mycotoxin on gilts

The objective of this study was to determine if the addition of the mycotoxin adsorbent Agrabond (a brand of Agranco) negated, lessened or postponed the effects of the mycotoxin zearalenone in swine feed, as well as determine the effect of all test diets on feed conversion.

On Aug 5, 2005, female pigs were purchased locally and test evaluated by a veterinarian, who determined that the animals were in good health. The pigs were randomly placed into groups of three, with each pig housed independently and having access to its own individual feeder and automatic water system.

Each group of three pigs was fed a different diet. The base diets to be evaluated were as follows:

The base diet was analysed for mycotoxins, E.coli and listeria prior to feeding. Testing showed no mycotoxins above the detection limits and testing for E.coli and listeria negative. Diets were mixed with zearalenone crystalline material and analysed to confirm zearalenone concentration. The zearalenone level was analysed prior to the study and found to be of over 99 percent purity. All pigs were 21 days old at the beginning of the trial. For the duration of the trial, the pigs were inspected twice daily. Feed consumption was noted as were any heath- and behavioural-related problems. From Aug 5 to 8, all pigs were fed standard base diets to minimise any stress associated with the move to new surroundings. Mixed diets were started on Aug 9.

Vulvar comparisons

Vulvar measurements (width and height) between groups

Source: Trilogy Analytical Laboratory, 2005

Source: Trilogy Analytical Laboratory, 2005

Pigs were fed each day, in the mornings and evenings. Each week, the pigs were photographed and weighed, and vulvar height and width were measured. These measurements were compiled and final calculations reported. The pigs were monitored by the veterinarian at the midpoint of the trial.

From these results, feed intake and conversion were calculated. On Day 22 of the feeding trial (Aug 31), the pigs were photographed and weighed. They were then euthanized and each specimen was necropsied in the same manner.

Vulvars were measured using a micrometer and measurements taken by the same individual throughout the entire feeding trial to minimise any differences in measuring techniques. Width and height of vulvars were measured, recorded and then multiplied. These measurements indicated that by the end of the first week, the group with the toxin diet, group T1, was beginning to show swelling as compared to the control group. Group T2 vulvar measurements were not statistically different from the control group after three weeks of feeding.

Observations and conclusion

The two test diets fed in this study were statistically compared with a control group, which was not fed toxin.

Results from the study showed that the addition of Agrabond at 0.5 kg/tonne (T2) was statistically the same as the control group in vulvar measurements for all three weeks of the feeding trial. With pictures and data as back-up, this trial suggests that the feeding of Agrabond delays and reduces the vulvar effects of zearalenone at a 1.5 ppm inclusion rate.

Pigs in group T1 that were fed a steady diet of 1.5 ppm zearalenone displayed visual effects (vulvar redness and swelling) of the toxin after one week. The group of pigs that were fed Agrabond at 0.5 kg/MT did not display vulvar effects of the toxin until well into the second week of the trial. The swelling and redness of the vulvar area were not evident at the same time or with the same intensity of the toxin-only group. Feed conversion was not negatively affected by the addition of Agrabond at any level. All test groups performed statistically the same as the control group for feed conversion.

The ovaries and bursa were not statistically different between the control group and the T1 toxin-fed group, however, there was a trend for increased size in the T1 group. There was a statistical difference between the control group and the T2 group. The weight ratio of the T2 group containing the toxin and the agrabond group was statistically different, at 54 percent.

The uterus measurements and statistics indicate that the T2 test group and the toxin-fed group were both statistically different from the control group. This indicates that Agrabond did not reduce the toxin effects on the uterus size at the conclusion of the 21-day feeding trial.

It should be noted that 1.5 ppm zearalenone is somewhat higher that the level that might be routinely found in any normal crop cycle. Additionally, it may be practically unlikely that a steady diet of 1.5 ppm zearlenone would take place over a 21-day period. What is more probable is a level of feed contamination that is somewhat sporadic, with zearalenone levels that fluctuate from below detectable levels to over 1 ppm. This feeding trial does not incorporate this “real-world” feeding style.