From April to June we weighed the four subjects of our research approximately weekly. Normally we try to weigh them every month, so this was considerably more data than we usually collect. They didn’t like it much, especially when at their most ‘plucked’ – probably because (as mentioned in Part 1) they don’t seem to like the feeling of being held onto with their prickly new pin feathers coming through.
Here’s the graph of those weights, including data back to December (at monthly intervals) to show their ‘normal’ range, plus their July weight (post moult for everyone except Bessie) plotted.
Looking at each of them in turn:
Poppy, who moulted first and pretty vigorously, dropped gradually from her laying weight at about 2.9 kg down to just over 2.4 kg (16%), before picking up steeply at the beginning of May. She laid again on the 23rd of June, a break of 124 days.
Frida, who looked to be having a really easy time of it, only dropped in weight very slightly over the time she was visibly moulting – only 100 g or so (6%). And she got back into laying quickest too – first egg back was the 28th of March, a break of only 81 days.
Claire, who seemed to have a tough time really lost condition substantially, from about 3 kg laying weight down to only 2.2 kg (28%), where she stayed for over a month. She finally laid again on the 11th of July, after 114 days off.
Lily, who also seemed to do it tough, and was moulting in the coldest of the weather also had a big weight loss – about 600 g, down to under 2 kg (26%). She was quickly back into laying though, with an 86 day break (first egg back on the 19th of July).
So it’s pretty clear that the visual signs are a resonable indicator of how the chook is getting on – certainly if we were to rank them on the basis of how bad they looked vs. how much weight they lost, there would be a reasonable correlation.
Less good would be the correlation between % weight loss and how long it took them to get back laying. Frida had small weight loss and the shortest time off, but Poppy had the next smallest weight loss, and the longest time off. Lily had the second largest weight loss but the second shortest time off. Given Lily’s large weight loss, her performance in returning to laying so quickly looks pretty impressive!
It’s also obvious that there is a lot a of variation in how chooks manage when moulting – from it being an occurrence of little consequence (Frida), to being really set back by it (Claire).
Post-moult weight gain
The graph also shows how they all packed on the weight after getting over moulting. Come July they were all heavier than when they were laying before their moult. In fact, except for Frida, they were all the heaviest they’d ever been. Proper big hens now, no longer little pullets!