It is very difficult to alter body condition score during a standard 60-day dry period, a recent study has found.
The study across nine Ulster dairy farms, involved 567 cows which were split into two groups – “high” for those with a body condition score (BCS) at or above 2.75, and “low” for those at or below BCS 2.5.
The cows in the “low” group were assigned one of three treatments: silage only for the whole period, silage and concentrates for the last three weeks of the dry period, and silage and concentrates for the whole dry period.
While those in the “high” group were only assigned to two treatments: silage only for the whole dry period, and silage and concentrates for the last three weeks of the dry period.
First-year results from the study show that over the first seven months of the subsequent lactation, cows in the “high” group averaged two litres a day more milk than those in the “low” group.
It was found that none of the treatments had a significant effect on milk yield or compositional quality. The concentrates were found to help gut fill in the “low” group to a certain extent, but there was no significant difference in BCS between treatments.
Furthermore, even on farms with low quality silage (<10 ME) there was no response to concentrates, which were found to have no impact on calf birth weights.
It was concluded that it was very difficult to alter body condition score during a standard 60-day dry period, and cows with a high BCS at drying off were more likely to lose condition in the run up to calving and in early lactation.
The Transition Cow Management study was funded by farmers through AgriSearch and the government through the DARD Research Challenge Fund.