Selenium Toxicity in Breeding Ring-Necked Pheasants (Phasianus colchicus)

Abstract

A flock of breeding ring-necked pheasants received feed with a high selenium content. Within 4 days of eating the toxic feed, the rate of egg production began to decrease, and bird aggression increased. Approximately 12% of the hens died within a week. Necropsy of the hens revealed colorless fluid around the heart and a friable, but otherwise normal, liver. The rapid onset of the problem and signs noted at necropsy suggested toxicosis. Based on analysis, the feed contained 9.3 ppm of selenium. Selenium toxicity was consistent with the histologic diagnosis of degenerative cardiomyopathy, vacuolar degeneration of hepatocytes, and centrilobular hepatic necrosis. After 8 days, the toxic feed was removed and replaced with fresh feed. Egg production, which had dropped to 50%, returned to normal within 10 days of feed replacement. Hatchability of eggs laid from days 8 to 14 after delivery of the toxic feed was 35%. Approximately 10% of the chicks that hatched had deformed beaks and abnormal eyes. Many of the chicks that died in the shell had deformities, bringing the total to more than 50% of all embryos that developed. The selenium content of eggs that had no embryonic development was 2.05 ppm. Hatchability of eggs laid from days 21 to 28 after the toxic feed was delivered was almost 80%, which was slightly lower than normal. The selenium content of these eggs was 0.30 ppm. These results show the rapid onset and correction of selenium toxicity and suggest that specific embryologic defects are diagnostic for selenium toxicity.

In-Ovo Inculation of Selenium Nanoparticles Improves Productive Performance, Blood Biochemical Profile, Antioxidant Status and Immune Response of Hatched Chicks

“…Hatchability, embryonic mortality and chicks body weight at hatch Hatchability (%) and body weight at hatch (BWH) are presented in Table (2), it is clearing from the data illustrated in the table that, hatchability and embryonic mortality rates were significantly affected by inovo injection nano-Selenium (Se) for broiler eggs .The control group recorded the highest hatchability value, while the 10 ppm inovo nano-Se group recorded the lowest hatchability percentage, followed by the 5 ppm nano-Se group, however, chick body weight had no significant differences between the treatments group and the control one. Although selenium had been credence as an essential trace mineral in poultry nutrition, dietary Se deficiency in poultry can lead to symptoms such as reduced fertility and reduced hatchability as well as reduced egg production (Latshaw et al 2004) . Therefore, Se must be used in a limited levels because Se injection into the egg with relatively high doses may be exert a potential toxic effect to avian embryos.…”

Metals and female reproductive toxicity

“…Selenosis in poultry results in birth defects that include deformed or lack of legs, toes, wings, beaks, and eyes in the young. 136 Field and research studies can differ in interpretation of the effects of Se. Smith et al 137 reported congenital alkali disease in a 14-day-old colt that was born to a mare that developed clinical signs of selenosis during gestation.…”

The Effect of Dietary Selenium Source on Embryonic Development in Turkeys

“…Approximately 10 % of the chicks from pheasant hens fed a diet with high selenium content had deformed beaks and abnormal eyes. Many of the chicks that died in the shell had deformities (LATSHAW et al 2004).…”