Dynamics of pro- and anti-inflammatory cytokine changes in serum and assessment of their diagnostic utility during lactation impairment in pigs.

Postpartum dysgalactia syndrome (PDS) in sows is a frequent and important clinical problem in the field. Currently, the diagnosis is based on physical examination performed during first days after the farrowing. The present study aimed at evaluation the dynamics of pro- and anti-inflammatory cytokine (IL-4, IL-6, IL-8, IL-10 and TNF-α) changes in serum of sows during peripartum period (day - 28 to + 28) and assessment of their diagnostic utility during lactation impairment in pigs. The study was done on 139 sows divided into 3 groups: clinically healthy sows, sows with lactation disorders, sows which had experienced difficult parturitions, lameness, etc. In order to measure the level of serum cytokines, the quantitative species-specific ELISA assays were used. The investigation demonstrated a different kinetics of changes of studied cytokines in sows from various groups. IL-6 and TNF-alfa shown high dynamic changes after farrowing in in sows. The levels of IL-8 and IL-10 were relatively stable in healthy sows, while in sows with peripartum disorders usually increased during lactation. However, the detailed examination revealed that investigated cytokines cannot be a useful early diagnostic markers of lactation impairments in sow. They do not allow to detect with high probability which sows are susceptible to lactation disorders before the parturition.

Assessment of the innate immune response in the periparturient cow.

The transition period is the most critical phase in the life of high yielding dairy cows. Within a few weeks, cows are submitted to many challenges (physiological, nutritional, psychological, management) that require prompt and effective adaptive responses. The immune system is involved in this process, and many changes of the cow's immune system components have been observed around calving. Cows are considered to be immunosuppressed in late lactation, and available data suggest that the immune system is dysregulated around parturition. Significant attention has been focused on modification of cellular functions (e.g. the reduction of phagocytosis and diapedesis), but growing interest concerns the components of the innate immune system, which often exhibits increased responses such as susceptibility to inflammatory events and the related acute phase response (APR). Systemic inflammation plays a significant role in early lactation, affects many liver functions and has been associated with the impairment of cow performance (i.e. reduced feed intake, milk yield, fertility, welfare). The assessment of variations in immune-metabolic indices offers opportunities to predict the onset of the health troubles and to anticipate the proper therapies needed to guarantee health, good welfare and fertility in the following lactation. The frequency of diseases (metabolic and infectious) before calving is rare, but several clues suggest that various metabolic and immune variations can begin during the dry period. Interesting preliminary results encourage this perspective and possible candidates are suggested.