In the Brief

With the lambings all bar finished, calvings again take centre stage. This year seems to be marked out by a great number of large calves, a quirk of feeding through the winter no doubt.

The most common issues encountered are small maternal pelvis’s. The small pelvis is most commonly a problem in heifers, especially those which are under weight and have not grown out as well as might be expected. These are the ones most at risk of needing a large amount of traction, which could be 150 to 250 kg of pull (bear in mind that some calving aides can pull in excess of 250 kg which can cause considerable damage to your cow and calf). If the calf is not making real progress through the birth canal then a caesarean may well be indicated, depending on individual circumstances. 

Some rules of thumb to go by are:

1) If the front feet (or hindfeet) are crossing over on entry into the birth canal then the shoulders/ hips may be too big, or the pelvis too small to allow a healthy birth.

2) The calf’s shoulders are not engaged in the birth canal until the front feet are out as far as a hand’s breadth past the fetlocks. If it was a struggle to get to there, then it’s only going to get tighter.

3) When coming backwards, the calf’s pelvis has not entered the birth canal until the back legs are out as far as a hand’s breadth past the hocks (that is a lot of leg to come out). Likewise, if you struggled to get it to there, it’s only going to get tighter. The umbilical cord is a lot more vulnerable to trauma and premature rupture when the calf is coming backwards, too. Once the hips are out it is then a matter of urgency to get the calf out quickly.

In calvings we attend, we often give an epidural injection of anaesthetic to stop the cow straining. As well as removing pain, stopping her straining also dramatically reduces the risk of trauma to the uterus and birth canal.

Richard Knight

These problems include:

•  Spreading infections such as summer mastitis and bovine keratoconjunctivitis (pink eye).
•  Causing irritations in the parlour- increasing tail swishing, kicking, and dunging.
• Distraction from eating leading to reduced feed intakes; reduced daily live weight gains; and milk yields.

So, what can we do? The control strategy will vary depending on your system, whether the cattle are housed or out grazing. Strategies to consider include:

· Environment and cow management:

•  During summer months pastures which are low lying, wet or near woodlands should be used sparingly.
•  Use fans in buildings, especially in the milking parlour.
•  Ensuring cows receive teat sealant at dry off.

· Chemical management:

•  There are a variety of insecticides available in many forms including: pour-ons, tags, aerosols and injectables.
•  Treatment interval will depend on the product used and fly burden.

 For all products, meat and milk withdrawals should be considered.

Having a plan—We know that prevention is better than cure. The use of an insecticide at the beginning of the season will help reduce fly numbers. When flies start breeding, it is worth taking action to control them before they become a major problem.

Ready for worms

Driving about on our farm rounds this past fortnight, the sun has been out, and we’ve seen plenty of good strong lambs on the ground!

A big factor to the continued success of growing lambs is the control of gut worms, which can really hamper growth rates. Here are a few useful pointers to help be as prepared as possible:

Watching for Nematodirus

Nematodirus battus worms are a particular risk to younger lambs. These worms cause disease much more rapidly than other species – and so as a result we can’t rely on faecal egg sampling to keep track of it in the flock. In a mass hatch, nematodirus can quickly cause severe disease and death. 

Risk factors:

• Nematodirus carries from last year’s infected pastures – try to put lambs on grass that was not used for lambs last year.
•  Lambs aged 6-12 weeks which will be consuming a lot of grass
•  Lambs that are also being challenged by coccidia (more common in mixed aged groups)  or are under stress (eg triplets, or on young/older ewes)
• Weather conditions causing a mass hatch……

Using the Nematodirus forecast

We would highly recommend visiting the SCOPS nematodirus forecast website.

It uses data from 140 weather stations across the UK to create a traffic light style warning system for the nematodirus hatching forecast. You can find the nearest weather station, check the risk and adjust it for your farm to create a more accurate prediction of when a mass hatch could occur.

For the vast majority of farms, a white wormer (benzimidazole) would be the treatment of choice for nematodirus. If you have, or suspect, resistance on farm then please speak to one of the farm team.