Drying off: First lactation cows that are due to calve for the second time in February should be dried off over the next few weeks, to give them a 12-week dry period. This might seem long, but it is considered best practice, even where body condition score is good. These animals are still growing and a long dry period will take some pressure off them and allow these cows to recover from their first lactation and prepare for their second, which can often be the most difficult. In many herds a higher proportion of second lactation cows don’t go in calf compared to other age groups. Mature cows in good body condition should get away with an eight week dry period.
This week we discuss selective dry cow therapy and some of the issues around it for the industry to tackle. At farm level, I would say that the vast majority of farmers I speak to that have tried it stick with it. It will be mandatory by 2022, so it’s no harm to get experience with it before then and learn what works on your farm. It’s not easy, but hygiene at drying off and during the dry period is critical to prevent infections.
Youngstock: Many farmers are housing youngstock this week. These animals tend to do more walking in wet weather and thus more damage than cows. Where there is sufficient grass, moving to 24 hour breaks and back-fencing will help to reduce damage. However, if it’s a question of extended grazing in the autumn or early turnout in spring, I would definitely say early spring turnout is much better. Getting yearling heifers out early turns them inside out and they do a lot less damage than in-calf heifers do at this time of year.
If housing weanling heifers, split them up according to size and weight and feed them meal accordingly. Weight gain over the winter on silage and meal is fairly poor at just 0.4 to 0.5kg/day, but for those that are at target liveweight now, it is sufficient to get to target liveweight at breeding. Weanling heifers should be at 40% of their mature liveweight now, or 230kg if the mature liveweight is 580kg. Animals that are at this weight need good silage and 1-2kg of meal to keep them ticking along, while those 10% above this don’t need any meal and those 10% below will need extra meal.
Grazing: After a lot of heavy rain over the last few days, more herds are having to be housed, either fully or partially. It makes sense to use facilities when they are present. If there are still fields to be grazed, they can be grazed when conditions improve. Decisions about when to stop grazing are driven by soil type on heavy farms and average farm cover on most other farms. There is always a debate about the appropriate cover to close at. In my view, where soil fertility is good, where there are good grass varieties that have been well grazed out and where there is a high demand in spring, closing at a higher cover (800kg/ha or greater) makes sense. Farms that close at a higher cover grow more over the winter and have more days at grass next spring.