The impact of full-fat Hermetia illucens larvae meal on the health and immune system function of broiler chickens

Bartłomiej Tykałowski; Andrzej Koncicki; Joanna Kowalczyk; Marcin Śmiałek; Tadeusz Bakuła; Daria Murawska; Wiesław Sobotka; Tomasz Stenzel

doi:10.2478/jvetres-2023-0022

The impact of full-fat Hermetia illucens larvae meal on the health and immune system function of broiler chickens

J Vet Res. 2023 Jun 16;67(2):197-207. doi: 10.2478/jvetres-2023-0022. eCollection 2023 Jun.

Authors

Bartłomiej Tykałowski¹, Andrzej Koncicki¹, Joanna Kowalczyk¹, Marcin Śmiałek¹, Tadeusz Bakuła², Daria Murawska³, Wiesław Sobotka⁴, Tomasz Stenzel¹

Affiliations

¹ Department of Poultry Diseases, Faculty of Veterinary Medicine, University of Warmia and Mazury, 10-719 Olsztyn, Poland.
² Department of Veterinary Prevention and Feed Hygiene, Faculty of Veterinary Medicine, University of Warmia and Mazury, 10-719 Olsztyn, Poland.
³ Department of Commodity Science and Animal Improvement, Faculty of Animal Bioengineering, University of Warmia and Mazury, 10-719 Olsztyn, Poland.
⁴ Department of Animal Nutrition and Feed Science, Faculty of Animal Bioengineering, University of Warmia and Mazury, 10-719 Olsztyn, Poland.

Abstract

Introduction: Alternative protein sources have recently been attracting growing interest as potential components of livestock nutrition. This study evaluated the effect on broiler health of replacing the soybean protein component of poultry feed with processed insect protein from farmed Hermetia illucens (HI) larvae.

Material and methods: A total of 384 male broiler chicks were divided into four diet groups (eight pens/treatment and 12 birds/pen) and reared to the 42^nd day of life (dol). Each treatment group received a starter diet until the 14^th dol, then a grower diet until the 35^th and finally a finisher diet until the 42^nd. The soybean meal in standard diets was replaced with full-fat HI larvae meal in the following amounts: 0% for the control group HI-0, 50% for group HI-50, 75% for group HI-75, and 100% for group HI-100. At 1 dol, chicks were vaccinated against Marek's disease, coccidiosis, Newcastle disease and infectious bronchitis and at 7 dol against avian metapneumovirus infections using live-attenuated vaccines. Blood and spleen samples were collected at three and six weeks of age and analysed using ELISA, flow cytometry, haematology and biochemistry.

Results: On the 42^nd dol, as the content of larvae meal in the chickens' diets increased, the birds' body weights decreased significantly. The substitution of the protein source had no effect on the haematological markers. In chicks that received larvae meal, there was a decrease in creatine kinase activity and phosphorus levels and an increase in calcium and uric acid levels in serum. Raising the proportion of full-fat HI larvae meal in the diet raised the percentage of T CD3⁺CD8a⁺ cells and lowered that of T CD3⁺CD4⁺ cells in both sample types. Chickens fed larvae meal had significantly lower post-vaccination anti-infectious bronchitis virus antibody titres.

Conclusion: The poorer production results and impaired health in experimental birds may indicate lower than 50% protein substitution with full-fat HI larvae meal to be optimal.

Keywords: Hermetia illucens; broiler chickens; health status; humoral and cell-mediated immunity; processed insect protein.