The purpose of the study was to evaluate the effect of the vaccination of Circovac (manufactured and marketed by Merial Animal Health, France) on reproduction performance. This vaccine is the only PCV2 vaccine on the market that has an authorisation for use in sows. In many countries, use in piglets has also been authorised.
The study was conducted in a 2,700-sow farrow-to finish, DanBred registered herd in Bulgaria, with every four days farrowing batches and strict all-in/ all-out pig flows.
· Before the observation period: Piglets used to be vaccinated with the vaccine at 28-30 days of age, 0.5 ml, intramuscularly, once.
· In August 2009, a mass sow vaccination was carried out twice, three weeks apart, followed by routine booster two weeks prior farrowing.
Results
There was a major increase in total and live born per litter (1.7 and 1.6) meaning for an average of 2.5 reproductive cycle in the farm: 4.25 and 4 total and live born piglets/ sow/ year.
In this study, mortality in farrowing pens was artificially increased by the elimination of underweight offspring (<840 g), subsequent to the improvement of the total and live-born piglets.
The final results corroborated, except for one parameter, the results described in many countries that consistently showed improvement in reproduction parameters after sow vaccination.
The research was carreid out by Hristov Stoykov, DVM; Milena Groseva, SAM BS, Bulgaria; Sophie Longo, BPC, France and Marion Pasini, Francois Joisel and Stéphane Imbert, Merial, France. The data were first published at this year’s Asian Pig Veterinary Society Congress in Pattaya, Thailand.
Table 1. Reproductive parameters (averages).
|
|
Before
|
After
|
Δ
|
p (K.W)
|
|
Number of service
|
130.6
|
136.7
|
6.1
|
0.276
|
|
Returns %
|
6.0
|
5.7
|
-0.3
|
0.463
|
|
Conception rates
|
87.6
|
90.3
|
2.7
|
0.081
|
|
Farrowing
|
120.8
|
118.4
|
-2.3
|
0.463
|
|
Total born/lit
|
13.4
|
15.1
|
1.7
|
0.000
|
|
Live born/lit
|
12.0
|
13.5
|
1.5
|
0.000
|
|
Stillborn/lit
|
1.4
|
1.6
|
0.2
|
0.168
|
|
Total weanings
|
117.5
|
118.8
|
1.3
|
0.856
|
|
Suckling days
|
28.7
|
29.2
|
0.4
|
0.116
|
|
Weaned per litter
|
11.3
|
11.4
|
0.1
|
0.124
|
|
Kg/pig weaned
|
7.4
|
7.6
|
0.2
|
0.048
|
|
Mortality % in Farrowing pens
|
12.6
|
16.6
|
4.0
|
0.000
|
(KW = Kruskal-Wallis) Results were considered as significantly different when p<0.05.
