River-sourced Cladophora glomerata macroalgal biomass as a more sustainable and functional feed raw material for growing rabbits

Abstract

Animal scientists actively seek strategies for ensuring the sustainable viability of animal ecosystems, with a focus on exploring alternative feed raw materials to reduce reliance on traditional ones. So, this study aims to analyse the impact of river-sourced Cladophora glomerata macroalgal biomass on the growth, slaughter performance, and physiological development of rabbits. Thirty weaned (52 days of age) Californian rabbits were assigned to three dietary treatments: standard compound diet (SCD), SCD enriched with 4% C. glomerata (CG4), and SCD enriched with 8% C. glomerata (CG8). Growth performance was recorded throughout the feeding trial, and at its conclusion (122 days of age), rabbits were euthanized, slaughtered, and subjected to intestinal analysis. Incorporation of CG diets showed no significant impact on body weight or average daily gain (p > 0.05); however, CG8 significantly lowered daily feed intake and feed conversion ratio (p < 0.05). The SCD resulted in a significantly higher lung percentage (p < 0.05), while CG diets had minimal effects on remaining slaughter performance traits. In duodenal content, CG-enriched diets increased acetic and propionic acid levels but reduced lactic (p < 0.05). Duodenal villus height remained stable, while in the ileum, CG4 inclusion resulted in a significantly higher villus (p < 0.05). Duodenal crypt depth increased with biomass supplementation; conversely, in the ileum, increased biomass led to decreased crypt depth (p < 0.05). In general, recent research suggests that adding C. glomerata to rabbit diets can be an effective alternative without adverse effects on growth, slaughter performance, or physiologial development.

HIGHLIGHTS

• C. glomerata macroalgal biomass is usually considered waste.

• Collecting C. glomerata macroalgal biomass from natural water bodies not only enhances their biodiversity and recreational value but also yields valuable raw material for diverse applications in biotechnology.

• C. glomerata macroalgal biomass, with its high fibre content, aligns with the unique digestive physiology of rabbits, making it a suitable nutritional component for their dietary requirements.

Keywords:

• Freshwater macroalgae
• alternative
• sustainability
• productivity
• histomorphometry

Ethical approval

The research adhered to the guidelines outlined in Directive 2010/63/EU of the European Parliament and the Council (22 September 2010) on the protection of animals used for scientific purposes. Additionally, it followed the Commission’s recommendation (18 June 2007) for the welfare of animals in farming. Ethical approval (Bioethical permit No. PK042495) was obtained from the Lithuanian University of Health Sciences Centre of Postgraduate Studies on 7 November 2022, sanctioned by the State Food and Veterinary Service through official letters (No. B6-(1.9)-2625 dated 16 October 2013 and updated on 28 March 2017, No. B6-(1.9)-852).

Authors’ contributions

Conceptualisation, MN, and VV; methodology, MN, SB, and AP; software, MN, and AP; data collection, MN, VV and ARS; investigation, MN, ARS, SB, AP and VV; resources, MN and VV; writing—original draft preparation, MN; writing—review and editing, VV and ARS; supervising, VV. All the authors have read and agreed to the published version of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability statement

The data that supports the findings of this study are available on request from the corresponding author.