The Best Flock Yet

25 years of innovation and attention to detail has resulted in phenomenal results for Coburn Farms
Dave Coburn, Coburn Farms and Jeff Walton, Belisle Solution Nutrition, Inc.
Tuesday, 10 April 2012
By Dave Coburn, Coburn Farms and Jeff Walton, Belisle Solution Nutrition, Inc.

At Coburn Farms, a bicentennial family farm located in Keswick Ridge in New Brunswick, attention to detail and never being afraid to try new things to improve the performance of the layer flock has been standard.  The implementation of various innovations on the farm in the past 25 years has resulted in the best flock performance ever, and the next flock is looking like it’s going to achieve a new record.

The journey began in 1986 when Coburn Farms built a new high-rise 25,600 bird capacity layer barn. Three years later, it was the first commercial egg farm in Canada to install a computerized ventilation control system that optimized and recorded house temperature and ammonia levels.

It was found that in the winter months, insufficient outside air could be introduced into the barn to remove enough ammonia in order to keep the level low enough, while still keeping temperature at a desirable level. 

In an effort to try and decrease the ammonia levels in the barn, it was agreed that the farm would participate in a trial with Alltech the following year (1990), where a yucca extract product called De-odorase was added to the feed at rate of 100g/tonne.  The fact that the barn had a computerized ventilation control system that recorded the temperature inside and outside the barn, as well as housing each flock at the same time each year, proved beneficial for making year to year comparisons on ammonia levels.

Over the next several years, it was found with the use of De-Odorase, ammonia levels could be halved, while barn temperatures could be increased.  Increasing the barn temperature resulted in a lower feed consumption (a 1 C change in temperature is equal to approximately a two per cent change in feed intake).  At the start of the trial, the barn temperature could not be higher than 24 C without having ammonia issues.  Over several years, we were able to increase this to 27 C without issues, and this temperature is maintained to this day.

Lowering the ammonia not only improved air quality, but also led to improved bird health and performance.  It was also noticed that the composition of the manure was altered, reducing the fly population and the need for insecticides.

The next step was the building of an in-vessel composter.  The thought was that if the manure had less odour and already appeared partly composted, why not compost it to add extra value.  Thus, a new cash stream was added to the farm.  Composted manure, along with pomace from the farms’ apple orchard, is branded “Natural Gold” and is sold in bags or bulk.  The composted manure is also used as fertilizer for the apple trees, as the high calcium content results in apples that are firmer and have a longer storage life.  The use of the manure on the apple trees also helped to extend cider production, adding to the profitability of the orchard.  The composter is a key element in making the farm a closed-loop farm, as wastes that are put through the composter are returned to the soil.

The next move was to install a computerized on-farm feed mill, which provided opportunities to utilize local ingredients, incorporate feed enzymes and have greater flexibility with diet formulation.  Prior to the installation of the feed mill, we were feeding oyster shell at 25 kg/tonne to the birds starting at 49 to 50 weeks of age to improve shell strength, but the new feed mill was not set up for this type of addition.  Around the same time, research on a product called Egg Shell 49 in the Czech Republic showed that it was found to be effective in improving shell strength after 49 weeks of age. In order to simplify things in the mill, it was added to a “Pak” with other Alltech products (including De-odorase and enzymes) into the feed when the birds were placed (week 17).

During this time Dr. Steve Leeson from the University of Guelph began work on redefining trace mineral requirements.  He demonstrated that layer performance could be maintained through the first cycle at levels comparable to that on traditional inorganic trace mineral levels, but with substantially lower levels when the minerals were provided in a chelated form.  There was even some indication that the lower level of supplementation had a positive influence on shell quality.  Thus, it was decided to replace all trace minerals in the diet formulation with this form of chelated trace minerals. 

There was the question of what to do at 49 weeks of age when the Egg Shell 49, based on Bioplex minerals had been added, to slow the rate of increase in cracked eggs.  It was decided to defer this decision until the flock reached that point.  When the time was reached an examination of the records showed that the per cent cracks was half that of the pervious flock.  Based on that, no change was made — Egg Shell 49 was not added. Cracked eggs were tracked on a weekly basis to the end of lay. 

Although well below the previous flock, there was still an upward trend in per cent cracks after 50 weeks of lay and the same pattern was starting to show with the subsequent flock.   Dr. Leeson’s work had shown that performance improved with low levels of supplemental trace minerals.  Adding Egg Shell 49 would cause a large rise in supplemental levels.  Together we decided to add 50 per cent more of the chelated trace mineral after 50 weeks of age to the levels then supplemented with Bioplex, but below that if Egg Shell 49 were added. This compromise worked as the upward trend was no longer evident.   This has become standard practice, and the pattern of increasing cracked eggs after 50 weeks is no longer is seen.  By using lower level total replacement with chelated trace minerals, the level of these minerals in the manure/compost was reduced, a very important consideration on a sustainably operated closed-loop farm.

About the same time there was a regulatory change that disallowed on-farm egg washing.  The egg grading station, located about three to four hours away was downgrading a substantial number of “dirt” eggs.  The thought pattern was, if the gut was healthy, fewer “dirts” would occur.  Bio-Mos, a yeast-based product was added and a decrease in the number of “dirts” was observed.  It was also noted that cracks also decreased.

The flock record (see Table 1) speaks well for the program.  However, this level of performance is based on many factors.  The feed additives in the Pak are an important part, but not the total story.  Our work together on closely monitoring the nutrition and feeding program of the birds has played an important part, and flock records are reviewed on a weekly basis.  Formulation is changed to optimize egg size for age of bird.  The replacement pullets are fed to the breeders’ recommended body weights; pullets below recommended weight for age tend to produce more smaller eggs early in lay, while pullets above recommended weight for age tend to produce larger eggs late in lay. 

The replacement pullet grower uses the same nutritionist and thus the programs are coordinated.

Several years ago, during a time when the mill was being serviced, whole kernel wheat was sent to the mixer and consequently used in the feed.  It was noted that the number of shell-less eggs decreased when the non-milled wheat was fed, and increased once the wheat was ground. Based on this, the standard practice was not to grind all the wheat.  However, grain prices changed and the grain rations became all corn, and shell-less eggs again increased. 

Although the numbers were not large, it was an interesting observation.  Changes were then made to the screen size used in the hammer mill.  It was found that by using a half-inch screen in the hammer mill there were minimal shell-less eggs, greater mill throughput and less electrical usage. 

This is not surprising since broiler growers have for many years fed some whole grain with their feeds, and this has been shown to improve digestion and improve gut health.  The same should therefore apply to layers.

Controlling egg size late in lay has been a struggle.  Fibre is a forgotten ingredient, and often nutritionists pay little attention to crude fibre levels.  In the past, oats and barley were common ingredients in layer rations, but with modern transportation there has been a movement away from these to corn.   However, control of bodyweight and egg size late in lay has led to the consideration of using lower energy ingredients.  It was found that utilizing oats or barley resulted in a lowering of the energy levels in the ration without the bird compensating with a greater feed intake.  Having the barn at a higher temperature is also helpful. Oats are grown on the farm, and they are now used in the rations.  The straw is used as a carbon source in the composter, which is important in a closed-loop sustainable farm.

Flock 25 (see Table 1 below), the 25th flock since the barn was built, is the best flock to date at Coburn Farms. Flock 26 results so far show that it is on track to beat flock 25.   The innovations made on the farm over the last 26 years will continue, and it’s likely that more will become part of the standard practice on the farm.

Table 1: Flock Data Report, Coburn Farms 2010/2011 (Flock 25)


Birds Housed



789 (3.1%)

Birds Shipped


Feed Delivered

932 Tons

Feed per bird per day

105.5 grams

Feed per dozen eggs

1140 grams

Water consumption

80.87 L/bird

Eggs per hen housed


Total Dozens


Average Inside Temperature

26.8 C

Average Outside Temperature

6.4 C

Egg Size and Downgrade Report


Large and Up
















Total Downgrades




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