper, that makes perfect sense.
But it has led some of my growers to wonder: when birds are growing as rapidly as they are at this stage, are we always delivering enough fresh air to where it matters most – the birds themselves?
Ventilation calculations are based largely on removing heat and moisture, with gas exchange forming part of the equation. However, if we significantly reduce airflow because the shed environment appears comfortable, are we maybe forgetting about the birds’ increasing demand for oxygen as they get bigger?
I’ve been chatting to several growers who have been experimenting with a slightly different approach. Rather than reducing ventilation as much as expected after thinning, they give higher air volumes through the shed and use heating to control bird comfort.
At first glance, it feels counterintuitive. More ventilation and more heating sounds like an expensive combination. Yet the theory is that the birds continue to receive plenty of fresh air and airflow, without becoming chilled because the incoming air is warmer.
Some growers believe this helps keep birds active, encourages feeding and drinking, and supports growth through the final days. The set temperature on the controller may even look higher than normal, but the temperature experienced by the bird remains where it needs to be.
Does it work everywhere? No. Like many things in poultry farming, there is no silver bullet. Different sheds, equipment and management styles all influence the outcome.
But these conversations are fascinating. They remind me that even a year after changing the stocking density, the birds can create new questions we never asked before.
Just when you think you’ve seen it all, a farmer comes along with a different way of looking at things.
A rather joyous part of the job: Every day is a school day.