Size difference in your poultry will give slim your earnings

Saturday September 25 2021

Uniformity: Because the percentage of carcasses within the desired weight range is a very important measure for a processing firm, when a broiler flock is processed, a complete histogram on the range of carcass weights is generated. In the end, uniformity is a good indicator of the production process. PHOTO/TOBBIAS JOLLU OWINY

By Tobbias Jolly Owiny

At Ms Imelda Aketowanga’s poultry farm in Anaka, in Nwoya District, three workers are deployed inside the perimeter fencing to ensure hygiene, safety and proper feeding among the birds.

Their daily routine ranges from stuffing the flood point at the entry with disinfectants to ensure that the workers and any other visiting farmer who enters the farm are clear of possible infection to the birds.

They also make sure the water troughs and feeders are stuffed with enough feed and water besides treating and ensuring that every bird is healthy and safe.

During the technical visit by a combined team of researchers from Makerere University and Seeds of Gold to the farm, everything appeared to be perfect until one of the visitors noted something abysmal.

Poor chicken growth 
Among the 2,800 three-week-old birds stuffed inside two separate units, Ms Aketowanga appeared not to have realised or ignored that other birds appeared to be one-and-half weeks younger than the rest even when they are of the same age.

While the majority of birds appeared to be two weeks away from being ready for the market, others needed another month (based on physical appearance) to gain the weight equivalent to the rest since they appeared smaller and lighter.


But she is aware that her buyers select based on stock uniformity, which she admits they usually assess visually and subjectively by weighing each bird.

However, on one hand, she is not aware that the level of uniformity dictates the final result; implying that poor flock uniformity goes hand in hand with delayed growth, and rejects.

“These were birds stocked on the same day and have all been subjected to the same feeds and same environment but the variation in the sizes always confuses me,” she said.

To satisfy the demands of the modern distribution network, bulk buyers that process and supply dressed chicken require uniform flocks with the correct average body weight. 

Causes of variations  
Ms Aketowanga’s dilemma is not limited to her. At another farm at Pece Pawel, in Gulu East Division, Gulu City, Ms Jacky Arach is experiencing the same situation.
She blames the variation on the supplier whom she said was supplying her for the first time.

“Somehow I think my problem stemmed from the dealers who supplied me since I did not go to the farm where they do incubation and perhaps they served me rejects,” Ms Arach said.

Broiler flock characters
All technical or health problems, starting from the day-old breeder up to the broiler delivered to the processing plant, impacts the broiler uniformity at the time of slaughter.

According to Mr Richard Ojera, a specialised breeder, several factors can explain why the sizes of birds in a flock may vary.
“Before reviewing the principal factors affecting uniformity, it is necessary to define the characteristics of a “standard” broiler population because there are several reasons that explain why sometimes minority or majority weights of the birds are systematically inferior to the average weight of the flock,” he says.

According to him, a key reason is purely statistical, “this is because a flock of “as hatched” broilers consists of equal numbers of males and females, each with their level of uniformity.” “Upon achieving the bodyweight target with regular weekly weight gain during the first 3-4 weeks of their life, the subsequent feed management and the correct level of sexual maturity for the breed are the most important criteria that will determine the uniformity of the chicks,” Mr Ojera says. 

“That will require good brooding conditions, moderate feed restriction before four weeks, blackout rearing and sufficient feed equipment,” he adds. Another factor Mr Ojera attributes to the disparity is the incubation conditions and mixing of the chicks.

“Trying to achieve maximum chick uniformity by weighing the eggs from the many different aged donor flocks or by storing eggs from a few breeder flocks, does not guarantee good final flock uniformity,” he says. He says eggs that are stored for more than seven days and eggs from very young breeder flocks require longer incubation time than the others. 

“The first chicks to hatch risk dehydration, waiting for the completion of the hatch. On the other hand, experience shows that mixing of the different “donor flock” micro-organisms may compromise the sanitary level of the whole hatch.”

First-time layers 
Mr Denis Olam, a commercial poultry breeder in Gulu City says he usually discourages raising a flock from first-time layers and those about to be laid off.

“If the birds were hatched from the eggs laid by hens that started laying for the first one or two weeks, it is not advisable to hatch the eggs since their performances is not always good and also hatches from birds that are about to be laid off, do not do well,” Olam advises.

Ideally, Olam says mixing chicks from young breeders and those from breeders older than 35 weeks destroys uniformity. 

Furthermore, the absence of pre-warming for the eggs, especially when they have been stored for long periods, increases the hatching time between the first and the last chicks, with the risk of dehydration of the early hatching chicks.
The temperature requirement of the chicks from young breeders is about 2°C higher than those from older breeder flocks. Whatever temperature is used, some of the chicks will be either under or overheating. 

Mr Olam says the different sizes among birds of the same age may also arise due to agronomic practices.
“When it comes to management, sometimes when a farmer mixes their feeds, they don’t do it so well where you find the levels of carbohydrates or proteins are higher than each other, and it impacts on their growth. Sometimes diseases attack and they succumb so badly due to weak immunity,” he says.

Look out for
Inadequate brooding conditions are usually the first cause of poor uniformity. During this period the daily weight gain is considerable. During the first 10 days, the chicks increase their weight by 20 per cent per day compared to 4 per cent between 30 and 40 days, provided that they do not have to struggle to survive. 

When chicks are struggling to survive, they use a small amount of available energy to maintain vital body functions. 
It is always useful to remember that chicks: cannot regulate their body temperature before 10-15 days of age, are stimulated to eat by light, and limit their intake when access to water or feed is difficult.

Sanitary problems 
Sanitary problems have a variable impact on uniformity. For example, when the highly infectious Gumboro disease affects a flock at 15 days old, the survivors are generally uniform.
The only explanation is that the birds with poor immunity are dead and that the others have all or nearly all been affected with the same intensity.

In contrast, a strong E. coli or other early bacterial infection has a very strong effect on uniformity, making it essential to react quickly in the case of morbidity or suspicious mortality in the first few days of life.