Field Margins: John Harvey talks all things calving

And the fact that there is little real optimism in the weather forecast in the short term doesn’t really help ...

In some respects, it’s incredible to think that in five weeks’ time we’ll be looking to get our first cut of silage, but there is still a lot of spring work hopefully to be done before that.

Thankfully we took advantage of the small dry window at the start of March and got our field beans sown. We are now busy getting fertiliser on the winter wheat and slurry on the grass fields.

On the cattle front, the youngstock are halfway through their spring vaccinations – Huskvac and Bravoxin – so will hopefully be ready to go once the weather does decide to improve.

An example of a breech calving with the back hooves coming out facing the sky (Image: Web)

One big change we have made in the last month is to the mineral pack for the milk cows. Our nutritionist, Donald Lawson, identified that with a level of bean inclusion in the diet (as a replacement for soya) there was a likelihood that the cows could be short of lysine (one of the essential amino acids). So, we’ve added lysine to the minerals for the fresh and high-yielding milk cow groups and have seen the milk solids increase from 3.07kg/cow/day to 3.22kg/cow/day (c5%).

It is worth saying, though, that lysine isn’t cheap, so the change is costing c20p/cow/day but that is balanced by c80p/cow/day from the increased milk solids. So it is definitely worth doing while we’re still feeding the beans.

Although cows are calving all year round, I thought it might be timely to write about our calving procedures as I guess a lot of people are coming up to their main calving period.

Cows that are in the last few weeks of their gestation are housed as a group on sand cubicles but we aim to have them calve down on a sand yard.

The reason we use a sand yard is for many of the same reasons we use sand cubicles. It’s relatively easy to clean as dung can be lifted off the top and urine either drains through or runs off, and this, combined with the fact it’s inert, controls disease risk.

To stop the calving pen getting too busy we try to move the cows to it as close to calving as possible. This used to be based on the educated guess based on the cow ‘dropping. This is when the sacroiliac ligaments, which lie to either side just infront of the tail head, slacken, causing a distinctive hollow between the hook and the pins.

Now we tend to be more guided by a drop in the rumen temperature as measured by the smaXtec bolus, with the algorithm giving us an alert typically about 12-24 hours before the calf is born. While the algorithm isn’t 100% accurate, it does pick up a lot of calvings we wouldn’t have spotted until too late.

Letting the cow get on with it and calving without assistance is always the preferred option, but as our confidence in the calving alert algorithm has grown, we’ve now got to the stage where if a cow has ‘dropped”’and alerted but not calved within 24 hours, we’ll investigate further to check everything is proceeding as it should.

Sometimes it’s the case of simply giving a cow a calcium bolus to improve muscle contraction and get things back on track but on other occasions a more proactive intervention may be required.

For example, if the calf is coming back legs first (breech) then there is a higher probability of the calf drowning, so we’ll aid the calving.

Breech calvings are pretty easy to identify: in a normal calving the calf comes out in ‘superman’ pose with its ‘arms’ (front legs) first and ‘palms’ (hooves) face down; in breech calving the back hooves come out facing the sky.

Even with calvings that progress normally, if we spot it’s going to be breech we will make sure the calf gets its first breath OK.

Pretty much all farming TV series seem to show an assisted calving at some point – I can see the attraction from the programme makers point of view – but they do wind me up.

Firstly, I do wish that people would wear gloves. After all, you really have no idea what zoonoses might be present.

And also the calving aid (I hate the word jack) isn’t really supposed to be used to pull the calf out – it should only be used to apply slight pressure during the cow’s contractions.

One tip the vet gave me once on using the calving aid with breech calvings is to only use a rope on one leg at a time as it allows the calf’s hips to rotate as it comes out of the birth canal and stops them ‘locking’ on the cow’s pelvic bone.Once the calf is born, we will check it is breathing OK and, if necessary, stick the ubiquitous straw up its nose to stimulate it.

Also, if its breathing is laboured (particularly with breech calvings), we will sit it up on its sternum with the hind legs either side (kind of like a frog) so that the lungs can inflate more easily and more evenly.

With the calf stabilised, we will then turn to the cow. If the calf is particularly small, we’ll maybe check there is not an unexpected twin lurking inside – it wouldn’t be the first time we’ve got to the parlour only to have to help a second calf out!

We will then give the cow a couple of pails (30-40 litres) of restart (NB other post-calving drinks are available!).

This helps gets fluids back on board to the cow quickly, encourages the rumen to fill the void where the calf was, and also provides a source of calcium and other nutrients to help the cow to get going.

Older cows which know the routine always seem really keen to get the fluids (nudging at you impatiently as you take the lids off the buckets). If they are not keen, it is normally an indication that they could be suffering subclinical ketosis/milk fever so we’ll give them calcium and yeast boluses.

With that done we will take the calf to the calf shed and the cow off to the parlour to get milked, with the aim of getting three to four litres of colostrum to give to the calf within an hour of it being born.

Hopefully this gives the calf a good start to life and the cow a relatively stress-free start to another successful lactation.