Herbage dry matter intake of individual dairy cow using a wireless bite counter for grazing based production system in Ethiopia; a case study

Measurement of intake of individual grazing animals remains one of the fundamental challenges to improving efficiency of livestock production. Information about the individual herbage dry mater intake (HDMI) of grazing dairy cow is important for an efficient use of pasture herbage and to ensure the release of adequate nutrients for maintenance and production. However, practical and reliable methods are not available to measure intake of pasture by individual dairy cow particularly for grazing based production system for developing countries. Thus, this research was initiated to estimating HDMI using the wireless bite counter system for individual dairy cow in comparison with other methods. A simple, compact bite counter was used to record dairy cow jaw movements to estimate feed intake. The device is composed of a pendulum, a microcontroller, and a transmitter attached to a collar. The utility of the bite counter recordings in estimating intake was experienced for 16 Dairy cows of which nine Local and seven Holstein Friesian crossbred dairy cows. The experiment was conducted for two consecutive years (2018 and 2019) during the main rainy seasons (June to October) of Ethiopia. For comparison, cage system intake estimation was also conducted using sixteen individual paddocks established in the grazing land of Andasa livestock research enter. The grazing herbage in the paddock dominantly comprised of Cynodon plectostachyus, Hyparrhenia rufa, Paspalum notatum, Setaria viridis and Trifolium species. For the calibration of the bite counter, the correlation between the number of bites measured by personal observation and the values reported by the bite counter was linear with an R2 value of 0.74. The average HDMI using the bite counter was 4.2 kg DM/day and 7.7 Kg DM/d for local and crossbred individual dairy cow, respectively. The HDMI could be estimated by applying linear regression to the number of bite counts with R2 values of 0.68. In conclusion, the wireless bite counter offer new opportunities for rapid estimation of HDMI. Moreover, the bite counter was easy to attach to the cows using the collar and could be used effectively by farmers in the grazing based dairy production system in Ethiopia.