NADIS Cattle Veterinary Report and Forecast – January 2009

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

2 February 2009

7 minute read

Europe

ADULTS

Fertility

The number of fertility reports was fairly static in December compared to November, with the number of cows presented as not having been seen in heat (either because of true anoestrus or missed heats) falling by just over 5%, against the usual December trend of a small increase. Usually the next three months (January to March) are the peak months for missed heats as housed cows seem to show oestrus far less than cattle at pasture so the quality of heat detection required is at a peak during this period. However since 2002, the proportion of cases reported in January – March has been around 3% lower than in 1997 – 2001 and in 2008 the figure fell to below 25% (Figure 1). Is this because of increased use of heat detection programs or targeted synchronisation during these months? It will be interesting to see if a similar pattern emerges in 2009.

Figure 1: Percentage of missed heats reported in January to March, showing the very large drop in 2008

Heat detection continues to be a major problem on many farms and a major part of the veterinary workload. In 2008 NADIS veterinarians diagnosed almost 16,000 missed heats in cattle, this figure is just above average and very similar to previous years which clearly shows that so far no magic bullet appears to have been developed to combat the problem. Technology may provide the solution but so far success always seems to be around the corner rather than in plain sight.

In the last two years the number of ovarian cysts reported by NADIS vets increased dramatically in December. In 2008, however, December figures were slightly below those seen in November and fell below the long-term average. This was unexpected as levels had above average for most of 2008 and December usually shows a rise. Ovarian cysts are the third most-commonly reported fertility problem, with over 200 recorded per year. The NADIS data show that following low numbers in the early years of the decade, reports are now back at levels seen in the late 90s.

Figure 2: Average number of reports of ovarian cyst per month, showing the reversal of the decline in cases seen earlier in the decade

Metabolic disease

Overall metabolic disease cases were over 30% below average in December. This was reflected in the figures for the year with fewer cases of metabolic and nutritional disease being reported in 2008 than any previous year since the NADIS records begin in 1997 except for 2007. The figures for the three classical metabolic diseases (milk fever, acetonaemia and grass staggers) were also lower than average this year, although high numbers of grass staggers in autumn meant that reports in 2008 were substantially up on those of 2007.

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 fell to the long-term average. Over the whole year the figures were very similar to those seen in 2007, so there is so far no evidence that DA cases are returning to 'normal' after the peak years in the middle of this decade. So the disease remains far more common in dairy cows than it was 8 to 10 years ago.

Figure 3: 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, with white line disease in particular showing a large and unexpected drop. Overall, lameness reports were similar in 2008 to those in 2007. This is the first year since 2004 where total lameness reports have not been appreciably lower than the previous years; however the rise was small and meant that the number of cases seen by NADIS veterinarians in 2008 was only just over half that seen in 1997.

This trend is reflected in the reports of digital dermatitis, white line disease and sole ulcers, all of are currently being reported at much lower levels than in 1997. In fact, for these three diseases the reduction has been much more prominent than for lameness overall, reflecting a change in the diseases seen by NADIS vets to the more unusual cases such as heel and toe ulcer rather than the traditionally important diseases. This is particularly the case for digital dermatitis (9 to 5%), but white line disease has reduced from 18.5 to 15% of all lameness while sole ulcer has fallen from 16 to 15%. Interestingly, the reduction in total cases in 2004 has not been matched by similar falls in these diseases, so their relative importance has increased since then.

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

Other diseases

Vet 48 ( Northern Ireland ) commented that he has seen a lot of Pasteurella pneumonia. He would like to know if any other vets are seeing an outbreak of this with no other underlying cause. He has seen severe Mannheimia haemolytica on 2 farms with 3 cows dying within 3 weeks of each other.

We had a question from Vet 78 (North Yorkshire) asking whether other vets saw an upsurge in Salmonella Dublin in cattle in late autumn/ early winter. The answers depended considerably on whether the disease was common in the vet’s area. In areas where Salmonella Dublin was commonly reported the same pattern was frequently observed. For example, Vet 77 ( Cumbria ) commented that he did the upsurge and that he thought it was probably fluke-related. He also described how S. Dublin once took out most of the farms down the River Lune. Vet 12 (Cumbria) commented that he didn’t always seen a seasonal increase in the autumn; he thought that that cycle was longer than a yearly one with an uprising in Cumbria every 3-4 years, leading to a large number of cases in one season followed by no cases for several years (as is the case at the moment). Vet 74 (Powys) reported that he see some S. Dublin in winter especially in the larger dairy herds. He associates the disease whole crop feeding is carried out and thinks that the disease is carried by starlings. Has not had any yet this year. In contrast Vet 86 (Staffordshire) thought that disease outbreaks were more commonly related to calving patterns on individual farms rather than season.

CALVES

In December, the amount of calf disease reported showed only a minor increase, with the small rise in pneumonia cases only returning numbers to October levels, scour cases remaining static and joint-ill reports dropping dramatically.

The declines in veterinary reports of scour, pneumonia and joint/navel ill have been broadly similar since 1997, but the patterns of the decline are quite different (Figure 5). For scour the general trend since 1997 has been downwards, for pneumonia the impact of 2001 was much greater and between 2002 and 2007 numbers were fairly static, although the 2008 figures suggest the decline may have restarted. The figures for joint ill are similar to those for pneumonia. These data alone are not conclusive but backed with anecdotal reports from NADIS veterinarians these figures suggest that on many farms we have achieved a significant improvement in calf health. However, there is still huge room for improvement. Vet 31 ( Preston ) reported that the dry cold weather at the end of December had reduced the incidence of pneumonia. However , prior to this there had been a lot of pneumonia cases in young stock, with the local knackerman having been reported to have collected 1000 dead young animals with pneumonia in the Christmas week. The vet commented that there had been little veterinary involvement in those cases.

Figure 5: Decline in the reports of calf joint ill, pneumonia and scour 1997 - 2008

Vet 81 (Northumberland) described an unusual problem in a group of 15 penned calves. The calves were being fed what seems to be a poor quality diet of silage which had a little bit of visible mould in it, straw, and a mix of about ¼ home grown mouldy barley and ¾ bought in clean mix with a protein balancer. When they were first presented to the vet, one calf was dead, one was recumbent and two were ataxic. A provisional diagnosis of barley poisoning was made but as they were between 200-300kg and being fed around 1.5kg of barley each, he thought this was unlikely. Two calves have died since the original presentation, unfortunately it has not been possible to get them post-mortemed confirmation of a toxin-related problem has not been possible.