Piglet Creching Decreases Protein Content in Colostrum

The structure of the porcine placenta precludes immunoglobulin (Ig) transfer into the fetus. Therefore, newborn piglets must absorb large amounts of colostrum during the first 24 hours of life, before gut epithelial closure takes place. It has been hypothesized that farrowing order may affect suckling, with those piglets born first likely ingesting more colostrum compared to those born in last place. The objective of this study was to assess whether creching (i.e. placing piglets into a warm box at birth to prevent suckling and returning all piglets to the sow at the end of farrowing) increases total plasma protein levels at 24-h post farrowing in the last 3 piglets born on each litter, and whether this increase is associated with higher milk protein synthesis in the mammary gland. A total of 56 litters (511 piglets) were either withheld from suckling for 4-h after the first pig was born (i.e. Creched; n = 28 litters), or allowed to suckle immediately (i.e. Control; n = 28). Blood was taken by jugular venipuncture at 24 h post farrowing in the first and last 3 piglets per litter. Colostrum samples were taken from front (fg), middle (mg) and rear glands (rg) in all sows immediately after farrowing the first pig and 3 h later. Total protein content in milk and blood, as an indirect measurement of Ig content, was analyzed using a Brix refractometer. Data were analyzed by ANOVA using a mixed model that included farrowing order, treatment and their interaction as fixed effects, litter as random effect, and birth weight as covariate. Total plasma protein levels at 24 h did not differ between piglets born first and last (P = 0.87), and were significantly higher in control compared to creched piglets (P = 0.0015). Similarly, there were no differences in total protein content in colostrum between sows when sampled immediately after farrowing (P = 0.18, 0.39 and 0.38 for fg, mg and rg, respectively), whereas it decreased in mg (P = 0.05) and tended to decrease in rg (P = 0.06) in sows with creched litters compared to those with controls. In conclusion, the lack of differences in plasma protein levels between first and last pigs born along with lower colostrum protein content in response to creching may militate against the use of this technique. Further studies are needed to explore directly the effect of creching on Ig levels and long-term pig survival