Pattern of milk production and behaviour of dairy cows according to the residence time per paddock
Résumé
Under rotational grazing systems, the residence time per paddock may vary from 1 to 10 days according to paddock size. The farmer’s decision to change a herd from one paddock to another one is not always easy. We hypothesised that recording grazing behaviour may help farmers to take decisions. The objective of this study was to determine the effect of the residence time (1, 2, 4 or 8 days per paddock) on the pattern of milk production and grazing behaviour in rotationally grazed dairy cows. Treatments were compared in a completely randomised design with 9 Holstein cows per treatment, during 72 days in spring 2018. Residence times were obtained from changing paddock size, and treatments were compared at similar levels of herbage allowance. Milk production and grazing time were recorded daily. The average milk production was similar between treatments. However, milk production and grazing time varied cyclically, with both duration and amplitude of the cycles directly proportional to the residence time. Cows never stopped grazing, even at longest residence time, with very low pasture herbage availability in the last days. It is concluded that recording of grazing behaviour is not sufficient to help farmers take grazing management decisions.