Set on the floodplains of Holland, breeding firm Cobb has developed a trial farm where 24 pens of broilers can be reared in the same environment. Antony Taylor and Martijn Gruyters share their findings.
Assessing bird performance in real world housing and management conditions has become an important part of all modern breeding programmes.
Being able to have many replicates of treatments, and with uniform environmental conditions throughout the building is key to a proper assessment of genetic potential.
So what have been the main lessons for Cobb for optimising welfare and performance in commercial broilers from their Dutch trial farm?
Uniform heating capacity/floor temperature
It is clear that heating capacity and ventilation control are two critical factors. That is why the farm boasts five 100kWh heaters and a heat exchanger.
The policy is to set a minimum concrete floor temperature of 28C and minimum litter temperature of 32C in each area and pen of the building.
Trials have found that:
- Concrete temperature of 28C-plus at placement results on average in a reduction of seven-day mortality of 0.35%, and an increase in seven-day weight of 8.8%, when compared with lower temperatures.
- A litter temperature above 32C at placement results on average in a reduction of final mortality of 1.25%, improved feed conversion of 3.24%, and lower rejects by 13.2%, compared with litter temperatures less than 32C.
Simmes trial farm
- One house with 24 pens
- Latest in heating, ventilation and computer control
- Capacity of up to 40,000 birds
- Feed and water rations can be controlled for each pen
While the increased heating capacity results in higher initial costs, this has achieved lower mortality, better growth rate, lower feed conversion and better bird quality, which after four cycles has easily paid for itself in production efficiency.
This heating capacity allows not only uniform and correct house temperature to be achieved, but also, by allowing more ventilation or air exchange to take place, maintains ideal air quality and optimum temperature for the birds, regardless of their age or outside environmental conditions.
Enough feed on paper
The floor area should be 50% covered in paper. It should have the strength to withstand the activity in the house for at least four days and the ideal quality is 47-55gsm at 55-68% brightness – newsprint paper.
The amount of feed on the paper should be a minimum of 65g a bird; and chicks from a young parent flock should have a minimum of 75g per bird, available from placement. If supplementary trays are used (45cm diameter), they should be distributed, allowing one for every 50 chicks.
The placement of the paper is also important: it should be placed either side of the nipple drinking system, but not underneath.
The Simmes family manage the facility, sited on their farm, for Cobb.
Clean water readily available
The quality of the water for the birds is as important, or possibly more so, as the food – it’s often the “forgotten nutrient”.
Therefore, chicks at placement need to have access to water at a temperature of 10C-14C – extremely important but difficult to maintain in a house with an ambient temperature of 30C-33C in the first seven days. As well as the temperature, keeping a low flow rate is crucial.
At this early stage, the system should be flushed at least three times a day to reduce the biofilm build-up and lower the water temperature.
Water quality should also be checked – both its pH and oxidation reduction potential (ORP).
The pH should ideally be below 7.5. Anything above 8 will be too alkaline and result in reduced water consumption due to its bitter taste to the bird.
If using chlorine for a sanitiser, then the lower the pH the more successful the chlorine will be with a minimum pH of 5.5-6.
Free chlorine is the amount of chlorine – a strong oxidising agent – available to act as a sanitiser.
ORP is measured in millivolts and the minimum acceptable level is 650mV. Water without a sanitation programme could be as low as 50mV or even a negative number.
The best way to deliver water is through a nipple drinker, allowing 10-12 birds/nipple, with an ideal flow rate of 80ml/min. The flow rate and drinker height should be increased with growth.