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Anyone read; Latest issue QW
Topic Started: Dec 3 2011, 01:54 PM (410 Views)
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What an outstanding article by Dr. David G. Hewitt in the latest issue of Quality whitetails.

The roles of Energy and Protein in WhiteTail Nutrition.

WOW ! What a pile of interesting info to say the least.

Anyone else read it

For you horn heads ,,,,,,,,,

Less then 7% of daily intake of protein goes to antler growth. A deer's daily requirement is 9% protein.

So of the 9% daily protein intake ,,,, only 7% of that is horn related.
7% of 100% protein intake.

So all those sales pitches of 30% protein bla bla bla Dose nothing . :sick: More proof of the prude study a few years ago.

Best part about protein is it helps store energy,,,,, still reading ,,,,, great read :allright:
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Renegade
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Atikokan, Ontario
Anything on the internet about this topic?
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Here is the same artical.

http://www.whitetaildomains.com/Articles/S...Deer+Management

Deer Nutrition - Part 1
Energize Your Deer Management

by David G. Hewitt

Poor nutrition can derail an otherwise well-planned deer management program; thus managers seek to provide high quality food. However, understanding and managing deer nutrition is complex because the quality of food can be defined in many ways and deer nutrient requirements vary seasonally and with a deer’s sex and age. To foster better understanding of deer nutrition, the CKWRI Deer Associates eNews will host a multi-part series on white-tailed deer nutrition, beginning with energy.

What is energy?
Energy is a difficult concept to describe. From a nutritional standpoint, energy is the potential to do work. Energy is made available when organic compounds are “burned” metabolically in the body. The total amount of energy in a food, called gross energy, is measured by actually burning a sample completely and measuring the heat produced. Energy can be measured in calories, or more commonly kilocalories (kcal = 1,000 calories). The composition of food determines its gross energy content. For example, minerals have 0 kcal/gram, carbohydrates have 4.5 kcal/g, and fats have 9 kcal/g of gross energy.


Forages like berries, acorns, forbs, and new, succulent browse leaves have high digestible energy because they have low fiber. Acorns and seeds may also have high energy because they contain fats and oils, which are high energy sources.

What makes a high energy food?
Carbohydrates and fats are the two primary sources of energy for deer. Fats are high in gross energy and are generally highly digestible; thus fats are an excellent source of energy. However, fats are not common in deer forage and are difficult to incorporate into pelleted supplements. Acorns and whole cottonseed are examples deer foods that may be high in fat and thus are good energy sources.

Carbohydrates may be highly digestible (think starch in corn) or poorly digestible (e.g. cellulose in mature grass). Poorly digested carbohydrates are considered fiber and thus the best indication of how much gross energy can be used by deer is the amount of fiber; the more fiber, the lower the digestible energy. Digestible energy is energy useful to the deer.

Excellent deer forages and poor quality forages often have the same gross energy. Such forages differ because of differences in the amount of gross energy digested. Thus, mature grass and corn have similar gross energy, but corn may have twice as much digestible energy.

Diets of free-ranging deer eating only forage may have less than 2 kcal/g digestible energy during dry seasons or in poor range conditions. During exceptionally good conditions, deer may consume diets containing 3 kcal/g. Most pelleted diets have 2.8 – 3.5 kcal/g digestible energy and therefore are good energy supplements.

What are implications of low energy intake?
- Low energy intake during autumn precludes bucks from acquiring fat needed during the rut. Entering the rut in poor condition could result in higher mortality rates (see the March 2010 Deer Associates e-newsletter).
- Energy intake immediately before and during the rut influences whether does ovulate, when they enter estrous, and potentially affects litter size. The effect of energy intake is dramatic for young does, which will not breed if on a low energy diet, but will breed if eating a high energy diet.
- Because body growth is energy expensive, low energy diets result in low growth rates and small bodied deer.
- Maintenance of body temperature in both hot and cold conditions requires energy. Poor energy intake may increase mortality during extreme weather.
- Low energy intake results in a cascade of metabolic changes that can affect a deer for the rest of its life and may have generational impacts. As discussed by Randy DeYoung in the April 2010 Deer Associates e-newsletter, poor quality diets early in life can stunt deer and can cause a female’s offspring to also be small, even if raised on a high quality diet. Because most nutritional regulation in an animal is tied to energy status, it is likely that energy intake is a primary factor causing these long term effects.
- Starvation occurs when an animal consumes less energy than necessary to meet its requirements and depletes its energy reserves. Starvation is the most severe consequence of low energy intake, but is uncommon in adult deer in South Texas.

Energy vs. Protein – Which nutrient is more limiting?
Energy has a step-child status in most people’s minds when considering the nutritional quality of forage or feed. Usually the only information provided about deer forage or food is the protein content. Adequate protein is essential for maintenance, reproduction, and growth; however several lines of research suggest that energy is more limiting than protein for deer.

- In the 1980s, CKWRI scientists quantified the quality of deer diets monthly for an entire year near Kingsville. They found deer always consumed more than maintenance concentrations of protein and consumed sufficient protein for production during all but 2 months. Energy was insufficient for maintenance during 3 months and barely met maintenance requirements in a fourth month. The shocking part was that the months in which energy was most limiting were May-August, when fawns are being produced and antlers are growing.
- In a similar study conducted near Carrizo Springs, former CKWRI graduate students Ryan Darr, Luke Garver, and Kent Williamson plotted protein and energy intake of deer seasonally and also showed that energy is more often limiting than protein (see Inside Deer Research Fall 2009).
- Verme and Ozoga measured body growth of captive deer fawns fed diets differing in energy and protein. They concluded that diets differing modestly in energy content (3.0 vs. 2.7 kcals/g) had much bigger influence on body growth, metabolic state, and body fat than diets differing considerably in protein (16.2 vs. 6.6%).
- Abler and colleagues offered captive deer fawns diets varying in protein and energy content. Nearly 80% of fawns on diets with 3.1 kcals/g ovulated whereas none of the fawns fed a diet with 2.5/g kcals ovulated. Dietary protein of 9.6 vs. 18.2% had no effect on ovulation rates.

How do I know if deer are getting adequate energy?
There are 3 primary measures of energy status in deer that can be readily applied by managers:

1) Fat. Despite bad connotations for human health, fat represents good nutritional conditions for deer because body fat accumulates to the extent deer eat more energy than necessary for maintenance. Fat around a deer’s organs and under its skin can be assessed at the skinning shed when processing harvested animals. There are 2 caveats when interpreting body fat:
- fat stores vary seasonally. Deer are typically fattest during autumn and lose fat throughout the winter, even with unlimited access to high quality food.
- female deer may be in poor condition during autumn, not because of low energy intake, but because they successfully raised fawns. Providing milk for fawns requires tremendous amounts of energy. Some of that energy comes from the doe’s fat reserves and thus successful does may be in poor condition around the time of weaning.
2) Body condition. You can detect large differences in energy status visually by assessing deer body condition as described in the photos below.
3) Fawn body weight during autumn. Female deer invest large amounts of energy in fawns through lactation and fawns require high energy food to continue growing after they are weaned. For this reason, large fawns indicate a deer population has ample energy. Small fawns suggest energy needs for production are only just being met.


Deer body condition is a good indicator of energy status. The doe on the left has been using her fat and muscle for energy. The doe on the right has been eating more energy than she requires and has stored the extra energy as fat, giving her a plump, rounded appearance.

Implications for Deer Management
Energy matters for nearly all aspects of white-tailed deer biology but few managers consider energy when addressing their deer herd’s nutrition. Forbs, succulent browse, and mast generally have high amounts of digestible energy because they have low fiber concentration; management for these forages will increase energy intake. Actions that reduce deer energy expenditure may also be beneficial, such as reducing the distance deer must travel to obtain resources, providing cover to reduce thermoregulation costs, and reducing frequent disturbance during times of energy shortage. The positive response of deer to supplemental feed in southern Texas occurs largely because the supplement has higher digestible energy than forage, especially during drought or when range conditions are otherwise poor. Finally, actions that promote forage intake can also increase energy intake; factors influencing forage intake will be covered later in this nutrition series.

Next month – Protein - Building Blocks for Everything Deer
The next installment in the CKWRI Deer Associate eNew’s nutrition series will be a description of protein’s role in deer ecology and management.



http://www.whitetaildomains.com/Articles/S...Everything+Deer

Deer Nutrition - Part 2
Protein - Building Blocks for Everything Deer

by David G. Hewitt

Last month’s CKWRI Deer Associate’s eNews initiated a series on deer nutrition by discussingenergy and its role in deer management. This edition of the eNews will cover protein, another nutrient deer require in large amounts and one most people readily recognize as being important for deer.

What is Protein?
Proteins are like a train in that they are composed of subunits, just as a train is made up of cars, linked to make one large molecule. Like a train, proteins can vary in the number, type, and sequence of subunits. The subunits of a protein are amino acids. There are 25 amino acids that make up the thousands of different proteins in a deer’s body. Amino acids are so named because they all contain an “amine” group, which contains nitrogen.

Protein is difficult to measure directly, so nutritionists estimate it indirectly by measuring the percent of the sample composed of nitrogen (remember the amine groups that contain nitrogen?) and multiplying by a constant. The resultingestimate is termed crude protein. This approach may not be accurate for some forages because not all nitrogen occurs in protein. For example, guajillo has several potentially toxic, but naturally occurring chemicals that contain nitrogen. Based on nitrogen in the leaves, guajillo appears to be a good source of protein, containing perhaps 20% crude protein. However, because of the non-protein nitrogen, the true protein content is lower.

Most people recognize that muscle, hair, and hooves are made primarily of protein. Many people do not know that antlers and bone are 45% protein, that skin is primarily protein, and organs in the deer’s body are composed primarily of protein. In fact, once water is removed, a deer’s body averages 74% protein (with 16% ash and 10% fat). In addition to structural function, proteins are used to transport materials around the body, such as hemoglobin that carries oxygen in the blood. Other proteins are hormones, such as insulin. Enzymes are proteins that serve as catalysts in all cells of the deer’s body, ensuring the machinery of life operates as intended.

Protein Metabolism –
Why Protein is not as Limiting as Most People Think
To understand protein metabolism and requirements in deer, it is important to remember deer are ruminants (for a refresher, see Amazing Insights from a Deer’s Insides). Microbes in the deer’s rumen use much of the dietary protein for their own growth and reproduction. This sounds bad for the deer until you realize that the microbes are continually passing out of the deer’s rumen to be digested by the deer. In fact, the conversion of plant protein to microbial protein benefits deer. To understand why, recognize that deer do not need protein per se, they need amino acids so that they can make their own proteins. Many amino acids can be manufactured from other amino acids by the animal. Those that cannot must be obtained from the diet and are known as essential amino acids. Animals without a rumen, such as pigs, chickens, and humans require 10 essential amino acids in their diet. Without these specific amino acids, their growth is poor and they may develop other deficiency symptoms. Ruminants do not have requirements for essential amino acids because the rumen microbes convert plant protein to microbial protein,which the deer then digests. Amino acids in the microbial protein closely match the deer’s requirements. So, one reason why deer are not as limited by protein as many people believe is that microbes help ensure the amino acid composition of the diet matches that needed by the deer.

Rumen microbes also increase the efficiency of protein use. When a deer eats a low-protein diet, waste nitrogen from normal protein metabolism is routed back into the rumen, where the microbes use the nitrogen to manufacture new amino acids. The ability to recycle nitrogen enables deer to meet maintenance requirements on diets low in protein.

Cattle and sheep are also ruminants, but seem to be more limited by protein than deer. Cattle and sheep are primarily grazers; cattle not only forage extensively on grass, but often eat mature grass. Mature, cured grass is often exceedingly low in protein. By contrast, deer eat shrubs and forbs, forages that contain more protein than cured grass. Unlike deer, cattle and sheep are more likely to be limited by protein and to respond positively to protein supplements. Carryover from the livestock industry may be the reason supplemental feeds for deer are typically called “protein pellets,” even though the energy in the pellets is probably more critical than the protein.

Are there any benefits, or problems, with diets containing high concentrations of protein? If a deer consumes more protein than it needs, the extra protein can be used for energy. However, using protein for energy is inefficient. Furthermore, forages with high concentrations of protein (e.g. greater than 25% crude protein) may cause ammonia toxicity. Thus, deer may limit intake of such foods. Additional research is needed to identify protein concentrations that may cause deer to reduce intake.

Protein Requirements
Maintenance requirements for adult deer are 8-9% protein in the diet. Antler growth requires 10% protein; the increase in requirements is small because less than 7% of daily protein intake is deposited in antlers. Does require 16% crude protein during late gestation and peak lactation, although this requirement assumes does meet some of the lactation costs by using protein from their muscles. Lactating does typically use muscle protein even when high-quality forage is available. Newly weaned fawns require diets with up to 19% crude protein to achieve peak growth rates. Donnie Kahl, a CKWRI graduate student, allowed 6 – 18 month-old deer to choose their own diets from feeds containing 8 to 25% crude protein. These deer selected diets with 13-16% crude protein and had growth rates similar to those of deer eating a pelleted diet with 17% protein. Thus, even deer with high growth requirements selected a diet with a lower protein content than most people would predict or would provide in the form of supplement.

What are Implications of Low Protein Intake?
- Just like low energy intake, low protein intake can reduce growth rates of young deer.
- Low dietary protein can result in smaller antlers, particularly in yearling bucks which need protein to support body growth.
- Although protein intake is not especially important in determining if a doe will enter estrous, protein intake during the third trimester of gestation can have a dramatic impact on fawn health and survival. Does forced to eat low-protein diets during late spring and summer give birth to small, weak fawns. The fawns may not be strong enough to nurse and therefore often die a day or two after birth.
- Protein could be limiting for deer during some seasons, such as during summer droughts. Cactus pads and various types of mast, such as fruits of prickly pear, persimmon, and brasil may be a large part of deer diets during dry summers when forbs are scarce. Mast and prickly pear pads are typically moderate to high in energy, but low in protein. Such forages may keep adult deer alive but do not have sufficient protein for body growth or fawn production.

Implications for Deer Management
Diets with 10% crude protein are sufficient for adult deer during autumn, winter, and early spring. Protein requirements increase during late spring and summer, when deer are most productive. Ensuring deer have access to forages or feeds with 16-20% protein during summer will enable deer to meet their requirements. Access to high-protein forages in autumn will enable recently weaned fawns to adjust to a forage-based diet and continue to grow. Management for forbs and diverse browse communities will improve both protein and energy status of deer. Succulent, newly growing grass may have over 20% protein and can be an important forage for a brief time after rainfall or disturbances such as fire.

The goal of a manager should be to provide deer with foraging choices to mix a diet with the appropriate amount of protein. Pelleted supplemental feed can be one of these foraging choices. Protein requirements are low during late autumn, winter, and early spring; a supplement with 10-15% protein could be mixed with most forages to meet deer requirements without causing the deer to avoid the feed because of excess protein. During late spring, summer, and early autumn, deer protein requirements are higher; pelleted feeds with 16-20% would enable deer to achieve an average protein intake to meet their needs. The higher protein supplement may be especially beneficial during summer drought when some forages are exceedingly low in protein.

Next in the Nutrition Series – Elemental Deer Management
The next installment in the CKWRI Deer Associates eNews nutrition series will be in November and will cover what is known about minerals in deer ecology and management.

About the Author: David G. Hewitt is the Stuart Stedman Chair for White-tailed Deer Research at Caesar Kleberg Wildlife Research Institute.
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"Are there any benefits, or problems, with diets containing high concentrations of protein? If a deer consumes more protein than it needs, the extra protein can be used for energy. However, using protein for energy is inefficient. Furthermore, forages with high concentrations of protein (e.g. greater than 25% crude protein) may cause ammonia toxicity. Thus, deer may limit intake of such foods. Additional research is needed to identify protein concentrations that may cause deer to reduce intake."

So ,,, again ,,, Those companies who claim 20-30%+ protein are not helping deer.

Again the more is better sales pitch might be doing more harm in your plot then good. Might even discourage deer from eating there.
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Wow, after reading that make's me think the "Algonquin Region" deer must be the fittest of all , seeing they don't even get to see a hay field let alone a food plot. I guess they store all there fat by way of beechnut's, no acorn's in that area. Where has all that research been done, southern state's, Texas , etc. Doe's make for an interesting read tho. :renedeer:
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You had to start something didn't you bigr, LOL, Here is a little tid bit i just found for our northern whitetail's. Beechnut's have same protein as corn,but 5 time's the fat content, also twice as much crude protein and twice the fat of white oak acorn's. Very interesting. :hick:
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See I don't always pick a fight LOL.
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bigr
Dec 7 2011, 10:34 AM
See I don't always pick a fight LOL.

LOL. lol)))
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