Browsing by Author "Pyhälammi, Anne"

The objective of this study was to investigate how the fiber content of dry period diet affects feed intake, energy intake, mobilization of tissue reserves and milk production. Sixteen multiparous Ayrshire dairy cows were used in a completely randomized block design. Cows were divided into pairs according their expected calving date, parity and body condition score. Within pairs the cows were randomly allocated to a grass silage-diet (GS) ab libitum or a total mixed ratio (TMR) – diet ab libitum. The NDF contents of TMR and silage were 651 g/kg DM and 531 g/kg DM, CP 122 g/kg DM and 126 g/kg DM and metabolizable energy (ME) contents 9,1 MJ/kg DM and 10,1 MJ/kg DM. Lead feeding was carried out with concentrate that was given 10 days prepartum starting from 1 kg per day, and increasing to 2 kg per day 5 days before parturition. Postpartum both groups had grass silage ab libitum and the amount of concentrate was increased with similar rates in both groups. During dry period feed intake was greater for GS than TMR (13,7 vs. 10,8 kg DM/day, p<0,001). Energy intake for GS was 144 MJ/day and for TMR 109 MJ/day (p<0,001). GS gained more live weight during dry period than TMR (p=0,03). However, no difference was observed in BCS change. Rumination time was over 90 min/day greater in GS than in TMR (p=0,002) during dry period. After parturition there was no difference in feed intake between groups. There was no difference in average milk yield between groups (42,8 vs. 40,1 kg/day, p=0,18) but milk yield of GS was greater in weeks 5 – 8 (time*treatment, p=0,05). Protein (time*treatment, p=0,05) and lactose yields (time*treatment, p=0,02) were greater for cows in GS during the last weeks of the experiment. Fat content was greater in GS during the two first weeks of lactation (time*treatment, p=0,003). High fiber content of TMR possibly caused lower feed intake and rumination activity in TMR –group. Lower milk yield and milk fat content may have been caused by short and limited lead feeding. Lead feeding was not efficient enough to adapt the rumen to lactation diet. It is possible to limit the energy intake during dry period by increasing the fibre content of the diet. Further investigation is needed for the effect of lead feeding on ruminal epithelium on high fibre TMR.