Note on the last picture the fat white bird in the background: that's a commercial broiler hybrid at exactly the same age, for comparison. It's about a third as much weight again as the heaviest of my home crosses. It eats like a pig, of course (poor thing). So far, though, it's not suffering any skeletal problems, and I think this is probably because it was bred in a backyard, where the owners would have selected only parent birds that were capable of breeding. It would be thrown out of a commercial meat farm for being too small, but I'm pleased it's not growing too fast to have a reasonable life (so far). Remember this is about the age when commercial hybrids go to slaughter!
The ISA Malay crosses aren't growing as quickly as I'd like. The leghorn-Australorp crosses were much better feathered, and also quite a bit bigger, at this age. I put this down to a number of factors including an egg exploding in the incubator, which took a toll on the hatchlings. Those birds that survived may have been slightly compromised (for instance the germ could have colonised their digestive tracts). Secondly it's to do with parent nutrition. The mother birds of this lot were partly fed on the sprout ration (for a while) and suffered a little setback from mycotoxins in mouldy wheat. They were put onto a better ration a month before I began collecting eggs, but may not have fully recovered, particularly in terms of B vitamins.
Next batch coming from the incubator will be pure Malays and pure leghorns. I'll be interested to compare growth. But for now, I'm pretty happy with these ISA cross birds, both in terms of appearance (I quite like the paler colours) and the fact that, after all those setbacks, the majority are now doing well.
Incidentally, they were moved to the large tractor yesterday. They've been on chick starter (medicated), but for the last 2 weeks have been given an increasing share of treats like chopped greens, garden spinach, wheat, lupins, cracked corn, seaweed meal (tiny amounts) and meat meal. I plan to take away all medicated feed in the next week, though I have to watch protein levels and make sure they're on the right nutrients. But with twice weekly moves in the tractor (or when the grass is considerably reduced) they should get quite a lot of vitamins from home grown.
Meanwhile of course it's coccidiosis-watch. The first sign is going off food, but these chicks are still tucking in. I'm not quite ready to try medication free chick rearing, but I will, when I've put in more research as to how to go about it. Unfortunately the disease hits so fast and can be so devastating I'm reluctant to just dive in!
