Whether you calve year-round or in a block, you will be aiming for cows to calve trouble-free and stay healthy so they can get back in calf after two to four months. The trouble is, the calving period is a high-risk time for cows.
Some of the diseases cows suffer from in this period include milk fever, sub-clinical ketosis, clinical ketosis, displaced abomasums, mastitis, metritis, endometritis, fatty liver and excessive body condition loss. All of these can conspire to make it very difficult to get a cow back in calf and there is pretty sound evidence that each of these conditions is individually linked to lower fertility.
Recent research has found about 50% of all calving cows will suffer from at least one of these diseases. The higher the milk yield potential of the cow, generally the greater the challenge. Many of the diseases are inter-linked, but some cows succumb to the whole list.
Before doing any post-calving checks, consider having a system for recording your findings. This is useful to follow up individual cows, but the main reason is to see how you are performing against targets. This then enables you to identify your strengths and weaknesses and put in place the right health management. An example of a simple recording sheet is suggested in Figure 1 below:
The targets need setting for your particular herd, and this is best done in conjunction with your vet. For example, 2% of cows getting a left displaced abomasum (LDA) is a very high rate for herds giving less than 8,500 litres. For herds with an even calving spread, it might be better to use number expected a month rather than percentage. For example, a 300-cow herd with a target of 24 calvings a month will aim for fewer than two cases of mastitis in cows less than 30 days in milk.
What you decide to record might vary; retained foetal membranes and ketosis are useful, but first decide with your vet how you define each case. Keep it simple and practical – then it’s more likely to be done. If you are starting out, don’t worry if you haven’t got the perfect list, as you can always add or take away things later.
A useful exercise is to review the information you have collected regularly with your vet, for example every six months.
North American research has shown that post-calving checks is one of the three main things affecting success of transition cow management (the other two being generous pre-calving feed space allowance and excellent cow comfort in the beds). In large US dairies, it is common to have a fresh cow group that receives particular attention. This can include daily milk yield monitoring, twice-weekly temperature checks, weekly vaginal examinations and routine drenches. However, the same research found the single most important screening test for sick cows was close observation by a skilled stockman, specifically checking the cows’ behaviour after milking. The best herds provide fresh feed during milking and observe cows as they return to their housing. Those cows that do not go to eat immediately are singled out for further attention.
Milk yield and rumen fill
In the UK, where fresh cows are more often part of the main herd, arguably the two most reliable things to check each day are milk yield and rumen fill. Rumen fill scoring is an under-used, but simple tool that gives an indication of the cows’ intake during the past 24 hours. Targets are different for dry cows (that have abdomens with large pregnant uteri in) and fresh calvers.
Look at the left-hand side of the cow, just behind her rib cage. The skin hanging down from the transverse process (“T-bones” of the spine) should hang vertically down and then bulge over the rumen: if it curves inwards because there is a big hollow, the cow hasn’t eaten enough, and she will be letting you know as the deep triangular hollow is her danger triangle. You can learn more about rumen fill scoring from the CowSignals books.
Finally, what is all this feedback from the cow telling you? It tells you how you have done – but not what you should have done differently. For that, go back to the pre-calving cows, and do some checks on them, too – rumen fill scores, condition scores, blood non-esterified fatty acids and feed space allowances. This information will ensure you are managing these cows well and can be considered as “feed-forward” – a more interesting and useful concept, perhaps, than feedback.