As the breeding season is now wrapped up, the priority turns to scanning your cows as soon as possible to allow for prompt decision making.
For dairy farms who start their breeding season on May 1, the bull has been pulled since late July in a typical 12-week breeding season.
This means that it has been well over a month now since the last cow on the farm has been served, which means it is time to scan your herd.
You need to make sure that the cows or heifers that you have bred are actually in calf, as it makes no sense to keep empty cows on your farm over the winter months.
Empty cows will eat up your expensive silage, which is already scarce this year, and they will also use up your nitrogen (N) allowances in some situations.
Scanning
Scanning should be done at least 30 days since the last cow in the herd could have been served to ensure accuracy, as it it can be difficult to pick up very early pregnancies.
Scanning will firstly tell you what is not in calf, which gives you the opportunity to get rid of the empty cows, which subsequently will allow more grass for productive milkers.
This will not only save on silage, but will also save money, time, shed space, slurry space, and spare you on your organic stocking rate.
Scanning will give you a good estimate of the number of weeks each cow has gone in calf, and this information can be used to predict the cow’s due date, which will then influence how she is fed and when she is vaccinated.
By knowing the calving dates, you can also predict the peak calving period so that extra help can be organised for that period.
Batching cows into early calving and late calving mobs will allow you to keep the early calvers close to the calving house, which will minimise stress on the cow.
Splitting the herd into two or three different mobs will also allow you to feed them accordingly – late calving cows on restricted feed to stop them getting overly fat, while early calving cows, thinner cows or first time calvers can get additional feed if necessary.
If the cow has not gone over 12 to 14 weeks in calf, a scanner can tell whether they are carrying twins or not, or some may be able to sex the embryo.
Farmers should aim for an empty rate of less than 10%. In the case of anything above this, the farmer should be asking himself questions around the fertility of the herd, heat detection, mineral deficiency, or whether the bulls being used were picking up the cows.
Scanning costs can vary, but generally cost around €5/cow plus a call out charge of €20 to €50, according to Teagasc.
Rates will vary depending on the number of animals being scanned and the time it takes to scan the herd of cows but it is money well spent.