CRYPTO

Cryptoporidium parvum is a protozoan parasite which can lead to outbreaks of calf diarrhoea when there is a build-up of infection. Oocysts (eggs) are shed in the faeces of infected animals. At peak shedding, millions of oocysts are shed for days, but only 5 oocysts are needed to cause infection, therefore a single calf has huge potential to infect other calves. Oocysts are resistant to most disinfectants and can survive for several months in cool and moist conditions.

In the calf, infection leads to severe damage to the lining of the intestines and destroys its ability to absorb nutrients, water and salts. Once infected, it takes approximately 4 days for scour to develop which usually lasts for 15 days. Affected calves suffer dehyrdation, lose weight and become dull, some will die.

Halocur is the only licensed product for the prevention and treatment of cryptosporidiosis. It reduces the shedding of infective oocysts and minimises the effect of calf scour. For treatment of scours, calves should be dosed for 7 consecutive days starting within one day of the onset of diarrhoea. Once several calves have been diagnosed and treated, all subsequent calves should receive preventative treatment with Halocur.

Diagnosis is quick and easy and available at the practice. All that is needed is a fresh muck sample. The test detects the 4 main causes of calf scours: Rotavirus, Coronavirus, E.coli, Crypto. Mixed infections are common problems.

The disease is difficult to control. Calves should be born in a clean environment and fed good quality colostrum. Calves should be kept separate for at least the first two weeks of life with strict hygiene at feeding. Great care must be taken to avoid mechanical transmission of the infection in the calf house. All calves should be isolated from healthy calves whilst scouring and for several days after recovery. Calf-rearing accommodation should be vacated and thoroughly cleaned out on a regular basis with a suitable product e.g. Kenocox.


SHEEP MANAGEMENT

It is quiet on the sheep side now but this is the time to review your performance, set priorities and plan vaccinations and fly treatments. All this comes under the header “Sheep Flock health planning”. It can be very useful to sit down and go through all this, ideally with us there! I can assure you it will be time (and money..) well spent! I will probably first catch up with you at the Sheep Event, another useful day out..

Clostridium is still a nasty killer on many farms, but this can be prevented, please vaccinate appropriately!! Another huge worry to the whole of the industry is sheep worming…

With many cohorts of lambs being given their second doses of drench and some cases of deaths due to worms its timely that we make note of drench resistance!

Here at Stapeley we are really trying to get all our farms on board with the national guidelines for anthelmintic management in order to prevent drench resistance (SCOPS). The first step in preventing drench resistance is recognising how effective you current drench group is or its “efficacy”. The quickest method to do this is a with post-dosing faecal egg counts. This is done by collecting a grouped faecal sample of at least 10 animals on the day of drenching and then 7 or 14 days after drenching. The time between testing depends on the group of drench used; 7 days for yellow drenches and 14 days for clear and white drenches.

It will be breeding time soon so have a plan and get your replacements vaccinated now. We are doing loads of teasers, you must value a tighter lambing period..


LUNGWORM

During July 2015, rainfall was above average over most of the country, with parts of Scotland, East Anglia and elsewhere approaching double the normal rainfall amount.  The overall UK rainfall total was 140% of average1 and therefore the livestock industry must remain vigilant when considering the increasing parasite pasture burden towards the middle of the grazing season.

Anecdotally, there have already been reports of lungworm disease recently in the Midlands, which confirms the NADIS prediction that August will be a bad month for livestock exposed to lungworm if not managed proactively.

The animal groups who are most at risk include unvaccinated dairy calves at grass for their first season or weaned Autumn-born beef calves after turnout the following spring. Even adult cattle may show clinical signs after grazing heavily contaminated pastures.

Studies have shown that over 80% of costs on a dairy farm infested with lungworm can be attributed to the loss in milk yield and mortality associated with this disease2. Classic clinical signs range from coughing to respiratory difficulty, often with associated anorexia and weight loss, but subclinical infections still have an appreciable effect on milk yields, of up to £3 per cow per day3.

Farmers should be aware that although prognosis will vary according to the severity of disease, deaths may occur despite treatment and supportive therapy. During the post-patent phase of the disease, clinical signs may well be improving, however lung tissues remain inflamed and lesions within the lungs will persist for weeks to months after initial infection; therefore economic consequences such as long term reduced feed conversion efficiency are more far-reaching than just those resulting from clinical disease.

Lungworm.jpg


PNEUMONIA

We are coming into the risk period for calf pneumonia and have recently been doing some work with livestock buildings expert Jamie Robertson form the University of Aberdeen. He is extremely knowledgeable about the physics associated with shed ventilation and demonstrated to us how small alterations to a building can impact massively on livestock health and also growth rates (200g/day increase in fattening bulls by improving ventilation). He has given us all some really good training on the matter so please get in touch if you are thinking of putting up new buildings or would like to know how to improve existing ones.

Ventilation and housing are very important in the war against pneumonia but other factors to consider are:

Vaccine

Protects against

Minimum age

 can be given

Follow up

Length of protection

Comments

Ripsoval intranasal

RSV, PI3

9 days

 

12 weeks

Can be followed with a course of Rispoval 4 at 12 weeks for further   protection.

Rispoval 4

RSV, PI3, BVD, IBR

3 weeks

3-4 weeks later (and again at 12 weeks if calves younger than this   when they have the 2nd dose)

6 months

Course should be completed 4 weeks before expected risk period i.e.   housing.

Bovillis IBR marker live

IBR

2 weeks

If first dose given <12 weeks old booster required at 3- 4 months.

6 months

Booster required every 6 months.

Booster vaccinations can be mixed with Bovillis BVD for easier administration.

Bovipast RSP

RSV, PI3, Pasturella

2 weeks

2-4 weeks later

Unknown

Booster required for before expected period of risk.