Nadis Cattle Veterinary Report and Forecast – January 2007

UK - This is a monthly report from the National Animal Disease Information Service (NADIS), looking at the data collected from their UK farm inspections.

7 February 2007

5 minute read

Europe

ADULTS

Fertility
After falls in November the number of fertility reports increased in December, mainly the result of the expected seasonal rise in non-detect oestrus. January to March is the peak season for missed heats. Housed cows seem to show oestrus far less than cattle at pasture so it is essential that oestrus detection is at a peak during this period. In the larger herds computer analysis can rapidly identify heat detection problems, allowing solutions to be developed before the costs get too high.

The other alternative is to dispense with heat detection altogether and use pharmaceutical control of the oestrous cycle as is done in many US herds. Such programmes have not yet become common in the UK but as herds get bigger and staff get fewer there is likely to be an increased of farms and their veterinary advisers looking at such programmes. We would be interested to hear your views on this.

The number of ovarian cysts reported by NADIS vets increased dramatically in December with the number of reports being higher than in any other year except for 2003. This increase was unexpected as levels had been at or around average for most of 2006 and lower than the 2005 figures.

Figure 1: Reports of ovarian cysts showing the steep rise in December

After an October which had the highest number of anoestrus reports of any October since NADIS began, the prediction was that it would be a bad winter for anoestrus as energy deficiency problems at the start of winter were only likely to get worse. However, the number of reports actually reduced in November and, for dairy cows, fell further in December to the lowest levels since November 2000. Any explanations for the sudden change would be gratefully received. Is the food in front of the cows better than it was in October?

Figure 2: Monthly figures for reports of anoestrus in dairy cows. The usual
winter rise seemed to have begun early this year,but was followed
by a marked fall in both November and December.

Metabolic disease

Overall metabolic disease cases were 40% below average in December. This was reflected in the figures for the year with fewer cases of metabolic and nutritional disease being reported than since the NADIS records begin in 1997 (even including 2001). The figures for the three classical metabolic diseases (milk fever, acetonaemia and grass staggers) were also lower than average this year, particularly milk fever and grass staggers the levels of which were both around half that seen in 1997.

Figure 3: Change with time in the number of reports per year of
metabolic diseases using 1997 as the base year

The number of cases of displaced abomasum reported in December remained above those in 2005. Over the whole year the figures were very similar to those seen in 2004 and 2005 at more than twice the average of all other years. These figures are in complete contrast to the metabolic diseases discussed above. Three years of these high figures for DAs confirms that something has changed in UK dairying and that these high levels are here to stay. At least we seem to have reached a plateau.

Figure 4: Change with time in the number of reports per year of
metabolic diseases using 1997 as the base year

Lameness

None of the main four causes of lameness showed an increase in December. Although January is usually the peak month for lameness December is, on average, not far behind, so these figures are consistent with those from the rest of the year which show that the ending of the OTMS was not associated with an increase in the number of lame cows seen by NADIS veterinarians. Indeed the 2006 figures are consistent with a slow decline in the number of lame cows seen by NADIS.

Digital dermatitis reports were almost at the same level as 2005 but clearly show that digital dermatitis is no longer as important a veterinary problem as it was in the late ‘90s. Some of this reduction could be because farmers are happier to deal with digital dermatitis problems themselves; but recent research data suggest that digital dermatitis has decreased on UK farms and it’s likely that the NADIS data is reflecting this. Reports of sole ulcer and white line disease are both currently lower than average, again mirroring the rest of the year. There is no evidence of an impact of the loss of the OTMS on the veterinary treatment of either disease.

Figure 5: Change with time in the number of reports per year
of lameness using 1997 as the base year

One disease that reporting may have been affected by the loss of the OTMS is the downer cow. The total number of reports in 2006 was only half the number reported in 2005 suggesting that the loss of value of a down cow may have reduced veterinary callouts. However there was also a 50% drop between 2004 and 2005 which was obviously unrelated to the loss of the OTMS so there may be other causes. We would be very interested to hear suggestions.

Figure 6: Change with time in the number of
reports per year of downer cow

Other diseases

Gareth Bell from Northern Ireland reported an unusual problem in a 300-cow dairy herd. Five mid-lactation cows intermittent problems at milking caused by congested, oedematous teats with thickened walls. Both the teat ends and the milk were apparently normal. The teat lesions were associated with swollen feet and moderate pyrexia (39.5°C). The condition lasted only a few days with the cows then returning to normal. An allergy or hypersensitivity is the main suspicion and investigating of possible causes (such as teat washes, or foot baths) is ongoing. We would be very interested to here of any similar cases.

Traumatic reticulitis, particularly which associated with tyre wire, is an increasing concern in dairy practice. One outbreak reported this month involved wire dropped by roofing contractors onto the grain store while they were working. They neglected to inform the farm of the problem!

CALVES

In December both calf scour and enzootic pneumonia remained at levels well below the long term average, with calf scour outbreaks having the lowest number of December reports except for December 2002. Calf scour outbreaks have now been below average since July 2005. Is this just better management or reluctance to call out the vet to treat calf problems?

Figure 7: Calf scour figures showing the low number of reports for this
year compared with the long-term average