Haematological and immunological adaptations of non-pregnant, non-lactating dairy cows to a high-energetic diet containing mycotoxins

Tannic acid modulates intestinal barrier functions associated with intestinal morphology, antioxidative activity, and intestinal tight junction in a diquat-induced mouse model

The concentration of 2.5 mg kg⁻¹ TA can ameliorate diquat-challenged jejunal injury in mice.

Effects of herd and physiological status on variation of 16 immunological and inflammatory parameters in dairy cows during drying off and the transition period

During drying off and transition period, cows are subject to changes in endocrine status, metabolic stressors and altered immune functions, which could lead to an increased risk of disease. To expand our knowledge on the immune/inflammatory status and to identify markers to define cow status during this interval, the pattern of 9 different cellular parameters, 5 cytokines, 2 enzymes and 3 cellular ratios in blood samples were assessed in 15 primiparous cows belonging to three different dairy herds in Lombardy. Our data showed that the variation of almost all parameters was influenced by the physiological period in which the samples were collected, except for apoptosis, IL-1β, IL-6, lysozyme and granulocyte/monocyte ratio. Several markers were directly correlated either to the herd alone (IL-1β, IL-6, lysozyme, granulocyte/lymphocyte ratio and granulocyte/monocyte ratio) or in association with the sampling time (white blood cell count, necrosis, lymphocytes count, CD4+ lymphocytes proportion). Hierarchical cluster analysis identified three herd-associated sample clusters showing different frequency along the follow-up period. The results of this field study highlight the importance of the herd factor in the immune/inflammatory response. Furthermore, these results suggest that cellular parameters are probably the most suitable markers to define cow status during drying-off and the peripartum period.

Animal models to study the impact of nutrition on the immune system of the transition cow

The immune system is particularly challenged in transition cows as marked physiological changes occur in this period which are driven by late gestation, partus and onset of lactation. As a consequence, the metabolic and nutritional state of the cow also changes significantly with possible implications for the plasticity and flexibility of the immune system. In order to understand how the balance between metabolism, nutritional status and the immune system is maintained under challenging conditions, such as an infection, various animal models can be used which specifically manipulate the nutritional status through various feeding and management strategies. Such models aim at exploring the immunological response to a challenge under largely varying nutritional and metabolic states. As energy balance (EB) is strongly associated both with the metabolic state and with the immunoreactivity of the cows the manipulation of the EB by either influencing energy intake or energy excretion with milk, or by both, offers model opportunities for studying EB effects on the immune system. For example, assigning cows with a higher body condition score (BCS) at least 6 weeks prior to calving to an energy-dense diet exceeding the energy requirement in combination with a decelerated increase in the concentrate feed proportion post partum was shown to be effective in inducing a ketotic metabolic state under ad libitum feeding conditions. Compared to an adequately managed control group this model allows studying immune responses in the transit period and in dependence on dietary interventions.

Fate of deoxynivalenol and deoxynivalenol-3-glucoside during cereal-based thermal food processing: a review study

Deoxynivalenol (DON), the most commonly occurring trichothecene in nature, may affect animal and human health through causing diarrhea, vomiting, gastrointestinal inflammation, and immunomodulation. DON-3-glucoside (DON-3G) as a major plant metabolite of the mycotoxin is another "emerging" food safety issue in recent years. Humans may experience potential health risks by consuming DON-contaminated food products. Thus, it is crucial for human and animal health to study also the degradation of DON and DON-3G during thermal food processing. Baking, boiling, steaming, frying, and extrusion cooking are commonly used during thermal food processing and have promising effects on the reduction of mycotoxins in food. For DON, however, the observed effects of these methods, as reported in numerous studies, are ambiguous and do not present a clear picture with regard to reduction or transformation. This review summarized the influence of thermal processing on the stability of DON and the formation of degradation/conversion products. Besides this, also a release of DON and DON-3G from food matrix as well as the release of DON from DON-3G during processing is discussed. In addition, some conflicting findings as reported from the studies on thermal processing as well as cause-effect relationships of the different thermal procedures are explored. Finally, the potential toxic profiles of DON degradation products are discussed as well when data are available.

Haematological, clinical-chemical and immunological consequences of feeding Fusarium toxin contaminated diets to early lactating dairy cows

Dairy cows experience a negative energy balance at the onset of lactation which results in an enhanced vulnerability for infectious diseases. Any dietary imbalances, including Fusarium toxin contamination, might therefore exacerbate this situation. The aim of the present investigations was to study the effects of increasing dietary concentrations of deoxynivalenol (DON) and zearalenone (ZEN) on clinical-chemical, haematological and immunological traits up to week 14 of lactation. For this purpose, ten cows each were assigned to a control group (CON; 0.02 mg ZEN and 0.06 mg DON per kg diet at 88 % DM), toxin level 1 (TOX-1; 0.29 mg ZEN and 2.31 mg DON per kg diet at 88 % DM) and toxin level 2 (TOX-2; 0.58 mg ZEN and 4.61 mg DON per kg diet at 88 % DM). The measured values of most parameters were affected by parturition but only a few of them were further modified by dietary treatment. For example, the time-dependent decrease in haemoglobin concentration, haematocrit and erythrocyte counts occurred at a significantly higher level for group TOX-2 while a serum glucose increase was missing in this group. Proportions of CD4+ and CD8+ cells decreased significantly over time solely in group TOX-2 while the CD4+/CD8+ ratio remained uninfluenced. Ability of granulocytes to mount an oxidative burst tended to increase at the end of the study in groups TOX-1 and TOX-2 while the opposite was observed in group CON. The results of this time-limited study indicate that feeding of Fusarium-toxin contaminated diets in early lactation affects health related parameters without compromising milking performance. However, long-term consequences of the observed effects on health need to be addressed in further studies.