Key result
Long-term vaccination of breeding stock with a PRRSV killed virus vaccine significantly reduced the culling rate due to reproductive failure (P<0.001) and increased culling due to old age (P<0.001).
Why the study?
Does PRRS KV vaccine reduce culling rate due to reproductive failure in PRRSV-infected sows?
Observational (n=1,100)
No
Does PRRS KV vaccine reduce culling rate due to reproductive failure in PRRSV-infected sows?
p-value: p=<0.001
Long-term vaccination with a PRRSV KV vaccine decreases culling rate due to reproductive failure and improves sow longevity in PRRSV-infected farms.
Should not yet change sow vaccination protocols; hypothesis-generating for PRRSV KV vaccine effects on reproductive culling.
In porcine reproductive and respiratory syndrome virus (PRRSV)-infected farms, there is an increase in the female culling rate, mainly due to reproductive problems and culling of young females. This has significant economic importance, as the low female culling rate is an important management factor. In the present study, in a farrow-to-finish farm with 1100 sows, all gilts and sows were vaccinated with a PRRS killed virus (PRRS KV) vaccine (PROGRESSIS®/Merial SAS, France) for a period of 18 months. For each gilt and sow, reproductive data were collected starting from 1-year prior until 18 months after the start of vaccination. Culling rate and the causes of culling (reproductive failure, death, old age, locomotor problems and other) were recorded. Blood samples from non-vaccinated animals were collected prior and after the start of vaccination. The purpose of this field study was to evaluate the sow longevity in a PRRSV-infected farm after their long-term vaccination with a PRRSV KV vaccine. The results indicated that the vaccination leads to a significant reduction (P < 0.001) of culling rate due to reproductive failure 1.5 years after the start of vaccination and an increase of old age (P < 0.001) totally 1.5 years after the start of vaccination. Eventually, culling rates due to deaths (P = 0.066), locomotor problems (P = 0.264) and other causes (P = 0.894) did not significantly differ per semester and totally prior and after the start of vaccination. In conclusion, the long-term vaccination of breeding stock with a PRRSV KV vaccine can lead to decrease of culling rate due to reproductive failure and improvement of the sow longevity.
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Vasileios G. Papatsiros (2012) conducted an observational in Porcine reproductive and respiratory syndrome virus (PRRSV) infection (n=1,100). PRRS killed virus (PRRS KV) vaccine vs. Pre-vaccination period (1 year prior) was evaluated on Culling rate due to reproductive failure (p=<0.001). Long-term vaccination of breeding stock with a PRRSV killed virus vaccine significantly reduced the culling rate due to reproductive failure (P<0.001) and increased culling due to old age (P<0.001).
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