Researchers at the Institute for Animal Health (IAH) and collaborators at the Jenner Institute at the University of Oxford in the UK, have discovered why some vaccines are not as effective at stimulating an immune response as hoped and have investigated ways in which improvements could be made.

The research was led at IAH by Dr Jayne Hope (who is now based at The Roslin Institute, University of Edinburgh), Dr Efrain Guzman and Dr Bryan Charleston. The work was published last week in the journal, Vaccine.

Dr Charleston said: "We knew that sometimes even when we know a bacteria or virus well, it has been a struggle to make effective vaccines against certain diseases. We discovered that dendritic cells – a type of immune cell – are activated better by some vaccines than others.

"There are a lot of human and animal diseases that we would like better vaccines for but until now we haven't been able to find a good reason why, for example, the BCG vaccine against tuberculosis isn't always effective but the bovine herpes virus vaccine is extremely efficient at establishing long–term immunity."

The study focussed on the BCG vaccine that has been used against tuberculosis in humans and animals and which is known to have variable efficacy, but this discovery is important for developing new vaccines against many different diseases caused by viruses as well as bacteria.

A three–year feeding study has shown no adverse health effects in pigs fed genetically modified (GM) maize.

By coincidence, also in the UK, research carried out by pig breeding company, PIC, into the effect of semen age on reproductive performance in AI has seen a surprising result – that fresh semen is not necessarily best.

In a test to quantify the effect of the storage of semen on reproductive performance, the research team found that semen age does affect fertility but 'fresh' was not best.

The researchers are now questioning whether this is a semen effect – capacitation – or the processes sperm pass through to achieve fertilisation.

The company's supply chain manager commented that the research needs to include more information on the motility of the sperm, which, it has been discovered, does not necessarily mean greater fertility.

Now, PIC has a range of new tests and studies it is to conduct to gain more clarity and information about the results of the trials that have already been conducted.

Another genetics company, Topigs, has announced its introduction of the Nador concept, which allows the possibility to select and use finisher boars that produce offspring with 40 per cent less boar taint.

In Canada, optimism among pig producers is on the rise. In 2011, three–quarters of hog producers (75 per cent) agreed that their farm or business will be better off five years from now.

Also in Canada, an associate professor at the Western College of Veterinary Medicine is encouraging pork producers to step up their focus on biosecurity to guard against the introduction of swine dysentery.

The Russian government has approved a reduction in meat import quotas for this year. Pork imports will decrease by 14 per cent – from 500,000 tonnes in 2011 to 430,000 tonnes this year.

And finally, nine new outbreaks of African swine fever (ASF) have been reported in South Africa in the last week. There is an unconfirmed report of a new outbreak of ASF in the Krasnodar region of Russia, and testing has been stepped up in the Ulyanovsk region.