The aim of the project was to investigate how the length of the dry period affects the health of the cows and the composition and quality of the milk.
Today, it is recommended that the dry period cover approximately 8 weeks, but today's dairy cows are often still in a high milk yield when it is time for drying off , which increases the risk of mastitis and metabolic problems during the dry period and around calving . A postponement of the dry period will decrease the yield at dry-off and in turn generate a more gentle dry off. This will ease the burden on metabolism after calving and fertility will improve in cows with shorter than traditional dry period.
But a short dry period can reduce yields during the next lactation. It is unclear how the dry period length affects the cows' health in general and udder health in particular, and how it affects milk composition and quality. In this study, we are looking for the answers to these questions, and if for some individuals there are reasons to favor a shorter dry period than the 8 weeks generally recommended today. We also examine the colostrum quality and the calves' health in relation to their dam's dry period.
Expected effects of a shortened dry period
• energy balance improves in the first weeks after calving
• milk yield , from dry-off to dry-off , increases with shorter dry period
• fertility and udder health improves
• feed efficiency , defined as the milk produced in relation to the feed consumed increases
• a short dry period is less suited for second time lactators than for older cows
• a short dry period is more suited for cows of Swedish Holstein breed than for Swedish red breed
• milk (including colostrum ) composition and quality is not affected
• improved profitability for dairy farmers and a higher milk yield quota in Sweden