Weaning is associated with several stress factors and their effects on the piglet’s body are fairly well known. Thus, changes were estimated in certain serum and faecal parameters after weaning owing to dietary protein level, though essential amino acid (AA) levels were maintained or reduced. Eighteen Topigs piglets were assigned randomly to three homogenous groups. The dietary protein level was reduced by 10% in diets 1 and 2 compared with diet C. Diet 1 had similar levels of essential AA to diet C, while the levels of essential AA in diet 2 were reduced by 10%. Blood samples were collected by jugular venipuncture in the farrowing unit on four occasions: before and after separation from the sow; the day after transfer to the nursery; and seven days after weaning. Faecal excreta were collected daily. No major health problems arose, and total pathogen germs were not different among treatments. Cortisol concentration reached similar values to those from the farrowing unit seven days after weaning. Whatever the diet, vitamin E in plasma decreased significantly in the first seven days post weaning. The reduction of dietary protein, as well as essential AAs, adversely affected the concentration of Cu (by 17.3%) in plasma. Selenium concentration in plasma increased slightly, irrespective of diet. The authors conclude that providing dietary protein at a particular level (diet 1), while maintaining AAs at normal level, limits faecal nitrogenous content without significantly modifying stress indicators (except vitamin E) or faecal composition.
"Experientia docet" - Experience is the best teacher