Effect of immune modulators on in vitro activation and proliferation of peripheral blood mononuclear cells from multiparous Holstein cows peripartum.

This in vitro study examined the ability of important immune modulators [ß-hydroxybutyrate (BHB), cortisol, prolactin, isoproterenol and insulin] to influence the responsiveness of peripheral blood mononuclear cells (PBMC) from multiparous dairy cows 29 ± 2 days before and 14 ± 3 days after calving. The activation and proliferation of PBMC in response to the mitogen phytohemagglutinin was estimated by the oxygen consumption rate after 24 hr and the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5diphenyl tetrazolium bromide) method after 72 hr respectively. In early lactation, the presence of 2 compared to 0.5 mmol/L BHB reduced PBMC activation (p < 0.05) and proliferation (p < 0.10), and the presence of 0.7 compared to 0.2 ng/ml insulin enhanced (p < 0.10) PBMC proliferation. In dry cows, the presence of low concentrations of BHB and insulin and both concentrations of prolactin (20 vs. 300 ng/ml) and isoproterenol (70 vs. 130 ng/L) enhanced activation (p < 0.10), but not proliferation (p ≥ 0.10) compared to cultures with no modulator addition. The presence or absence of high or low concentrations of hydrocortisone (20 vs. 45 nmol/L) did not (p ≥ 0.10) influence the activation and proliferation of PBMC from dry and early lactating cows. It is tempting to speculate that in antepartum PBMC the modulators represented an energy source or positive extrinsic signals to use nutrients for the activation process. On the other hand, PBMC from postpartum cows are known to be exposed to a metabolic challenging endocrine background. Under such conditions, high BHB concentrations and high insulin concentrations seem to act as negative and positive signals for PBMC, respectively, to utilize nutrients for activation and proliferation.

A High-Energy Diet and Spirulina Supplementation during Pre-Gestation, Gestation, and Lactation do Not Affect the Reproductive and Lactational Performance of Primiparous Sows.

Feeding high-energy (HED) or high-fat diets during gestation and lactation to pigs may help cover the energy requirements of high-prolific sows but may also adversely affect their reproductive performance. The microalga Arthrospira plantensis (Sp), rich in bioactive compounds, has been described to exert beneficial health effects. The present study investigated the effects of HED and Sp intake during gestation and lactation in pigs. Twenty-four primiparous crossbred sows were fed either a HED or a control diet. Half of the sows per group were supplemented with 20 g/day of Sp. Despite a higher gross energy intake, consuming the HED did not affect the sows' reproductive and lactational performance but significantly modified the colostrum fatty acid (FA) composition and tended to decrease the number of weaned piglets. The Sp supplementation did not affect the reproduction and lactation traits, but slightly affected the colostrum FA composition. A trend was observed for an interaction of diet and Sp in terms of offspring sex ratio with a 50% lower male-to-female ratio in the HED group compared to all other animals. These findings suggest that an HED and Sp intake hardly influence reproduction in sows. However, the HED modified the colostrum FA composition, whereas the Sp had only fewer effects, which may potentially affect offspring performance.