Mr. David Graham:

I will discuss several of the issues that have been raised. A technical question was asked concerning the basis on which a calf whose mother is not persistently infected becomes persistently infected. The infection takes place prior to birth. If the unborn calf in the first 90 to 120 days of pregnancy becomes infected with the virus and is carried to term, it will be born persistently infected. If it is not persistently infected at birth, it will not become persistently infected subsequently. Evidence shows that the majority of PI calves are created where the mother has no previous immunity, comes in contact with another persistently infected animal and undergoes what is described as a transient infection. She then becomes infected and develops an immunity of her own and while she will fight off the infection, the virus passes to the unborn calf. Having said that, under the programme, where a virus positive calf is identified, the mother will be flagged as being at particular risk and will need to be examined. If one takes the prevalence figure for calves, which is between 0.6% and 0.7% , one finds that, depending on how one does the measurement, between 6% and 10% of the mothers are virus positive and persistently infected. The vast majority of infections of PI calves are created through a transient infection of the mother. For this reason, it is critical to identify and remove PI calves as soon as possible after birth because they are the source of the widespread transient infections. This is the point at which we can break the cycle.

On the impact of retaining persistently infected animals, part of the communications strategy in the programme has been to emphasise three key points. First, persistently infected calves typically do not thrive or survive and only a minority of them will reach breeding or slaughter age, depending on breed and sex. There is, therefore, a significant element of throwing good money after bad in cases where farmers invest in, feed and attempt to rear such animals. Second, these animals are a source of infection for other animals, particularly calves. They weaken the immune system of their comrades which become infected with a transient infection, resulting in more scars, cases of pneumonia, poor response to treatment and deaths in that group. Third, they are also a source of further persistent infections if they transmit the virus further to other pregnant, susceptible cattle. The biggest risk is certainly within the herd because, as Mr. O'Flaherty noted, taking measures to address the trade in such animals has a significant impact on eliminating the risk of spreading the disease outside the herd.

On the question of the economics, the €102 million figure is based on an aggregate of the dairy, suckler and finishing sectors when one models the costs that would arise in the absence of any intervention. The work done on this matter suggests that year-on-year losses arising from a decision to do nothing would amount to €102 million.