LDAs - the risks and how to prevent them
Spring is here and we are seeing the typical increases in displaced abomasum (LDA or RDA, or 'twisted stomach') that are common at this time of year. Transition cows have the extra stress of turnout and a change from a silage-based to a grass-based diet, which can increase the risk of:
Negative energy balance
These increase the risk of displaced abomasum as well as impacting on future fertility and production.
The signs of displaced abomasum may initially be vague but most commonly the cow has a reduction in yield, a poor appetite (especially for concentrate feed) and may be slower or appear off colour. If you see these signs get us to check your cow out sooner rather than later, as the sooner the cow is treated (usually surgically) the better her prognosis. If the cow also has other problems e.g. metritis, we may treat this prior to doing any surgery.
Maximising the cow's health and appetite over the transition period will minimise the risk of a displaced abomasum. There are some factors (such as having twins) which we cannot change. Factors which we can influence are:
1) Feed intake - maximising intakes in the last week of pregnancy, at calving, and in fresh-calved cows will keep the rumen full and minimise space in the abdomen. More importantly, though, it will reduce the risk of ketosis. Housed cows should have at least 75cm of feeding space each and this should be comfortable when they reach for food (if your cattle have rub marks on their necks you need to adjust the feed barrier). Feed should be pushed up regularly as this stimulates them to get up and eat. Make sure that fresh-calved animals, especially heifers, are not bullied away by other cows.
2) Energy density of diet - transition cows need more energy in their diet than far-off dry cows. The recommended energy density is 11-12MJ ME/kg DM and they need truly ad lib access to feed in order to get enough energy. This will require regular forage analysis, and good grassland management to ensure you know what they are getting. The ration plan will need updating as grass growth changes. Routine monitoring of ketone levels of fresh-calved cows (in milk or in blood) is a good idea to check that all the effort you are putting in is working optimally.
3) Milk fever prevention - it is vital that the transition diet has adequate mineral supplementation to prevent milk fever around calving. There are different ways of doing this and the options depend on the diet they are fed. If you are seeing milk fever cases in more than 5% of your cows speak to a qualified nutritionist or a vet to make a plan.
4) Calve cows at the correct body condition score - 2.75-3.25. Cows should be monitored regularly (ideally monthly) as they want to dry off at the same condition. If you have cows that are too fat, the best time to change this is in late lactation. In summer it is possible to have a 'fat club' which is tightly grazed. In the winter it may be possible to feed them as a separate group and reduce their energy density. Reducing the concentrate fed is another option but may reduce milk yield.
If you have not been shown how to condition score ask in the office - Sue or any of the vets can show you how to score them. AHDB (formerly DairyCo) also have resources to help.
5) Make sure all cows have free access to good clean water - it should be clean enough for you to drink! If not, it's time to think about trough cleaning.
Please speak to myself or Geoff if you are concerned about transition diseases such as LDA or ketosis in your cows. We can provide a tailored farm visit to assess all aspects of transition cow management to help pinpoint the most cost-effective solutions.