Good advice pays for itself over and over again, whereas bad advice or no advice can cost you dearly.
This truism rings out for accountancy and tax as much as it does for the field of veterinary medicine.
This year, I have opted for mid-breeding season scanning for our dairy herd.
Like a business review half way through the financial year, it gives the equivalent snapshot of the biological health of my business.
The dairy farmer’s job, to the outsider, is about getting milk out of cows, but examine this closer, and the dairy farmer’s job is actually to get milk into their cows.
Maxing out cow capacity to produce milk can be broken up into various denominators.
Getting milk into cows involves feeding a premium diet, mainly of good quality grass, plus appropriate supplements; maintaining premium health for the cow; and ensuring cows go back in calf, or in other words, enabling and repeating the cycle for next year.
A few years back, I had the unfortunate occurrence of subfertile bulls, which left me with about 30% of the herd empty.
Since then, I have paid much more attention to the breeding cycle, and making sure cows are in calf.
For the last number of years, I have been using the milk-testing facility available from a number of labs in Ireland, and found these to be pretty accurate.
What I like about the milk testing is its simplicity (a few squirts into a bottle) and stick on a label and send it off for testing, it is easily performed from the milking parlour pit, and is non-intrusive for the cows.
The disadvantage is that the results lack detail. Generally, pregnancy is detected from about 28 days in these types of tests. The cow either shows up positive or negative for pregnancy, with no indication of embryo size nor of calving date.
This year, I opted for mid-term scanning with Cathal O’Shea of Reprovet.
The main advantage of scanning is that expected calving dates are predicted.
For me, this helps with scheduling of cows for drying off. Cows expected to calve in the last days of January will be targeted for drying off in late November.
Without a calving date, cows are simply dried off when milk yield drops below 10 litres per day, which can leave some cows having a very short dry period.
Our dry-cow therapy tubes have a 56 day plus five post calving withholding period, so it is critical to get eight weeks dry before calving, to prevent the risk of antibiotics in milk in the weeks following calving (which could happen due to short dry periods).
A second advantage, and the most important from my perspective, is to monitor bull performance.
Reviewing your ‘how far along’ dates lets you see if bulls have stopped working along the way.
Identification of twins is another major advantage, these cows can be given special treatment prior to calving, such as moving to a loose straw bedded house a week or so earlier than planned, with additional feeding during the dry period to maintain body condition, and advance treatment to prevent ketosis, and advance treatment to prevent milk fever.
These cows also need to be watched carefully prior to calving, as twins often can get “knotted”, or will present incorrectly at birth, leading to still-born calves.
A third advantage for mid-term scanning is picking up on cows not yet in calf and, importantly, determining whether there are any underlying reasons, and planning appropriate actions to help these cows go in calf before the breeding season ends.
A fourth advantage comes in the form of grouping cows together for winter housing.
Like most dairy farms, cow housing is spread amongst a number of buildings, and grouping bunches of cows due to be dried off together gives easier wintertime management, and prevents bullying from the mixing of cows.
Scanning also has the advantage of picking up pregnancy slightly earlier that the milk samples.
Unfortunately, neither method will tell you what cows have just recently gone in calf, but a repeat round of scanning or milk testing will confirm these.
The breeding season on the farm is eight weeks in, but effectively the scan is determining those cows which have been put in calf in the first five weeks, as the last three weeks cannot be determined yet.
The first four weeks were covered by two Friesian bulls, and I’m glad that a sufficient number of cows are pregnant to these two, which should give me an adequate number of replacement heifers.
This year has worked well for me, with 80% of the herd due to calve within the first five weeks, all going well.
A repeat round of scanning or milk testing, to be carried out six weeks after breeding is finished, around September 10, will tell me which cows failed to go in calf, and these cows can be fed on prior to drying off.
Having done the mid-season scan, I’ll know I have done my best to get these cows to stay within the herd for next year.
The information available as a result of scanning can make all the difference for cow management, whether that’s potentially an extra cow in calf, a set of twins saved, or the prevention of a down cow with milk fever.