Egg handling before hatching

Conteúdo disponível em: Español (Spanish)

What starts out as a fertile egg on the breeder farm must end up as a healthy chick on the broiler farm. After the hen lays the egg, its quality can only worsen, it will never be the same, so we must pay attention to the flow chain between the laying of the hatching egg and the start of the incubation.

Most of the causes that can influence the variability in hatchability or quality losses of the chick are caused by inadequate management of the egg handling processes pre-incubation.

The nesting box and the ribbon will influence:

• Broken, cracked, dirty eggs, laying on the ground
• Environmental temperature
• Hatchability and setpoint temperature

Broken, cracked, dirty eggs laid on the ground:

• Increases bacterial contamination
• Increases the risk of “exploding” eggs
• Decreases chick quality
• Decreases hatchability

• Keep nests closed until the first eggs appear
• Keep nests and slats clean, in good condition
• Close the nest boxes 1 h before the lights go out and open them 1 h before they come on.
• If there is a high rate of laying, open (2-4 hours before turning on the lights) Low slat height (from ground level in nests with pits up to 30 cm from the ground) Slats inclination <5%
• Maximum 40 females / linear meter
• Feed for the first 30 minutes after power on or 6 hours after power on
• Access to water at all times from the start of feeding
• Do not use electric shepherds
• Monitor behavior during feeding
• Uniform light distribution with correct intensity (minimum 40-60 lux)
• Eliminate shady or dimly lit areas
• The intensity at the entrance to the nest should be lower than that of the bed area
• Ventilation systems must maintain temperatures between 18 and 24 ° C
• Avoid drafts in nest box area
• Uniform distribution of ventilation throughout the hall
• Encourage birds to climb the slat
• Tour the house 10-12 times/day during the first 3 weeks of laying.
• Move birds that are trying to nest
• Carefully lift birds that are trying to nest on the ground and place them in a nest
• Accustom the birds to the noise of the nest.
• Running it several times a day, even before the first egg is laid
• Eggs can be collected up to 25% of laying in the afternoon, preferably once the nest is closed (most are commercial)

Lots of floor and dirty eggs produce “exploding eggs” and spread contamination in the incubator.

They also disperse contamination to the chick, which increases chick mortality in the broiler farm. It is recommended not to incubate dirty eggs or floor eggs, yet work must be done to improve management to reduce this incidence. Normally, it is not economical to hatch them (when the chick price is high or production is insufficient).

The egg comes equipped with many defense mechanisms to fight against contamination:

• Cuticle
• Shell
• Membranes
• Antimicrobial proteins in albumen

Many of the techniques used to disinfect can impair many of these mechanisms or interfere with the functioning of the shell. We can use various techniques to get a “clean” egg, but what we simultaneously risk making things worse. Sandpaper, sponges, damp cloths used on farms will help make them LOOK clean but…in reality they get contaminated quickly. In addition to contaminating them, we cover pores making the incubation process more difficult for the embryo. Floor or dirty eggs that are washed present hatch rates of up to 20% less than those that are clean, and up to 7 times more chick mortality at the end of the first week (4-7%).

It is a room that must be dedicated solely and exclusively to the storage of the eggs. It must have a storage capacity of several days and air conditioning capacity between 18 and 23 ºC.

SPECIFICS:

• Good insulator
• Air curtain at both entrance and exit doors of the room.
• Fans to evenly distribute air.
• Thermograph to check temperature fluctuations.

When we stack the eggs in cartons, it is vital to leave space between the stacks and place them evenly. If we make very large stacks, in a very short time the inner temperature of the stack will increase and will cause heavy incubation losses.

Eggs that have cracked shells or noticeable fissures should not be incubated, since the embryo will die of dehydration. Many times, micro-fissures (hairline cracks) are not detected and these eggs go on to hatch. Of course, the hatchability of these eggs is low and the chicks hatched from them show a mortality up to 4 times more (5-7%) by age 14 days, than those hatched from clean eggs.

In these cases, the weight losses during incubation are greater than in normal circumstances, producing smaller chicks and with higher levels of contamination. These issues may be related to:

• Farm equipment
• Layers, tapes, centralized collection system, packing machines, …
• Chilled very quickly
• Transport
• Shell thickness
• flock age
• Nutrition

We must make checks after each egg handling process and note the number of eggs with micro-cracks or cracks. If the values are too high at any time then we must take measures to reduce them.

Today, the necessary technology is already available to discard these cracked eggs and prevent their incubation.

The distances between breeder farms and hatchery can vary heavily, but what is certain is, in the vast majority of cases, the method of transport is by truck. Maintaining the same environmental conditions between the truck and the farm’s egg store is important to conserve hatching potential. Normally the temperature of the truck should be the same as that of the farm storage room.

We must avoid bumps between egg carts and strong shaking, trucks must have a good suspension system and fix the carts well inside. The accesses to the farms and incubators must be in the best possible conditions.

We must use temperature recorders during transport to check the temperature fluctuations. Likewise, it would be advisable to measure the external and internal temperature of several eggs from different locations to verify the temperatures.

After transport, the eggs should rest at least 12 hours before starting the incubation. The cleaning and disinfection of all the elements involved in the transport of eggs is of vital importance to avoid the spread of pathogens.

Cooling of freshly loaded eggs should always be avoided, especially if the truck is already loaded with eggs from other farms. When we cool the egg, the volume of the albumin and the yolk is reduced, so the volume of the air chamber increases which allows the entry of outside air (contaminated or not) by suction inside the egg. Conversely, if the temperature of the truck is higher than that of the farm’s storage, there is a risk of “sweating” of the egg (condensation that forms when the coldest surface of the egg is exposed to the hottest and/or humid air). Even when the temperature is the same between both ends, the same “sweat” can occur during loading or unloading if the environment is excessively humid, in which case it is best to increase the temperature of the storage from the recommended 18-20 ºC to 23ºC, or preheat them to the same temperature of 23ºC four hours before eggs are moved.

“SWEATING OF EGGS”

It occurs when there are increases in temperature and/or humidity:

• From storage to truck
• From the truck to the hatchery
• From the hatchery’s storage to the incubator

If they have sweated, let them dry before:

• Fumigating them
• Moving them to a cooler room
• Put them in a room with air movement to facilitate drying if this happens.

Egg storage conditions The binomial of egg storage temperature and days in storage and its relation to hatchability loss and chick quality, as well as the SPIDES technique together with new guidelines for handling hatching eggs is a topic that deserves its own chapter.