2.6. The production of eggs for hatching

The production of eggs for hatching is a matter for breeders (parent stock).

The eggs supplied to the hatchery are of two types:

- Eggs from heavy breeds whose chicks, male and female, are destined for the production of broilers.

- Eggs from light and middle weight breeds whose female chicks (pullets) are reared to the age of 20 weeks to become hens producing eggs for consumption.

It should be noted that a breeder of broilers or egg layers is looking for high-yielding birds (growth, laying rate) with as low as possible a consumption index. A producer of breeding hens must also be concerned with the acclimatization and reproduction (fertility, hatching rate) capacity of the breed in Sahelian environmental conditions.

For example, in Europe, the production of broilers is currently dominated by the demand for well-developed pectoral muscles from the abattoirs which cut up the carcasses. This leads to the selection of very heavy type breeds and the management of the parent stock is a very delicate operation.

Choice of broiler parent stock

There are many breeds whose performance (growth, consumption index, carcass quality) is about the same. These are very heavy breeds which can be difficult to raise in Africa (laying rate, male fertility, hatchability) if husbandry and feeding conditions are not perfect. Amongst these breeds we may mention: Cobb, Hybro G, Ross.

This is why selective breeders suggest breeds which are less high-yielding but also less delicate and more suitable for the Sahelian environment: Arbor Acres, Hybro N, Shaver, Vedette.

Ask the breed producers about the strength and weaknesses of their products. It is recommended that producers of parent stock should work with two or more breeds at the same time and spread their orders of parent stock over the year.

Choice of layer parent stock

Light layers are characterized by: white shelled eggs - adult body weight of about 2 kilos - high laying performance - low feed consumption (110-115 g per day) - sensitivity to feeding balance and environmental conditions. The producer of light breeding stock will look for breeds in which the sexes are clearly distinguished (difference in the arrangement of wing feathers in males and females), as the cost of sexing by experienced chick-sexers is very high. Such breeds include Babcock 300 Isa - Lohmann SL - HyLine W77.

Light layers mature earlier than middleweights, but at the beginning of laying, their eggs are smaller.

Middleweight layers are characterized by: brown shelled eggs - adult body weight of 2.3 kilos - laying performance slightly below that of light breeds -feed consumption of 120 -125 g per day - a slightly higher degree of hardiness than light breeds - visible differences between the sexes. Types of breed: Isa Brown - Lohmann Brown - Hisex Brown - HyLine Brown.

PRODUCTION OF HATCHING EGGS · CHOICE OF PARENT STOCK: BROILER OR LAYER · FOR MEAT, VERY HEAVY BREEDS ARE NOT RECOMMENDED IN THE SAHELIAN ZONE · FOR LAYING, CHOOSE WHITES WITH VISIBLE SEX DIFFERENCES OR BROWNS · OBJECTIVES, LAYING RATE, MORTALITY, FERTILITY, HATCHABILITY · QUALITY OF FEED AND DRINKING WATER · ENVIRONMENT: TEMPERATURE, VENTILATION, STOCKING DENSITY

Eggs for hatching must:

- Be harvested at least four times per day.

- Be clean, possibly brushed with a soft brush.

- Weigh more than 50 g (this weight is usually obtained when the hens reach about 28 weeks of age).

- Be stored under specific conditions: optimum temperature 12°C (between 10 and 15°C) -relative humidity: 70 to 85% - duration of storage varying depending on breed, with an average loss of hatchability of 1 to 1.4% per day of storage.

Heavy breeds: maximum one week's storage

Light and middleweight breeds: hatchability is slightly reduced in the first weeks of storage, more in the second and by 15% in the third week.

Recommendations

- Scrupulously follow the feeding and management instructions in the manual for the breeding question.

- Points to watch

· rearing weight of pullets and cockerel chicks
· weight at 5% laying (optimum age 24 weeks) of layers and cockerels
· homogeneousness of the lots

Production levels

- Normal period: 125-140 eggs per laying hen
- Very hot period: 110 eggs per laying hen
- The hatchability of the eggs is around 80% when the hen is 28 weeks of age, reaches 88% around the 40th week and slowly decreases to reach 70% around the 70th week. This data is valid at normal ambient temperatures. It must be borne in mind that at temperatures over 25°C, the fertility of the cockerels decreases sharply as the temperature rises.

The production of heavy breeding stock is 170 eggs per laying hen, of which 160 are sent for hatching, supplying 135 day-old chicks per laying hen, in European conditions.

Poultry farming specialists estimate that in good conditions in Africa, the target should be 112 (between 110 and 115) day-old chicks per laying hen or 140 hatching eggs per laying hen (hatchability 80%).

Example:

A hatchery owner has to supply 6,000 day-old chicks per week. He must therefore place 6,000/ 0.8 = 7,500 eggs per week in incubation.

How many breeding hens will he need to supply these 7,500 eggs per week? Rearing of breeding stock must start with 6,000/112 i.e. 54 hens per week, i.e. for a laying season of 42 weeks: 42 x 54 = 2,270 hens.

Qualities of a good chick

It should be remembered that the qualities of a chick are above all a reflection on the quality of the parent stock and the hatchery which produced it. These qualities are in practice more important than the breed itself. Hatcheries usually supply 2% additional chicks free to compensate for losses during transport which should not last more than 30 hours.

One-day-old chicks should weigh at least 35g (below this, mortality rates are high); they should be healthy and vigorous and should have no deformity of the beak or feet.