Foot and mouth disease will not stop making headlines any time soon, mainly due to its negative socio-economic impact not only on the affected farmer, but also on local, national, regional and international livestock stakeholders.
But the disease has been put under control in some parts of the world, including in African nations such as Botswana and Namibia.
The big question, however, is how much is saved through FMD control and what is the best strategy?
In a research carried out last October in Nakuru by the regional veterinary investigation laboratory in collaboration with the county veterinary authorities, four medium-scale dairy cattle keeping household heads (HHH), two whose animals had experienced FMD, and two which had not, were selected from each of the 10 of the 11 sub-counties in the county.
The 10 had reported cases of FMD from July 2019. The researchers sought to know the herd structure, the infection and death rates of each category, the milk production before, during and after an FMD outbreak, how long it took for the animals to recover, what percentage of HHH recovered 25, 50, 75 and 100 per cent of their pre–FMD milk production, charges for vaccinating against FMD, treatment cost for a case, price of milk, estimated prices of each animal category and the vaccination regime adopted by the HHH over the years.
The results were displayed in two ways. The first one is descriptive statistics, which reports the summary of the information collected while the second one is the inferential statistics, which uses the data collected to come to some conclusions about the population from which the sample came.
The number of animals sampled was 540 and the herd structure (profile) was 20, 13, 60 and 7 per cent female calves, male calves, cows and bulls respectively.
Listing the parameters in question in the same herd structure showed the infection rates were 33, 25, 30 and 21 per cent while death rates were 12, 1, 2 and 5 per cent, which translates to an infection rate (morbidity) of 29 per cent and a death rate (mortality) of 4 per cent.
In 40 per cent of the affected HHH, all the four categories (female calves, male calves, cows and bulls) were infected.
The average milk production from the animals that were being milked was 11.7kg each before FMD and 4.7kg per animal during FMD.
DISEASE CONTROL STRATEGIES
The animals took a minimum of two days and a maximum of 21 and an average of nine days to recover from the disease.
Milk recovery to pre-FMD status was 100 per cent for 10 per cent of the affected HHH, 75 per cent for 35 per cent HHH, 50 per cent for 20 per cent HHH, 25 per cent for 30 per cent HHH and zero per cent for 5 per cent HHH.
The cost of vaccinating against the disease ranged between Sh0 and Sh300, with the nil-charge services being offered by the county government while the upper figures by private animal health service providers.
The average cost of treating an animal was Sh1,000, average milk price Sh37 and the average animal values were Sh25,450 for female calves, Sh14,800 for male calves, Sh76,125 for cows and Sh52,500 for bulls.
A majority of HHH with no FMD used the recommended biannual vaccination while majority of those with FMD vaccinated their animals irregularly.
The collected data was used to infer to the county’s estimated dairy cattle population of 343,811. Three disease control strategies, each executed for three years, were proposed.
These are biannual vaccination covering 80 per cent of the animals, vaccinating when there is an outbreak and covering only 40 per cent of the animals, normally referred to as ring vaccination and carrying out no vaccination at all.
Further, a number of assumptions supported by scientific evidence were also made. They included small to medium scale producers account for 80 per cent of the dairy herd, 51 per cent of the cows will be in lactating at any one given time, probability of animals vaccinated against FMD was put at 15 per cent and animals that have not been vaccinated at 85 per cent.
The results showed after subtracting the costs, the expected benefit to the farmers is Sh7.25 million from the biannual vaccination; Sh4.62 million from ring vaccination and Sh1.4 million if no vaccination took place. The associated control costs are were 325 million, 86.7 million and Sh27.5 million respectively.
This is after discounting the benefits and costs such that at the end of the control strategy, they are brought to their net present value.