Vaccination of broiler breeders can reduce the number of Mycoplasma synoviae (Ms) infections by two thirds. An investigation into the spread of Ms on breeding farms shows this. Royal GD carried out this research over the period 2015-2019 on behalf of the poultry sector.
MS regularly leads to many problems in poultry, from respiratory and joint problems to eggshell abnormalities and production problems. A live MS vaccine has been registered since 2014 and is regularly used in broiler breeders. On behalf of the poultry sector, GD investigated whether this vaccine reduces the risk of MS contamination in Dutch commercial poultry.
Ms has been part of the poultry monitoring program since 2015. GD Animal Health used the data from this monitoring program from the 2015-2019 period to find out whether vaccination can reduce the risk of MS infection.
The risk of MS infections was determined for broiler breeder farms, layer breeder farms and farms supplying hatching eggs for vaccine production. At broiler parent farms, a distinction is made between MS-vaccinated and non-MS-vaccinated farms. None of the vaccine or egg breeding farms were vaccinated against Ms. The risk of Ms spreading within companies was also determined.
Less infections with vaccination
The research shows that vaccination reduces the risk of Ms infection by two thirds on broiler parent farms. The MS risk of infection for non-MS vaccinated broiler breeders was 11.8 cases per 1,000 weeks. For MS vaccinated broiler breeders this was 2.9-4.8 cases per 1,000 weeks. In other words, without vaccination, the risk of infection with Ms is about 12 cases per 25 farms. With vaccination this drops to less than 4 cases per 25 farms.
This appears to have a long-term effect whereby the risk of Ms infections decreases if several rounds are consecutively vaccinated against Ms. This is because the risk of Ms contamination decreased sharply during the monitoring period in Ms-vaccinated farms. On farms that vaccinated the entire monitoring period, it was easy to see that the infection occurred later and later during the round and eventually stayed away.
Less spread within the company
There is a clearly lower risk of Ms contamination within holdings with vaccinated poultry compared to holdings with poultry that have not been vaccinated. In non-vaccinated farms, the risk of MS spreading to other houses was 146-165 cases per 1,000 weeks.
The risk of spreading to another barn on an infected farm is therefore quite high. In Ms-vaccinated farms, the chance of spreading to another barn on the same farm was only 32 cases per 1,000 weeks, a decrease of 80 percent.
Good hygiene is important
The risk of MS infection is relatively small on the vaccine and egg breeding farms, with 4.2 and 3.4 cases per 1,000 weeks, respectively. This is about the same as on the broiler parent farms that vaccinate and 65 to 71 percent lower than for the non-vaccinated broiler parent stock. The main reason for this seems to be the very strict hygiene measures on the vaccine and egg breeding farms. The hygiene policy is very consistent at these companies. The policy is somewhat more varied on broiler parent farms.
Vaccination can therefore significantly reduce the risk of infection on parent farms and the spread within the company and it has a long-term effect. In addition, this research shows that taking good hygiene measures plays an important role in the control of Ms.