Nadis Pig 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

WThe after-effects of the hot summer months are starting to recede and most farms that suffered a drop in fertility have recovered production. Record analysis at routine visits however is still identifying drops in litter size in the autumn in sows served during the hot weather. The occasional cases of autumn infertility were reported and the effect becomes evident in farm records. However, the majority of the sow production problems reported in December were either of indeterminate cause or were accounted for by managemental error: eg-

High return rates associated poor hygiene at insemination with dirty catheters used.
Poor onset of oestrous post weaning identified as occurring in foster sows with prolonged lactation, believed to be associated with oestrous prior to weaning.
Milking deficiency associated with inadequate water supply.

In addition, source of semen was reported to be related to fertility levels with a switch of source stud coinciding with a lift in conception rates.

Infections infertility did not feature in this months report although occasional clinical outbreaks of swine influenza were seen in sows (and other age groups) and this might be expected to manifest as increase in returns to service over the next few weeks.

Weaners

The first cold snap of the winter early in the month, as always, caught some producers out with chilling a regular feature in weaned pigs. Attention to bedding and airflows had been inadequate.

With many producers now using novel breed type boars, patterns are beginning to emerge with a general feeling that the benefit – measured by reduced health problems in weaners – is greater with the Hampshire boar than with Piertrain X boars. There may also be significant differences in levels of umbilical hernias between breeds.

Vice - manifested as tail, flank ear or back biting was a regular feature and in some cases was associated with overcrowding as either other aspects of production (eg. Preweaning mortality) have improved or a surge of farrowings has come through following the hot weather repeat services.

Various infectious diseases featured prominently during the month with evidence of PMWS possibly increasing in the colder weather. Enteric diseases associated with Ecoli and Lawsonia infection featured, including one episode of “bloody gut” (PHE), which is not a common disease nowadays.

Respiratory infections in weaners were variably assigned to swine influenza, enzootic pneumonia and Glassers disease – the latter producing high levels of pleurisy at post mortem examination.

Growers/Finishers

Specific Enteric disease problems declined during December although colitis levels still feature prominently in ongoing incidence reports. Stomach ulceration featured prominently in the month with grist size of cereals/meal a significant feature. Rectal prolapses were also reported.

Respiratory disease levels increased in the older growing pigs with mixed pneumonia common. Comments from slaughter assessments suggest levels of pleurisy and Actinobacillus pleuropneumonia were of concern. Glassers disease and swine influenza both featured as significant clinical problems.

Overstocking was identified as underlying a number of problem farms despite the general drop in production in the summer. The long term effects of reduced overall mortality following breeding changes (novel boar lines) may be starting to have a significant impact on pig flow with a number of producers being forced to sell off weaners to create space.
Chilling and vice also featured in the reports as temperatures dropped early in the month.

Mycoplasma arthritis was seen in a number of cases although it is not possible yet to assess any seasonal patterns; there is a belief that this is very much a cold weather disease.

Paradoxically different veterinary surgeons have commented on Salmonella ZAP scores both increasing or decreasing with no consistent picture (high levels of environmental contamination in hot weather might have been expected to raise Salmonella scores at slaughter which might now start to decline). Full analysis of ZAP levels through the full year by BPEX would be interesting.

Piglets

Limited reports of problems in piglets were received although of specific interest were:

Outbreaks of stillbirths and splay legs in association with PRRS infection.
Outbreaks of streptococcal arthritis in baby piglets.

Response to treatment of piglets with Baycox at day 4 in terms of improved weaning weights is strongly suggestive of sub clinical coccidiosis being a significant condition. It is disappointing that no dedicated licensed product for pigs to treat this disease is yet available in the UK.

As the expected cold weather arrives, watch out for:-