Sow performance after vaccination with Porcilis PRRS

A study to determine sow performance after vaccination

Method

200 gilts and sows were divided into 2 groups of 100 animals each.
Group 1 - Untreated controls
Group 2 - Vaccinated with Porcilis PRRS
All health and reproductive parameters were recorded from the time of vaccination up to the next weaning.

Results

Several of the recorded parameters were improved after vaccination.

Sow/gilt health status and fertility parameters
	Group 1 (controls)	Group 2 (vaccinated)
Return to oestrus	20%^a	10%^a*
Abortion	1%^a	1%^a
Removals	22%^a	11%^b
Farrowing rate	78%^a	89%^b
Post-partum dysgalatia syndrome	15.38%^a	5.62%^b

Percentages in a row with different superscripts (a and b) differ significantly (P < 0.05).
* Tendency for significance (P = 0.053).

Comparison of fertility parameters in control and vaccinated sows.

In the figures below the effect of vaccination was clearly seen in certain reproductive periods, as reduced days to return to oestrus and increased gestation length.

Sow/gilt performance and fertility parameters (mean ± S.D.)
	Group 1 (controls)	Group 2 (vaccinated)
Weaning-to-oestrus interval (days)	5.26^a ± 1.29	5.46^a ± 1.48
Days to return to oestrus	28.00^a ± 10.59	21.80^b ± 2.15
Oestrus-to-abortion interval	78	64
Gestation length	114.24^a ± 2.01	115.06^b ± 0.92
Lactation length	26.82^a ± 1.73	26.37^a ± 1.64

Means in a row with different superscripts (a and b) differ significantly (P < 0.05).

Shows fewer days to return to oestrus in vaccinated sows compared to control group.

The number of piglets born did not differ between the two groups (p > 0.05). However, in the vaccinated group, more piglets were born alive and fewer pigs were born dead or mummified compared to the unvaccinated group (p < 0.05). Finally, vaccinated sows have weaned on average 0.7 pigs more than unvaccinated sows (p < 0.05). See the table below .

Litter size and litter performance parameters (mean ± S.D.)
	Group T1, unvaccinated sows/gilts	Group T2, vaccinated sows/gilts
No. of piglets born	10.41^a± 1.65	10.65^a± 1.55
No. of piglets born alive	9.38^a ± 2.20	9.98^b ± 1.24
No. of piglets born dead	0.94^a ± 1.34	0.65^b ± 0.68
No. of piglets born mummified	0.09^a ± 0.33	0.02^b ± 0.15
No. of piglets weaned	8.54^a ± 2.48	9.24^b ± 1.53

Means in a row with different superscripts (a and b) differ significantly (P < 0.05).

Conclusion

Vaccination of gilts at the age of 180 days and sows 10 days post-partum with Porcilis PRRS of a farm suffering from both PRRS and PMDS, resulted in improvement of the health status and performance of gilts/sows and their litters, as shown by:

the longer gestation length as a result of the reduction of sows with premature farrowing due to PRRSV;
the tendency for lower return-to-oestrus rate
lower removal rate;
the higher farrowing rate;
the lower prevalence of sows with post-partum dysgalactia syndrome;
the higher number of piglets born alive per litter;
lower number of dead and mummified born piglets;
the higher number of piglets weaned per litter.