Pond Boss Forums GENERAL QUESTIONS Wildlife Management Does Corn Hurt Deer

It gives'em high cholesterol.
Dan

depends where u put the cob ??

Or if you have a sign like this:

Saw a deer (buck starting to grow antlers) yesterday in one of the wetlands/duck-ponds. It was standing in the water gorging on what looked to be milfoil, but it could have been another slimmy submerged weed. Have any of you heard of this? Maybe it thought it was moose...

At the end of turkey season I saw a couple of bucks that had antlers that were 2" long. Saw one about 5 days ago that had antlers about 1.5 times ear length.

Never saw one in a pond eating plants tho!

Not sure what they are eating, but they do wade into up to the bellies or deeper and feed on something in the back cove of the creek my dad's house is on. A lot of eel grass grows back in the cove, so I am guessing that is what they are feeding on.

If a buck is that far out past the ears this early, he's gonna be a tank come velvet shedding time.

I went to Cal poly to study animal science; and large part of my curriculum and interest was in animal nutrition and diet formulation. I am also currently a 2nd year veterinary student, which means i don't know a whole lot, but I will write some gibberish for you guys to justify my vet school tuition. It makes me sleep better at night.

I'll give you the short story on feeding concentrates to ruminants (deer, goats, and cows are pretty damn similar concerning their digestive tracts and how they react to feeds)...

The problem with feeding a diet consisting largely in part of concentrates (Corn in this case) is that it can and will cause a dramatic shift in the bacterial population in the ruminant's stomach. The stomach will over a relatively short duration of time become much much more acidic.

As humans, we think of acidic stomachs as being normal, but deer and cows (ruminants) have special parts of their stomach that are supposed to be free of acid.

So in the case of feeding primarily concentrates, the bacteria and protozoans that thrive on eating concentrates (corn) rise in numbers, and their biproducts are acid.

This acid will kill / displace the other types of bacteria and protozoa that would normally break down grass (cellulose).

The problem here is that the bacteria and protozoa that break down grass (cellulose) are the ones that contribute the most to the energy supply of ruminants. Grass is broken down into Volatile Fatty Acids known as VFA's.

These VFA's (volatile fatty acids) are then converted in the liver into glucose, which is the energy source that animals use to fuel their bodies.

So now lets talk about the bad stuff that happens as a result of the "grass bacteria" dying, and the "corn bacteria" proliferating.

The acidic environment makes the deer produce a lot more buffer (bicarbonate) than it normally would, and eventually it runs out of buffer. The animal's blood then becomes too acidic --> Bad stuff (death).

At the same time, the deer isn't getting the VFA's (volatile fatty acids that "grass bacteria" produce) that are turned into glucose (the bodies main energy source).

As a result, the body panics and goes into an emergency survival mode and begins producing ketone bodies (a really shitty, alternate energy source for emergencies only that increases blood acid concentration... It isn't mean to operate for a long time).

Too many ketone bodies build up, and the deer's enzymes that make life possible stop working. The acidity of the deer's blood increases at the same time (and we talked earlier about how there isn't any buffer left to keep this from happening).

So again... Ketoacidosis happens... Acidity of blood increases --> Death (if this happens for a short, but somewhat extended period of time).


So feeding too much concentrate = Bad

It would be better, but also more of a pain in the ass, to feed a mix that didn't consist of just concentrates.

But if the deer seem to be living long enough to harvested, then why mess with it? If you start finding dead deer in and around your property that don't have bullet holes in them, then maybe i would think about changing things up a bit.


As a quick side note; try not to waste money buying high protein feed (soybean meal); It sounds like a great idea, but the deer won't use the protein.

They get their protein source by eating the dead bacteria and protozoans that wash out of the top compartments of their stomach into the rest of their digestive tract.

The microbes (bacteria and protozoans) get the first shot at everything you feed; so the protein would essentially be wasted (never get to the deer's main absorption mechanism).

Interesting stuff Gflo, I had ideas about this but that is a good technical explanation. I think in free range deer, the odds of them consuming so much corn they die of too high blood acidity in unlikely. I could definitely see it happen in pen raised deer though.

My biggest concern is if you haven't been feeding the deer and then in February when they are about starved to death and then you start feeding them. You are going to do them more harm than good. Biggest reason, they are wasting all that time and energy consuming corn in which their stomach microbes aren't current ready to digest.

The same can be said you have have been heavily feeding deer corn and then all of sudden stop. They now have to switch back to an all natural browse diet, again they could face serious issues.

Tell me more about how deer digest protein? So it's a waste to feed them high protein pellets of even roasted soybeans?

So what happens when the corn is harvested in farm areas where the supply is limitless for the deer until harvest. We don't seem to have deer laying around dead at that time of year without arrows or lead in them. Seems like they grow pretty fat around my part of the country. Looks a bit like a hypothesis to explain something that does not seem to happen, but then again I am no animal physiologist...

Typically, you only find grain overload in animals that are penned and fed improperly (not enough hay but heavy on the concentrates - a very expensive error; hence, not common) or in animals that escape their pens and find their way to an unsecured feed room (this, unfortunately, occurs much more often). Also, grain load comes into play around the first weeks prior and after parturition. I agree with CJB that it is the sudden complete switch in diets that cause more issues...

Just saw this as I was about to head out the door. I'll post something tomorrow morning concerning protein.

Concentrates typically won't pose problems unless there is a sudden change in diet, which typically only happens in feedlot situations (as several of you have pointed out).

The simple answer to if corn hurts deer is that it won't, unless you stick them in a pen and force them to eat it without a fiber / grass / hay source. A feeder on the property shouldn't cause any harm.

You guys are pretty much all right on the money. I just think of deer like cows since they work the same.

CJBS2003 --> The situations you have described are correct

RAH --> It isn't a hypothesis; it happens i promise, but you are correct that it isn't going to happen very often (if at all) in nature; even if a landowner is supplementing their diet with corn.

FullCircleTx --> 100% correct


Tell me more about how deer digest protein? So it's a waste to feed them high protein pellets of even roasted soybeans?

Yes, its a waste to feed high protein pellets to ruminants, even if its roasted soybean; however, it would help if you were feeding those food items to monogastrics (like pigs, humans, dogs) and here is why.

Monogastrics (pigs, humans, dogs for example) have limited machinery to break down plant matter (or deal with trypsin inhibitors).

It has to do with "bioavailability" of protein with monogastrics, and I like to think of it in two ways.

1) Trypsin inhibitors are present; which will effect how chymotrypsin, carboxypeptidase and other important protein degredation enzymes work. Trypsin inhibitors will suppress activation of these enzymes, consequently making them not work very well.

So if you heat treat soybeans, which have trypsin inhibitors, then the heat will denature the trypsin inhibitors and render them ineffective, which leads to better digestion and absorption from monogastrics (pigs, humans, dogs etc).

But with ruminants (deer and cows) never think that you are directly feeding the animal. You are indirectly feeding the animal no matter what food you give it.

This is because you are directly feeding the microbes which call first dibs on everything the ruminant eats.

So it works kind of like this...

You give the deer soybean (heated or non-heat treated, doesn't matter they treat it the same as a protein source) ---> Microbes ferment it and use the amino acids that you paid for their own personal use -----> microbes die eventually and enter the ruminants TRUE stomach ---> The dead microbes supply almost all of the Essential Amino Acids required by the ruminant and are the primary protein source.

At the same time you can estimate that 16% of the soybean protein that you purchased is going to sneak by the microbes and make it to the ruminants TRUE stomach unmolested.

So, you can see that you paid top dollar for a high quality protein source and 84% of that protein was wasted because the microbial population did whatever they wanted with it.

Even if there wasn't sufficient amounts of protein entering the diet for the microbes to use for themselves, the ruminants have developed a cool little trick. Instead of urinating to get rid of all their Urea like most other animals, they recycle it into the parts of their stomach where the microbial population lives, and they COMBINE that urea with carbon skeletons from carbohydrates (CORN) to create amino acids. So they can essentially create protein from non-protein sources... Pretty cool huh?

Just to give you an idea of how good they are at this...


1 pound of urea + 6 pounds of corn grain = the same amount of crude microbial protein as 7 pounds of soybean meal.

So, just by feeding them corn, you are indirectly giving them a protein source by supplying carbon skeletons for them to attach the recycled urea to --> amino acids



Scenario #2) You feed protein to a monogastric (pig, human, dog) that is plant based in origin. Some of that protein is not able to be used, or has low "bioavailability" because it is surrounded by cellulose.

So you have protein that has a wall of cellulose around it; so the crude protein on the label could be high, but the animal can't use it because it can't break the cellulose bonds to get to it.

So you treat it / process it --> now monogastrics can use the protein.

You don't have to do this for ruminants because again, the microbes will just ferment it and break down the cellulose, so the protein is available for the microbes to use anyways. Microbes die, and the ruminant eats the microbes. Same stuff happens.

Its kind of funny to think about it, but ruminants (deer and cows) are actually pretty carnivorous in that they eat microbes to get their protein requirements.


Here is the super short story now that you probably read all of that crap...

Feed corn and they will make their own protein from it so you will kill 2 birds with 1 stone.

1) They will make protein from corn

2) they will use the corn as a potential energy source for growth

If you still want to supplement protein just incase, then decrease the soybean meal to a very low percent like 10%

These recommendations would be totally different / precise if this were a feedlot setting with pens, but it isn't.

Ruminants are really good at making low quality foods into really useful stuff, so don't stress out too much trying to optimize a diet plan for the deer. I would just opt for what is cost effective for you, because in the end the results won't differ too much. Genetics are of more importance.

Thanks Gflo - My point was that all that theory has very low practical value for those providing supplimental corn. I am a scientist by profession, but a farmer by nature. Evidence trumps theory every time.

It may be just the opposite, Ask my farmer where I hunt, they tear up his corn and in turn they do get hurt when they come to my corn pile. We can legally bait deer here.

That was also my point also RAH. I agree with you fully; I roll my eyes at my classmates that have their noses jammed so far up into their books that common sense just well... Isn't so common to them anymore.

The challenge for most people is realizing at what point information is actually useful (practical) and when it becomes a handicap (unpractical theory-crafting that is of little help).

Gflo - Getting into vet school is no small feat. You must be a bright guy. Even humans must adapt to different diets (microbe species populations must adjust in our gut). I just wanted to re-enforce the practical aspects of the deer/corn situation.

So why do deer biologists preach high protein diets... Say 16%+ to grow bigger racks? Without a doubt, all summer long and into the fall until the soybean fields around my father's turn yellow, there will be many deer pouring into them each evening to feed on the high proteins leaves. Then later after the beans have hardened, they're back in those field eating the beans that are stilling hanging or were missed when harvested... The big buck I shot last year was packed full of corn and beans.

I threw out my dogs dry dog food cause i did'nt want any critters nosing around my cottage screen room. i threw the food about 15 feet in front of my trail cam,and for the next week i have deer in the yard eating up all the dog food.I've never had so many pictures of deer.To tell the truth I was hoping to get some interesting fox,coyote,or wolf shots. But i guess the deer got there first,hope their stomachs are O.K.

CJB - A short answer: Deer, like any ruminant, have 4 compartments which makes up the stomach - the rumen, reticulum, omasum and the abomasum. The rumen and reticulum makes up approximately 84% of an adult cow's stomach but a much smaller % of a deer's (sorry - it is late at I cannot currently pull its %). Basically, the rumen (or paunch) is the central holding area for feed and it is where the majority of microbial activity occurs (VFA production - around a half of the starch/sugar is digested here -> energy if you will). The reticulum's (or honeycomb's) purpose is to move the feed back to the rumen until the feed has been broken down into small enough particles to be passed on to the omasum. The omasum (or manyplies) is made up of many folds and its purpose is to absorb water and nutrients. The feed particulate matter then passes to the abomasum (or "true stomach") where hydrochloric acid, pepsin (the enzyme responsible for breaking down protein), lipase (breaks down fat), etc., do their thing prior to the final absorption of the nutrients in the intestinal track. So, as the excess protein passes through to the abomasum where it is directly utilized by the deer, it makes sense to pay attention to protein levels. Hence, the biologists recommend a high protein diet. Also, unlike cattle who are bulk grass/roughage eaters due to their larger rumen/reticulum areas (as a % of body area), deer are considered to be concentrate feeders (as are giraffe). They prefer more easily digested and nutrient rich food products (ie., prefer legumes over a grass pasture - high protein/ starch). Also, they have a limited ability to digest cellulose/fiber when compared to cattle. (It makes sense as they cannot be loaded down with a large belly full of food - nor do they have the luxury of being able to chew a cud for hours after eating). This is probably why you are seeing them in your Dad's soy fields and why they raid the corn fields.

Hope this helps

http://www.thecattlesite.com/articles/2095/understanding-the-ruminant-animals-digestive-system

gives a nice breakdown on how all of this functions and explains much more clearly than I have as to why a higher protein diet is beneficial.

A quick note - just found this. While regular soybeans have 25-30% UIP (the bypass protein), roasted soybean contain 45-55% so roasting absolutely helps! Ref: http://www.gnb.ca/0170/01700003-e.asp

Last year, I tried feeding soybeans. The deer in my area wouldn't touch them. As usual, the coons and hogs didn't let them go to waste.

I think what we should remember here is that supplemental feeding is intended to be supplemental. Deer will seek out what their bodies need, and will select for high protein forage if their energy requirements have been met or bolstered by supplemental feeding.

If someone is fine with and can afford to foot the bill for protein in their supplemental feeding rations and they are happy with how that has been working out for them, then there is nothing wrong with that.

Also keep in mind that just because a feedstuff is not classified as a protein feed by nutritionists, it doesn't mean that it cannot contain more than a moderate amount of protein.

For example: whole corn --> 10% Crude protein content (That is a pretty good amount of protein)

Now lets look at what is considered a protein food item...

Soybean meal --> About 54% crude protein (You can see why its classified as a protein item)

So if you are feeding Corn + a low % of soybean meal, then you would be offering a great deal of protein for supplemental feeding. (I would never recommend this in a feedlot / pen situation due to the risk of acidosis occuring)

The deer should be able to fulfill the rest of its protein requirement from the land, which they are forced to do at a level of approximately 6 to 8% anyways so that they don't die as a result of their microbes dying. Most of the time they should be able to find between 10 to 13% of their protein requirements.

Here is the resource that I find myself referring to from time to time. It is a little long, but I wouldn't recommend it if I hadn't read it myself and found it useful.

If antler growth is important, then page 93 may be useful.

http://texnat.tamu.edu/files/2010/09/supplemental_feeding_deer.pdf

That is a great link. I like the Foreward - it applies to fisheries as well as deer mgt. You guys go read some of it -

"Expect to hear several recurring themes during this conference. For example, “it
depends”, “your particular situation”, “supplemental feeding is not a cure-all for poor
habitat management”, and finally, “I don’t know !” Such caveats suggest that neither the state
of the science nor the art on this subject is exact.
Ben Franklin once reminded us that “every person that I meet is in some way my
superior, and if I will listen to him, I can learn from him.” Speakers at this symposium bring
with them a wealth of practical experience, insight and thought-stimulating questions. Listen
to their respective presentations and evaluate them critically. Challenge them with your
questions and evaluate their debates among themselves. Finally, apply those technologies
that hold promise for your respective deer management situation. And that pass the acid test.
Education is a lifelong process."

Eric, the thing that I have really appreciated about Dave Willis is often made comment of "We really don't know."