Bull Pre-Entry Testing and Disease Control
Our procedure for disease control in bulls coming on centre is based on:
1. Avoiding bringing disease on to our centre and infecting other stock 2. Ensuring semen produced does not spread disease
3. Protecting your bull from infection derived from other stock
Dealing with the diseases in turn:
; BVD – we test the bull to ensure it is not a carrier (PI). PI bulls are highly
infectious to other stock and through semen. Once established as not PI
we require the bull be vaccinated to prevent it becoming transiently
infected (TI). The vaccine we require is Bovilis BVD. It needs to be done
prior to entry and boosted 3-4 weeks later.
; EBL – very few herds are positive in NZ but there are some – this reliable
test ensures your bull is clear.
; Johnes Disease – widespread in NZ this test helps ensure the bull is not
a risk to our centre and through semen.
; IBR – bovine herpesvirus is very widespread in NZ with up to 50% of adult
bulls infected. We take positive bulls on centre but keep them isolated
; Leptospirosis – the blood test for Lepto helps identify recent infections.
As further precautions we also require vaccination (and booster 3-4 weeks
later) and we routinely treat the bull with antibiotics on arrival to the centre. ; Campylobacter and Trichomonas – venereal diseases of bulls causing
infertility in cows – bulls are tested 21 days after arrival while still in
; Brucella abortus – NZ is free of Brucella but due to it’s severe
implications for the cattle industry and exports we test bulls prior to entry. ; Tuberculosis – TB cards must accompany bulls coming and going from
the centre. This and our pre-entry certificate confirm the farm of origin
status does not present a risk. Further to this we TB test bulls prior to
; Clostridial Diseases – several risk factors for clostridial diseae are
heightened as a bull is trucked to the centre and fed well prior to collecting
semen. A highly effective vaccination all but eliminates this risk.
Covexin 10 is the vaccine of choice as it includes Clostridium sordellii. It
needs a booster 3-4 weeks later.
; Salmonella incl. Brandenburg – risk factors increase with trucking etc –
vaccine and booster provides effective protection.
; Parasites – internal and external parasites are controlled with an
endectocide given prior to entry.
We require a veterinary examination to detect other diseases not
detectable with the routine regime. The vet also warrants the completion
of the procedures and will detect injury or condition which will make the
bull unlikely to produce good semen.
Isolation on Farm
We require the bull to be isolated on farm for 30 days before coming onto
the centre. This is to ensure that, while it might test clear for disease
prior to entry, that it does not contact other diseased animals in the
meantime and come down with the condition.
Isolation on Centre
We isolate the bull for 30 days on centre as an added precaution. We
retest the bull in that period
A common difficulty clients convey to us is that vaccinating 1 or 2 bulls
with 4 vaccines is a logistical issue for them and / or their vet. In the past
we have had to vaccinate some bulls after arrival which defeats the
purpose. To overcome this we are offering to send out a vaccine pack
including a shot and a booster of the following vaccines:
; Bovilis BVD
; Lepto 3 – 3 serovars of leptospirosis
; Covexin 10 – Clostridial vaccine
; Salvexin +B – Salmonella
Please ask about this option as you arrange to have the bull prepared to
come on centre. There will be a charge to cover this.
This brings everything together. It is important that it is completed
correctly and comes ahead of or with the bull. This must be signed by
your vet. We also require the lab test results to accompany the certificate.
Please note the lab test results on their own are not enough – the
certificate must be used.
MAF audit our centre every 6 months. Compliance in general is getting
tighter but it does have a positive effect of improving our standards of
operation. It is important that we keep all the processes tidy to comply –
your assistance with this is appreciated