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To test the complex, acute biochemical effects of combined, naturally co‐occurring fusariotoxins, a 5‐day rat study was performed. Mycotoxin treatment was invented by intraperitoneal injection: FB1 (F): 9 µg/animal/day (approx. 30 µg/kg bw/day), DON (D): 16.5 µg/animal/day (approx. 55 µg/kg bw/day) and ZEN (Z): 12.75 µg/animal/day (approx. 42.5 µg/kg bw/day). The binary groups (FB1 and DON [FD], FB1 and ZEN [FZ] and DON and ZEN [DZ]) as well as the ternary (FB1, DON and ZEN [FDZ]) group were dosed at the same combined level as the individual mycotoxins. Body weight, feed intake and mortality were not affected by any of the treatments. FB1 and DON in combination (FD) increased the plasma aspartate aminotransferase activity synergistically (compared to the individual FB1 and DON). In the liver, both the total glutathione (GSH) and the glutathione peroxidase (GPx) activity were increased (p < 0.05) by the binary FB1 and ZEN (FZ) and the DON and ZEN (DZ) groups as well as the ternary FB1, DON and ZEA group (FDZ) compared to the control. The GSH level of the ternary group was significantly increased compared to the FB1 group, whereas the GPx activity of the ternary group was significantly increased compared to all three the individual mycotoxin groups. The Bliss independence method revealed synergism between DON and ZEN (DZ), as well as FB1 and DON (FD) on liver GPx activity. None of the toxins alone or in combination exerted strong genotoxicity on lymphocytes, neither on the gross histopathological characteristics. However, even at these low levels acute exposure of more than one of these mycotoxins (FB1, DON and ZEN) affected metabolic and detoxification changes.

Background: Accumulation of detrimental mutations in small populations leads to inbreeding depression of fitness traits and a higher frequency of genetic defects, thus increasing risk of extinction. Our objective was to quantify the magnitude of inbreeding depression for survival at birth, in a closed rabbit population under long-term selection. Methods: We used an information theory-based approach and multi-model inference to estimate inbreeding depression and its purging with respect to the trait 'kit survival at birth' over a 25-year period in a closed population of Pannon White rabbits, by analysing 22,718 kindling records. Generalised linear mixed models based on the logit link function were applied, which take polygenic random effects into account. Results: Our results indicated that inbreeding depression occurred during the period 1992-1997, based on significant estimates of the z-standardised classical inbreeding coefficient z.F L (CI 95% − 0.12 to − 0.03) and of the new inbreeding coefficient of the litter z.F NEWL (CI 95% − 0.13 to − 0.04) as well as a 59.2% reduction in contributing founders. Inbreeding depression disappeared during the periods 1997-2007 and 2007-2017. For the period 1992-1997, the best model resulted in a significantly negative standardised estimate of the new inbreeding coefficient of the litter and a significantly positive standardised estimate of Kalinowski's ancestral inbreeding coefficient of the litter (CI 95% 0.01 to 0.17), which indicated purging of detrimental load. Kindling season and parity had effects on survival at birth that differed across the three periods

To test for the presence of purging in populations, the classical pedigree-based inbreeding coefficient (F) can be decomposed into Kalinowski’s ancestral (FANC) and new (FNEW) inbreeding coefficients. The FANC and FNEW can be calculated by a stochastic approach known as gene dropping. However, the only publicly available algorithm for the calculation of FANC and FNEW, implemented in GRain v 2.1 (and also incorporated in the PEDIG software package), has produced biased estimates. The FANC was systematically underestimated and consequently, FNEW was overestimated. To illustrate this bias, we calculated FANC and FNEW by hand for simple example pedigrees. We revised the GRain program so that it now provides unbiased estimates. Correlations between the biased and unbiased estimates of FANC and FNEW, obtained for example data sets of Hungarian Pannon White rabbits (22,781 individuals) and Dutch Holstein Friesian cattle (37,061 individuals), were high, i.e., >0.96. Although the magnitude of bias appeared to be small, results from studies based on biased estimates should be interpreted with caution. The revised GRain program (v 2.2) is now available online and can be used to calculate unbiased estimates of FANC and FNEW.

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