Embrace the long-life layer and adapt accordingly
Extending egg-laying hen production comes with many benefits. However, we should be aware that when the hen ages, egg quality declines and nutritional needs change. Feeding regimes should therefore be adapted accordingly in our quest for the long-living bird.
Did you know that flocks are often replaced around 72 weeks of age due to a decline in egg production and shell quality? However, thanks to recent genetic advancements, it is now possible to keep layers productive up to 100 weeks of age without moulting. This has a direct positive impact on productivity. As a general guideline, a hen can produce approximately 500 eggs over 100 weeks, compared to 360 eggs in 80 weeks. But there are more benefits.
By increasing layer longevity, we have more saleable eggs per hen, saving on production costs (due to spread of investment costs pullets over longer period) or (in some cases / concepts) get a premium. It also leads to better use of resources and reduced carbon footprint per kilogram of eggs and contributes to having more quality eggs available to meet the growing demand for poultry products. However, going for long-living birds is not just a matter of adding weeks to a hen’s life. It is about enhancing the quality, which should be done by prioritising nutrition, health and managing stress.
Aging starts at day zero
Egg production is a complex system involving the oviduct, ovary, liver metabolism, hormones, body reserves, and more processes and mechanisms. To sustain laying persistency, it is vital to understand these processes and provide the right set of nutrients in the right amounts for all production phases. However, many older studies lack feeding guidelines for extended production periods, and nutritional requirements / feed tables often do not align with the evolved genetic potential and nutritional needs of modern breeding lines. We do see that an increased number of breeding companies are working on extending the feeding manuals of their genetic lines beyond 80 weeks.
Dr Saritha Saraswathy, global applied poultry nutritionist at Trouw Nutrition has been actively working on this topic and explains: “Besides good management, disease control and (heat) stress prevention, we know that nutrition is a powerful tool in the layer longevity concept. We also know that layer longevity is about taking a comprehensive approach, looking at the specific needs and risks throughout the whole life cycle of the bird. And this already starts at day zero, as this is the day that aging begins. Over the years, we have gained a much better understanding of the specific needs per production stage, so we can adjust the diets accordingly or influence processes such as eggshell quality or fat mobilisation. But also, the use of vitamins for example have gained greater interest in the egg-producing industry, due to their influence on reproduction, antioxidant capacity and other physiological mechanisms.”
Meeting the specific needs
So, what are some of the specific feeding recommendations that we need to consider when working with long living hens? Saritha explains that the first weeks are crucial. “Just after hatching, the pullet’s body changes drastically and has a spike in functional growth. This requires a lot of highly digestible protein and high levels of energy. At the same time, nutrient reserves, feed digestibility and feed intake levels are low. If we do not provide the right amount of nutrients at this stage, we risk that pullets do not reach target body weights, uniformity, and feed intake capacity: the basics for layer longevity. Underfeeding in the first stages of life can also lead to less developed organs and bones, making the birds less robust to handle longer cycles and produce strong eggs.”
The energy demand reaches a peak at the onset of lay and pre-peak period. This is also the time that the liver starts to deposit more fat for example and calcium demand is high. This is also where the body condition (fat level) of the birds can become relevant as a factor for long-term egg production, as suggested by Van Eck et al (2023). At peak production (60 weeks), the main concern is to maintain optimal eggshell quality and egg size. Saritha explains: “Peak production comes with an increased pressure on mineral turnover and liver function. When layers need to be vaccinated during peak production periods, we should also be aware that this can negatively influence feed intake levels and increase stress for the birds. During peak and beyond, immune depression, inflammation, hepatic challenges and oxidate stress can increase, which can be overcome by adjusting the trace minerals, vitamins, amino acids, antioxidants or adding anti-inflammatory/anti-oxidative phytogenics for example. We need to fine tune feed and premix formulations to address the specific metabolic challenges.”
Translating theory to practice
Dr Reza Akbari Moghaddam Kakhki, poultry researcher at Trouw Nutrition R&D, elaborates a bit more on some of the nutritional considerations within the layer longevity concept. He explains: “From earlier research we know that energy level is linked to feed intake. In the pre-peak period, we therefore go below the actual energy requirement and keep the level of other nutrients at the requirement level. This way we stimulate feed intake. At Trouw Nutrition R&D, we investigated optimal energy reduction levels and the best sources for achieving this reduction to enhance feed intake. Our research also focused on dietary fat and amino acid levels to increase egg weight in young layers, as sub-optimal pre-peak diets may lead to smaller (less saleable eggs). In addition, we showed that pre-peak diets may result in similar egg production performance but can affect liver health in long-term by altering fat deposition in the liver, jeopardizing the health of this vital organ, which is crucial for long-term egg production.”
Reza addresses that egg quality might be one of the biggest challenges in our quest for longer production cycles. Because as the laying cycle progresses, egg weight increases, and eggshell quality is compromised. “Dietary amino acids play a crucial role here. However, not a lot of research is available on amino acid balancing in the later stages of the laying cycle to mitigate further increases in egg weight. At Trouw Nutrition R&D we demonstrated that reducing dietary digestible lysine levels in 62-week-old ISA Brown hens below established requirements resulted in a deviation from optimal egg weight. However, it effectively slowed down the decline in eggshell quality (Akbari Moghaddam Kakhki et al., 2023). These findings underscore the untapped potential of nutritional strategies to improve eggshell quality in older laying hens beyond 70 weeks of age.”
Layer longevity journey
The concept of layer longevity is gaining interest and traction in the industry and is considered a crucial part of the journey to sustainable growth in egg production. However, this concept is not just a matter of adding days to a hen’s life, but it is about enhancing the quality, which should be done by prioritising nutrition, health, and managing stress. Older hens simply need a different diet to make sure they remain productive and healthy. And the data and research on how to adjust diets accordingly is growing fast.
Trouw Nutrition is contributing to support poultry producers on the layer longevity journey and has combined its R&D, nutrition, formulation, and modelling expertise into practical layer longevity feeding recommendations and programs, supported by innovative feed products such as Erliva ChickCare and Erliva PullyCare. And we continue to remain actively involved in this important topic. By embracing the layer longevity concept with a comprehensive approach (from day zero to end of lay), we are working towards a more sustainable and profitable egg production.
