Effects of a monensin controlled release capsule on reticulorumen temperature and pH determined using real-time monitoring in fresh dairy cows

Abstract

Monensin has been shown to decrease mortality and morbidity in feedlot cattle by reducing the incidence of acute and subacute rumen acidosis (SARA). Lately, the technique of real-time observance of reticuloruminal temperature and pH, which involves placement of indwelling pH probes in the reticulum or in the rumen has gained in popularity. In this study, we aimed to determine, using real-time monitoring in fresh dairy cows, how monensin controlled release capsules affect the reticulorumen temperature and pH. We used a slow-release rumen preparation, which emitted daily monensin doses of 335 mg. Following the manufacturer’s instructions, the preparation was administered through an oral balling gun. The following points indicate the method for determining the two experimental groups: (1) monensin-supplemented test group (TG) (a 32.4 g monensin controlled release capsule, MCRC, n = 20) and (2) a control group (CG) (capsule containing no monensin, n = 20). Both began a day after calving, and one month after calving the experiment was finished. A set of smaXtec boluses fabricated for animal care was used to measure the temperature and pH of the reticulorumen. After the first day of the study, a statistically significant difference between reticulorumen temperature in CG (38.67 ± 0.10 °C) and TG (39.08 ± 0.09 °C; P < 0.01) was found. The use of the monensin controlled release capsule, which emitted daily monensin doses of 335 mg, in the first 30 days after calving increased the reticulorumen pH by 1.89% (P < 0.001), and the temperature of the reticulorumen by 0.82 % (P < 0.001). We conclude that using monensin in the form of monensin controlled release capsules reduces the risk of SARA. Real time observation of temperature and pH levels in the reticulorumen in fresh dairy cows allows for evaluation of the risk of SARA and provides the opportunity to determine the prophylactic effect of those capsules.