Date post: | 25-May-2015 |
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Health & Medicine |
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Julio Alvarez, Javier Sarradell, Robert Morrison, Andres Perez
DVM, PhD
Department of Veterinary Population Medicine
College of Veterinary Medicine
University of Minnesota
Impact of PED in growing pigs
PED impact
• Primarily due to losses in suckling piglets– Mortalities between 50-80%b – Time to recover baseline production of
>10 wksc
• Further impact?– Infected growing pigs: 1-3% mortalityb
– Pigs exposed to PED as piglets that make it to the growing phase?
a Swine enteric Coronavirus disease testing summary report, Sept 3 2014b White Paper (Geiger and Connor, 2013)c Swine Health Monitoring Project (Goede and Morrison, 2014)
a
Objective
• To quantify the impact of PEDv infection in growing pigs by comparing– Mortality– Average daily gain (ADG)– Average daily feed intake (ADFI)– Feed conversion rate (FCR)
in batches exposed/unexposed to the virus
Peek at the results
• Impaired performance of pigs from first PED+ batches compared with PED- pigs– Increased mortality (6-18%)–Decreased ADG (0.07-0.26 lb/day)– Increased FCR (0.3-0.8)
Material and methods
• Screening of productive records to select batches from positive flows– Only nursery/WF batches
• Selection of 33 flows– 11 nursery– 22 WF
Commercial sow
Nursery
FinishingWean to
finish
PED detection
• Selection of first PED+ batch within a given flow (“infected” batch)
• Selection of the closest preceding PED- batch from the same flow (“control” batch)– At least 14 days before the infected batch (increase
specificity)– Not more than 4 months before the infected batch
Inclusion criteria
PED+ batch
Control batch (closest available)
Weeks
Data analysis
• Pairs of batches - paired non-parametric comparison (Wilcoxon test) of performance records
• Comparison of nursery to WF paired differences (Mann-Whitney test)
Study population• 18 flows fulfilled the inclusion criteria (18 case + 18
control batches)– 4 nursery– 14 WF (double stocking: first stage in growing, ≈60d)
• Average mortality, ADG, ADFI and FCR in the previous four months (before PED) within normal limits
Descriptive results• First PED+ batch change in trends
– Increase in mortality (4.9 to 15.2%)– Decrease in ADG (0.79 to 0.72)– No change in ADFI– Increase in FCR (1.75 to 2.28)
• GRAFICA GLOBAL
4 3 2 1 PED!
Paired comparison• Mortality
Control Infected
12.5% increase (95% CI: 6.4-18.4)
• Performance
Control Infected Control Infected Control Infected
ADG ADFI
FCR
↓0.16 lb/d↑ 0.55
So, as previously mentioned…
• Impaired performance of pigs from first PED+ batches compared with PED- pigs– Increased mortality (6-18%)–Decreased ADG (0.07-0.26 lb/day)– Increased FCR (0.3-0.8)
Conclusions (II)• Caveats of the study
– Reduced dataset – No adjustment by covariates (site)
• However…– Robust trend suggesting a decreased performance of
growing pigs from PED+ batches• Increase in mortality (6-18%... Or more!)• Decrease in ADG, ADFI unaffected Increase in FCR (0.3-0.8)
– Rough numbers: with 0.3$/lb feed from wean to 40 lbs, 0.55 poorer FCR costs approx $0.16/lb gain
• Impact of PEDv goes beyond suckling piglets