A major aspect of achieving successful layer flocks is ensuring good pullet quality. During the rearing period, close attention must be paid to flock growth and preparation for laying in line with the following considerations:
BIOSECURITY OF LIVESTOCK
Biosecurity is fundamental into a layer farm, ensuring a high biosecurity level is essential to guarantee a good quality pullet and the future layer. Biosecurity is made of multiple aspects, as the management of flows (people, vehicles, etc) as well as the management of rodent but also the prophylaxis and vaccination practices.
WEANING AND BREEDING CONDITIONS
The breeder’s recommendations should be taken into consideration when making decisions on stocking density and on how to manage the different stages of the feed and lighting programmes. These recommendations should be used as guidelines; it may be necessary to adapt them according to local conditions, flock body weight and uniformity.
Table: NOVOGEN stocking density recommendations by production system, climate and age.
In order to develop the animals’ growth and especially their appetite, it is recommended to include a daily period when the feeders are empty, in the middle of the day from 4 weeks of age. This practice stimulates a fast daily intake of feed during the rearing period, which in turn induces a good eating capacity at the onset of lay. The number of feed distributions should be reduced as much as possible in order to prevent the birds from selecting feed particles.
Feeding schedule chart.
REGULAR BIRD WEIGHING
By around 7-8 weeks, the chicks have already developed their structure as future layers, as such, early weight gains are essential. Indeed, a weight shortfall in the first few weeks impairs production performance. As shown in the figure below, most of the bone structure, muscles and organs are completed by 8 weeks of age. If regular weekly growth is not ensured, there is the risk of an excessive accumulation of body fat and insufficient muscle mass and organs. It is recommended to concentrate on increasing the pullet’s body weight before 7-8 weeks of age to favour a good-quality layer right until the end of the flock.
A common practice is to weigh the pullets weekly in order to monitor the evolution of their growth and adapt the flock management and nutrition accordingly. Flock uniformity should also be measured, with a target of over 80%. A high uniformity favours a high laying peak and persistency as well as a good uniformity in the egg weight.
Graph: Pullet growth development
MANAGING SEXUAL MATURITY
Sexual maturity and production are largely influenced by the changes in day length to which pullets are exposed. A carefully chosen lighting programme will help to optimize the performances of commercial layers. Sexual maturity and bodyweight at sexual maturity influence egg production, egg size and liveability.
It is difficult to advise a universally optimum and perfect lighting programme, it always has to be adapted to your own situation. The lighting programme during rearing can be divided into 3 phases as illustrated here:
- This first phase of the lighting programme has a direct effect on pullet growth. A slow step-down programme allows a longer feeding time per day and thus favours early growth.
- Light duration during the plateau can vary according to different parameters:
- Dark house: Plateau from 8 to 12h of light can be adapted according to pullet growth.
- Open side house: Maximum day length depends on natural day length encountered at 16 weeks.
In any case: Never increase day time before sexual stimulation! Bodyweight is the main indicator to determine age during light stimulation. It will depend on the production and egg weight target. In open house and hot climate conditions, it is recommended to wait for 2 to 5% of production before starting stimulation.
Introducing light stimulation too early might stimulate as yet immature pullets, which would then lay smaller eggs and be more susceptible to prolapse issues. Pullets that start to lay too early also tend to use up their reserves during production. As a consequence, such birds stop laying earlier.
Control of the lighting programme and its anticipation is a key point for proper flock management. It has to be monitored according to its target of production even though other parameters (feeding programme, sanitary challenges and conditions of production) can attenuate its effects. In all cases, it has to be adapted according to the local conditions.
As a conclusion, body weight and uniformity are the main indicators for monitoring the condition of a layer flock during rearing. It is therefore essential to carry out regular monitoring! A low average weight and/or high flock heterogeneity during the rearing period will have adverse effects on future production capacity. Multiple parameters (lighting and food programmes, compliance with breeding, sanitary standards, etc.) must therefore be respected and adjusted if necessary in order to allow the breed to best express its genetic potential. NOVOGEN teams always remain available to discuss these topics in detail. – Andréa Beneventu – Poultry Technical Specialist, NOVOGEN.