Author
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Allen, Patricia |
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Fetterer, Raymond |
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Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/27/2001 Publication Date: N/A Citation: N/A Interpretive Summary: Eimeria maxima, a coccidian parasite of the chick mid small intestine, causes major economic losses to the broiler industry. Two trials were conducted to determine if dietary supplementation with high levels of vitamin E (VE), a potent antioxidant and immunomodulator, could reduce the pathology of E. maxima infection. The infection in Trial 1 was mild, and that in Trial 2 severe as judged from weight gains, lesion scores, plasma carotenoids and nitrite/nitrate. High VE supplements did not substantially decrease the pathology of the infections. In Trial 1, infection reduced plasma VE an average of 35.3% across all dietary VE levels, and in Trial 2, an average of 73.1%. The percentages reduction in VE paralleled reductions in carotenoids. Both these substances are fat-soluble and are absorbed through the intestine by being packaged in lipoprotein particles. Coccidia infections of the small intestine are known to interfere with lipid digestion and absorption. In these trials, then the main effect of the infections was lipid malabsorption which prevented the VE from becoming incorporated into intestinal tissues during parasite development and exerting any antioxidant or immunomodulatory effects. Therefore, administration strategies other than dietary supplementation, need to be devised in order to treat disorders that promote lipid malabsorption with fat soluble vitamins such as VE. Technical Abstract: Eimeria maxima, a coccidian parasite of the chick mid small intestine, causes major economic losses to the broiler industry. Antigenic strain variation makes it more difficult to control by vaccination, and there are efforts to reduce the use of pharmaceuticals to minimize infections. Vitamin E (VE), a natural product, and a potent antioxidant and immunomodulator, has been used as a dietary supplement to reduce effects o Escherichia coli, and several viral diseases in chickens. High dietary supplements have also shown some promise in preventing weight gain depression and reducing lesion scores in infections with Eimeria tenella, a coccidian parasite of the chick cecum. Therefore, two trials were conducted to compare the effects of VE supplements, ranging from 13.2 to 200 ppm, in processed broilers, both uninfected, and infected with E. maxima. The infection in Trial 1 was mild, and that in Trial 2 severe as judged from weight gains, lesion scores, plasma carotenoids and nitrite/nitrate. High supplements of VE did not substantially affect the pathology of the infections. In both trials, plasma VE increased with increasing dietary VE level. However, in Trial 1, infection reduced plasma VE an average of 35.3% across all dietary VE levels, and in Trial 2, an average of 73.1%. The percentages reduction in VE paralleled reductions in carotenoids, strongly suggesting that the main effect of the infections was lipid malabsorption which prevented the VE from becoming incorporated into intestinal tissues during parasite development. Therefore, administration strategies other than dietary supplementation, need to be devised in order to treat disorders that promote lipid malabsorption with fat soluble vitamins such as VE. |
