Adverse effects on reproductive performance and lameness of feeding grazing dairy cows partially on silage indoors

Abstract

SUMMARYEighty autumn-calving (A) and 82 spring-calving (S) British Friesian cows were divided during the grazing season into two groups: one group received silage overnight indoors and grazed herbage during the day (partial storage feeding, P) and the other was conventionally set-stocked (C). The effects of the four treatments (AC, AP, SC and SP) on reproductive performance and herd health are reported for the 27-week grazing season and the subsequent 25-week housed period in 1985/86 in North Wales. Calving to conception interval was not affected by treatment but, in treatment SP, pregnancy rate to all services was lower and number of barren cows was greater than in the other treatments. Partial storage feeding increased the incidence of under-run heel and laminitis in the early part of the grazing season, and this was reflected in poorer locomotion. Treatment SC resulted in an increased incidence of punctured sole with pus later in the grazing season. Both autumn-calving treatments resulted in a large decrease in lameness and poor locomotion at drying off, but these increased in the autumn before housing. The mean duration of each lameness incident was 1·88 months and, in 40 out of 97 incidents, lameness was preceded by uneven gait. The incidence of lameness and poor locomotion was low for all treatments throughout the housed period. It is concluded that a high standard of buildings and reproductive and herd health management is necessary for partial storage feeding to be practised successfully.