BackgroundOne possible way to support raising large litter sizes in pigs is to offer supplementary, artificial milk ad libitum in the farrowing pen in addition to the sow’s milk. In order to evaluate the potential use of this method and its effects on performance and health, supplemented (n = 60) and control sows (n = 60) with their litters were tested over 15 batches in one herd during one year. In the supplemented group (SG), piglets had access to supplementary milk in addition to sow’s milk from their 2nd day of life until weaning (day 27). The litters of SG sows were adjusted to contain as many piglets as the sow had functional teats, whereas in the control group (CG), piglets were set to the number of functional teats minus one, due to animal welfare reasons.Case presentationWith supplementary milk provision, the weaning of large litters was achieved without any negative impacts on performance and health. On average, 13.5 and 12.4 piglets were weaned in SG and CG, respectively (P < 0.05). While average weaning weights (SG: 7.8 kg v. CG: 7.8 kg; P > 0.05) and average daily weight gain of the piglets (SG: 0.25 kg v. CG: 0.25 kg; P > 0.05) did not differ, total litter weight was consequently higher in SG than in CG (104.9 kg v. 96.7 kg; P < 0.001). The average milk replacer intakes were 1.1 kg milk powder per day and batch, and varied significantly between the “warm” and “cold” seasons (1.5 v. 0.9 kg milk powder per batch and day; P < 0.001). No significant differences in the mortality rate or the occurrence of diarrhoea were detected in the piglets of both SG and CG (P > 0.05). With regard to documented medical treatments, facial lesions were treated less frequently in piglets of SG (46 v. 32 treatments; P < 0.05). There was no effect of supplementary milk on the loss of body weight, backfat thickness and body condition score of the sows (P > 0.05).ConclusionsTo summarise, in the presented case offering ad libitum supplementary, artificial milk supported the sow in raising large litters by compensating possible negative impacts of high piglet numbers on the weight gain of piglets and the body condition of the sows.

The postpartum dysgalactia syndrome (PDS) represents one of the most important diseases after parturition in sows. The genetic background of the disease has been investigated some time ago and heritability estimates around 0.10 have been obtained. To compute current estimates, a dataset of 1680 sampled sows and their 2001 clinically examined litters was used for variance components estimation with a threshold liability model. Affected sows were defined through clinical examination 12-48 h after parturition. Posterior mean of additive genetic variance was 0.10 and estimated heritability for PDS averaged 0.0879 with a 95% confidence interval of 0.0876 and 0.0881. The results are in agreement with those of other studies and emphasize the importance of considering the genetic predisposition for susceptibility to PDS as well as of additional factors including hygiene and management conditions.

Postpartum dysgalactia syndrome (PDS) in sows is an important disease after parturition with a relevant economic impact, affecting the health and welfare of both sows and piglets. The genetic background of this disease has been discussed and its heritability estimated, but further genetic analyses are lacking in detail. The aim of the current study was to detect loci affecting the susceptibility to PDS through a genome-wide association approach. The study was designed as a family-based association study with matched sampling of affected sows and healthy half- or full-sib control sows on six farms. For the study, 597 sows (322 affected vs. 275 healthy control sows) were genotyped on 62 163 single nucleotide polymorphisms (SNPs) using the Illumina PorcineSNP60 BeadChip. After quality control, 585 sows (314 affected vs. 271 healthy control sows) and 49 740 SNPs remained for further analysis. Statistics were performed mainly with the r package genabel and included a principal component analysis. A statistically significant genome-wide associated SNP was identified on porcine chromosome (SSC) 17. Further promising results with moderate significance were detected on SSC 13 and on an unplaced scaffold with an older annotation on SSC 15. The PRICKLE2 and NRP2 genes were identified as candidate genes near associated SNPs. Several quantitative trait loci (QTL) have been previously described in these genomic regions, including QTL for mammary gland condition, as teat number and non-functional nipples QTL, as well as QTL for body temperature and gestation length.