Free-range Chicken Eggs as a Functional Food:
Quantifiable differences in the nutrition provided by

a  supplement of free-range eggs vs.

a supplement of grocery eggs in Cornish Cross chicken chicks

 © 2000, Donna Fezler, Grand Cypress Ranch, 1620 Baldwin Road , Jacksonville , IL 62650

gcr@rhealiving.com

 In two separate studies, the first without a control, chicks were fed commercial feed supplemented with either cooked grocery or free-range egg for 4 weeks. The data consistently showed a nutritional difference between grocery and free-range eggs.

 Mortality, Leg Rotations, and Weight Difference in Grocery vs. Free-range Egg fed chicks 

 There were significant differences in mortality between the groups in the first study.

 The second study showed significant differences in weight gain between the two groups, demonstrating  the grocery eggs were actually negative nutrition. The control group, fed no egg supplement, fared better than the group fed grocery eggs. The birds in the grocery-egg fed group had poor feed efficiency, consuming the most feed and having the lowest weight gain. The free-range egg fed birds were 22.4% heavier than the grocery-egg fed birds and they ate nearly equivalent amounts of feed and egg.

 The free-range eggs were from a home flock of free running chickens free fed ground corn and having access to rabbit pellets, llama feed and pasture and timber to forage.  They were not fed any standard chicken food or layer formula.  No attempt was made to enhance the egg quality.

Test Design

 It should be stressed that this is not a test of good chicken nutrition but a challenge to determine if there is a difference in life-sustaining qualities of battery-produced eggs or free-range eggs.

 In both groups, the free-range eggs were from a home flock of free running chickens free fed ground corn and having access to rabbit pellets, llama feed and pasture and timber to forage.  They were not fed any standard chicken food or layer formula.  No attempt was made to enhance the egg quality.

 The original nutritional difference came into question when 80 rhea chicks were switched from rhea egg as a supplement to grocery chicken egg.  Within 14 days over half of the rhea chicks developed leg rotations and had to be destroyed.  The only change in their environment had been the change in diet, so we needed to quantify if there was a developmental difference between animals fed grocery or free-range egg. 

Test 1, March 2000:

We needed to establish what differences, if any, we might see in a group of chicks fed free-choice, non-medicated feed supplemented twice daily with 90 grams of either cooked free-range chicken eggs or grocery eggs.  There was no control.  We started with 27 mixed-sex chicks in the grocery- egg group and 25 mixed-sex chicks in the free-range group. 

Test 2, August 2000:

 Having established that the males do show a weight gain difference in the first test, the second test group of 31 male Cornish Cross chickens was divided into 3 groups:

 1.      The control group of 11 chicks fed free-choice non-medicated commercial chick starter and NO egg supplement.

2.      The free-range egg supplemented group of 10 chicks fed a free-choice non-medicated commercial chicks starter, and two 90 gram servings of cooked egg in the AM and in the PM.  Each chick averaged 1.8 grams for 28 days totaling 540 grams of scrambled egg.

3.      The grocery egg supplemented group of 10 chicks fed a free-choice non-medicated commercial chicks starter, and two 90 gram servings of cooked egg in the AM and in the PM. Each chick averaged 1.8 grams for 28 days totaling 540 grams of scrambled egg.

The chicks were raised in a single 8 x 8 foot pen separated into three separate groups by plastic mesh for the first 28 days.  Each section had its own heat lamp, feeder, and waterer. At 28 days, the egg supplement was stopped and the birds were put together in one moveable "chicken tractor" pen.  The pen was moved to fresh pasture daily.  Commercial non-medicated chick starter was offered free-choice.  No eggs were offered.

Results

Test 1: March

 Due to mixed sexes, with different weight gains and predation there are no reliable weight gain numbers, just trends.  However, we did see mortality of 9 birds or 33.3% of the grocery- egg fed birds.  There was 1 mortality, 4%, in the free-range egg fed birds.  When the birds were slaughtered, the grocery egg-fed had visibly higher amounts of fat deposits. 

The free-range fed males were 15.4% heavier than the grocery egg fed males. 
There was no statistical difference between the females of the two groups. 

At slaughter, there was a marked difference in fat deposition between the two groups.  The grocery egg birds had much larger fat deposits than the free-range fed birds.  Since this was a surprise and such a study requires considerable advance preparation and cost, no attempt was made to quantify the difference.

 Weight and Mortality at 37 days of age

Test 2: August

 In the second study we used eggs from a different hatchery.  On the third day of egg supplementation, the grocery-fed birds refused to eat the egg.  Only by removing the free-choice feeder for several consecutive feedings could they be coaxed to eat the egg.  The feeder was returned immediately when the egg was consumed, which was less than 30 minutes on all days.  The free-range egg group ate the eggs without coaxing.

 Mortality was zero, although there were 2 leg rotations in each egg supplemented group.  At 28 days the grocery egg fed birds weighed the least, but ate the most.  Even though the egg supplementation was stopped at 28 days, the birds still had lower weights than the free-range egg fed group and the control, no egg, group. 

Since the eggs were cooked scrambled, but not dried, it is not possible to total the commercial feed and the egg to calculate a feed efficiency ratio.  However, we did calculate feed:gain ratio on the commercial feed consumed.  At slaughter we could not visibly discern any difference in fat deposition.

The weight and feed intake differences in chicks supplemented with

Free-range eggs or Grocery eggs.

 Conclusions

 The data consistently showed a quantifiable nutritional difference between grocery and free-range eggs.  The first test group of chickens was larger and faster growing than the second test group which may have contributed to the high mortality we encountered in the first test. 

 The first test did not produce a difference in weight in hens, but the free-range egg fed cocks were 15.4% heavier than the grocery fed cocks.

 The second test showed the free-range eggs enhanced growth while the grocery eggs were actually negative nutrition.  The birds in that group had poor feed efficiency, consuming the most feed and having the least weight gain. The free-range egg fed birds were 22.4% heavier than the grocery- egg fed birds and they ate nearly equivalent amounts of feed and egg.  This weight gain difference lessened to 8.14 % when the groups were combined, but the initial 297 g difference increased to 384 g, so the numerical difference actually increased.  There were residual effects of the grocery egg on the chicks' development.

Growth and life-sustaining qualities are not equal between free-range and battery produced chicken eggs when fed to chicks.