Are the Sussex the exact same age as the Australorps ? They seem so much bigger !
I've been asking myself that very question! That's the problem with buying chickens, there's no guarantee of precise age.
Either the sussex are maturing faster or they're a little older. Whichever, I felt it was time for pullet grower food.
When I went to the mill last week, they recognised me from October and we had a chat about cockerels and feed. They said it's called pullet grower, but they intend the label to indicate age. When they were designing the product and packaging, they considered calling it "Pullet & cockerel grower" but it didn't have the same conversational ring to it and most people raise pullets anyway. So it's a feed for that age group and it's good for both sexes, even though it's called Pullet Grower.
My one concern is that it's a mixed grain and I've had a lot of trouble with FLHS in the past when feeding grain mixes. I much prefer a pellet.
Long ago when I was feeding a grain mix, Peggy put herself on a corn-only diet and fractured her liver.
Once Dr Mark had taken a look at her liver, he knew exactly what was wrong and said "Feed these specific pellets, with these specific supplements." Which I've stuck to ever since, except when I can't get the supplements.
Through that diet, she and her friends have thrived.
From the comments I've read on BYC, I have no doubt the quality of pellets I can buy in Australia is better than those available in other markets. The hens find them palatable and they're very healthy on that diet, with large, well-digested poops.
Anyway, the mixed grain format of the pullet grower troubles me. However the lady at the mill said it was nutritionally optimised for the age group and that they're checking the market tolerance and roi of producing it in crumble or short cut pellet format.
The competing brand is in crumble format but it's medicated which doesn't go over very well with experienced chicken keepers on byc. I haven't really understood their reasons, but I still follow their advice which is frequently given in quite urgent terms.