Validation of an automatic jaw movement recorder

A team of Swiss researchers evaluated and validated an automatic jaw movement recorder (RumiWatch, hereafter called RWS) for ingestive and rumination behaviours of dairy cows during grazing and supplementation in the barn. The results have been published in the Journal of Dairy Science.

Experimental set-up

The data were collected from an experiment carried out with 18 lactating Holstein cows in a crossover block design including 3 treatments and 3 measuring periods. All cows grazed night and day, 19 h/d, and were either unsupplemented or supplemented, with chopped whole-plant corn silage, or chopped whole-plant corn silage mixed with a protein concentrate. During the measuring periods, cows were equipped with the RumiWatch Halter, and their ingestive and rumination behaviours were recorded concurrently by the RumiWatch Halter and by direct observation (690 × 10 min).

Validation of an automatic jaw movement recorder. Photo: Jan Dijkstra

Classification errors

Comparison of concurrently measured data showed that the RWS detected jaw movements reliably, but classification errors occurred. A low relative prediction error of ≤0.10 for the number of rumination boluses, rumination chews, and total eating chews was found. A high relative prediction error of >0.10 was found for the number of prehension bites and time spent in prehension and eating. Both converter versions performed equally well in differentiating ingestive and rumination behaviours when cows were supplemented in the barn or when grazing and supplementation activities were combined. For grazing cows, with no supplementation, more reliable results for the total number of eating chews, rumination chews, prehension bites, and time spent in these activities were obtained, by using the RumiWatch Converter 0.7.3.11.

More research needed on accuracy

Based on these findings, the researchers suggest to do more research to improve the accuracy of the RWS and to allow a differentiation between mastication chews and prehension bites while eating.

The full paper can be read here.