A high proportion of the diseases in a cow’s life occur around the calving period, such as, metritis, milk fever, and mastitis, or are triggered by events around calving, sych as endometritis and non-cycling.
Doing the best you can for cows through this period will reduce risk of disease, increase production and reproduction, and save a lot of time onfarm.
A body condition score of 5 around calving is important to achieve optimal production and reproduction. It’s very difficult to get body condition score on in the last month or so before calving as dry matter intake and gut fill are reduced, so it’s important body condition score is managed to achieve a condition score of 5 starting well before calving and to ensure that animals do not lose body condition score approaching calving. In the couple of weeks leading into calving the aim is to ensure there is sufficient energy going into the cows to meet the requirements for the growing foetus as well as maintenance for the cow. To achieve this, cows, depending on size, need 10-12kg drymatter day of moderate energy food at greater than 11 megajoules of metabolisable energy.
It is important that cows adapt before calving to what they will be fed after calving. So use of the feedpad, or if in bail feeding is to be used, then running cows and heifers through the dairy pre-calving will allow adaptation to the post-calving diet. Those cows not eating well before calving are at higher risk of uterine disease after calving.
Calcium intake should be restricted before calving to stimulate calcium absorption from the gut, so post-calving cows can increase their absorption and efficiently mobilise calcium from the bone to meet the massive increase in calcium needs early after calving.
Cows also need adequate magnesium. This can be achieved by dusting or by using magnesium chloride or magnesium sulphate through water systems. While the latter approach is convenient, there can be issues of palatability, and particularly with a lot of rain or access to waterways, cows may not have adequate intakes.
Close attention to cow health in the colostrum mob should also be a focus. Early detection and treatment of milk fever cows is obviously important. Using oral calcium and energy supplement after calving, particularly for high-risk cows such as older cows or Jerseys, may be a useful strategy.
Cows are also at high risk of environmental mastitis through the calving period so daily stripping, and use of the rapid mastitis test before moving cows from the colostrum to the main mobs enables earlier detection of problem cows and protects against spikes in the bulk milk somatic cell count.
All cows will lose body condition after calving as energy intakes will not meet the requirements for milk production in the first month or so after calving.
Optimising feed intake after calving will minimise body condition loss and minimise the period of time a cow is in negative energy balance. Losses of more than one condition score will result in poorer reproduction downstream. Cows losing excessive amounts of body condition will mobilise excessive amounts of fat which may result in ketosis bodies, which in turn reduces immune function. Monitoring for ketosis using a recently introduced cow-side test will give early warning of excessive body condition stripping.
Recording cows that have disease around calving is useful, as these cows are at higher risk of uterine disease and poorer reproductive performance. It’s worth checking any cow with disease around calving for uterine disease a month or more before the planned start of mating. Keeping track of the total number of animals with calving disease will give you an idea whether the overall transition period management is effective.
Having more than 2% of cows with milk fever or retained cleanings, or more than 5% of cows with clinical mastitis or 5% of cow deaths or culls within a month of calving should trigger a review of transition cow management.
Effective management through the calving period will result in happier healthier cows, better production and reproduction and reduced workloads for the farm team.
Scott McDougall is a vet with Cognosco, Anexa Animal Health, Morrinsville.
