Two different forms and levels of CuSO4 in piglet feeding: liver, plasma and faeces copper status

A 35-d experiment involving 150 crossbred pigs weaned at 26 ± 2 d of age was conducted to evaluate the effect of different forms of CuSO4 on the copper content of liver, plasma and faeces. Piglets were randomly allocated to five dietary groups with increasing supplementation of protected and unprotected Cu in the diet as follows: 0 ppm (CON), 75 ppm Cu unprotected (Cu 75UNP), 75 ppm protected (Cu 75P), 150 ppm unprotected (Cu 150UNP) and 150 ppm protected (Cu 150P). After 18 days of the experimental trial, 30 piglets were sacrificed to determine liver and plasma copper status. Faecal samples were taken for determination of copper content at the end of the whole experimental trial on the 35th day. The highest liver Cu concentration (P < 0.001) was found in Cu 150UNP compared with all other groups. The plasma Cu concentration showed a significant (P < 0.05) increase in the Cu 150P vs CON group. Groups Cu 150, either in the protected or unprotected form, showed a higher content in faeces compared with the CON and Cu 75 groups. The protection did not negatively influence bioavailability at Cu 75 ppm integration.