Control of Cilliate Protozoa in the Rumen by Using a Mixture of Saponin and Stevia Extracts

  • Ahmet Akcay

Student thesis: Master's ThesisMaster of Science


Saponins are plant secondary metabolites and have been reported in a variety of plant families. Producing foam in water, saponins name is derived from the Latin word of ‘sapo’ which means soap. In consequence of poorly being absorbed in intestine, saponins main effects occur in the gut or rumen only. Many studies have reported the effect of saponins on ruminants both in vivo and in vitro such as removal of protozoa from the rumen microbial system and also manipulation
of the end products of fermentation. Engulfment and degradation of bacteria by ciliate protozoa in the rumen significantly reduced microbial protein flow from the rumen by causing rapid intrarumen nitrogen cycling and then excreting excess ammonia in the urine. In this case the presence of protozoa is undesirable in the rumen. Saponins kill or damage protozoa via forming complexes with sterols in the protozoal membrane surface which cause impaired membrane and finally disintegration. Saponins have been used in many studies to show the methane mitigation in livestock. Saponins are safe, economical, and effective strategy which may decrease this potent greenhouse gas and also, may eliminate loss of ingested feed energy for productive purposes. In the present experiment eight rumen cannulated sheep, fed a diet balanced to meet maintenance requirements, have been used. The study builds on previous experiments carried out and aims to build on data to confirm the effect of saponins in sheep which kill or damage protozoa. The aim of this study is to assess the effect of Ivy and Stevia extracts, either on their own or combined, on rumen fermentation in cannulated sheep. The experiment focused on the use of a saponin containing diet (Ivy) to improve nitrogen utilization and mitigation of the methane production by targeting protozoa and combining in the diet with a glucosidase inhibitor (Stevia, DMDP; 2,5-Dihydroxymethyl-3,4-dihydroxypyrrolidine) which subsequently, protects the saponins from degradation in the rumen flora. Treatments were; control (no addition of supplement), Ivy (10 g/animal/day), Stevia (20 g/animal/day) and Ivy+ Stevia (basal diet with 10 g/animal/day of the Ivy extract and 20 g/animal/day of the Stevia extract) mixture. The results have not shown any significant changes (P˃0.05) based on the apparent digestibility of nutrients, metabolic weight, N balance and methane production in Ivy, Stevia nor Ivy+ Stevia diets comparing to the control group
Date of Award2016
Original languageEnglish
Awarding Institution
  • Aberystwyth University

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