Aart Lammers

The aims of this study were to (1) investigate the relationships between prepartum body condition, metabolic status, dam milk variables, and colostrum yield and its immunological and nutritional components; (2) investigate the relationships between colostrum variables of dams and female offspring's growth and metabolism from birth to weaning, from weaning to calving, and during the first 100 DIM; and (3) evaluate the correlation between dam colostrum variables in dams and those of their offspring after their first calving. Data and colostrum samples originated from a previous experiment that was designed to evaluate the effect of voluntary waiting period on health of dams and female offspring. In the current study, Holstein-Friesian dairy dams (n = 62) that calved female offspring with different calving interval (CInt) were included. The available prepartum variables of those dams included BW, BCS, milk yield, DMI, and energy balance (EB), and blood metabolites were assessed before calving. After calving, colostrum variables were measured, including yield, Brix value, protein, growth factors, and antibodies. Body weight and blood metabolites of female offspring (n = 62) from those dams were monitored across 3 stages: calf from birth to weaning, heifer from weaning to calving, and lactating offspring during first 100 DIM, and colostrum variables after their first calving. To investigate relationships between prepartum dam condition, dam colostrum, and female offspring development from birth to weaning and until lactation, each dam variable or colostrum variable were included separately in a regression model, with fixed effects of dam's CInt, parity, time, and their 2-way interactions, repeated over time. Higher BCS before calving was related to lower lactoferrin concentration in colostrum. Greater prepartum EB was related to higher IgM concentration in colostrum, which was related to higher keyhole limpet hemocyanin (KLH)-IgM and IgG levels in offspring plasma from birth until lactation. Greater milk yield in the last week before dry-off was related to higher concentrations of insulin-like growth factor-І (IGF-І) and transforming growth factor-β2 (TGF-β2) in dam colostrum. Higher concentrations of IGF-І and TGF-β2 in colostrum were related to higher plasma nonesterified fatty acid concentrations of calves from birth to weaning, as well as higher milk lactose content during lactation. The positive relationships between KLH-IgG titers in colostrum and offspring plasma remained consistent from birth until lactation. Additionally, higher colostrum yield in dams was associated with higher colostrum yield in female offspring. In conclusion, dairy dam DMI and EB were positively related to natural antibody levels in colostrum, which, in turn, were positively related to natural antibody levels in offspring plasma from birth to weaning and through lactation. Overall, colostrum, influenced by prepartum dam conditions, is related to offspring long-term immunity.

Lactobacillus rhamnosus CNCM I-3698 (LR98) and L. formosensis CNCM I-3699 (LF99) are two probiotic bacterial strains used in industry in a co-fermentation process to produce a probiotic (Pro) and the associated postbiotic (Post). The latter is produced through inactivation of the viable cells in the Pro by a high-temperature short-time (HTST) treatment. The impact of the inactivation process on the metabolomic profile of the Post was investigated. A growth substrate (Control) was fermented using a co-culture of LR98 and LF99 to produce the Pro and then HTST treated (~105 °C; 5 bar; 7 s) to derive the Post. Analysis of the semi-polar metabolome yielded 1412 unique features, from which 105 compounds were identified. The HTST process decreased the peak area in the Post of most features by 2; adjusted-p < 0.05) in the peak area was observed for 29 identified compounds, including 15 with known immunomodulatory, anti-oxidative or antibacterial property. The HTST treatment decreased the peak area of 4 of these compounds by >10% and 25 compounds by <10%. The HTST treatment to yield the Post induced minimal changes in the metabolomic profile, while the fermentation to produce the Pro yielded metabolites with known biological activity.

Lipopolysaccharide (LPS) challenges are commonly used in animal studies as a model for infection with gram-negative bacteria and innate immune activation. We used a low-dose LPS challenge for evaluating interindividual variation in innate immune responses in calves. This was part of a larger study aimed at predicting interindividual variation in feed efficiency in veal calves by variation in feeding motivation, digestion, metabolism, immunology, and behavioral traits. However, due to unexpected high mortality, this LPS challenge was performed in 32 calves rather than in 130 calves, which was initially intended in that larger study, and the 32 calves subjected to the LPS challenge were removed from that larger study. The objective of this short communication is to report the effects of a low-dose LPS challenge in those 32 calves and to examine whether the high variation in calves' responses to LPS could be explained by parameters related to feeding motivation, digestion, behavior, and immunology measured in early life. Thirty-two male Holstein-Friesian calves of Dutch origin were intravenously injected with LPS (0.05 mu g/kg of body weight) at an age of 72 +/- 0.6 d. Rectal temperature and respiratory frequency were recorded before injection and every hour after injection up to 6 h. In the 8 wk before the LPS challenge, measurements were performed related to general health, feeding motivation, digestion, behavior, and immunity. Following LPS administration, 3 calves died of shock, a fourth calf was euthanized because of severe symptoms of shock and 3 other calves were treated with corticosteroids to counteract observed symptoms of shock. Within the group of 25 relatively mild-responding calves, large interindividual variation in clinical responses to LPS was observed. The maximum increase in rectal temperature varied from 0.6 to 1.9 degrees C and averaged 1.2 +/- 0.39 degrees C (coefficient of variation was 32%). The maximum increase in respiratory frequency varied from 16 to 132 bouts/min and averaged 60 +/- 28 bouts/min (coefficient of variation was 48%). Little differences were found in early-life measurements between the 7 heavy and 25 mild responders, although heavy responders tended to have a better umbilical hernia score, and had a lower score in a human approach test (i.e., were less reactive) and lower presence of fecal pathogens. The maximum increase in rectal temperature correlated negatively with blood hemoglobin concentration at arrival of the calves at the facilities (r = -0.59) and in wk 4 (r = -0.53). The maximum increase in respiratory frequency correlated negatively with fecal color score (r = -0.43) and positively with fur score in wk 5 (r = 0.50). Overall, mortality (12.5%) and variation in clinical response was high after a low-dose LPS challenge in clinically healthy calves and some hematological and health measurements in early life were related to the clinical response of calves to LPS.

Activation of the maternal immune system may affect innate and adaptive immune responses in the next generation and may therefore have implications for vaccine efficacy and dietary immune modulation by feed additives. However, transgenerational effects on immune responses in chickens have been investigated to a limited extend. The present study investigated effects of intratracheal (i.t) specific and aspecific immune activation of laying hens on specific antibody production in the next generation. In two experiments laying hens received intratracheally an immune stimulus with human serum albumin (HuSA) or lipopolysaccharide (LPS). In experiment 1, hatchlings of the immune activated hens were at 4 weeks i.t. immunized with HuSA or HuSA+LPS. Maternal immune activation with LPS increased HuSA specific IgY and IgM responses in offspring. These results suggest a transgenerational effect of the maternal immune system on the specific antibody response in the next generation. In experiment 2 hatchlings received either β-glucan-enriched feed or control feed and were i.t. immunized with HuSA. Maternal immune activation with LPS decreased IgY anti-HuSA responses after HuSA immunization within hatchlings that received β-glucan enriched feed. The results of Experiment 2 suggest a transgenerational link between the innate immune system of mother and specific antibody responses in offspring. Despite variabilities in the outcomes of the two experiments, the observations of both suggest a link between the maternal innate immune system and the immune system of the offspring. Furthermore, our results may imply that maternal activation of the innate immune system can influence immune modulating dietary interventions and vaccine strategies in the next generation.