Another project involves a leghorn over commercial meat hybrid pullets to cut back some of the excess weight gain and aim for heavy bodied but survivable birds.
Of the two projects I expect no troubles with the first, but probably quite a few with the second. For starters, even on limited twice-day feeding, the meat hybrids are enormous and probably have quite a lot of fat in the cavity. This always gets in the way of laying, and can cause heart issues. For now though they have good red combs without the maroon/purple tinge that can come as the heart develops an insufficiency. They're right at point of lay and have started squatting; I'm just waiting to see the first egg.
The first generation of the meat hybrid cross may also be too quick growing and heavy bodied to survive into maturity. However if I cross those birds to the ancona/layer cross (using Nulkaba layers instead of ISA browns for temperament reasons) I should get some interesting dual purpose birds.
The idea of both these projects it to water down something I see as a negative in the commercial birds. With commercial layers it's propensity to develop reproductive problems like internal lay, ovarian tumours and sheer exhaustion at 18 months. With the meat birds it's the massive overweight, the short lifespan and the likely weakened immune systems. By outcrossing both of these types to defined heritage breeds whose characteristics I know (having kept the same bloodlines in the past), I can hopefully retain all the characteristics I need.
These include good feed-growth ratios (without being too much for the bird's health); fast maturity; acceptable table birds by 16 weeks; good layers; and reasonably long lifespan; good vigour and immune systems. I don't want or need the massive growth of the meat hybrids, so of the two commercial strains those are the ones whose genes I intend to water down the most. Thus I'll be crossing them to a second generation layer type (the ancona x commercial layer most likely) to further reduce meat.
The results will be enormously varied at first, but if I breed only from the best then I should be getting somewhere in a couple more generations. If the whole thing fails I suspect it will be due to some of the inherent weaknesses in commercial birds; then it will be time to go right back to heritage birds and start over (Indian game and leghorns or similar should produce a decent dual purpose backyard bird).
But as I've said in the past, there are significant down sides to heritage breeds, one being that while commercial breeders have cleared their flocks of Mycoplasma Gallisepticum, it has tended to linger in many flocks that have been breed by backyarders down the years. (On the other hand the birds may have better immunity and milder germ strains, so it may show up less frequently or only due to major stressors.) Secondly Indian game are in general poor layers, so they're a harder bird to work with in terms of getting the numbers. They're also remarkably broody prone, which can be a hindrance as often as it's an asset.
Still, there are plenty of things to like about all the birds I've got at the moment. And if the meat pullets come into lay successfully and the leghorn cockerel develops as he should (both he and the ancona are really starting to shape up now, with a diet of half meat bird finisher and half sprouts with kefir and so forth), I'll be happy indeed.
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