Switching to Layer Crumbles at 17 Weeks?

[Dogfighter]

Thank you all for your answers. I see now why I was getting a little bit confused when I tried to search for other posts on the same subject before I posted my own question. It is because there really are a lot of different opions on this subject (and just about any other chicken subject I have looked up).

 

[speckledhen]

Ideally, dont give them layer till you see an egg, however, I had a situation with having lots of different ages down to about 15 weeks old and I put one feeder with starter and one feeder with layer. By the age yours are, I'd just switched to all layer. It wont hurt them for a short period, I dont think.

 

[digitS']

I believe the concern is mostly with quite young birds. There have been studies that show that pullets several weeks before laying have improved eggshell quality if given layer rations with no indication that they have any negative response to the increased calcium.

Here's a citation on the original research, or at least the work most quoted when advice on calcium levels in starter feed is given.

"Shane et al. (1969) reported on a growing pullet study showing that levels of calcium above 2.5 percent fed between 8 and 20 weeks of age would cause nephrosis, visceral gout, calcium urate deposits, and high mortality. Parathyroid size and activity were reduced, along with feed consumption and weight gains. They recommended that diets should not contain more than 1.2 percent calcium for pullets under 18 to 20 weeks of age."

Shane, S.M., R. J. Young, and L. Krook. 1969. Renal and parathyroid changes produced by high calcium intake of growing pullets. Avian Dis. 13:558, American Association of Avian Pathologists

Layer rations contain about 3% calcium because of the layer's need to make eggshells.

Steve