Rumenozentese: Eine geeignete Methode zur pH-Bestimmung im Pansensaft beim Rind?

A retrospective study on transabdominal ultrasound measurements of the rumen wall thickness to evaluate chronic rumen acidosis in beef cattle

BACKGROUND

Chronic and subacute rumen acidosis are economically important in the beef industry. The aim of this study was to evaluate the potential suitability of the transabdominal ultrasonographic examination of the ruminal wall to diagnose chronic rumen acidosis in beef cattle compared to direct measurement of ruminal pH, as a fast non-invasive tool to be used in field condition. Ultrasonographic examination of the rumen was conducted in 478 beef cattle before rumenocentesis (chronic rumen acidosis group = pH ≤ 5.8; healthy group = pH ≥ 5.9). Rumen wall ultrasound measurements included rumen wall thickness (RWT) and rumen mucosa and submucosa thickness (RMST).

RESULTS

The Analysis of Variance showed the high significant effect of the pH class for RWT and RMST (P < 0.001). Spearman RANK correlation analysis showed interaction between rumen pH and RWT (- 0.71; P < 0.0001) and RMST (- 0.75; P < 0.0001). A significant Spearman's correlations were found between volatile fatty acids (VFA) and RWT and RMST. The differentiation efficiency of RWT between healthy and chronic rumen acidosis groups, as a result of the receiver operator curve (ROC) analysis, was quite good with an area under the receiver operator curve (AUROC) of 0.88: P < 0.0001; 95% CI: 0.83-0.98. Using a cut-off value of > 8.2 mm. The differentiation efficiency of RMST between healthy and chronic rumen acidosis groups, as a result of ROC curve analysis, was good with an AUROC of 0.90: p < 0.0001; 95% CI: 0.85-0.94. Using a cut-off value of > 5.3 mm.

CONCLUSIONS

In this study, the thickening of RWT and RMST is correlated with the changes of ruminal pH. Transabdominal rumen ultrasound has the potential to become a powerful diagnostic tool useful to identify fattening bulls affected by chronic rumen acidosis.

Randomised prospective study compares efficacy of five different stomach tubes for rumen fluid sampling in dairy cows

The objective of the study was to compare the performance of five types of stomach tubes for rumen fluid sampling. Rumen fluid was sampled in rumen fistulated cows assigned to a 5×5 Latin square study design. The pH values of samples taken by stomach tubes and via fistulas were measured; the results were compared with indwelling sensor measurements. The practicability of the stomach tubes for regular use was tested in the field. Rumen fluid samples were obtained rapidly. Volumes for transfaunation could be obtained. The pH-values of samples taken with the four out of the five tubes (Dirksen, Geishauser, tube 4 and a simple water hose used with a gag) did not show significant differences to samples taken via rumen fistulas. Mean differences ranged between -0.02 and +0.09. Samples taken with tube 4 and the water hose showed also no significant differences to pH-sensor measurements. This study demonstrates that stomach tubes are suitable for rumen fluid sampling. Tube 4 seems to be the best probe for work in the field. It was well tolerated by the animals, saliva contamination is negligible. We, therefore, conclude that the evaluation of rumen acid base status in the field is possible.

Continuous measurement of reticuloruminal pH values in dairy cows during the transition period from barn to pasture feeding using an indwelling wireless data transmitting unit

This study was performed to investigate the effect of the transition from barn feeding to pasture on the pattern of reticuloruminal pH values in 8 multiparous dairy cows. A indwelling wireless data transmitting system for pH measurement was given to 8 multiparous cows orally. Reticuloruminal pH values were measured every 600 s over a period of 42 days. After 7 days of barn feeding (period 1), all of the animals were pastured with increasing grazing times from 2 to 7 h/day over 7 days (period 2). From day 15 to day 21 (period 3), the cows spent 7 h/day on pasture. Beginning on day 22, the animals had 20 h/day access to pasture (day and night grazing). To study reticuloruminal adaptation to pasture feeding, the phase of day and night grazing was subdivided into another 3 weekly periods (periods 4-6). Despite a mild transition period from barn feeding to pasture, significant effects on reticuloruminal pH values were observed. During barn feeding, the mean reticuloruminal pH value for all of the cows was 6.44 ± 0.14, and the pH values decreased significantly (p < 0.001) during period 2 and 3 to 6.24 ± 0.17 and 6.21 ± 0.19 respectively. During periods 4, 5 and 6, the reticuloruminal pH values increased again (pH 6.25 ± 0.22; pH 6.31 ± 0.17; pH 6.37 ± 0.16). Our results showed that the animals had significantly lowered reticuloruminal pH during the periods of feed transition from barn to pasture feeding. Despite these significant changes, the decrease was not harmful, as indicated by data of feed intake and milk production.

Continuous and Long-Term Measurement of Reticuloruminal pH in Grazing Dairy Cows by an Indwelling and Wireless Data Transmitting Unit

The aim of the present study was the continuous measurement of ruminal pH in grazing dairy cows to monitor the diets effects on ruminal pH value. A novel indwelling pH-measurement and data transmitting system was given to 6 multiparous cows orally. Ruminal pH was measured every 600 sec over a 40 d period. After barn feeding and changeover to pasture, the following 3 treatments (2 cows/treatment) were included in the measurement period: continuous grazing (G), continuous grazing plus 4 kg/d of hay fed twice daily (GH), and continuous grazing plus 4 kg/d of concentrate (GC). Ruminal pH decreased significantly (P < 0.05) from 6.58 ± 0.15 to pH 6.19 ± 0.19 during feed changeover to pasture. Mean ruminal pH for G, GH, and GC was 6.36, 6.56, and 6.01. Mean 24-h minimum pH was 5.95, 6.20 and, 5.58. The time pH was below 6.3, 6.0, 5.8, and 5.5, for G it was 583, 91, 26, and 3 min/d, for GH it was 97, 12, 0, and 0 min/d and for GC it was 1126, 621, 347, and 101 min/d, respectively. Results were significantly influenced by the diet. The indwelling pH-measurement and data transmitting system is a very useful and proper tool for long-term measurement of ruminal pH in cows.

Evaluating the Effects of Rumenocentesis on Health and Performance in Dairy Cows

The objective of this study was to evaluate the effects of the rumenocentesis procedure on dairy cows by determining selected metabolic and physiological variables representing the health status. Two groups of 6 cows either underwent rumenocentesis (GA) or sham (GB) procedures. Superficial skin temperature of the rumenocentesis area was measured using infrared thermography before the procedure (-1 h), immediately after (0 h), and at 48 h, 96 h, and 20 days following rumenocentesis. Blood samples were collected at all times, except for immediately after the procedure (0 h), and selected immunologic response variables were determined. Milk yield and rectal temperatures were measured daily. Rumenocentesis did not influence the white blood cell count, haptoglobin or total protein concentrations. Electrophoretic protein fractions were not different between GA and GB treatments. Milk yield and rectal temperature were not affected by rumenocentesis. Skin temperature of the rumenocentesis region in GA group cows increased by 1.0 °C immediately after rumenocentesis and returned to baseline after 48 h where it remained constantly until the end of the study; similar to observation in GB group cows. Results of this study would suggest minimal adverse effects on cow health and production when performing rumenocentesis for the diagnosis of subacute ruminal acidosis. Additional more intensive studies addressing animal welfare issues relative to the diagnostic techniques are needed.