Hannah Adams

Effects of Mycotoxins and Coccidiosis in Turkey Poults Hannah Adams

Mentor: Milton Daley College of Agriculture and Human Sciences

Introduction: Mycotoxins and coccidia are reported to induce immunological stress and damage to the gut that may predispose a bird to the more severe clinical presentation of either or both diseases. Fusarium mycotoxins and coccidia irritate and damage the intestinal epithelial cells resulting in reduced production of these protective agents. The interaction between Fusarium mycotoxins and coccidia may be potentiating, additive or synergistic in nature resulting in increased adverse effects in turkeys. Many studies have shown that the adverse effects of mycotoxicosis and coccidiosis can be reduced with the use of physical, chemical, nutritional, and biological interventions/ adsorbents. One of the most effective of this adsorbent is the polymeric glucomannan mycotoxin adsorbent (GMA) derived from the cell wall of Saccharomyces cerevisiae1026(Carrington, C., A du Plessis, V. Naidoo, 2007). The objective of the study was to investigate the effects of feeding grains naturally contaminated with Fusarium mycotoxins and supplemented with GMA on the performance and health parameters of turkey poults when challenged with Eimeria species. Materials and Methods: Experimental birds, diets, and design: 144-day-old male hybrid turkey poults were used in the study for 24days, consisting of 3 experimental diets (Control, Control + 0.2% GMA, Contaminated grains + 0.2% GMA (with and without coccidiosis). Poults were initially maintained at 29˚C, and the temperature was lowered by 1˚C per week. Twenty-four birds per treatment group (6 birds in a pen, 4 replications per treatment). On day 14 of the trial, half the birds were inoculated with a mixed culture of Eimeria, with a dosage of approximately 43,000 oocysts per bird. Also, on day 19 and day 24, twenty birds per diet were randomly selected and killed humanely by cervical dislocation. Finally, representative feed samples were taken at the beginning of the experiment and were analyzed for enumeration of variable mycotoxins according to the association of the official Analytical Chemist. Experimental Parameters measured: Oocyst count: Turkeys’ fecal samples were collected from birds from Days 21-24 and were determined using the technique of Kaufmann. Excreta were weighed and placed in a beaker. Water and saturated sodium chloride were added to the excreta in a 7:13 ratio, with volumes depending on the amount of excreta collected (average 2 L of final volume). Measurement of tissue lesions and gut histology: At Day 20 and at Day 24, 2 birds per pen were randomly selected by wing band number and killed humanely by cervical dislocation. Lesions in the small intestine were scored (0 to + 4 scale). Intestinal samples (2.5 cm) for histology were fixed in 10% neutral buffered formalin from the duodenum, jejunum, and ileum Analysis of Dietary Mycotoxins: The dietary contents of Fusarium mycotoxins such as DON, 3 acetylDON, T-2 toxin, iso T-2 toxin, HT-2 toxin, zearalenone, zeranol, and aflatoxin, were analyses by gas chromatography and mass spectrometry

Statistical analyses: Data were analyzed by analysis of covariance or variance using a PROC MIXED model of SAS. Tukey’s test was used for multiple comparison among each treatment. Day-old BW was used as a covariate for analysis of BW, and 4-wk BW was used as covariate for organ weights analysis. Data representing percentages or ratios were transformed before statistical analysis and were based on P.

Results and Discussion

Table 1. Mycotoxin concentrations(mg/kg) in experimental diet Table 2. The efficacy of GMA on Fusarium mycotoxin contaminated diet and coccidiosis challenged on body weight (g), feed intake(g) and feed conversion

A

*Birds were fed grains contaminated with Mycotoxin

B

*In the infection stage, birds on the GMA diet had a significantly higher body weight, feed intake and better feed conversation ratio with and without coccidiosis when compared to the control. *In the recovery phase, birds on the GMA diet had a significantly higher body weight, feed intake and better feed conversation ratio with and without coccidiosis when compared to the control.

* In the pre infection phase, birds on the GMA diet had a significantly higher body weight gain when compared to the control. Additionally, they had significant feed intake and feed

C

*Diets significantly affected the relative weight of liver (P≤0.01), but had no effects on spleen, bursa of Fabricio’sor pancreas (P>0.05). *Diet significantly (P≤0.01) affected white blood cell levels, but not hemoglobin, hematocrit or mean corpuscular hemoglobin concentrations.

Conclusion: With low dietary mycotoxin (5.7 mg DON/kg of feed) inclusion and moderately mild mixed cocktail of Emeria infection it appeared that GMA supplementation did not prevent or minimize most of the adverse effects brought on by these challenges in turkey poults.

Reference:

Carrington, C., A du Plessis, V. Naidoo, 2007. Index of Veterinary Specialities. Johncom publishers, Johannesburg, pp. 38–40.

Awardee and Student:

Dr Milton Daley is an Assistant professor in the College of Agriculture and Human Sciences. He is very interested in research that deals with animal pathology.

Hannah Adam is a Junior student at the College of Agriculture and Human Sciences. She majors in Agriculture with a concentration in Animal Science. She is aspiring to be a future veterinarian.