Intensive indoor breeding of piglets: weaning, distress and recovery.

BERARDO D; BIANCO M.; MAYER N; LAFALLA G.; GARCÍA G; RODRIGUEZ N; VIVAS A,; GRECO C; ASHWORTH G,

Jornada; XXVIII Jornadas Científicas de la Asociación de Biología de Tucumán.; 2011

Weaning distress affects the immune status, which may predispose animals to disease. We analyzed parameters of distress, immune status and recovery after weaning in intensive indoor pig farming systems with controlled light and temperature. We worked with 50 piglets before weaning and 12 days after weaning. The following were determined: total number of leukocytes (LT), lymphocytes (L) and neutrophils (N) and neutrophils/ lymphocytes (N/L) ratio, T cells response to mitogenic stimulation with ConA, plasma levels of IgG using ELISA and cortisol using RIA. Significant differences were found in all parameters analyzed between pre- and postweaning with the exception of IgG and T cells. LT and N increased (p=0.006 and 0.0004 respectively). L was lower (lymphopenia) at weaning (p=0.002). The N/L ratio increased from 0.36 in the preweaning to 0.62 in the post-weaning period (p=0.0006). Cortisol levels increased (3.5 μg/dl) after weaning (p=0.00017) but did not represent distress. Probably, at twelve days after weaning, neutrophilia was responsible for higher LT counts. Lymphopenia and neutrophilia were responsible for the N/L ratio increase, possibly a response to high levels of cortisol at weaning (10 μg/dl, data not shown), normal values not being recovered at twelve days after weaning. The higher levels of cortisol could be a response to greater stimulation by the new social and housing conditions. In conditions of controlled light and temperature and appropriate management, piglets recover a good immune status at twelve days post weaning.