How much fat is too much in layer ration?

[bearcreekbees]

I posted a thread awhile back about my homemade layer ration that includes meat/organs/fat for protein and fat. I "think" that this ration is working out really well. I have three pullets that recently started laying and I often get three small pullets eggs a day form them so not sure how they could be doing much better. They are the healthiest "looking" chickens I have ever had- feathers full, bushy, birds are active, bright eyed, busy busy busy, etc. So I am pretty happy at this point- except- I am close to running out of field peas. I purchased these from a farmer last year, lost his contact info, and can't find the guy. I have posted all over the local buy/sell/trade sites in hopes of finding him, but no go. The only field peas I can find are from a feed store that wants $35 a bag for them- which is almost three times what I paid for the last ones I got.

I can afford to pay that much but prefer not to, so I am looking for alternatives. I don't mind changing up the diet a little- I do that anyway from time to time- but I am struggling to find a good mix utilizing the ingredients that I have on hand or can get cheaply.

The issue I am facing is in getting enough protein without increasing the fat content too much. Part of the problem is also because I made a "mistake" when I ground up the meat/organ/fat portions- I mixed all three together, which seemed like a good idea at the time, but maybe not because now without the field peas I cannot adjust the amount of animal fat. I have about three weeks' worth of the venison mix let- after that is gone I will start grinding and storing the meat/organs/fat separately and that will give me some wiggle room to play around with the fats from various seeds and grains- but until then I am trying to figure out a good mix. I have read that 5% fat is a good amount for layers, yet oddly, in my area, all of the available layer rations only contain between 3-4% fat. Using my feed calculator spreadsheet, most of the variations I am coming up with contain closer to 7% fat and I wonder if this is too high? I can't even include sunflower seeds, which I have on hand, because those add too much fat. But we are in a cold climate where we expect nighttime temperatures to drop to around 30 or 40 below 0 F any day now, with daytime highs in the 'teens. My chickens are in an unheated barn with no heat lamps. So I am wondering if 6-7% fat is too high for them given their environment? I can only find "recommended" amounts so far, but no info n how much is TOO much. And I have no idea how to tell unless/until I butcher some birds and see what they look like on the inside.

Would love some info on this subject if anyone has actual knowledge on it.

 

[NatJ]

I have read that 5% fat is a good amount for layers, yet oddly, in my area, all of the available layer rations only contain between 3-4% fat. Using my feed calculator spreadsheet, most of the variations I am coming up with contain closer to 7% fat and I wonder if this is too high?

I can only find "recommended" amounts so far, but no info n how much is TOO much. And I have no idea how to tell unless/until I butcher some birds and see what they look like on the inside.

Would love some info on this subject if anyone has actual knowledge on it.

I see why you're having trouble finding sources. I didn't turn up very many either.

https://lohmann-breeders.com/crude-fat-in-layer-nutrition/
I think that website is from the company that produces "Lohmann Brown" commerical hybrid laying hens (or really, the chicks that grow into them.)
I would expect them to have done research about what nutrition will let a hen lay lots of eggs in her first year without dying of major excesses or deficiencies.

That page appears to be recommending diets with 5% fat and up, and includes this bit: "The maximum amount is defined more by technical reasons than by nutritional ones, as diets of up to 7.5% of crude fat are excellent for layers. This has been proven in different circumstances and climates all around the world."

No, they do not list sources showing what fat levels are good. I gather the "technical reasons" for limiting fat are because they want a powdery or pelleted feed, not something gooey or sticky.

https://www.sciencedirect.com/science/article/pii/S0032579119483260
This page has a link to download a .pdf of an article that compares feeds with different levels of protein, fat, calories-per-pound, and other factors. I see one feed in the table has about 12% protein. The first few paragraphs also mention results from previous studies on the subject.
In case the link doesn't work right, the article is called "Studies with Laying Hens: 1. Effect of Dietary Fat, Protein Levels and Other Variables in Practical Rations"
The authors are listed as Combs G.F. and Helbacka N.V.
This dates from 1959

I think I'm seeing that percent protein and percent fat can be important, but the ratio of protein to energy is also important. Energy would include calories from all sources, including fat and carbohydrates and protein. I've seen the breeder-management guides from some of the big commercial producers state the percent protein to feed and also how many calories per pound the feed should have (or calories per kilogram, if they are using the metric system.) So I think it's still considered relevant, not something studied in the past and completely ignored now.

If you have too many calories per pound, the hens might stop eating when they have enough calories and run short of protein or other important nutrients. Or they might keep eating until they have enough protein but then become obese and unhealthy. Or in cold weather, the hens might need extra energy to stay warm, eat enough feed to meet those increased energy needs, and get enough protein and other nutrients to be just fine, at least until warm weather comes and their needs change again.

 

[skeeeter]

Hi, I live in a subtropical environment so take my comments as you will.
If you are keeping your fowl naturally, w/o heat, and your area is that cold, I don't see how the extra fat will hurt them. Also, those formulas are calculated for high production leghorns living in non freezing barns, possibly in cages all "cozied up" together.
Protein is burned for energy if there isn't enough carbohydrate in the diet. So, adding fat to the diet in cold weather saves the protein for better ends and saves the kidneys from exta labor of having to excrete the excess of ammonia produced in the process.

 

[U_Stormcrow]

Nobody summoned me??? I'm almost disappointed.

So... Fat. Complicated answer. "Too much fat" is a quick answer to a complex question.

First, why "too much fat" is bad. I'm sure you've seen the inside of a bird, and a piece of nicely marbled beef. You'll notice that, unlike us human-types, cattle, and heritage pigs, poultry have very little intra-muscular fat. Genetically, they just aren't wired to store fat that way.

Instead, chickens deposit excess fat in the organ cavity where it buidls until it puts pressure on the heart and lungs (leading to symptoms making them more prone to disease, frostbite, predation - reduced blood flow, reduced energy, reduced oxygenation of blood) as well as an enlarged, friable [crumbly] liver, and potential egg binding. In severe cases, that can result in FLHS / Fatty Liver Hemorrhagic Syndrome. Usually first noted as a suddenly dead chicken (most typically a hen), with seemingly no prior symptoms.

As you've probably noted, most commercial chicken feeds (except those designed for Meat birds, who "produce" best on a special diet with NO concern for long term health), are "around" 3.5% fat. There's a well known national brand promising at least 2.5% fat, a bunch disclosing at least 3.5%, and a smaller number in the 4.5-6% range. At least, when talking about layer feed, starter, grower, and All Flock formulations. Meat bird formulations are, as mentioned above, different.

The fat content required to be published on the label isn't the whole story, however. Its only a hint at what we are really concerned with - the calories per unit weight of the feed. Unfortunately, there are big arguments in the industry as to how best to measure that, and it is NOT required to be published on the guaranteed feed label. So almost no one does. Calories per unit weight (my personal preference, mKe/kg [metabolizable Kinetic Energy per kilogram], but you may also see AMEn [apparent metabolizable energy, N-corrected] or AME w/o Nitrogen correction) vary based on reporting, but for my preferred calculation, a kg of feed should have between 12 and 13.8 MJ/kg mKe.

That calculation looks at the fat, the crude protein, carbs and the digestible fiber content to determine how many megajoules of energy the bird can extract from the feed. And a commercial feed between 16 and 20% CP, with around 3.5% fat, and around 3.5% fiber, made primarily from corn, soy, and another (typically wheat) grain will consistently fall w/in that target range.

Birds that free range - because of their greater energy consumption - can tolerate higher mKe numbers. Birds which are contained, as is typical of commercial hens and required by zoning for many backyard owners, can't.

Excess calories (or mKe, or AME(n)) or however you choose to measure are stored as fat. Storing fat as fat is easiest. Storing excess carbs as fat is nearly as easy. Storing excess protein as fat is much more difficult, particularly as birds usually excrete excess protein daily - they don't have a "reserve" they can draw from. The protein first has to be converted to energy, and from there, to fat. Not a "high risk" behavior. Also, exothermic, generates significant heat - waste energy.

Which is the long way of saying that what you really whant to know is the mKe of your feed in MJ/kg, of which fat is an important consideration, but not the sole consideration. You can either calculate that using information on individual ingredient assayed averages (as I do), or a quick estimate formula from Cobb/Vantive (which I wrote down somewhere, but would need to dig for).

and all of the above is why (among MANY other reasons) I won't try to make my own chicken feed. The more I know, the more inclined I am to leave the job to someone who does it, in bulk, professionally. I just check the guaranteed nutrition label against targets.

You know, trust. But verify.