Dana Simpson DVM MRCVS
Within the current global economic and environmental situation and the associated challenges, the development of ‘longer life’ laying hens becomes much more of a priority.
A decline in egg numbers combined with a deterioration in shell quality are the main reasons for currently replacing flocks at around 74-77 weeks of age. These birds are essentially healthy, and if their egg production cycle can be lengthened without loss of shell quality there are significant welfare, as well as economic benefits, to be gained.
There are obvious benefits such as more efficient use of diminishing resources, the reduction in pullet depreciation, the number of empty days on an annual basis and an overall reduction in carbon footprint.
Looking at the average depletion age of flocks in the UK and The Republic of Ireland (currently 76 weeks) and comparing the financial figures with a flock that stays in production up to 90 weeks, we can estimate the financial benefit of the longer living hen. Using £4.80 as the pullet price and £400 as the cost for a tonne of feed we estimate a reduction in pullet depreciation of £0.03 per dozen eggs resulting in a financial benefit of £0.18 per bird. However, there are other factors which may contribute towards increased profitability which are less easy to evaluate. These often differ between flocks and include greater average egg size and an increased number of eggs laid per bird amongst other factors
This persistency in lay however cannot be achieved without knowledge and consideration of the bird’s physiology. This will then enable us to understand how she can be supported and helped to develop to her full laying potential, while allowing her to maintain production levels and continue to produce a high-quality robust shell.
Challenges to the bird vary depending on the age, stage of reproduction, management system, the presence of physiological and environmental challenges such as disease, (heat)stress, high ammonia levels etc.
Supporting longer productivity
Maintaining production for an extended period does not come without risks. It is imperative to be aware of the waning immunity status, gradual increase in egg size and reduction in shell quality. The focus from the very beginning of the pullet’s life needs to be on providing her with the necessary support to make an extended laying cycle achievable.
We believe that by understanding both the physiological and nutritional needs of the hen we can prepare her for a long and productive life. This allows you as a producer to take advantage of the ever-improving genetic potential of the modern commercial layer.
For the hen to be able to come into lay with minimal stress the hens must have attained target body weight at 14-16w. This plus the proper protein to body fat ratio to allow them to react to light stimulation appropriately and to sustain her physical requirements as egg production rises rapidly. Be under no illusion this is a hugely stressful event during which time the birds’ immune system can become significantly compromised. We are all familiar with the dreaded post peak drop as the hens slowly but surely run out of energy. Managing egg size and opting for a flatter egg curve aid in sustaining a longer laying cycle.
Maintaining energy levels
Aspiring to have continued good production and shell quality beyond 90 weeks, these energy levels must be maintained along with protein to body fat ratios. This means we can manage egg size to the desired specifications.
Good skeletal development with a ready source of Calcium which can be repeatedly mobilised from the medullary bone and replaced requires careful management of Calcium intake and a very stable gut microflora. This is particularly important in the rear gut. As the hen matures her requirements change and so too should the nutritional support provided in order to help her sustain intestinal health, shell quality, egg size and production level.
The part played by the microbiome (the intestinal microflora) is becoming better understood both in animals and people. The benefits of a well-balanced and stable microbiome are found in an improvement in general health and a well-developed and competent immune system.
With years of experience in seeding the avian gut with the most beneficial bacteria and supporting the growth of these in preference to less favourable bacterial species to facilitate colonisation we have developed a great understanding of how the bacterial flora in the gut can influence welfare and productivity. We aim to provide sustainable, holistic, farm specific and cost- effective strategies and solutions.
Many studies have shown that the presence of favourable bacteria in the intestinal tract can significantly improve resistance to pathogen colonisation. By ensuring the intestinal environment is suitable for the growth and replication of the beneficial bacteria, the ‘healthy’ microbiome can be sustained.
The gut is the first port of entry for a variety of external pathogens and forms an important barrier between the outside world and the internal bodily systems. When unstable, the gut can be a source of systemic toxins and bacteria due to leakage through the intercellular junctions of the gut lining following the reduction of the barrier function offered by the tight junctions. These junctions can be amongst others affected by stress, (myco)toxins and mechanical challenges occurring in the gut over time. These toxins and bacteria become blood borne and can lead to a systemic infectious process (septicaemia) which is costing the hen energy to fight infection, potentially leading to a loss in productivity, not to mention the potential expense of therapeutics.
Most beneficial bacteria thrive under acidic conditions whereas potentially pathogenic bacteria such as Clostridia and Campylobacter are averse to these conditions.
It is important to appreciate that during the hen’s life the nutritional and physiological needs change significantly with the growth requirement only being present for the first few weeks at the onset of egg production.
Attention to detail, good management and nutraceutical support can provide the follow-on support required for the extension of the laying cycle. Energy required for maintenance in the post peak production period depends on body weight and feather coverage and therefore increases with hen age.
Once the hens get over the 50-week mark additional support is advised in order to sustain eggshell quality alongside production and the birds’ health for the duration of the laying period.
The following support options are available:
- Nutraceutical support in the first days of life to facilitate a good feed and water uptake as well as laying down the basis for initiation of the immune system development and support
- Supporting the pullets’ skeletal development during the growth period to ensure a good frame size, bone development and uniformity
- Providing ongoing support which allows the immune system to develop efficiently and potentially help improve the immune response of the pullet
- Providing intestinal support during key periods in the hen’s life so she can better maintain her energy levels and body condition allowing her to sustain production for longer
- Providing essential nutraceutical support to the older hen to help maintain good shell quality for longer
- Providing supportive intestinal management of the hens post 60 weeks to reduce the risk of salmonella colonisation.
However, the nutraceutical support programme is one of a variety of tools required to make extending the birds’ laying cycle possible. A holistic approach is required which incorporates both veterinary support tools such as responsible antimicrobial usage and effective vaccination programmes as well as on farm factors such as stress management, vermin control, pest management, brooding conditions etc.
We can advise on a variety of tailored support strategies to help accomplish an extended laying cycle. Please feel free to contact us if you wish to find out more about our support programmes.