الكاتب: Multiple References

The effects of induced subclinical hypocalcaemia (SCHC) on feed intake and chewing activity during eating and rumination were studied in dairy cows Two non-lactating and non-pregnant cows were subjected to three different treatments, with one test per day. such that the plasma free (ionized) calcium Ca) concentration was maintained at the eucalcademic level or at one of two constant SCHC levels The cows and test days followed a2x3 crossover design SCHC was maintained for 7h by repeatedly infusing 5 Na2EDTA so that constant Ca concentrations of 0. 8 mmol / L or 0. 6 mmol / L in plasma were achieved, Control conditions were achieved by infusing isotonic saline Feed intake and the number of the rumination periods were recorded during test days. The proportion of feed ate during each test meal (EatPro) was related to the mean plasma Cad. An almost linear decrease in EatPro was observed when the plasma Ca was 0. 60. 9 mmol / L. The cows shown no other clinical signs of hypocalcademia during Na2EDTA - infusion. The time spent chewing during eating and rumination, and the number of rumination periods during a test day, decreased with decline in plastna FCa CGficentration, It was concluded that induced SCHC depresses the feed intake and ruminative activity of dairy Cows