Browsing by Subject "verkkomahan pH"

After calving dairy cows increase their dry matter intake rapidly and at the same time the diet changes from dry period diet to a diet containing more concentrates. These changes can increase the risks of health problems in rumen and decrease the rumen pH. Long and repeated periods of low rumen pH can lead to subacute rumen acidosis (SARA). Adding small amounts of concentrates to the diet before calving is a traditional method to alleviate problems around calving. Lately some researchers have questioned the benefits of lead feeding. Some Finnish farms don’t give lead feeding anymore because it increases the labor work and costs. The experiment was a randomized complete block design, where 16 ayrshire cows were divided into pairs according to their previous milk yield, body weight and estimated calving day. One cow in each pair was fed cereal concentrate 3 weeks before calving in addition to grass silage while the other cow was fed only grass silage. The silage (D-value 715 kg/kg DM) was fed ad libitum. Reticular pH and temperature, ruminating time and eating behaviour was measured 3 weeks before calving and 8 weeks after calving. Treatments did not affect the reticular pH (p>0.10). None of the cows had a reticular pH under the SARA-treshold (over 5.24 h/d under 5.8 and mean pH<6.16). The mean reticular pH was 6.6 before calving and 6.5 on days 1-10 after calving. The lead feeding group spent less time eating in a day (180 vs. 230 min/d, p<0.001) and had higher eating rate (kg DM/min) than the non-lead fed group (p<0.01). The effect remained after calving. During days 1 to 10 d after calving lead feeding group ate less than non-lead fed group (15.0 vs. 16.3 kg DM/d, p=0.02). Before calving the non-lead fed group had longer rumination time than the lead-feeding group (465 vs. 395 min/d, p=0.01). After calving the difference in the ruminating time tended to sustain (p=0.13). The lead feeding shortened the daily eating and ruminating times pre- and postpartum. Reticular pH did not differ between treatments but lead feeding group had higher reticular temperature, lower rumination time and decreased feed intake during very early lactation which may indicate problems in pH-balance.