Avian Aqua Miser: Automatic, poop-free chicken waterers


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Chicken growth rate

Chickens roostingWe keep a close eye on our flock, and I've started noticing that chickens don't hatch from the egg and grow steadily until they reach full size.  Instead, just like humans, they go through a series of growth spurts.

My obsessive note-keeping on feed conversion rates as we slaughtered our broilers confirmed my observation.  Just like last year, I got the best feed to meat ratio from birds just shy of or right at 12 weeks.  As our pullets and cockerels reached the end of their third month of life, they were growing so fast that I felt like I could see a difference in size every day.  Just a week later, though, the chickens hadn't grown at all, which set my feed to meat ratio plummeting.  No wonder heritage breed broilers were traditionally slaughtered at or before 12 weeks --- that's simply the economical way to raise them.

Chicken growth rate

After extensive internet searching, I compiled the data above, showing the growth rate of various breeds of chickens over time.  Cornish Cross, of course, is the primary commercial broiler breed, Paraiso Padres is a Brazilian broiler, and ISA is a commercial brown egg layer.

Chicken tractorWhat I found interesting about the chart is that you see the growth curve peak at 6 to 10 weeks for each type of chicken.  This is why the big chicken farmers kill their broilers at 6 weeks --- their chickens have reached the peak of their growing curve and will probably start eating more feed for each pound they put on in the future.  Of course, with heritage breeds (and especially if growing layers for meat), you have to weigh the con of lower feed to meat conversion rate with the pro of a heavier bird that's more worth your while to slaughter and dress.

What I don't know is when (or if) further growth spurts occur, and whether if we waited until the traditional fryer age (14 to 20 weeks), grain conversion efficiency would rebound.  I suspect that people grew chickens to the fryer stage not for efficiency, but to allow the characteristics of individual birds to become clearer so that they could cull  those they were less interested in from the flock, but perhaps chickens go through another growth spurt?

Our chicken waterer makes raising broilers a breeze, cutting daily chore time in half.


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I am curios how a bird like a jersey giant would "weigh" in in the chart?
Comment by David L at noon on Wednesday, August 3rd, 2011
Interesting question. I suspect they'd line up with other heritage breeds --- even though they get big, my understanding is that Jersey Giants don't grow any faster than other non-Cornish Cross. However, I don't have any personal experience with them and would love to hear from someone who does.
Comment by anna Wednesday afternoon, August 3rd, 2011






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