Preparing for depletion: feed withdrawal, catching, transport and quality at the processing plant

The last days before depletion

• Set the slaughter date and time with the processing plant or the buyer: everything else is calculated from that time.
• Check the records: for every medicine or vaccine given, the withdrawal period stated by the veterinarian or on the leaflet must be over before slaughter, so that no residue remains in the meat.
• Shorten the night by one hour a day over the last 5 days (5, 4, 3, 2 then 1 hour of darkness): birds less used to the dark are less flighty at catching.
• If catching is done in daylight, raise the light intensity to 10 to 20 lux 48 hours before, to get the birds used to it.

Source: Cobb.

Feed withdrawal: 8 to 12 hours

Feed is withdrawn 8 to 12 hours before slaughter. The aim is to empty the digestive tract: after 8 to 12 hours of fasting, the intestine is almost empty yet still strong enough not to tear during evisceration. This stops feed and droppings from contaminating the carcasses. The effect of the fast on live weight is small. Local regulations on fasting time must also be respected.

• The 8 to 12 hours are counted up to slaughter, not up to catching: catching, waiting and transport are part of it.
• Water stays available until catching starts.
• Record the date and time feed was withdrawn.

Source: Cobb.

Catching

• At night if possible: the birds are less active.
• Lights dimmed at catching time. If they cannot be dimmed, blue or green lights calm the birds.
• Remove or raise any equipment that gets in the crew’s way (feeders, drinkers).
• Keep good ventilation during catching: birds bunched together heat up quickly.
• Between two loads: turn the lights up, give water back and walk gently among the birds.
• In daylight, dark strip curtains over the doors keep the house dim: the birds stay calm and air flows better, with less risk of piling.
• The farmer or technician stays present throughout catching to make sure the right handling is followed.

Source: Cobb.

Crates must be clean and filled according to the manufacturer’s recommendations, with fewer birds per crate in the hot season. Transport takes place in the cool hours (lesson 6 of this track).

Partial depletion (thinning)

In some countries, more chicks are placed and the flock is reared to two selling weights: at the first weight, 20 to 50% of the birds are removed for customers who want lighter birds; those that remain then have more space and are reared heavier. Stocking density must stay within the limits at every stage (lesson 9 of this track).

• On the first night after thinning, give the remaining birds 6 hours of darkness again.
• Crates and vehicles are washed and disinfected before entering the farm, and the catching crew wears protective clothing: with partial depletion, birds stay in the house and can be contaminated.

Source: Cobb.

What the processing plant tells you

Yield is the share of live weight that remains after slaughter: carcass weight ÷ live weight × 100. It depends on the processing plant and on how the carcass is prepared: ask the plant or the buyer for the weight of each load and the downgrades, and record them with the start and finish times of catching. A well-timed fast and catching without damage are the farmer’s two levers.

Source: Cobb.