E L Packer1, E H Clayton, P M V Cusack. 1. School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia.
Abstract
OBJECTIVE: To determine the prevalence of subacute rumen acidosis (SARA) in beef cattle grazing lush pasture and the effect of monensin on reducing SARA and improving animal performance. DESIGN: Commercial Angus and Murray Grey steers received a monensin slow-release capsule (n = 19) or remained untreated (n = 19). Cattle grazed an oats crop or tetraploid ryegrass pasture for a total of 91 days. Rumen fluid pH, volatile fatty acids (VFA) and lactic acid concentrations and body weight data were collected prior to treatment and again 28, 56 and 91 days after treatment. Changes in measures over time were analysed using mixed model repeated measures analysis. Differences in average daily gain between treatment groups were determined. RESULTS: The prevalence of SARA was low during the study, with only one animal satisfying criteria for SARA at one time point. Cattle treated with monensin capsules were 11.9 kg heavier at the completion of the study compared with untreated controls (414.5 ± 3.88 kg vs 402.6 ± 4.03 kg, P = 0.04). Rumen VFA and L- and D-lactate levels did not differ between cattle treated with monensin and untreated cattle. However, the ratio of propionate to acetate plus two times butyrate was higher (P < 0.001) when cattle were treated with monensin. CONCLUSIONS: Subacute rumen acidosis was not consistently detected under the conditions of the study. The higher body weight of cattle treated with monensin may have been due to improved energy utilisation of the pasture, indicated by increased propionate proportions in the rumen, rather than prevention of SARA.
OBJECTIVE: To determine the prevalence of subacute rumen acidosis (SARA) in beef cattle grazing lush pasture and the effect of monensin on reducing SARA and improving animal performance. DESIGN: Commercial Angus and Murray Grey steers received a monensin slow-release capsule (n = 19) or remained untreated (n = 19). Cattle grazed an oats crop or tetraploid ryegrass pasture for a total of 91 days. Rumen fluid pH, volatile fatty acids (VFA) and lactic acid concentrations and body weight data were collected prior to treatment and again 28, 56 and 91 days after treatment. Changes in measures over time were analysed using mixed model repeated measures analysis. Differences in average daily gain between treatment groups were determined. RESULTS: The prevalence of SARA was low during the study, with only one animal satisfying criteria for SARA at one time point. Cattle treated with monensin capsules were 11.9 kg heavier at the completion of the study compared with untreated controls (414.5 ± 3.88 kg vs 402.6 ± 4.03 kg, P = 0.04). Rumen VFA and L- and D-lactate levels did not differ between cattle treated with monensin and untreated cattle. However, the ratio of propionate to acetate plus two times butyrate was higher (P < 0.001) when cattle were treated with monensin. CONCLUSIONS: Subacute rumen acidosis was not consistently detected under the conditions of the study. The higher body weight of cattle treated with monensin may have been due to improved energy utilisation of the pasture, indicated by increased propionate proportions in the rumen, rather than prevention of SARA.
Authors: Keith W Savin; Peter J Moate; S R O Williams; Carolyn Bath; Joanne Hemsworth; Jianghui Wang; Doris Ram; Jody Zawadzki; Simone Rochfort; Benjamin G Cocks Journal: PLoS One Date: 2022-05-19 Impact factor: 3.240
Authors: Gaye L Krebs; Daniel W De Rosa; Dana M White; Bronwyn L Blake; Kenneth C Dods; Christopher D May; Zi X Tai; E H Clayton; Emma E Lynch Journal: Transl Anim Sci Date: 2021-11-12
Authors: Ethan K Gough; Erica E M Moodie; Andrew J Prendergast; Sarasa M A Johnson; Jean H Humphrey; Rebecca J Stoltzfus; A Sarah Walker; Indi Trehan; Diana M Gibb; Rie Goto; Soraia Tahan; Mauro Batista de Morais; Amee R Manges Journal: BMJ Date: 2014-04-15