Egg production – Resilience for laying persistence

In egg production longer laying cycles can help to cut costs, so they are a promising solution in a tough economic climate. Plus, they can reduce the environmental impact of egg production. Therefore, there is an increasing focus on improving laying persistence and egg quality at the end of the laying cycle. However, due to increasingly intensive metabolism for egg formation, laying hens are more susceptible to diseases, which requires a shift in breeding and nutrition towards greater resilience of birds to improve laying persistence for longer laying cycles.

There is a fast decline in egg production after the hens reach 480 d of age leading to reduced commercial value of laying hens. Understanding the mechanisms of the deterioration of the laying performance can help to slow down the process. The ovary and the liver are key organs involved in egg production of the laying hen, which is why knowing how to support them effectively by nutritional means can make a difference to laying persistence.

Oxidative stress in aging organs

Ovarian aging is one of the highest risk factors that lead to the decline of ovarian functions and hence a reduction in egg production. Studies have shown that oxidative stress plays a driving role in ovarian aging. The antioxidant status of the ovary decreases with age (Figure 2) as a result of a reduction in antioxidant enzymes and antioxidants in the hen’s own defense mechanisms. Oxidative stress is initiated by the gradual accumulation of reactive oxygen species (ROS) in the ovary and a reduction of the antioxidative capacity during the aging process. This will be exacerbated through stressors, such as heat, mycotoxins, endotoxins and others, which increase the production of ROS in the hen on a cellular level. A growing body of evidence suggests that oxidative stress is involved in most of commercially relevant stresses in poultry production. Oxidative stress is defined as an imbalance between production of ROS and their elimination by protective mechanisms. This imbalance leads to damage of important biomolecules and cells, with potential impact on the whole organism. It can also lead to inflammatory responses which can affect energy efficiency of the laying hen.

Age-related changes in the antioxidative capacity of the hen’s liver, is an important factor that influences liver function. Studies have demonstrated that the total antioxidant capacity of the liver declines as the hen ages (Figure 2) and this has also been linked to a decrease in egg production and in the ability of yolk precursor formation.

Feeding for resilience in egg production

To extend the laying cycle of commercial flocks, long-term maintenance of organs involved in producing eggs is required. Feeding for antioxidative capacity in laying hens has been shown to retard the antioxidant decline of aging ovaries and can thus help to maintain functioning ovaries for longer. It is also known to maintain a healthy liver for longer. However, feeding to improve the adaptive capacity of birds to stressors helps to minimize stress reactions, such as oxidative stress, as well as inflammatory responses and reduced feed intake, which can further increase resilience in birds and reduce the potential for stressors to diminish the chances for producers to successfully extend the laying period. Animal resilience has been defined as “the capacity of the animal to be minimally affected by challenges or to rapidly return to the state pertained before exposure to a challenge.

The gut agility concept in Anco FIT Poultry was specifically developed to increase the capacity of the bird to adapt to challenges more efficiently and to reduces stress reactions that would otherwise reduce the hens performance and potential to sustain longer laying cycles. A trial carried out in a commercial laying hen flock in Brazil, demonstrates how Anco FIT Poultry improves the resilience of birds to stressors compared to birds on a control diet (Figure 3). The impact of stressors was smaller on egg production and birds recovered quicker from stressors leading to greater laying persistency and more eggs produced per hen over the trial period.

 

Published in International Poultry Production by Gwendolyn Jones

Related articles

Farm resilience starts in the bird – feed for adaptability

Resilience economic value in animal production

 

Animal Nutrition journal – New scientific paper on Anco FIT Poultry

The Animal Nutrition journal published a scientific paper with research involving the application of Anco FIT Poultry in broilers and its effects on the expression of cytoprotective genes at the gut level.

Link to full scientific paper published online in Animal Nutrition

Abstract

Priming of intestinal cytoprotective genes and antioxidant capacity by dietary phytogenic inclusion in broilers

Konstantinos C. Mountzouris, Vasileios V. Paraskeuas, Konstantinos Fegeros

The potential of a phytogenic premix (PP) based on ginger, lemon balm, oregano and thyme to stimulate the expression of cytoprotective genes at the broiler gut level was evaluated in this study. In particular, the effects of PP inclusion levels on a selection of genes related to host protection against oxidation (catalase [CAT], superoxide dismutase 1 [SOD1], glutathione peroxidase 2 [GPX2], heme oxygenase 1 [HMOX1], NAD(P)H quinone dehydrogenase 1 [NQO1], nuclear factor (erythroid-derived 2)-like 2 [Nrf2] and kelch like ECH associated protein 1 [Keap1]), stress (heat shock 70 kDa protein 2 [HSP70] and heat shock protein 90 alpha family class A member 1 [HSP90]) and inflammation (nuclear factor kappa B subunit 1 [NF-kB1], Toll-like receptor 2 family member B (TLR2B) and Toll-like receptor 4 [TLR4]) were profiled along the broiler intestine. In addition, broiler intestinal segments were assayed for their total antioxidant capacity (TAC). Depending on PP inclusion level (i.e. 0, 750, 1,000 and 2,000 mg/kg diet) in the basal diets, 1-d-old Cobb broiler chickens (n = 500) were assigned into the following 4 treatments: CON, PP-750, PP-1000 and PP-2000. Each treatment had 5 replicates of 25 chickens with ad libitum access to feed and water. Data were analyzed by ANOVA and means compared using Tukey’s honest significant difference (HSD) test.

Results

Polynomial contrasts tested the linear and quadratic effect of PP inclusion levels. Inclusion of PP increased (P≤ 0.05) the expression of cytoprotective genes against oxidation, except CAT. In particular, the cytoprotective against oxidation genes were up-regulated primarily in the duodenum and the ceca and secondarily in the jejunum. Most of the genes were upregulated in a quadratic manner with increasing PP inclusion level with the highest expression levels noted in treatments PP-750 and PP-1000 compared to CON. Similarly, intestinal TAC was higher in PP- 1000 in the duodenum (P= 0.011) and the ceca (P=0.050) compared to CON. Finally, increasing PP inclusion level resulted in linearly reduced (P≤ 0.05) expression of NF-kB1, TLR4 and HSP70, the former in the duodenum and the latter 2 in the ceca.

Conclusion

Overall, PP inclusion consistently up-regulated cytoprotective genes and down-regulated stress and inflammation related ones. The effect is dependent on PP inclusion level and the intestinal site. The potential of PP to beneficially prime bird cytoprotective responses merit further investigation under stress-challenge conditions.

Relevant articles

Animal Production Science – Anco FIT Poultry mode of action proof

Experience with Anco FIT Poultry is growing globally

Priming the poultry gut to deal with stressors