Poultry breeding companies have long preached the value of uniformity in improving performance on the farm but now it is the processing plant that is reaping the greatest benefit or paying the penalty for poor uniformity.

Customers for chicken meat fast-food companies, food-service and retail operators have tight purchasing specifications and if the bird size in the processing plant does not match their requirements, output from the processor will be downgraded to a less profitable product. Depending on the size of the integrator or processing company, there may be additional expense in shipping to another plant where the bird size better fits the desired product requirements.

For years, breeding companies have striven to select birds for improved uniformity within their breeds. Initial crosses in a programme will normally exhibit greater variation and lack uniformity. Enhanced uniformity comes from consistent, careful selection of pure lines over many years to achieve breed goals. The selections depend on regular and managed analytical programmes to achieve steady progress in priority traits.

Furthermore, these companies have technical service teams to assist and guide customers to realise the genetic improvement and potential on offer. Their after-sales technical service helps customers manage the variables of production which may be unique to their facilities in order to achieve the improvements on offer.

Natural sexual dimorphism overcome

The natural lack of uniformity in bodyweight between the sexes in chickens has challenged breeding companies to reduce this sexual dimorphism. This difference in size between males and females has often led hatcheries to employ people to sex chicks, so that the sexes can be grown separately to achieve the desired weights.

These size differences have now reduced to the point where many countries have moved to an as-hatched' grow-out programme, removing the need for the onerous and expensive practice of sexing chicks. In the USA, for example, over 90% of the industry uses as-hatched programmes and it is rare to find sexing nowadays.

Variation leads to downgrading

In poultry processing, investment in automation has been accelerating due to the rising cost and decreased availability of semi-skilled labour. This has imposed new constraints. During the broiler growing period, a multitude of factors influence bodyweight, size and uniformity, yet during automated processing, equipment has to be set for a specific carcass size or a defined range of sizes to meet tight specifications. While there is a certain tolerance in bird size that the equipment will accept, the equipment will not operate efficiently in handling overly small or large birds in flocks with wide variation. Damage to some carcasses will cause them to be downgraded, lowering their value by more than 40%.

Losses in the stunner, scalder and eviscerator

At the processing plant, the first stage is the stunner. If uniformity is poor, small birds may miss stunning completely and may not be slaughtered or bled properly, causing them to be classified as rejects due to an unacceptable colour and hence, lost as waste. These represent expensive losses as the birds make up part of the weight already paid to growers.

Additionally, a flock with excessive numbers of small birds will encounter further problems during scalding. Temperatures in the scalding equipment are set for a specific size of bird, and small ones may suffer over-scalding. This, in turn, may lead to denaturing of protein and poorer quality meat as well as effectively rendering the fat beneath the skin, which further compromises product value.

At the evisceration stage, uniformity is even more important nowadays due to the advent of high-speed evisceration equipment handling 140 birds per minute more than double the speed of earlier equipment. Along with the advantage of high speed come even tighter bird size specifications to ensure optimal processing. While this equipment will accept a normal range of bird sizes, if variation is too large the birds falling outside of this range will suffer damage from machinery such as the eviscerator, vent cutter or hock cutter. This contributes to further value losses.


Product sizing

After evisceration, uniformity is a key factor in product sizing. Birds that are either too large or too small cannot be used for premium-priced ranges and will finish up as much less profitable catch-all' sized products or, as we suggested earlier, be shipped at additional expense to a location that can utilise them.

A good example of the impact of sizing is the eight-piece, cut-up, fast-food product. Leading fast-food companies place very strict criteria on bird sizes allowed to be cut for their product. Their prime requirements are for uniform cooking times for the different cuts, uniform appearance and portion-control. Most processing plants designated for fast-food products prefer to cut up chicken for multiple customers with slightly different weight ranges, which overlap and so offer a wider weight range for the plant to handle. Even with this wider target, a flock with poor uniformity will have a large proportion of birds falling outside the range.

This segment of the industry is well established and requires large numbers of birds to be processed to supply the multitude of chicken fast food outlets within their organisations. The premium price paid for birds meeting the desired product specification is sought after, providing attractive margin products' for the processor. Within a large multi-plant organisation serving a range of fast-food products, a 1% difference in uniformity may have a US$100,000 to $120,000 impact on annual revenue.


At the other end of the product scale, uniformity also has value in the processing plant for a large bird deboning operation. These companies are encouraged to automate their processing operations due to acute shortages of labour, moving to mechanical deboning rather than traditional hand procedures. This trend places additional emphasis on uniformity in the quest to optimise yield and to use appropriate machine settings.

While a manual deboning line can adjust to every single bird as it rides the cone down the line, the mechanical deboning machine must be set for the expected bird size. The more uniform the bird size, the better the machine can be fine-tuned to remove the maximum amount of breast meat, so optimising yield. With poor bird uniformity, the deboning machine will leave premium breast meat on the carcasses of larger birds and may leave bone fragments in the meat from smaller birds. Any meat left on the carcasses can be scraped off and sold as trim.

Last year in the USA, downgraded product sold on average for 45% less than premium-sized, skinless and boneless breast meat. Breast meat with bone fragments will be detected and downgraded or at least, it will need to be re-worked manually to remove the bone fragments. This adds to the cost and detracts from the investment in automation.


Uniformity also has an effect after the deboning process, when portioning equipment is used to cut product from the deboned fillets. The emergence of highly sophisticated breast meat portioning technology has encouraged many companies to grow larger birds, improving efficiency and portioning the breast fillets into multiple, prime, whole-muscle products. The cut patterns of the portioning machines must be set up very precisely to maximise the prime product yield of every fillet run through the equipment. Product falling outside the cut-pattern' can only be sold as trim, resulting in over US$1.00/lb (US$2.20/kg) reduction in revenue and major decrease in potential profitability.

Uniformity and processing bottom line

When asked about the value of uniformity in the plant, processing managers typically assess it as critical', the single biggest improvement (in our business)', scores a high 4 to a 5 out of a total score of 5' and getting more birds in the fast-food window is worth US$0.22-0.24/kg in revenue'. This is well recognised within the processing facilities.

Now the immediate opportunity is to exploit the value of uniformity through selecting breeds that can achieve the highest standards of uniformity, even better flock management on the farm, and fuller use of automation and advanced cutting technology to more of the product that the customer requires.

This is the formula for healthier returns all round.