Why it’s critical to weigh your birds from day one
A farmer recently posed an important question to me, what is uniformity in broilers? For the benefit of all poultry farmers, I will address this issue today.
Uniformity in broilers is the measure of extent of variability of sizes in a flock of broilers. It is the wish of farmers to grow all their birds within a specific weight band for the market that they target, harvest them at a go and have ample time to clean and sanitise the units for next placement.
For best results, sampling of flock weights and uniformity must be done at day 1, 7,14,21,28 and every day there after, till slaughter.
Demand for broilers
As we approach the festivities, demand for broilers will increase and they will be supplied and sold based on weight at the point of sale.
Most Kenyan retailers, butcheries, restaurants and brokers will be demanding dressed chickens weighing between 1.25 and 1.35 kg. This is the fast-moving range and is achieved by attaining alive weight of 1.65-1.75kg. Any weights outside this range will be hard to sell or if you do, at lower margins.
It is worth noting that when farmers buy day-od chicks from hatcheries, they weigh between 40 and 42 grams, but at cropping some farmers end up with some birds weighing 1.35kg while others are at 1.85kg at slaughter on the same feed and in the same house.
To avoid these surprises, farmers need to monitor uniformity as from day one all the way to slaughter and create opportunities to adjust in their growth management programs to achieve more birds in the desired range of 1.65-1.75kg.
How do you measure uniformity?
This can be done through 1) Visual or subjective evaluation depending on who is judging or inspecting, 2) by weighing birds 3) by calculating coefficient of variation (%CV) and finally 4) by weighing carcass yield after slaughter.
Every method has its advantages and challenges and an experienced broiler farmer can assess with good certainty by flock appraisal. Weighing birds and calculating percentage of birds +/- 10 per cent of the mean weight is the most popular. In large operations, percentage coefficient of variation and carcass yields are more frequently applied.
How do you calculate percentage uniformity of a flock of 1,000 birds by weighing method?
I have used this method for a long time and I highly recommend it to farmers. The aim is to weigh five per cent sample (50) of the total population. Make an imaginary division of your flock unit into five (the four corners and the centre).
Pen off randomly about 10 birds in each location, weigh each bird and record, be careful not to overcrowd birds and handle them humanely. Do this for all the five locations. Add up all the weights and divide by the total number of chicks to get the mean average weight. Then count the number of birds with weights within +/- 10 per cent off the mean average weight. If for example 45 birds are within this range of mean weight, your uniformity is 45/50 X100 per cent gives you 90 per cent uniformity. Any uniformity above 85 per cent is very good.
The farmer must aim at attaining feed conversion ratio of 1.7 (total kg of feed fed to attain 1kg of live weight), average daily body weight gain of 50g and not more than 5 per cent mortality loss at depletion in 35 days is a good performance. This will be achieved by choosing the right breed, quality diet and all round bio-security, housing and comfort to your birds.
[For more info contact Dr Watson Messo Odwako Head Vet @ Kenchic]