Seaweeds: a natural approach to improve ruminant productivity, quality of animal products and reduce environmental emissions

Abstract

This thesis builds on the growing area of scientific research aimed at addressing the feasibility and potential benefits of seaweed provision to ruminant livestock with emphasis on the effects on emissions output, animal production and end-product quality for human consumption. To date research indicates that red seaweed species show the greatest methane mitigating potential, whilst no brown temperate seaweed species has currently been identified which elicits the same reducing effect on methane. The brown seaweeds could have other benefits such as improving nitrogen use efficiency or improving end-product quality for human consumption. The primary objectives of this research project were to: explore how ruminant nutrition and nutritional additives are used as methane inhibitors currently and identify gaps in the research completed on seaweed as a methane mitigator for ruminants; to investigate the methane mitigating potential of temperate seaweed species in-vitro with a grass silage substrate at commercially viable inclusion rates; to assess the effects of 4% Himanthalia elongata and 4% Himanthalia elongata extract provision to late-lactating dairy cattle on production, gaseous output, nitrogen efficiency, rumen microbiome taxonomy and end-product quality; to evaluate the impact of SeaFeed™ provision at two inclusion rates on finishing beef cattle performance, gaseous output and end product quality.

Thesis is embargoed until 31 July 2027.

Date of Award	Jul 2025
Original language	English
Awarding Institution	Queen's University Belfast
Sponsors	Northern Ireland Department for the Economy, WM Morrison Supermarkets PLC, Professor John Glover Memorial Fund, ERN-NET SUSAN & Sea Forest Ltd, Australia
Supervisor	Katerina Theodoridou (Supervisor) & Sharon Huws (Supervisor)