Analysis of rumen motility patterns using a wireless telemetry system to characterize bovine reticuloruminal contractions

Abstract Text: The objective of this study was to characterize rumen motility patterns of cattle fed once daily. Eight ruminally-cannulated Holstein steers (BW = 321 ± 11 kg) were fed alfalfa cubes once daily at 1.5 × NE_m top-dressed with a TM-salt pre-mix. Three 24-h collection periods were conducted and each commenced immediately following feeding. A wireless telemetry system (emkaPACK4G telemetry system, emka TECHNOLOGIES USA, Falls Church, VA) was used to monitor real-time pressure changes in the rumen. Pressure transducers and transmitters were housed in a plastic container with screw-on lid that served as the cannula cap. A weighted (300 g), water-filled (1 L), balloon-tipped catheter was connected to the transducer through an adapter and placed below the mat in the ventral sac of the rumen. Data were recorded and stored using iox2 software (iox 2.9.4.27, emka TECHNOLOGIES USA) which utilized a rhythmic analyzer to analyze the raw rumen pressure data, identify ruminal contractions, and calculate the following parameters for each contraction: baseline pressure, peak pressure, amplitude, frequency, time to peak, relaxation time, duration, and area under the curve. Mean results were calculated for each parameter (Table 1). All parameters were affected (P < 0.0001) by animal and hour. Baseline and peak pressure of contractions increased through 14 h post-feeding, which may have been due to animals laying down more often. Amplitude of ruminal contractions was greatest the first 5 h post-feeding and then decreased quickly. Frequency, duration, and area decreased throughout the collection period, but increased shortly before the next feeding. Mean water intakes for the first and second 12 h post-feeding were 35.5 ± 2.19 L and 0.92 ± 0.26 L, respectively. These data demonstrate that wireless telemetry can be used to noninvasively monitor rumen motility patterns in freely moving steers. Feeding management impacts the values obtained and must be considered when designing experiments. 

Table 1. Means values and range between animals for rumen contraction variables measured 

Item, units		Mean1		SEM2		Range3
Baseline, mmHg		22.99		2.35		8.35
Peak, mmHg		30.28		2.47		8.26
Amplitude, mmHg		7.29		0.40		1.04
Frequency, contractions/min		2.87		0.17		0.83
Time to peak, s		4.06		0.33		1.18
Relaxation time, s		5.22		0.47		1.14
Duration, s		9.28		0.62		1.74
Area, mmHg*s		30.41		2.43		6.35

¹ Mean = overall mean

²SEM = standard error of the mean, n = 8

³Range = range of means between the 8 animals

Keywords: forestomach, motility, rumen pressure