the effect of subclinical ketosis in early lactation on productive and reproductive performance of dairy cows in mazandaran province

the objective of this study was to determine cows with subclinical ketosis (sck) with metabolic profile test and subsequent health and productive performances compared to cows without sck. ninety six holstein dry cows were blocked within parity for similar expected calving dates. blood samples were drawn from tail vein 1wk before calving and 1wk after calving. nefa and bhba concentrations were determined by computerized analyzer (ra-1000 technicon, usa). data were consider with variance analyze. results showed 41.6 percent of cows had sck after calving. incidence percentage of retained placenta, metrit and mastitis were higher in cows with sck compare to cows without sck (p < 0.05). day to first service (dfs) and open days (op) were increased in cows with sck compare to cows without sck (p < 0.05) whereas conception rate from first service in cows with sck decreased. in conclusion sck can affect animal health and with increased sensitivity to diseases and metabolic disorders during calving and after calving can be a threat for productive and reproductive performance of dairy cows.