6.3.1 – Feed treatments for improved laying hen health

In vitro tests were carried out to evaluate the antiparasitic and immunomodulatory effects of ethanol extracts of plants (C. officinalis, S. hortensis L., C. sativum, A. absinthium L., A. sativum and C. pepo). Based on this powders, oil extracts or essential oils from the plants showing the most promising effects were added to the feed administered to layers experimental infected with Ascaridia galli. Besides the plants tested in vitro, fermented rape seed meal/seaweed (European Protein EP199, Fermentation Experts, Denmark) and powder from Aronia melanocarpa were also administered to the layers. With respect to the practical control of A. galli, no firm recommendations can be given based on the present results. However, among the additives tested in vivo during the project (C. sativum, A. sativum and C. pepo, from Aronia melanocarpa and fermented rape seed meal/seaweed), the best candidate seems to be garlic, which can be mixed into the feed as dried powder. However, it should be said that most of the plants added to the diets had a beneficial effect on gut health as evaluated by microbial fermentation and higher numbers of potentially beneficial bacteria (lactic acid bacteria) and lower numbers of potentially harmful bacteria considering E. coli as an indicator of related pathogenic enterobacteria, i.e. Salmonella.

Presentations

• Effect of fermented rapeseed meal and seaweed on immune-profiles in layers infected with Ascaridia galli – On line – 7^th EVIW Conference – 29-31 August 2021
• Nutritional interventions for reduced parasite load in organic chickens -On line – Bilateral forum in the Korean/Danish project – 24 March 2022
• The effect of garlic (Allium sativum) and black chokeberry (Aronia melanocarpa) on worm load and gut health in Ascaridia galli infected laying hens – XXII Congress of the World Veterinary Poultry Association – Verona – xx 2023
• Wurmbefall bei Legenhennen – Alternative Lösnungsansätse für ein altes Problem – German National Day – 28 Bioland-Geflügeltagung – Bonn – 27-29 February 2024
• Improving the gastro-intestinal health and welfare of laying hens by the use of dietary plant additives – PPILOW Final Conference – Brussels – 12-13 June 2024

Thesis dissertations

• Højmark, M. (2021). Feeding strategy to support health in organic laying hen – The effect of fermented rapeseed meal with seaweed on Ascaridia galli in organic laying hens (Gallus gallus domesticus) (Master thesis), MSc in Agrobiology, Aarhus University
• Pan, G. (2022). Immunomodulatory effects of garlic and aronia berry and their antiparasitic potential against Ascaridia galli in chickens. (Master thesis), MSc in Agrobiology, Aarhus University
• Ørndrup, M. D. (2024). Use of alternative methods to control helminths in organic layers – The effect of propionic acid, coriander seed oil and pumpkin seed oil on Ascaridia galli in organic laying hens (Gallus gallus domesticus) (Master thesis), MSc in Agrobiology, Aarhus University