Ruminal effects of excessive dietary sulphur in feedlot cattle

CASTRO, DAMIÁN JESÚS; CERÓN-CUCCHI, MARÍA ESPERANZA; ORTIZ-CHURA, ABIMAEL; DEPETRIS, GUSTAVO JESÚS; IRAZOQUI, JOSÉ MATÍAS; AMADIO, ARIEL FERNANDO; CRAVERO, SILVIO; CANTÓN, GERMÁN JOSÉ

JOURNAL OF ANIMAL PHYSIOLOGY AND ANIMAL NUTRITION

WILEY-BLACKWELL PUBLISHING, INC

Año: 2021

0931-2439

Sulphur (S) dietary excess can limit productive performance and increase polioencephalomalacia (PEM) incidence in feedlot cattle (FC). Sulphur excess ingested is transformed to hydrogen sulphide (H2S) by sulfo-reducing ruminal bacteria (SRB), being high ruminal H2S concentration responsible for aforementioned damages. As the ruminal mechanisms involved in H2S concentrations increase have not been elucidated, this study aimed to evaluate the ruminal environment, and the association between ruminal H2S and dissimilatory SRB (DSRB) concentration in FC experimentally subjected to S dietary excess. Twelve crossbred steers were randomly assigned to one of two dietary S levels (6 animals per treatment): low (LS, 0.19% S) and high (HS, 0.39% S obtained by sodium sulfate inclusion at 0.86%). The study lasted 38 days, and on days 0, 22 and 38, ruminal gas samples were taken to quantify H2S concentration, and ruminal fluid to determine total bacteria, DSRB, protozoa, volatile fatty acid and ammonia nitrogen concentration. For ruminal H2S concentration, S dietary × sampling day interaction was significant (p