Ruminal ciliated protozoa in cattle fed finishing diets with or without supplemental fat.

Abstract

Ruminal samples were collected at slaughter from 364 unfasted steers fed different finishing diets to obtain information on numbers and species distribution of ciliated protozoa in feedlot cattle. Total numbers of protozoa averaged 1.59 X 10(5)/g of ruminal contents. A total of 47 steers (12.9%) were defaunated, but 4.1% of the steers possessed numbers of protozoa greater than 10(6)/g. Entodinium species did not always dominate the protozoan populations; 41 faunated steers (11.2%) were devoid of entodinia, and 79 additional steers (21.7%) possessed populations dominated (greater than 50%) by other genera. Isotricha was the most commonly occurring genus supplanting Entodinium, but Polyplastron and Epidinium were frequently present in high concentrations. Tallow and soybean soapstock supplementation reduced (P less than .05) numbers of protozoa in steers consuming wheat diets. However, yellow grease supplementation did not affect numbers of protozoa in steers fed either sorghum or corn diets. Average ruminal pH was 6.20 on the wheat diet, 6.05 on the corn diet, and 5.69 and 6.23 for the two sorghum diets, respectively. We found no correlation between ruminal pH and numbers of protozoa on any diet. The presence of relatively high protozoan concentrations and few defaunated animals in feedlot cattle necessitates reevaluation of the role that ciliated protozoa play in ruminal metabolism of animals fed processed, high-concentrate diets.

Rumen fermentation and rumen microbes in Nellore steers receiving diets with different lipid contents

“…The predominance of the genus Entodinium in the rumen is consistent with the observations of other authors, who researched protozoan populations in cattle under different feeding conditions, such as diets rich in sugar cane (Franzolin & Franzolin, 2000) or concentrate, diets with or without addition of fat (Towne et al, 1990), and the addition of ionophores to diets rich in forage or concentrate (Guan et al, 2006).…”

Rumen microorganisms and fermentation

“…On the other hand, when the amount is not exceeded, a small increase of fat may improve bacterial growth by incorporating the dietary fatty acids and reducing the need for synthesizing them (Amorocho et al 2009). There also have been reports that fattening steers with tallow supplementation causes a decrease of ciliated protozoa populations, however, yellow grease supplementation did not affect numbers of protozoa in steers fed either sorghum or corn diets (Towne et al 1990).…”

Efeito de sementes oleaginosas inteiras e óleo de soja sobre a digestibilidade in vitro e os padrões ruminais de bezerros holandeses

“…Apenas no tratamento controle observou-se presença de Isotricha e Dasytricha. A evidência da sensibilidade dos protozoários em nível de gordura na ração também foi observada por TOWNE et al (1990), quando a adição de 4% de gordura amarela nas rações de bovinos provocou queda no número de Isotricha e Dasytricha, variando o número de Entodinium com a fonte energética utilizada. Isto demonstra que o número e o tipo de população de protozoários é variável e dependente da fonte de gordura utlizada.…”