Peacombe,
Most birds process food much the same way most carnivorous and omnivorous animals do save for two major differences. Most birds have crops (chickens do) that store ingesta (what has been consumed) and releases ingesta in a metered / controlled rate to the gizzard (a structure I am sure you have delt with before) which is the second unique component. The gizzard, with the help of hard particulates (i.e. pebbles, grit, oyster- shell) triturates (physically breaks up ingesta) like a mammals teeth does. Thus sequence is different. There after sequence / processes very similar although birds process digesta faster than mammals of a similar size since former typically have a higher energy demand.

I consider chickens to be omnivores that include grains, fruits and small terrestrial invertebrates in their diet. Chicks come closest to being carnivores in being insectivores if given their preference. Chickens do not make cut for being carnivores mostly because that do not feed almost exclusively on proportionally large prey items that require appropriately designed food processing for such items that are largely meat. Digesting meat is simple. Chickens are setup even better than we are to handle high fiber / plant diets as adults.

I consider chickens (under normal conditions) to be continuous feeders from shortly after leaving roost until about 4 hours after returning to roost. Despite birds feeding only in bouts (periods where feed intake through mouth), which are most obvious in early morning and late in afternoon, the crop enables a nearly continuous flow of ingesta for extraction of nutrients just as if bird were feeding in small amounts throughout day and about 4 hours into night.

Most continuous feeding animals studied do not benefit from periods of food deprivation, at least other than those events occurring every night during early morning hours.

Some of benefits many carnivores gain from extended periods of deprivation are that it allows removing mass (in gut) that does not facilitate prey capture. Another very important factor is associated with energetic cost of stalking, subduing and sometimes dismembering prey. Processing (digesting and assimilating) nutrients requires a substantial amount of energy that may otherwise
be required to secure next meal. Usually feeding on even the most evasive grasshopper usually does not require tapping into energy reserves directed towards processing the chicken’s previous meal. Have do your dogs hunt with a full belly?

In respect to you observations about feeding following a day off feed I suggest you try the following if you have a few birds to play with. Skip feeding for half and feed other half as normal on Sunday. Monday, weigh out more than twice as much feed you know the birds will consume and let them eat all they want during the course of the day. Weigh what is left in bowl and record. If your birds like mine you to have find way to keep them spilling. For shits and giggles, repeat weighing process the following day. This makes assumptions birds all about same size / weight / age and stage in molt cycle. You will be able to answer question yourself from this. I predict you will see what is called compensatory feeding.

By the way, when I eat a 2 lb. bag of cherries including the seeds, approximately 18 hours following the meal seeds start clunking on porcelain of crapper and stop usually by the crapper stop 36 hours after the cherry meal. Most of time mostly meat meals take longer and sometimes high fiber meals (especially something like baby ear corn) come a running in your 12 hour time frame or less. TMI?

peacombe what does IMO stand for
silver

IMO=In My opinion ^^

thanks cockmistress
silver

Thank you Centrarchid. A very infomative post that answers my question.
I agree that fowl are omnivourous but when free range insects do make up a lot of the diet and in some climates mice and reptiles are also eaten. I feed raw mince once or twice a week and to see how beserk they go to get it shows how much meat means to them.
But your post has said it all and I shant be missing a days feeding.

Peacombe,

Something that might be interesting to try is feeding freshly killed and minced bait minnows. The birds will likely come to consider such a meal very highly. I am trying to find such treat that will motivate short flights to be photographed. A risk is some parasites fresh fish may carry. Besides that it is likely that the minnows will provide a healthier diet in respect to the types of fat.

Many of your formulated poultry feeds are based in part on fish meal so such a feed would not be totally alien.

centrarchid