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The Occurrence of a Toe Abnormality in Chicks Fed Propylene Glycol
THE OCCURRENCE OF A TOE ABNORMALITY IN CHICKS FED PROPYLENE GLYCOL T. E. BOWEN AND P. W. WALDEOUP Department of Animal Sciences, University of Arkansas, Fayetteville, Arkansas 72701 (Received for publication March 27, 1968)
FIG. 1. Typical toe deformity resulting from feeding propylene glycol to broiler chicks.
TABLE 1.—Influence of propylene glycol on the incidence of toe abnormalities of broiler chicks % Propylene glycol
0 2.5 5.0 7.5 10.0
Incidence of toe defects1 9/168" 19/168"b 29/168bc 39/i68<= 57/168'1
1 Indicates the number of chicks having a toe defect out of total number examined. Means having the same superscript do not differ significantly (P=<.05).
cally significant increases in toe defects. It is interesting to note that Rutter et al. (1953) reported a lactose-induced crooked toe deformity in broiler chicks which appears to be similar to that observed in trials in our laboratory. Propylene glycol is converted to lactic acid and hence to glucose in the rat (Rudney, 1950; Miller et al., 1953). Therefore, these compounds may be broken down to a common metabolite responsible for the toe defect. REFERENCES Bayley, H. D., S. J. Slinger and J. D. Summers, 1967. The use of propylene glycol as a source of energy for the chick. Poultry Sci. 46: 19-22. Maplesden, D. D., 1954. Propylene glycol in the treatment of ketosis. Canad. J. Comp. Med. Vet. Sci. 18: 287-293. Miller, O. N., C. G. Huggins and K. Arai, 1953. Studies on the metabolism of 1, 2-dipropanediol-l-phosphate. J. Biol. Chem. 202: 263-271. Rudney, H., 1950. The metabolism of 1, 2-propanediol. Arch. Biochem. 29: 231-232. Rutter, W. J., P. Krichevsky, H. M. Scott and R. G. Hansen, 1953. The metabolism of lactose and galactose in the chick. Poultry Sci. 32: 706-715.
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Propylene glycol (1, 2-dihydroxy propane) is unique among the glycols because its low toxicity permits it to be taken internally. In recent years it has been shown to be effective in the prevention of bovine ketosis (Maplesden, 1954). Bayley et al. (1967) reported that up to 8% propylene glycol could replace an equivalent amount of corn starch in the diet of chicks. During the course of feeding trials conducted at this laboratory to evaluate propylene glycol as a feed ingredient for poultry diets, a peculiar deformity of the toe was observed (Figure 1). The toes turned outward at each joint with the incidence of the condition increasing as the level of propylene glycol increased in the diet (Table 1). These chicks were maintained in electrically heated battery brooders with raised wire floors and a small incidence of deformed or crooked toes were observed even in the control group with no propylene glycol. However, the severity was not as great as that which occured at the higher levels of propylene glycol. Increasing the level of the propylene glycol resulted in statisti-
FIG. 1. Typical toe deformity resulting from feeding propylene glycol to broiler chicks.
TABLE 1.—Influence of propylene glycol on the incidence of toe abnormalities of broiler chicks % Propylene glycol
0 2.5 5.0 7.5 10.0
Incidence of toe defects1 9/168" 19/168"b 29/168bc 39/i68<= 57/168'1
1 Indicates the number of chicks having a toe defect out of total number examined. Means having the same superscript do not differ significantly (P=<.05).
cally significant increases in toe defects. It is interesting to note that Rutter et al. (1953) reported a lactose-induced crooked toe deformity in broiler chicks which appears to be similar to that observed in trials in our laboratory. Propylene glycol is converted to lactic acid and hence to glucose in the rat (Rudney, 1950; Miller et al., 1953). Therefore, these compounds may be broken down to a common metabolite responsible for the toe defect. REFERENCES Bayley, H. D., S. J. Slinger and J. D. Summers, 1967. The use of propylene glycol as a source of energy for the chick. Poultry Sci. 46: 19-22. Maplesden, D. D., 1954. Propylene glycol in the treatment of ketosis. Canad. J. Comp. Med. Vet. Sci. 18: 287-293. Miller, O. N., C. G. Huggins and K. Arai, 1953. Studies on the metabolism of 1, 2-dipropanediol-l-phosphate. J. Biol. Chem. 202: 263-271. Rudney, H., 1950. The metabolism of 1, 2-propanediol. Arch. Biochem. 29: 231-232. Rutter, W. J., P. Krichevsky, H. M. Scott and R. G. Hansen, 1953. The metabolism of lactose and galactose in the chick. Poultry Sci. 32: 706-715.
1036
Downloaded from http://ps.oxfordjournals.org/ at UCSF Library on April 9, 2015
Propylene glycol (1, 2-dihydroxy propane) is unique among the glycols because its low toxicity permits it to be taken internally. In recent years it has been shown to be effective in the prevention of bovine ketosis (Maplesden, 1954). Bayley et al. (1967) reported that up to 8% propylene glycol could replace an equivalent amount of corn starch in the diet of chicks. During the course of feeding trials conducted at this laboratory to evaluate propylene glycol as a feed ingredient for poultry diets, a peculiar deformity of the toe was observed (Figure 1). The toes turned outward at each joint with the incidence of the condition increasing as the level of propylene glycol increased in the diet (Table 1). These chicks were maintained in electrically heated battery brooders with raised wire floors and a small incidence of deformed or crooked toes were observed even in the control group with no propylene glycol. However, the severity was not as great as that which occured at the higher levels of propylene glycol. Increasing the level of the propylene glycol resulted in statisti-