The effect of individuality of animal on diurnal pattern of pH and redox potential in the rumen of dry cows

Abstract

The aim of this study was to continuously monitor ruminal pH and redox potential of individual dry cows using a newly developed wireless device. Three dry Holstein cows fitted with rumen cannulas were used for the individual measurement of ruminal pH and redox potential (Eh) using a newly developed wireless device. The experiment was carried out in the period of 14 days consisting of a 10-day preliminary period followed by a 4-day measurement period. Cows were fed twice daily the diet based on maize silage, lucerne hay and concentrate. During the measurement period ruminal pH and redox potential were monitored continuously using a developed wireless probe. Average daily feed intake throughout the experiment was 8.2 kg/day. The mean ruminal pH was almost identical in Cows 21 and 25, being 6.79 and 6.75, respectively, and was lower than in Cow 26 (6.86; P < 0.05). The mean Eh of the ruminal fluid was -274 mV in Cow 21 and 26 and -270 mV in Cow 25, while the results did not differ significantly (P > 0.05). The diurnal pattern of ruminal pH and Eh showed a similar trend in all animals. Mean values of rH (Clark's exponent) calculated for Cows 21 and 25 being 4.43 and 4.48, respectively, were lower than the value calculated for Cow 26 (4.59; P < 0.05). This method may be useful for investigating factors affecting the dynamics of ruminal fermentation and may also help in the identification of variables associated with various metabolic disorders.

Keywords

• keywords: redox potential
• ph
• rumen
• measurement in vivo
• wireless device