Protein requirements

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kenny thomas

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Often the question is ask on CT of how much to feed a calf. I know it varies depending on the contents of the feed but what are some thought on actual pounds of protein needed?
Locally I could get 10%, 12%, 14%, or 16% feed. 10lb of 10% has 1 lb of protein and 10lb of 16% has 1.6lb of protein. Big difference.
And how do costs compare? Could someone just feed more of the 12% and the cost be near the same?
This is for discussion and learning. I feed the 16% if it matters and for calves I'm buying from the stockyard I also add wet molasses to get them to start eating.
Thoughts and opinions?
 
Too many unanswered questions to answer. All protein supplements are not the same. Big difference in consumption of tubs dependent of moisture content. Cheap tubs = high moisture so consumption will be a lot higher than the dryer more dense tubs.
Cost per pound of protein isn't a straight forward as it may seem initially.
Must be figured as part of total cost of nutrients.
For me as well as many others in the intermountain west. One of the most expensive cost per pound of protein (alfalfa )is actually the best overall feed and has one of the lower costs when you figure cost per pound of gain. When all health and nutrition costs are actually calculated.
 
There is no blanket answer it all depends upon your reasons and needs for feeding.

I may stir the pot some on this question or start another post depending on how this goes after a bit.
 
There is no absolute straight answer. It depends on a lot a variables. Size, sex, desired rate of gain, present condition, stage of pregnancy, rate of milk. There are tables available which you can look up the answer. But as my old animal nutrition professor said they are a best guess starting point but the real answer is in the eye of the cattle man.
That said the book value on a medium framed steer weighing 400 pounds for a 0.5 lb a day gain needs 0.87 pounds. Same steer with a 3.0 pound a day gain needs 1.65 pounds of protein.
A 1,200 pound cow nursing a calf 3-4 months postpartum with average milking ability (10 lb milk/day) needs 2.7 lbs of "total protein" per day. Or 11.5% of her total diet.
I lost most of the books in a house fire back in '84 so I have to use what I have. The table I have just lists it as protein. I don't know if that is crude protein or digestible protein. There is a difference.
 
I think you have to also look at the rest of the ration because it also depends on the total digestible nutrients and carbs. Figure out desired rate of gain and then balance the ration based on what you have available. I took feeds and feeding in 1985 or thereabouts so has been a long time, but there are a lot of resources available to figure it out.
 
Often the question is ask on CT of how much to feed a calf. I know it varies depending on the contents of the feed but what are some thought on actual pounds of protein needed?
Calf size and air temperature matters... also rumen development as to the ability to utilize lower % protein feeds.
To find answers the most research has been done on dairy calves because they are raised in controlled environments and individual intakes can be measured or weighed.

20-20 milk replacer 8 oz in 2 quarts per feeding twice a day = 1 lb of replacer per day. 1 lb x 20% = .20 lbs protein per day
100 lb calf in 50 degree weather takes 3 qts of 20% to maintain and 6 qts to produce 1 lb of gain = .30 lbs of protein
100 lb calf in 10 degree environment takes 4.1 qts to maintain and 7.75 qts per lb of gain = .3875 lbs of protein

Calves can be weaned when they are eating 3 lbs of 18% starter per day 3 lbs x .18 = .54 lbs of protein per day
But you have to look beyond just % protein, to the total energy (calories) consumed per day to balance rations.
 
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Some very good comments that are based on actual protein needed. More please.
And I started this thread with the idea to get some comments. Not really seeking to change what I'm doing but I'm always learning.
Is there a point, let's say with a 400lb calf, that a higher % protein will be too much and just go out the rear end?
 
Is there a point, let's say with a 400lb calf, that a higher % protein will be too much and just go out the rear end?
Man Kenny, it's a pain reading through nutrition websites that only talk in generalities without answering a direct question such as yours.
But it's a good question and I needed to read more to learn for my benefit too, so I kept at it.
What I concluded was for a 400 lb calf 8.5% was the bare minimum and over 17% was excessive unless ideal conditions were met.
The sweet spot for a 400 lb calf seems to be about 14.5% protein.

One of the problems with giving a direct answer is individual variation with some calves eating just 2.25% of their body weight
on dry matter basis, while aggressive calves will eat up to 3.5% depending on the palatability of the feeds available.
 
Man Kenny, it's a pain reading through nutrition websites that only talk in generalities without answering a direct question such as yours.
But it's a good question and I needed to read more to learn for my benefit too, so I kept at it.
What I concluded was for a 400 lb calf 8.5% was the bare minimum and over 17% was excessive unless ideal conditions were met.
The sweet spot for a 400 lb calf seems to be about 14.5% protein.

One of the problems with giving a direct answer is individual variation with some calves eating just 2.25% of their body weight
on dry matter basis, while aggressive calves will eat up to 3.5% depending on the palatability of the feeds available.
Very good reply.
 
When figuring protein, energy, DM, etc, be sure to take the moisture out. Moisture has no nutritional value. Alfalfa at 20% protein fed 10#/day, with 10% moisture would be getting
1.8# crude protein, not 2.0#.

Too much protein can cause acidosis.

Hope this helps.
 
What form are you feeding protein in is also a factor.
14 percent protein alfalfa and 14 percent protein grass hay when fed to cattle will have total different effects on cattle. Alfalfa hay will be totally digested and out of the cow in 24 hours grass hay will still be being digested in 48 hours. Grass hay is usually 45-50 tdn
Alfalfa hay is usually around 60 percent tdn
Which feed will meet the increased energy needs of cattle in cold temperatures and which will be struggling to have energy needs meet when only difference in ration is one is fed grass hay and one is fed alfalfa hay.
 
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This is a very educational thread. I will be the first to admit that I am no expert on this. But the bioavailability of and the type of protein is also a big factor as @GoWyo said. Lots of cheaper feeds that may say "high protein" actually are made from chicken feathers which are not a good source of protein for cattle. While chicken feathers are super high in protein, they lack the required amino acids that cattle need. Some of the cheaper lick tubs that claim high protein use feathers as the primary source of protein.
 
Protein is just one part of the equation. That 400 pound calf at 0.87 lb of protein requires 54% TDN. While the one fed 1.85 lb of protein needs 85% TDN to get that 3 lb a day. Raise the protein without raising the TDN and not only will it run out the back end of the calf you will not get your desired gain.
 
I see people here all the time worried about protein. I worry more about TDN. They put protein on the labels on feed sacks. I remember as a young kid when they put both protein and TDN. They probably took that off so they could use lower energy feeds. Most people only know what they see which is protein.
 
Ken I know I can't answer your question. My barn is full of mixed breed beef, dairy beef cross and dairy bulls. I'm struggleing to understand it all too. And cost now is playing a role on my decision on how to feed them. For example calf starter feed here just went up $3 in 2 weeks on a 25kg sack. Its getting a bit crazy now to be feeding sack feed. But how do you give them what they need without breaking the bank??
 
Ken I know I can't answer your question. My barn is full of mixed breed beef, dairy beef cross and dairy bulls. I'm struggleing to understand it all too. And cost now is playing a role on my decision on how to feed them. For example calf starter feed here just went up $3 in 2 weeks on a 25kg sack. Its getting a bit crazy now to be feeding sack feed. But how do you give them what they need without breaking the bank??
I think that's a very good question, but every pound added now is worth more.
See if you can figure your average cost per pound of gain. Hopefully it's still less than selling prices and there is a profit ahead.
 
This is a very educational thread. I will be the first to admit that I am no expert on this. But the bioavailability of and the type of protein is also a big factor as @GoWyo said. Lots of cheaper feeds that may say "high protein" actually are made from chicken feathers which are not a good source of protein for cattle. While chicken feathers are super high in protein, they lack the required amino acids that cattle need. Some of the cheaper lick tubs that claim high protein use feathers as the primary source of protein.
If you will notice most feeds have Hydrolyzed feather meal. That's not the same as chicken feathers.
 

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