The reticulo-ruminal motility pattern in goats

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A recent study has provided new insights into reticulo-ruminal motility patterns in goats, through the use of cutting-edge imaging technology. Investigators from Hunan Agricultural University in Changsha, China, have found that reticulo-ruminal motility was divided into primary and secondary contraction, and the movements of ruminal digesta depended on reticulo-ruminal motility.¹

The study, published in Frontiers in Veterinary Science, allowed for visual analysis of reticulo-ruminal motility video, noted variation of motility times, and determined that the rumen dorsal sac and the rumen dorsal blind sac had common motility after reticulum contraction. The research offers new insights for the study of gastrointestinal motility, encouraging future studies of artificial rumen, according to the study's authors.¹

Investigators used 6 Xiangdong black goats as model specimens. Using medical barium meal imaging and dynamic digital radiography (DR) technology, the team obtained 56 complete reticulo-ruminal motility videos—32 from bucks and 24 from does—in addition to 10 stages of images captured in 3-minute segments. The videos were analyzed using image annotation and the centroid method, which found there to be 24 instances of secondary motility across all videos; 14 for the bucks, and 10 for the does.¹

There were 4 stages of reticulo-ruminal primary movement indicated in the study:

• Stage I: The initial stage, marked by the 2-phase contraction of the reticulum.
• Stage II: Common for relaxation of the reticulum, contraction of the rumen dorsal sac and the rumen dorsal blind sac.
• Stage III: Common for relaxation of the rumen dorsal sac and the rumen dorsal blind sac.
• Stage IV: The contraction and relaxation of the rumen abdominal blind sac.

Investigators noted that the motility frequency of the rumen abdominal blind sac was low during the complete reticulo-ruminal motility cycle. Rumen digesta were distinguishable in the images because of the dispersion of the barium sulfate solution.

In the video, ruminal digesta motility was divided into 3 continuous stages¹:

1. Contraction of the reticulum squeezed the digesta into the rumen.
2. Relaxation of the reticulum and contraction of the rumen dorsal sac and the rumen dorsal blind sac divided digesta movement in 3 directions.
3. Relaxation of the rumen dorsal sac and the rumen dorsal blind sac, as well as contraction of the rumen abdominal blind sac, leading to reciprocated motility. Additionally, there is movement of some digesta from the rumen abdominal sac/rumen abdominal blind sac to the rumen dorsal sac.

Results of a comparative analysis indicated that stages I, II, III, interval, and secondary contraction time were longer in bucks, whereas stage IV was longer in does. This is something that researchers attribute to variations in nerve regulation between sexes. Additionally, through video analysis tracking the capsule cavity area “labeled” by barium sulfate solution, investigators were able to determine that reticulum motility involved a 2-phase contraction. Through the same analysis, they found that the rumen dorsal sac and the rumen dorsal blind sac had common motility following reticulum contraction.¹

The study verified the feasibility of using dynamic DR, barium meal imaging technology for the assessment of reticulo-ruminal and digesta motility. Early studies in reticulo-ruminal motility relied on methods including fistulas and electromyography, which improved the understanding of rumen contractions. Tools including ultrasound and CT provided investigators with noninvasive alternatives to observe motility, though they came with their own limitations—ultrasounds had a restricted field of view and CT required anesthesia, which could affect motility patterns.¹

Findings of the study aligned with previous research, but the use of dynamic DR allowed for a more detailed view of the sequence and interactions within goats’ digestive tracts. The study is a significant contribution towards the overall understanding of ruminant digestion, emphasizing the potential of further improvements in imaging techniques, according to the authors. Investigators expressed their interest in future research, ideally combining motility with artificial rumen—flexible material 3D printing—in order to simulate natural motility characteristics and construct a comprehensive in vitro flexible artificial rumen simulation device.¹ 

Reference

1. Song Y., Lan X., Liu L., et al. Exploring the reticulo-ruminal motility pattern in goats through medical barium meal imaging technology. Front. Vet. Sci. 2024;11. https://doi.org/10.3389/fvets.2024.1371939