Feed additives containing sequestrant clay minerals and inactivated yeast reduce aflatoxin excretion in milk of dairy cows.

The objective was to evaluate the efficacy of 2 dietary mycotoxin sequestrants, Toxy-Nil (TN) or Unike Plus (UP), in reducing aflatoxin (AF) M1 concentrations in milk of dairy cows challenged with dietary AF. Thirty-two mid-lactation Holstein cows were blocked by parity, days in milk, and milk yield and were randomly assigned within block to receive one of the following treatments: (1) 2.8 mg of AF/cow per d (positive control, PC), (2) 2.8 mg of AF + 100 g of TN/cow per d, (3) 2.8 mg of AF + 100 g of UP/cow per d, or (4) no AF and no additives (negative control, NC). For 7 d, treatments, dispersed in 150 g of sweet feed carrier, were top-dressed twice daily by mixing into the top portion of the TMR at each feeding. After the experimental period, cows were fed the NC diet and clearance of AFM1 via milk was monitored for 7 d. Feed and water were available ad libitum throughout the trial. Treatments had no effect on feed intake, milk yield, milk composition, or milk somatic cell count. Relative intake of AF was similar among PC, TN, and UP, averaging 106.5, 107.6, and 102.5 ± 2.9 µg/kg of diet dry matter, respectively. Relative intake of mycotoxin sequestrants was similar between TN and UP, averaging 0.4 and 0.4 ± 0.1% of diet dry matter, respectively. Concentration and mass of AFM1 secreted in milk and in urine were similar between TN and UP, but were lower than PC; concentrations in milk averaged 0.2, 0.3, and 0.6 ± 0.1 µg/kg, respectively, and mass secreted in milk averaged 8.1, 9.8, and 20.5 ± 1.7 µg/d. Concentrations in urine averaged 6.9, 7.4, and 14.2 ± 1.5 µg/L, respectively, and mass secreted in urine averaged 225.7, 250.8, and 521.6 ± 53.1 µg/d. Likewise, concentration and mass of free AF excreted in feces were similar between TN and UP, but were lower than PC; concentrations averaged 7.7, 8.9, and 12.4 ± 0.6 µg/kg, respectively, and mass excreted averaged 57.8, 69.6, and 95.6 ± 4.8 µg/d. Transfer of AF from feed to AFM1 in milk was reduced by 63 and 52%, and in urine, by 57 and 52% for TN and UP, respectively. Transfer of AF from feed to free AF in feces was reduced by 38 and 26% for TN and UP, respectively. The clearance rate of AFM1 in milk did not differ among PC, TN, and UP (46.1, 66.5, and 50.0 ± 6.7%/d, respectively). Results indicate that dietary inclusion of 100 g of TN or UP significantly reduced AFM1 in milk of cows consuming TMR containing approximately 105 µg of AF/kg of diet dry matter. Results also suggest that both TN and UP reduced absorption of AF.

Mycotoxin-contaminated diets and deactivating compound in laying hens: 1. effects on performance characteristics and relative organ weight.

The current experiment was conducted to determine the effect of mycotoxin-contaminated diets with aflatoxin (AFLA) and deoxynivalenol (DON) and dietary inclusion of deactivation compound on layer hen performance during a 10-wk trial. The experimental design consisted of a 4 × 2 factorial with 4 toxin levels: control, low (0.5 mg/kg AFLA + 1.0 mg/kg DON), medium (1.5 mg/kg AFLA + 1.5 mg/kg DON), and high (2.0 mg/kg AFLA + 2.0 mg/kg DON) with or without the inclusion of deactivation compound. Three hundred eighty-four 25-wk-old laying hens were randomly assigned to 1 of the 8 treatment groups. Birds were fed contaminated diets for a 6-wk phase of toxin administration followed by a 4-wk recovery phase, when all birds were fed mycotoxin-free diets. Twelve hens from each treatment were subjected to necropsy following each phase. Relative liver and kidney weights were increased (P < 0.05) at the medium and high toxin levels following the toxin phase, but the deactivation compound reduced (P < 0.05) relative liver and kidney weights following the recovery period. The high toxin level decreased (P < 0.05) feed consumption and egg production during the toxin period, whereas the deactivation compound increased (P < 0.05) egg production during the first 2 wk of the toxin phase. Egg weights were reduced (P < 0.05) in hens fed medium and high levels of toxin. An interaction existed between toxin level and deactivation compound inclusion with regard to feed conversion (g of feed/g of egg). High inclusion level of toxins increased feed conversion compared with the control diet, whereas deactivation compound inclusion reduced feed conversion to a level comparable with the control. These data indicate that deactivation compound can reduce or eliminate adverse effects of mycotoxicoses in peak-performing laying hens.

Effects of mycotoxin-contaminated diets and deactivating compound in laying hens: 2. effects on white shell egg quality and characteristics.

An experiment was conducted to determine the effect of dietary inclusion of Mycofix Select (Biomin GmbH, Herzogenburg, Austria) on discrete egg parameters and quality characteristics of hens fed mycotoxin-contaminated diets (aflatoxin; AFLA) and deoxynivalenol (DON)) during a 10-wk trial. A 4 × 2 factorial design was used with 4 contamination levels: control, low (0.5 mg/kg of AFLA + 1.0 mg/kg of DON), medium (1.5 mg/kg of AFLA + 1.5 mg/kg of DON), and high (2.0 mg/kg of AFLA + 2.0 mg/kg of DON) with or without the inclusion of mycotoxin deactivating compound. Three hundred and eighty-four 25-wk-old laying hens were housed 3 per cage. Birds were fed contaminated diets for a 6-wk phase of toxin administration followed by a 4-wk recovery phase, when all birds were fed mycotoxin-free diets. Parameters evaluated included egg weight, Haugh unit value, specific gravity, eggshell thickness, egg shape index, and relative albumen and yolk weights. Albumen height and Haugh unit value were depressed (P < 0.05) at the high mycotoxin level 2 wk postinclusion. Egg weight was significantly reduced (P < 0.05) with the high toxins level by the third week of toxin administration and remained throughout the study during toxin administration. Egg shape index indicated a variation (P < 0.05) in shape with all toxin levels compared with the control. Relative yolk weight was decreased (P < 0.05) by the high toxin level. An interaction existed between the deactivating compound inclusion and toxins level with regard to specific gravity. Following the toxin phase, the deactivating compound inclusion increased (P < 0.05) egg specific gravity in the control and low toxin groups whereas a decrease (P < 0.05) was observed at the high toxin level. These data indicate that mycotoxins present in feed can reduce egg quality, size, yolk weight, and alter egg shape and that inclusion of a mycotoxin deactivating compound can ameliorate some of the negative effects of mycotoxin consumption.

Leukocytic responses of broilers following dietary contamination with deoxynivalenol and/or treatment by dietary selenium supplementation.

1. This experiment was to investigate the effects of natural dietary contamination with a mycotoxin product (deoxynivalenol: DON) and/or with dietary selenised yeast (Se-yeast), on respiratory burst and phagocytic activity of granulocytes and the frequency of B- and T-lymphocytes in peripheral blood of broilers. 2. Sixty one-day-old chicks of both sexes were divided into 4 groups, each of 15 birds, fed on a control diet that contained 0.2 mg DON/kg and 0.4 mg Se/kg (CON group), a diet supplemented with 1 mg Se-yeast/kg (Se-yeast group), a diet contaminated with 3 mg DON/kg (DON group) or a diet contaminated with DON and supplemented with Se-yeast (DON plus Se-yeast group). 3. Blood samples collected from the birds at the age of 4 weeks showed that neither B- and T-cell numbers nor granulocytic respiratory burst were influenced by 3 mg DON/kg. Blood granulocyte phagocytic activity was not reduced by DON but numbers of heterophils were increased. In the DON plus Se yeast group phagocytic activity was the same as in the CON group. The Se-yeast and DON plus Se-yeast groups had increased numbers of CD3(+), CD4(+), and CD8(+) T-cells as well as IgM(+) B-cells in their blood compared to both CON and DON-groups. 4. The results show there is no significant effect of dietary DON up to 3 mg/kg on leukocytes apart from the compromised blood granulocytes phagocytic activity and increased numbers of heterophils. The increased numbers of B- and T-lymphocytes in blood of birds fed on diets with supplementation of organic Se indicates some positive effects of this essential microelement on poultry lymphoid cells.

Effects of excessive selenium supplementation to diet contaminated with deoxynivalenol on blood phagocytic activity and antioxidative status of broilers.

This study examined the effects of excessive dietary supplementation with organic selenium on phagocytic activity and antioxidative status of chickens for fattening fed diet contaminated with deoxynivalenol (DON). Sixty chickens of Ross 308 hybrids were at day of hatching divided into four groups with 15 birds in each. The background DON dietary levels in both negative and positive control groups were 0.2 mg/kg. The complete feed for positive control group was supplemented with Se dose 1 mg/kg in the form of Se-yeast. Group 3 was fed diet with DON level 3 mg/kg while diet for group 4 combined DON level 3 mg/kg with a excessive supplement of Se-yeast (Se dose 1 mg/kg). After 6 weeks of dietary intake, six randomly-chosen chickens from each group were sampled. Feeding of contaminated diet resulted in significantly reduced blood phagocytic activity (19.5 ± 1.1% in the negative control vs. 12.8 ± 0.8% in the DON-treated group, p < 0.05). Se-yeast supplemented to the DON contaminated diet prevented suppression of phagocytic activity. Dietary intake of DON at levels 3 mg/kg did not influence the plasma α-tocopherol level while excessive dietary Se dose reduced it in both Se supplemented groups. Neither the birds of DON-treated group nor the birds from group 4 with DON and Se-yeast showed any response in plasma γ-glutamyltransferase (GGT) activity. Subtoxic dietary level of DON significantly increased the activity of glutathione peroxidase (GPx) in the duodenal mucosa, while additional Se supplementation prevented such a response to mycotoxin. On the other hand, both Se supplemented groups showed significantly elevated GPx activities in blood, liver and kidney, (p < 0.05). The results suggest a potential ability of excessive supplementation of organic selenium to prevent the blood phagocytic activity suppression and changes in GPx activity in duodenal tissue induced in broilers by subtoxic dietary levels of DON.