transfer and piglet survival

ABSTRACT
Birth to weaning is a high-risk period for piglets. The present paper reports the efficacy of supplementing the sows diet with Stimune® (specific fatty acids) to increase the survival of piglets by enriching the colostrum and stimulating the immune system of piglets. A trial involving 70 sows and their offspring compared two groups : a control group without marine fatty acids and a group supplemented with 50 g/day/sow (top feeding) for the 15 days before farrowing and during the first 15 days of lactation. The percentage of losses decreased with the addition of marine fatty acids (- 4.6 points, p<0.10). Litter weight at birth was improved (+7.8%; p<0.10) but not the average weaning weight. There were higher amounts of IgG (+303%) and of specific added fats (+25%) in the colostrum, demonstrating the transfer from the feed to the colostrum. Milk contained more IgG, even 21 days after farrowing (+50%). The marine specific fatty acids had a significant effect on IgG, lymphocyte and monocyte concentrations in piglet blood, proving that immunity had been stimulated by the ingestion of colostrum and milk. This positive effect on the immune system of piglets was still noticeable 36 days after birth.

INTRODUCTION
Birth to weaning is a high risk period for piglets. In 2007, in French pig farms, we notices a pre-weaning mortality of 20.6% (GTTT, 2007). Most of losses appear during the first 48h of piglet life. Colostrum is essential to insure the future immune status of piglets (Farmer and Quesnel, 2008) and it covers 44% of piglet energy expenditures.
One solution to improve immune status of piglets, and consequently future performances, is to enrich the colostrum by the feeding way (Kim et al., 2007). This study introduces results obtained on sow reproductive performance and immunity transfer to piglet, by adding a feed specialty

1. MATERIALS AND METHODS
1.1. Animals and experimental protocole
The trial took place in the Nivot College of Agriculture (France) on 3 bands of 70 sows distributed in 2 groups according to litter ranks, performances in previous litter and body status. The control group was fed with feeds normally supplied to sows at the end of gestation and during lactation. Feeds supplied to the trial group contained Stimune, feed specialty based on specific fatty acids from marine origin. Stimune was supplied to sow feed in top feeding way during the following period 15 days before farrowing till 15 after farrowing (Stimune dosage: 50 g/day/sow).
1.2. Measures and analysis
Quantities of feed consumed by sow have been recorded, births and mortalities have been counted, as well as weights of litter and average weights of piglets.
Collections and analysis of colostrum, milk and piglet blood have been proceeded at different time during a preliminary study run by INRA(French National Research Institute of Agriculture). The objective was to control different parameters : specific fatty acids, IgG, lymphocytes, monocytes. Data have been analyzed by variance analysis (ANOVA) with a SPSS software (version 1.13). Results have been cumulated on the 3 bands in trial.

2. RESULTS AND DISCUSSION
2.1. Sow reproductive performances
Added fatty acids from marine origin improve the weight of litter at birth (+7,8% ; p<0,10) and significantly decrease the number of stillborn piglets by 0,3 point compared to control group (Table 1). Furthermore, The total losses compared to born alive piglets are reduced (-4.6 points ; p<0.10). The trial group tends to increase the number of piglets (+0,5 weaned/sow, p>0,10). The average age at weaning is significantly reduced compared to control group (-0,4 jour ; p<0.10).

2.2. Immunity transfer to piglets
In the trial group, we observed an increase of specific fatty acids (+25 points) and IgG in sows colostrum and milk (Table 2). The concentration of IgG in piglet blood is significantly higher in the trial group, after farrowing group(+90% ; p<0,05) and till 36 days after farrowing (+75% ; p<0,001). Fatty acids from marine origin also increase leukocyte concentrations in piglet blood after weaning (Table 3 ; p<0,05). Those results demonstrate the imunity transfer from sows to piglets via the colostrum, then the milk. The positive effect of Stimune is remanent and persists after weaning. 

3. CONCLUSION
The supply of fatty acids from marine origine to sows at the end of gestation and at the beginning of lactation allows to stimulate piglet immunity and to increase reproductive performances of farms. The mode of supply in top feeding or direclty mixed in feed allows a daily supply of the required quantity on the pre-farrowing and lactation feeds. The enrichment of colostrum will have to be coupled with zootechnical and management practices insuring an early colostrum consumption by each piglet at birth.

BIBLIOGRAPHY
· GTTT, 2007. IFIP.
· Farmer C., Quesnel H., 2008. Nutritionnal, hormonal and environmental effects on colostrum in sows. J. Anim. Sci., published online first on Sept. 12 2008: http://jas.fass.org/cgi/content/abstract/jas.2008-1203v1.
· Kim S.W., Mateo R.D., Yin Y., Wu G., 2007. Functional amino acid and fatty acids for enhancing production performance of sows and piglets. Asian-Aust. J. Anim. Sci., 20, 295-306.