Egg Production
Breed companies forecast that birds will produce for up to 90 weeks of age as a standard. This provides the producer with an excellent opportunity to maximise profits. A 20% extension of a bird’s working life must be planned for as a 72-week old layer differs considerably from that of a 90-week bird, with immune status and skeletal integrity being the obvious differences. We are working towards a point where 90-week cycles are the expectation, not just aspiration.
As we move towards 90-week cycles being an expectation rather than aspiration, reviewing the breed standard becomes an important part of the planning process. It provides a useful manual, detailing “what is possible” as well as factors to consider that will help the bird reach her potential. It isn’t something that is prioritised but will keep producers informed of any subtle changes to the way birds should be looked after. This is especially important on sites where multiple breeds are used, all of which may require subtly different management in order to maximise health, welfare and production. It is an athletic achievement for birds to lay consistently to target. Often flocks are laying ahead of what the management guides indicate, so need even more tender loving care than the average bird.
Planning and executing worm, water, red mite and Infectious Bronchitis (IB) control strategies should be mainstay, as healthy and consistent production is challenging when any one of the these four are poorly managed. This is especially true on multi-age sites. Parasites (worms and mites) present physical and immune challenges to the birds, as well as being vectors for other diseases (Blackhead and Mycoplasma).
IB is the most common respiratory disease affecting layers and is easy to control with regular vaccination. Finally, it is important to ensure that consistently clean water is supplied to the birds. There are a plethora of ways poultry water can be sanitised, either manually or automated, so it is easy to get a system in place that best suits the site.
The topic of lighting is something we do not always discuss enough. To sustain good production for an extended period it is important not to over-stress the birds unnecessarily; this is a marathon and not a sprint. For instance, if target production has been achieved with 15 hours of light, why add another hour? Dawn and dusk periods incorporated into the daily lighting schedule are useful ways of starting and finishing the bird’s day.
On some of the older lighting systems, flickering lights can really stress birds. Flickering is not usually visible with our naked eye. However, by video-recording lighting flickering shows up easily. Ensuring the lighting is as even as possible is key, from a stress, intake and floor egg perspective. Newer lighting systems are spec’d to deliver light far more than what is recommended for layers. Birds are very light sensitive, and they often do not like ranging on bright days. It is important to be mindful of breed standard recommendations and the guidelines set by auditing bodies. However, it is not always necessary to keep light intensity at 100%, if the correct lux, can be evenly distributed, on a lower setting.
Egg Sizes
There is a lot of advice from the breed companies, and those providing nutritional advice on how best to manage egg size. Breed choice, management of early lighting programmes, body weight and tailored nutrition all require consideration and planning where producers wish to influence egg size.
Egg size can be a very useful indicator of overall flock health. Usually, egg size will reduce slightly during the sub-clinical part of a challenge. This is often caused by the bird holding onto their energy and protein reserves to bolster immune function and to try and maintain body weight and function during periods of illness and disease challenge. This can then directly impact egg mass as less energy and protein is available. It is worth noting that egg size usually alters prior to other parameters, such as body weight or egg production.
Knowing the average weight of eggs on a weekly basis helps producers remain vigilant for signs of health challenges. Some packers are able to provide this information. Weighing eggs from both the start and end of the daily egg pack is a more accurate reflection of average egg size across the flock.
Typically, producers manage egg size by reducing the protein and energy in the ration. Firstly, it’s important to remember that egg size won’t keep increasing exponentially. Generally, egg size increase follows a sigmoid curve and eventually flat lines, no matter how old or how heavy birds are. In many flocks, the increase is very subtle, and so changing the ration as a matter of course is not advisable. Unfortunately, sometimes a change in ration can be stressful for the birds so it is important it is carefully managed.
Poorly managed ration changes can sometimes result in birds eating more; they need to continue to meet the demands of their daily egg production. This can result in an increase, rather than a plateauing in egg size.
Whilst larger eggs can increase profits, it is not possible to encourage every flock to lay larger eggs. Conversely, trying to encourage a flock to lay predominantly medium eggs when it naturally lays large eggs can also be troublesome.
Although house designs are more light-proof, spring flocks tend to want to come into lay more quickly, and hence smaller eggs are more likely. Occasionally there are issues causing a delay in bodyweight gain, meaning birds are not lit as quickly, and these birds then tend to lay larger eggs. Some flocks will lay exceptionally well, and these birds cannot be expected to lay large eggs too.
Feed intake problems, such as heat stress, or lower water consumption will also be a cause a drop in egg size. Whatever the scenario, it is important to be guided by the bodyweight of the bird first and foremost.
