Veterinary technical adviser Kim Kelly of Coopers’ parent company MSD Animal Health said there were several reasons why a five-in-one at tailing was a good idea.
“If ewes were given a pre-lamb booster and responded well, and we know most do, and the lambs drank plenty of colostrum within six to 12 hours of birth then you can be confident the passive immunity passed on will last until close to weaning.
“But if you can’t be sure they got enough colostrum, or that all the ewes were effectively vaccinated, then there will be a proportion of lambs at tailing whose immunity is waning,” she said.
“If you don’t want to risk some of these dying between tailing and weaning then there’s a case for using the five-in-one at tailing.”
Regardless of colostrum intake and the passive immunity lambs gain from that if ewes were effectively vaccinated pre-lamb, lambs would need two clostridial vaccinations to stimulate their own immune response, Kelly said. So giving them the first jab at tailing – the sensitiser – and then the booster at weaning is a good way to make sure they are fully protected from weaning.
“You’ve got the lambs there anyway at tailing and weaning so it is convenient too. There will be a proportion that don’t need it at tailing but you can’t tell who does and doesn’t and if you give them the second shot at weaning then the job’s sorted. You don’t need to worry about doing them later on.”
Without the second shot immunity from the first injection is weak and won’t last, Kelly stressed.
She said because many lambs were reared on much higher-quality feed than in the past, and were genetically able to grow faster too, the risk of clostridial diseases – notably pulpy kidney – was likely considerably higher than when clostridial disease vaccines were first available in the 1970s. However, there’s been little recent research into their use and just how widely they’re used isn’t known for sure either.
Kelly thought about 80% of farms would have used clostridial vaccines but at farmer meetings last year this was not the case.
“When I asked who uses a five-in-one or 10-in-one, next to no hands went up.”
For most farms there’s no need to go beyond the basic five-in-one vaccine, Kelly said.
“If you get your timing right with a five-in-one – and a lot don’t or they only use one shot where they should be using two – but if you do get your timing right and you are still getting issues then that’s when you might need to switch to a six-in-one or 10-in-one. Your vet will be able to advise you.”
Kim Kelly of MSD Animal Health.
A mob of 126 maiden, twin-bearing Romney two-tooth ewes on a farm near Masterton was split at random into two treatment mobs of 63.
One mob was given Multine five-in-one at two to four weeks pre-lamb, the other Ultravac five-in-one. At tailing, 50 lambs were treated with Multine, 50 with Ultravac, and 20 marked as an untreated control. The treatments were repeated 49 days later at weaning. Pulpy kidney and tetanus antitoxin concentrations were measured at tailing, weaning and 14 days post-weaning.
At tailing, mean pulpy kidney antitoxin concentration in lambs born to Multine-treated mothers was 3.0u/ml and in lambs born to Ultravac-treated mothers the mean was 1.4u/ml. Tetanus antitoxin was also higher in lambs from Multine-treated ewes, albeit only marginally (1.7u/ml versus 1.3u/ml).
Two weeks after the lambs’ weaning boosters, those treated with Multine had a mean pulpy kidney antitoxin concentration of 14.1u/ml to the Ultravac mob’s 5.7u/ml and the control mob’s 3.1u/ml. For tetanus the concentrations were 10.2, 5.8 and 0.4u/ml. The European minimum standard for responses to such vaccines is 5u/m; for pulpy kidney and 2.5u/m; for tetanus.
Pulpy kidney antitoxin levels increased in 13 out of 19 lambs remaining in the untreated control mob at the end of the tailing to weaning plus 14-days treatment period, indicating some had natural exposure to the disease. All 50 Multine-treated lambs increased antitoxin, and 39 out of 50 of the Ultravac-treated.
Tetanus antitoxin concentrations declined in 18 out of 19 of the control mob, indicating no natural exposure to the disease.
In the Multine-treated mob 49 out of 50 increased antitoxin concentrations, and 41 out of 50 did in the Ultravac-treated mob.
In a summary of the research MSD concluded that: “Lambs born to ewes vaccinated with Multine had twice the [pulpy kidney] antitoxin concentration at tailing than lambs born to ewes vaccinated with Ultravac five-in-one. Vaccination with Multine at tailing overcame maternal antitoxin and induced an immune response that was superior [to Ultravac]. Thus vaccination with Multine can begin at tailing.”
MSD veterinary adviser Kim Kelly said the work was only now being publicised, three years after it was conducted, because of the time it had taken to get the use-at-tailing recommendation for Multine through the AVCM registration process. Pulpy kidney and tetanus antitoxin levels were the only ones monitored in the trial because they were the two most common clostridial diseases.
“If you had to put them in order, malignant oedema would be third most important,” Kelly said.
