Effective brooding grows in importance

Brooding and feeding were just two of the subjects tackled at the first ever Northern Broiler Conference, as Philip Clarke reports

Effective brooding of the new arrivals to a broiler shed has never been more important, as growing times have shortened and the brooding period takes up an ever greater proportion of the bird’s life.

Addressing the Northern Broiler Conference in Bury, Greater Manchester, broiler specialist Richard Weatherly of Cobb Europe explained that, in 1978, it took on average 63 days for a bird to reach a target slaughter weight of 2kg. The first seven days of brooding amounted to just 11% of the bird’s life.

But by 2012, the number of days to slaughter was just 34 days, meaning that the brooding period now accounted for almost a quarter of the bird’s life.

“There is no room for error at all,” Mr Weatherly said. “There isn’t time to catch up if we make a mistake during the brooding period.”

Internal temperature

Brooding was all about attention to detail, starting with monitoring the bird’s internal temperature, he said.

“The temperature will not be the same all the way through the bird’s life. After three or four days it will probably be between 41C and 42C – though 41.5C is the maximum I’d really like to see. But for the first three days of life, we’d like to see the rectal temperature between 40C and 41C.

“You should check this several times: as soon as the birds enter the shed, again in the evening, and after 24 hours, to see how the bird has adapted to its environment.”

Mr Weatherly demonstrated that there was a clear correlation between internal chick temperature and intestinal development. Birds that were too cool had to use more energy to maintain body temperature and less to grow. “Not only is there less intestine, but it also means that the villi in the intestine will be reduced, and so there is less surface area for nutrient absorption.”

This in turn would lead to issues of lack of uniformity later in the flock’s life.

External temperature

Achieving good chick temperature was primarily influenced by the ambient, litter and floor temperatures in the shed, Mr Weatherly explained.

“Through our research we know that the concrete temperature should be 28C and the litter temperature should be about 32C.”

If the floor and litter temperatures were too cool, birds that were sitting would soon become chilled.

The temptation would be for the farmer to then increase the ambient temperature. This would help those birds that were sitting. But birds that were active would be too hot, leading to dehydration and poor uniformity.

The key to getting the right floor temperature was a pre-heating time of 48 hours. This was not always easy with the short turnaround times typical on many units. Producers should therefore think of their concrete floors as a storage heater. Simple things such as closing the door during mucking out would help retain warmth.

“Another very important fact is the heater capacity of the house. This should be 0.05kW/m cu. If you work it out for your house and it is less, it is going to be difficult to get uniform temperatures and also to get the floor to 28C.”

Mr Weatherly recommended that stockmen paid very close attention to chick behaviour to tell them if the building was set up properly, more so than computer readouts. “Every time you go in the house they should be eating, drinking, playing, talking and resting.”

If birds were avoiding a particular area, it was obviously a draughty patch. This was seen increasingly with windows that may have been poorly insulated or badly installed.

Feed and water

Apart from temperature, early feed and water was critical to successful brooding. Failure to achieve it would result in reduced weight gain, higher mortality and poor flock uniformity.

“We recommend that 50% of the brooding area is covered with paper, placed either side of the drinkers. And the amount of food that you put on the paper should be a minimum of 65g a bird.”

The birds would have the best feed conversion ratios of their lives in the first week, with each gram of food leading to 1.3g of bodyweight. Those that had good feed and water intake would also have higher internal temperatures, leading to healthier, more uniform birds.

Of the total energy intake in the first week, just 20% would be going for maintenance and 80% for growth. “We don’t want to be playing catch-up for growth at four weeks of age when it’s very expensive to do so. Seven-day weights are key.”

The chicks were born with a very immature gastrointestinal tract, Mr Weatherly explained, which meant they could not convert carbohydrates and proteins very well.

The aim was to achieve a 600% increase in the size of the intestines in the first seven days, otherwise the chick would use the yolk sac as a feed source, rather than for developing its immune system.

Lowering feed pans closer to the floor was a good way of encouraging more intake.

Mr Weatherly also stressed the importance of water access. “The crop fill that we require is 95% of both feed and water 24 hours after placement.”

This would mean ensuring that each chick took in 1ml an hour for the first 24 hours – equivalent to over 50% of its bodyweight.

Lighting

Another key element was getting the lighting pattern established. Mr Weatherly recommended introducing the first four-hour dark period at about 5pm in winter, when it was getting dark naturally.

The lights could come back on again at 9pm, when the stockman went in to do the night check, followed by another two-hour “off” time. “Once we’ve established the dark time, we should never change it throughout the life of the flock.

“The bird has a very good body clock and it knows just an hour before dark to ‘crop up’, to get ready for the dark period.”

Birds would quickly develop a tendency to eat more at the beginning and end of each day. Any changes to eating times would increase the stress levels and could impair growth.

The aim of brooding

• Accelerate growth to achieve the first 100g of bodyweight
  
• Promote skeletal and cardiovascular development
  
• Stimulate early feed intake
  
• Ensure flock uniformity
  
• Ensure temperature regulation
  
• Maintain good air quality

Keys to successful brooding

• Concrete floor temperature of 28C
  
• Internal chick temperature of 40-41C
  
• Pre-heat for 48hrs
  
• Heater capacity 0.05kW/m cu
  
• 600% intestinal growth in first seven days
  
• 50% of floor area covered in paper
  
• Minimum 65g a bird of feed on paper
  
• Crop fill of 95% by 24 hours after placement
  
• Water intake of 1ml a bird an hour for first 24 hours