Browsing by Author "Exell, Katariina"

Transition from pregnancy to lactation is a critical period for dairy cows. During this time period the cow is vulnerable to different metabolic diseases. The rumen function may be disturbed, when rapidly switching to increased concentrate feeding after calving. The cow and its rumen do not have time to get used to the changed feeding and this may cause, for example, rumen acidosis. Lead feeding with concentrate may prevent illness and problems associated with eating feed near calving and in the beginning of lactation. The goal of this study was to determine how lead feeding containing concentrates affects cow’s metabolism, dry matter intake, reticular function, milk yield and milk composition. The experimental feeding of concentrate mixture was based on grass silage, straw and a homemade concentrate (barley 26%, oat 40%, rapeseed meal 13%, faba been 10%, molasses 10%, propylene glycol 1%). The study was a randomized complete block design. The study conducted with 16 Ayrshire cows and it started 3 weeks before calving and ended 8 weeks after calving. Cows were divided into two groups: the lead feeding group and control group. Before the start of the experiment both groups received ad libitum feeding that contain grass-silage (64% of dry matter; D-value 700 g/kg DM), straw (28% of DM) and rapeseed meal (8% DM). Starting from three week before the expected calving date, the lead feeding group received ad libitum a total mixed ration (TMR) of grass silage (49% of DM), straw (21% of DM) and concentrate mixture (30% of DM). The group without lead feeding received still the same ad libitum feeding that contained grass-silage, straw and rapeseed meal. After calving both groups received a similar TMR where roughage/concentrate -ratio was 65:35 (DM). Roughage in TMR included grass-silage and oat whole crop silage mixture (60:40 DM). In addition, the cows received commercial concentrate (max. 6 kg/d) and protein supplement (max. 2 kg/d). The lead feeding did not affect dry matter intake, body condition score, blood composition, milk yield or milk composition of the cows. Average dry matter intake (DMI) nearly doubled in both groups (time p<0,001) to 24 kg/d. Average milk yields were 44 kg/d and 46 kg/d in non-lead feeding and lead feeding groups. Reticulum minimum pH-values (6,2 vs. 6,1, p=0,09) and average pH-values (6,6 vs. 6,5, p<0,05) were greater in the non-lead feeding group and lead feeding group. In conclusion, lead feeding with concentrate did not affect feed intake, milk yield, milk composition or blood concentrations in dairy cows. In this study, lead feeding showed no significant positive effects. However, lead feeding lowered the pH of the cow’s reticulum, suggesting acidification of the rumen.