Haywood Farm Vets Newsletter MAY 2024

Staggers - have you got a bottle of Mag to hand?

A bit of sunshine has brought about a welcome flush of grass growth - this fast growing grass tends to be low in magnesium and low in fibre so it passes quickly through her guts before the mag can be absorbed. There are no stores of magnesium in the body for the cow - she gets all she needs from what she eats every day so the next few weeks will be a challenging time for mag availability.

What does staggers look like?

• initially odd neurological signs: high head carriage, twitching muscles, appears blind, staggering and wobbly
• quickly becomes a flat out cow, paddling, fitting and sweating - these are dangerous animals to go near so PLEASE be careful in handling or treating a possible staggers

Sadly, often the first thing you see is a dead cow, so if you are worried about a possible staggers - you need to act fast; it is one of the true veterinary emergencies.

How do we treat it?

Safety here is VITAL - a thrashing, flat out cow can be a very risky patient.

We need to get blood levels of magesium back up as quickly as possible - but magnesium can kill a cow if you give it too much into the vein.

In mild to moderate cases we would recommend a bottle of calcium into the vein if you can restrain her safely enough, and a bottle of magnesium under the skin but sometimes they are thrashing so madly that it is an emergency vet job and we need to sedate them and give muscle relaxants before we can treat them.

What can we do to prevent staggers?

1. Buffer feed with extra roughage to slow down the grass passing through the guts.
2. Supplement with additional magnesium during high risk periods.

Mag licks are convenient but it doesn't guarantee every cow has had enough - and always beware how you feed molassed licks - badgers love them.

Mineralised concentrates can help to make sure every cow is supplemented but not all cows need extra energy from concentrate at this time of year.

Rumen boluses guarantee every animal is protected but they are labour intensive.

Mag salts can be added to the water supply which is quick and easy but it's pretty unpalatable for the cows so make sure there are no other water sources.

Sunshine & Cell Counts

Historically, turn out and "Dr Green" meant an improvement in udder health with fewer cases of clinical mastitis and lowered cell counts, but as mastitis pathogens and patterns change on farm, and winter housing and environments improve, we can see a seasonal spike especially in cell counts during the summer months.

Strep. uberis is the usual suspect; an environmental bug that can also pass cow to cow and there are typical hot spots at pasture especially around shaded trees where stocking density can be very high when the weather is warm! Strep. uberis can survive for up to 21 days on pasture before UV light destroys it so make sure your rotation is set to reduce this risk.

Pre-dipping what look like already clean teats in the summer months can seem a bit OTT, and obviously adds time to the milking routine, but it massively helps to reduce the environmental load of bacteria sat on the teat skin. It is these bacteria that can then get into the udder during the milking process and cause the sub-clinical infections which show up as an increased cell count. Remember the pre-dip is a rapid kill product but still needs at least 30 seconds contact time in order to be effective.

Please get in touch if you are struggling with summer cell count issues and you want to know a bit more about control strategies that would work on your farm.

Fly Treatments - start early for maximum effect

We're heading into fly season, and as you will all know - flies can be both costly and a nuisance to the UK’s cattle, sheep (and human!) population. In addition to the irritation caused, flies can also transmit a number of diseases, causing both financial and welfare concerns.

Fly eggs over-winter in the soil, in undisturbed bedding or on muck heaps, and re-emerge as soon as temperatures rise above seven degrees. Once temperatures rise, female flies are prolific breeders capable of laying 3,000 eggs over their three-week lifespan. If flies are not controlled on the farm, they can produce 15 generations in one season. Adult flies that you see on and around animals only represent 15 per cent of the total population present on the farm, so it is important to act early to reduce the chance of the fly population booming.

As well as the direct irritation and stress caused by painful bites there are significant productivity losses associated with flies and external parasites on cattle, such as reduced calf weight gain and a reduction in milk yields of up to 20 per cent (Taylor et al. 2012).

IRRITATION

The horn fly, Haematobia irritans, can feed on the blood of an animal up to 40 times a day (Bramley et al. 1985). This can lead to anaemia in calves, as well as constant irritation. It can take as few as 10 to 20 head flies, Hydrotaea irritans, per animal to have a negative economic impact on a farm (Wall and Shearer 2001) so make sure you include your calves in your fly treatment protocols.

SUMMER MASTITIS

Biting flies, such as the sheep head fly, are responsible for the transmission of the three bacteria that cause summer mastitis or "August Bag" in cattle. August Bag is a severe bacterial infection in the affected quarter, with knock on abortions in severe cases or you may see an increase in heifers calving in with blind quarters from milder, missed cases.

PINK EYE

Face flies and the stable fly act as vectors transmitting the bacteria which cause Infectious Bovine Keratoconjunctivitis or ‘Pink Eye’. This can cause severe damage to the eye, as well as a knock-on, long-term effect on their productivity; affected calves can suffer a decrease of 17 to 18 kilograms live-weight at 205 days, when compared with healthy calves (Troutt and Schurig 1985).

BLOWFLY STRIKE

Blowfly strike is the most common ectoparasitic infestation affecting sheep in the UK: every year up to 80% of farms will report one or more cases of strike, and this equates to at least 500,000 animals affected in the national UK flock. The blowflies lay their eggs in damp or dirty wool and when the eggs hatch, it is the maggots that go on the rampage eating skin and burrowing into the deeper tissues. Toxins are released by the feeding maggots which can soon lead to toxic shock and death if left untreated.

The early signs of strike are individuals staying away from the flock, itching or nibbling at the fleece and a serious drop in appetite. Don't forget it isn't just dirty fleece that attracts blowflies, they also like infected feet.

A combination of cleanliness alongside topical fly treatments, fly traps, fans and parasitic wasps are often needed in combination to minimise the effect of flies on farm.

We stock SPOTINOR and SWISH - and both are best started now to keep a lid on the adult fly populations.

SPOTINOR

Active Ingredient: Deltamethrin 10mg/ml

Uses: to reduce the numbers of flies that land on and bite cattle, as well as to treat established blow fly strike in sheep

Milk Withdrawal: Zero

Meat Withdrawal: 17 days (cattle) 35 days (sheep)

Dose:

• 10ml for all cattle applied in one spot at the shoulders - lasts around 4 weeks.
• 5ml for sheep affected by blowfly strike - apply directly to the maggot affected area affected to kill blowfly larvae.
• 2.5ml for lambs affected by blowfly strike - again, apply directly to the maggot affected area to kill the blowfly larvae.

Costs: 39p per dose for cattle

SWISH

Active Ingredient: Deltamethrin 7.5mg/ml

Uses: control of biting and nuisance flies and lice in cattle

Milk Withdrawal: Zero

Meat Withdrawal: 20 days

Dose: pour on the product along the backline of the cattle from head to tail using a Swish gun. Lasts around 8 weeks.

• Up to 100kg - 10ml
• 100-300kg - 20ml
• Over 300kg - 30ml

Costs: 72p per dose for adult cattle