Hatching Egg Care
Hatching eggs suitability:
The objective should be to get the maximum of hatching eggs, which means they are clean, free of cracks and of a minimum weight. We recommend incubating only eggs of a minimum individual weight of 52 g and from breeder flocks that are at least 24 weeks of age. At the beginning of lay, eggs weighing less than 52 g should not be set, as the quality of the chicks hatched from these eggs will not be suitable. Chick quality will depend not only on egg weight and breeder age, but also of female breeder’s growth at the onset of lay. To control egg weight throughout lay, and especially to avoid too large eggs at the end of production, the following points must be considered:
Pullet weight at 5 % of lay: average egg weight is largely determined by the pullet’s
weight on coming into lay. Too heavy pullets at onset of lay will lay larger eggs throughout flock lifetime.
Oil content in feed: when the oil in the diet is increased, birds increase their feed intake and this increases egg weight. We advise limiting feed oil content or replacing it by saturated fats.
Amino acids: reducing the amino acid level in the laying diet reduces egg weight but also brings about a sharp reduction in lay rate. We therefore advise against any change in amino acid levels during lay.
Energy intake : if necessary, from 40 weeks of age, a slight reduction of about 50 Kcal in energy level could be considered to stabilise egg weight, as long as those changes in feed composition do not lead to under-consumption,
Temperature: too low house temperature causes over-consumption and consequently increases egg weight, so it should be avoided.
Nests should be equipped with a closing or ejection system to avoid nest staining at night. The nesting material must be clean and without mould and be changed regularly. In automatic nests, plastic bottoms must be washed regularly. Collection of eggs to be used for incubation should be done at least 4 times per day; increase this rate in hot or cold weather. Hands should be frequently re-sanitized during egg collecting time and whenever returning from other tasks.
Floor eggs should not be used as hatching eggs. However, due to economical constraints, if they are clean and collected quickly, they can be used for incubation provided they are disinfected quickly after lay.
Hatching eggs must be disinfected quickly after collection, within 3 hours after being laid. Various methods are available, but fumigation with formalin remains the best technique when regulations permit.
The efficiency of fumigation depends upon following clear rules: - Disinfect eggs as soon as possible after lay when they are still hot. - Fumigate at a temperature of 24°C and relative humidity of 80%. - Use 30 ml of 40% formalin solution and 20 g of permanganate for each m3, or 10 g of
formaldehyde powder. - Fumigate for 20 minutes and then ventilate the fumigation chamber; formaldehyde gas should be eliminated in 10 min.
Disinfection by spraying
When eggs are sprayed in the farm, an approved hatching egg sanitizer should be used and each tier or flat must be treated before placing the next level over the last one.
partial disinfection when eggs are on cardboard cases - internal contamination when there is excessive spraying or the droplet size is too large.
Eggs which are too wet get cool quickly and “absorb” egg shell germs through the pores.
Storage of eggs
Allow the eggs to cool down for 1 to 2 hours before placing in the storing room. The temperature in the egg storage room should be kept between 15° and 18°C depending on the length of the storage period. In countries where temperatures exceed 22°C, an air-conditioned storage room is an excellent investment.
For longer storage periods (more than 7 days), keeping them oriented with the broader end down in the egg storage room helps to reduce the hatchability loss with age
Hatching eggs should never be packed directly on the floor, but on wooden or preferably plastic slats.
PROCEDURES FOR SELECTION OF BREEDER MALES
Selection is the process to improve a population by keeping the best individuals for a desired characteristic such as weight while ensuring those individuals with unfavourable characteristics such as leg defects are culled.
The practical and efficient selection of parent stock males.
The theory of selection of parent males is outlined in Technical Advice Sheet - Theory And Key Points For Implementing Selection Of Breeder Males
Before selection, males should be grown to achieve the target body weight goals for the strain of parent males
These goals do not represent the genetic potential of the males. The goals define target weights prior to selection that if attained permit males to grow fast enough to allow any defects to be expressed while not compromising the potential for persistency of semen production. Proper selection of turkeys is dependent on careful rearing. Poor housing conditions, high stocking densities and inadequate nutrition do not allow the birds to express enough of their genetic potential to enable an efficient selection.
The exact age at which selections are carried out can be planned to fit in with a vaccination programme as this will avoid having to handle the birds twice, which reduces the overall level of stress placed on the flock. Birds to be discarded may not need to be vaccinated.
Another determinant of the age at which selection is carried out may be the space available, e.g. if space is limited then it may be best to select early at say 12 to 14 weeks so that the growth of the bird is not compromised by high stocking density if selection were left to a later age.
The same trained and experienced personnel should carry out the selection wherever possible, as this will ensure consistency of procedures
It is normal to weigh all the birds at each of the two selections with the weights being recorded on a special record sheet (or electronically if using a digital load cell) so that the summary statistics can be calculated later.
Start by calculating how many birds need to be retained and how many need to be discarded. To do this multiply the placement number by the selection percentage e.g. 50%, and then subtract the mortality to date. The number remaining is the number of birds to be discarded.
Start by weighing approximately 50 birds and calculate their average weight. Then calculate a
weight that is 10% less than the average that will provide the break point weight, below or above which birds are either discarded or retained. The number in each category will depend on the total flock size and the selection pressure being applied.
When deciding whether a bird’s gait is normal or not, it is advised to watch the bird walk into the sample pen and walk away after weighing.
Care must be taken not to reject good birds after weighing, as they can sometimes be a little unsteady on their feet for a few moments after weighing.
Discarded birds should preferably be placed in a separate pen ready to be dispatched to the processing plant. Alternatively the birds to be kept and discarded can be spray marked with different colours to be sorted later. Sometimes, it is useful to mark good but small birds with a third colour in case additional birds are needed.
When the selection is complete the summary statistics should be calculated.
Labour – a team of four or five people is required to catch, weigh, record and select a flock of turkey males. An additional person might be needed if the selection is to be combined with a vaccination.
Sample pen – this can be formed using a portable catching frame consisting of three sides each approximately 3m (10’) x 0.9m (3’) high.
Pen dividers, sufficient to form an area in the house large enough to hold the discarded birds at the same stocking density as the remainder of the flock and with sufficient access to feed and water.
Spring balance – scale 0 to 50kg (110lb) readability of 20g (0.05lb)
Manual or automatic electronic load cells – scale 0 to 50kg (110lb) readability 10g (0.025lb)
Rope for suspending manual devices from the ceiling
Holding shackle for manual systems or a hanging platform for automatic systems
Clipboard, pen and calculator.
Three coloured marker sprays.
Lamp lead to provide a bright light source to enable the scale of the balance to be easily read. Compatible printer or PC connecting cable to download data from electronic devices.