Individual variation in concentrate consumption rate of pregnant ewes

The aim of this study was to examine the variation within and between individuals in concentrate consumption rate and the effect of social facilitation. Eight pregnant ewes (four primiparous and four multiparous), were fed a low amount, 250 g, of concentrate twice a day with ad libitum access to forage hay. The ewes ate their ration of concentrate individually to examine the variation in consumption rate (Experiment 1) and in pairs to look at the effect of social facilitation (Experiment 2); both experiments had eating bouts limited to 60 s. On average, the eight ewes had a concentrate consumption rate 172.0 ± 10.5 g/min (mean ± SD) when fed individually and 183.0 ± 8.9 g/min (mean ± SD) when fed pairwise. The coefficient of variation (CV) of consumption rate within and between ewes fed singly averaged 6.0% and 5.6%, respectively. When fed in pairs, the CV within individual ewes decreased to 4.9% and the CV between ewes increased to 9.4%. In conclusion, the overall CV for consumption rate was small, and when ewes are kept in groups under commercial conditions and fed concentrates in a long trough each ewe will consume approximately the targeted amount of concentrates.