All commercial poultry eat with reasonably good precision to balance nutrient intake with requirements. Short term, there can be some variation in feed intake related to local situations, but long-term, the mechanisms of feed intake regulation are quite precise. Matching nutrient needs with intake is an obvious inherent evolutionary necessity to ensure survival and reproduction. A bird’s da...
An excellent presentation. At what stage do you think that a laying hen would be able to self-select for calcium intake by taking oyster-shell or granular limestone from pan feeder? Would it make sense to offer such a mineral supply alongside a Pre-Lay ration, with ~2% calcium, in order to prevent any immediate shell quality issues when the first eggs are aid?
@Kevin Stickney In theory, yes. You could offer feed and oyster shell, etc., and they would balance their nutrient needs. The practical issue is that birds invariably take too much oyster shell because of its novel texture. We see this in small flocks where a calcium feeder is set up. Birds consume 8-10g/d of oyster shell and then soft shelled eggs appear because of an induced P deficiency. You could give two diets, High and Low in Ca, and they would balance themselves, but that becomes a logistics challenge. A pre-lay diet with most Ca as large particle will work, assuming it’s a mash diet.
Excess calcium is consumed by birds which are on controlled feed (feeders are empty) when grit is offered on free choice basis. Layer hens which are on full feed (feeder has feed) the hens eat as they need. They don't over consume the grit
Hi Dr. Leeson, I enjoyed reading your detailed post about feed intake, bird growth and all of the other great information you provided. As i was reading your article, i was reminded of the many lectures that you and Dr. Somers gave a few years back. Thanks for my updated course on Why Chickens Eat.
I disagree with you Steve. Generaly animals are like children. candy or soup, children chooze candy. So we give a mix with all feedstuffs they need. and give this mix in peels. So they cannot choose. I apologise for my English. Sorry.
Many thanks, Dr. Leeson, for an excellent article. I have only one comment regarding ideal temperature for layers. I agree with you that 26 degrees is ideal for layers in post-peak production but before peak production a lower temperature is desirable to stimulate them to eat more to meet adequate production and desirable body weight. I enjoyed your article immensely. Best regards
Chickens eat to get the energy and nutrients they need to survive, grow, lay eggs, and stay healthy—just like all animals. Their diet typically includes grains, seeds, insects, greens, and sometimes small animals like worm
Just remember that chickens do not have AMYLASE in their saliva. So feed digestion is not immediately as other animal species. As an adult, they love to have GRIT on their CROP and many of the stone pieces will stay for days in there. So soluble calcium will be released at different concentrations each day. Calcium grit is usually provided at molt time rather than as calcium supplement. So regulation of GRIT intake from layers would take a few days to be constant.
