Start & grow feed vs Flock Raiser

[Shadrach]

Yes, but it is usually expressed as a percent of the food, and assumes each chicken will eat a certain amount of food each day relative to how much the chicken weighs.


Yes, too much can be a problem. But lysine, methionine, and protein in general tend to be some of the most expensive ingredients in chicken feed. So most feeds target the very bottom end of the acceptable range. As long as you're looking at commercial foods labeled for chickens, you are quite unlikely to find a level high enough to be harmful.

Yes I agree and understand this which is why I questioned one is better than another. As long as both meet the RDA then I fail to see that a bit extra of this or that makes much difference.
The quality of the ingredients and how they are extracted may make a difference but one rarely knows this.
Same for the crude protein. Does it just contain the seven essential amino acids or does it supply a range which with say forage will supply an alternative protein construction.
One of the great advantages of fish meal based feed was it supplied all the essentials to both create a full protein, plus extra amino acid and mineral and vitamin content.
It's why vegans have to be very careful about what they combine at each mean to ensure they get all the nutrients required at one sitting so to speak.
An eight oz steak may seem better than a four oz steak but if the body can only digest 35 grams of protein in one sitting then a lot of that eight oz steak goes to waste.

 

[U_Stormcrow]

I did read the charts which is why I wondered about your conclusion.
Don't chickens have a recommended daily intake of nutriants much like humans? More of something isn't necessarily better and with some chemicals can be harmful.
From what I've seen in the nurtitional analysis most fall into a fairly small range, the largest variations being Calcium and Protein.
I'm trying to learn a bit about the RDA measures for chickens and it does seem to be a quite complex subject. For example from what little I've read it's recommended to give hard feathered fowl extra protein while the RDA for laying hens ranges from 15% to 18%.
I'm just curious and not after an arguement.

OK< good question. I didn't think you were arguing - you want to get in the weeds, welcome to my jungle!

I'll link sources. CHICKS have higher nutritional needs than adult chickens do. and the two amino acids they most need are Methionine and Lysine. When people look at a bag of feed, checking the protein level, they are indirectly assuming that higher protein equals higher level of those two most critical amino acids. Lots of reasons. One, its easy. Two, until recently, amino acid levels were hard to measure directly, with methionine measurement only becoming commerically practical in the last few decades. Three, in America, protein for animal feeds is (relatively) cheap. In the EU, on the other hand, with much less farmable area relative to population (and much of it not suited to grain crops, besides), they've made use of much lower protein feeds, supplimented by increased levels of synthetic amino acids - dl-Methione and L-Lysine. They have been at the cutting edge of that research for a while. That has the advantage of lower N "production" as waste in factory farming conditions as well, mostly in the form of ammonia and urates, as well as reduced total feed costs.

That leads to my last comment about the science and the studies. For essentially everything (except calcium - over which people continue to argue) except fat, the difference between the desired level of a thing, and an unsafe level of a thing is typically somewhere on the scale of an order of magnitude (10x) - so a little bit too much of a trace ingredient generally isn't a problem. Too little is always a problem, though the severity varies, and chickens (all living beings, really) have ways they can compensate (for some). i.e. a chicken short on Cysteine can make it internally, by converting Methionine - but it can't turn Cysteine BACK into Methionine - so Met shows up an a feed label, Cys does not. Tryptophan can be converted into seratonin, melatonin, and with enough B6 and Iron, a chicken can even turn it into Niacin! But anyhow, the studies are now mostly focused on maximizing production, seeking the minimums, no longer focused on finding maximums. Additionally, they are largely concerned with COMMERCIAL management practices - short lifespans, not the typical backyard experience.

Some amino acid needs references - these are the most handy ones I keep in my click list.

This is the old NRCS list for broilers, high yield broilers, turkeys, and LAYING hens - mostly based on the 70s research, with a few updates from the early 2000s. Its limited in part because Met couldn't be directly measured in the 70s.

This is from UGA's Extension, and has some updated data, but largely agrees - it has some pullet data, too.

This is an incredibly useful meta-study, with reference to lots of modern studies, mostly being done outside the US now. China, India, etc all VERY concerned with feeding their populations.

Speaking of India (this is much more basic, its intended for their population to use, but again, similar conclusions)

UVM - Broilers (page 33 - from the manual for raising Ross 308 Broilers)

etc.

I can also link (though I don't keep them favorited) various studies showing improved resistance to bacterial, parasytic, and even (limited) viral challenges in birds with improved key amino acid intakes. Protein (you asked above) is comprised of a bunch of amino acids, in different proportions. MOST of the amino acids we can completely ignore - chickens can produce needed levels on their own. Some (as alluded to above) can be made from others. But adequate levels of Methionine, Lysine, Threonine, and Tryptophan they MUST get by eating it. So those are the ones we focus on.

Hope that helps.

 

[NanaK]

Love to understand the science behind the feed but plain and simple I buy Flock Raiser crumbles because I have birds of varying ages from 10-12 weeks to 9 years old. It lets me stock 1 feed for everyone. I just always keep out several places with oyster shell. Really helps keep thing easy!

 

[Shadrach]

OK< good question. I didn't think you were arguing - you want to get in the weeds, welcome to my jungle!

I'll link sources. CHICKS have higher nutritional needs than adult chickens do. and the two amino acids they most need are Methionine and Lysine. When people look at a bag of feed, checking the protein level, they are indirectly assuming that higher protein equals higher level of those two most critical amino acids. Lots of reasons. One, its easy. Two, until recently, amino acid levels were hard to measure directly, with methionine measurement only becoming commerically practical in the last few decades. Three, in America, protein for animal feeds is (relatively) cheap. In the EU, on the other hand, with much less farmable area relative to population (and much of it not suited to grain crops, besides), they've made use of much lower protein feeds, supplimented by increased levels of synthetic amino acids - dl-Methione and L-Lysine. They have been at the cutting edge of that research for a while.
That leads to my last comment about the science and the studies. For essentially everything (except calcium - over which people continue to argue) except fat, the difference between the desired level of a thing, and an unsafe level of a thing is typically somewhere on the scale of an order of magnitude (10x) - so a little bit too much of a trace ingredient generally isn't a problem. Too little is always a problem, though the severity varies, and chickens (all living beings, really) have ways they can compensate (for some). i.e. a chicken short on Cysteine can make it internally, by converting Methionine - but it can't turn Cysteine BACK into Methionine - so Met shows up an a feed label, Cys does not. Tryptophan can be converted into seratonin, melatonin, and with enough B6 and Iron, a chicken can even turn it into Niacin! But anyhow, the studies are now mostly focused on maximizing production, seeking the minimums, no longer focused on finding maximums. Additionally, they are largely concerned with COMMERCIAL management practices - short lifespans, not the typical backyard experience.

Some amino acid needs references - these are the most handy ones I keep in my click list.

This is the old NRCS list for broilers, high yield broilers, turkeys, and LAYING hens - mostly based on the 70s research, with a few updates from the early 2000s. Its limited in part because Met couldn't be directly measured in the 70s.

This is from UGA's Extension, and has some updated data, but largely agrees - it has some pullet data, too.

This is an incredibly useful meta-study, with reference to lots of modern studies, mostly being done outside the US now. China, India, etc all VERY concerned with feeding their populations.

Speaking of India (this is much more basic, its intended for their population to use, but again, similar conclusions)

UVM - Broilers (page 33 - from the manual for raising Ross 308 Broilers)

etc.

I can also link (though I don't keep them favorited) various studies showing improved resistance to bacterial, parasytic, and even (limited) viral challenges in birds with improved key amino acid intakes. Protein (you asked above) is comprised of a bunch of amino acids, in different proportions. MOST of the amino acids we can completely ignore - chickens can produce needed levels on their own. Some (as alluded to above) can be made from others. But adequate levels of Methionine, Lysine, Threonine, and Tryptophan they MUST get by eating it. So those are the ones we focus on.

Hope that helps.

Excellent. Thank you. I'll work my way through the links. Anything else on the topic you may have would be appreciated. I have a key to some of the university web sites if you have such information.

 

[U_Stormcrow]

Excellent. Thank you. I'll work my way through the links. Anything else on the topic you may have would be appreciated. I have a key to some of the university web sites if you have such information.

I've read virtually every study (that had a free or register, then free) copy I could find on the web which is mentioned by the meta study. Its enough to make your eyes bleed. Plus tons of studies related to poultry diseases and diet - mostly because someone said "I heard feeding my birds essential [x] oil will cure...", so I looked at the science before advising them to stop practicing magical thinking and either do pharmacy, or at least do the witchcraft correctly. and a lot of studies those studies referenced.

Threonine and Tryptophan don't show up on feed labels, but in the traditional grain based poultry diets, those numbers are hard to miss if you get the first two right. There is some brand new research (last half decade?) looking at Glycine supplimentation (one of the ones we, chickens, and basically everything else) can make on their own, in conjunction with reduced protein diets to further improve feed efficiency, bu twhether or not it turns out to be worth pursuing in a decade or so? Lets just say I don't expect to see it making an appearance on a label any time soon.

and obviously, I do feel comfortable enough with what I've read to make what I beieve to be reasonable suppositions based on what is known, particularly when talking about backyard "dual purpose" birds being kept for much longer than the typical commercial production period - even though those birds aren't directly studied. The existing literature provides strong hints in their direction, I believe.

 

[U_Stormcrow]

Oh, and somewhere on BYC there is a link to free (older) books about how to feed poultry, if you just want a general grounding in the subject. I thought it had been Stickied, but seems not. I'll stop thinking about it for a while, and then I'll remember how to find it.

In the interim, this may (or not) interest you.

 

[NanaK]

particularly when talking about backyard "dual purpose" birds being kept for much longer than the typical commercial production period - even though those birds aren't directly studied.

I believe with so many people raising poultry today and so many are kept as pets and for eggs there may someday be studies on optimal nutrition for chickens with longevity in mind. Pets are a big $$$ industry too.

 

[U_Stormcrow]

I believe with so many people raising poultry today and so many are kept as pets and for eggs there may someday be studies on optimal nutrition for chickens with longevity in mind. Pets are a big $$$ industry too.

Not to be a contrarian, but I'll take that bet, against.

Pragmatically, there are a lot of breeds out there, and optimal nutrition for a bantie polish frizzle (is there such a bird?) is likely different from the needs of my free range culling project birds, which are likely different from a mixed flock of vanity layers. So that's a lot of research.

Cynically, I think there is more money to be made in prolonged consumer ignorance.

 

[NanaK]

prolonged consumer ignorance

Yes, much cheaper and the usual way. lol

 

[Shadrach]

Oh, and somewhere on BYC there is a link to free (older) books about how to feed poultry, if you just want a general grounding in the subject. I thought it had been Stickied, but seems not. I'll stop thinking about it for a while, and then I'll remember how to find it.

In the interim, this may (or not) interest you.

I've got a few of those "old school books" not to mention some very interesting advice/opinions/experiences from chicken keepers whose families have been keeping chickens for many generations. There is an awful lot of knowledge that just doesn't feature on modern day chicken keeping sites that to me seems more relevant and accurate than much of todays internet advice.