Biting rate in grazing cattle is difficult to record automatically compared
with grazing time, ruminating time, or total jaw movements per day. We tes
ted the feasibility of an automatic system for measuring biting rate based
on the sound made by severing of the herbage, which is specific to the bite
. The portable device described is based on two sensors: a microphone, loca
ted beneath the lower jaw, and a mercury switch to determine the inclinatio
n of the head, located in a case attached to the neck of the cow. Bites are
detected in real time and data are stored in memory every minute before se
rial transfer to a computer. The bitemeter was validated during 11 sequence
s for a total of 514 min on Four Holstein dairy cows strip-grazing on veget
ative perennial ryegrass (Lolium perenne L.) swards by comparing with visua
l observations, comparison bring possible each minute. The mean bias betwee
n bitemeter and manual recording varied between sequences from -5.8 to +3.1
bites.min(-1) (-12.2 to +7.5%) with an average of -1.6 bites.min(-1) (-3.3
%). It was not related to award height. The within-sequence variability of
this bias was on average 3.5 bites.min(-1) and was not related to the numbe
r of bites.min(-1). It is concluded that the automatic recording of biting
rate in grazing cattle is possible with a good degree of precision on the b
asis of the sound created by severing of the herbage. Nevertheless, additio
nal protection of the microphone and a better standardization of its positi
on would appear necessary for a routine use of the bitemeter in experimenta
l trials. ((C) Elsevier / Inra).