[Agr. Biol. Chem., Vol. 34, No. 9, p. 13081313, 1970]

Availability of Energy in Alcohols, Aldehydes and Ketones by Growing Chicks

By Minoru YOSHIDA, Hiroshi MORIMOT0,* Masanao MATSUI** and Ryohei ODA* * *

National Institute of Animal Industry *Japan Scientific Feeds Association **Faculty of Agriculture, Tokyo University ***Faculty of Technology, Kyoto University Received February 9, 1970

Biological availability of 23 alcohols, 16 aldehydes and 2 ketones was compared by the mini-test with chicks. Chicks can utilize methanol and ethanol, but not the alcohols of carbon chain from 3 to 9. Lauryl and myristyl alcohols were well utilized but those of higher carbon chain than 14 were not, mainly due to low digestibility. Glycerol and D- sorbitol were well utilized but not 4 other poly alcohols tested. Aldehydes and ketones with free carbonyl group showed low availability or even toxicity, but their derivatives with masked group showed no detrimental effect. Acetaldehyde, acetal and aldehydes of carbon chain longer than 9 were partially utilized.

This is the second paper of the studies on synthesized in Matsui's Laboratory, Tokyo University; the possibility of various chemicals as energy paraacetaldehyde was purchased and purified by dis sources of poultry feed. In the previous tillation; and parapropionaldehyde was synthesized in Yoshida's Laboratory, National Institute of Animal paper," biological availability of 54 aliphatic Industry. All of the other samples were obtained as mono-, di- and tri-carboxylic acids was com reagents, whose grades were shown in Note in Tables pared by bioassay procedure, mini-test, de I and II. veloped specifically for this purpose.2 ) Gross energy of the test materials was determined In this paper, similar comparison on biologi by an automatic bomb calorimeter, CA-1 manufactured cal availability was reported on 23 alcohols, by Shimadzu Seisakusho. 16 aldehydes and 2 ketones. Bioassay. Details of the procedure of bioassay were exactly the same to those reported in the previous 2 EXPERIMENTAL papers.1,2) Standard dose-response curve was so pre pared that available energy of the test material was Test material. Among 41 materials tested in this estimated directly on the curve. paper, 5 polyalcohols, i.e. 1,2-dimethylol cyclopropane, Among the samples tested, methyl, ethyl, propyl, D-sorbitol, trimethylol propane, 2,2,6,6-tetramethylol n- and isobutyl alcohols, isobutyl aldehyde and para- cyclohexanol and vinyl alcohol polymer were prepar acetaldehyde were infused directly into crop. Since ed in Oda's Laboratory, Kyoto University; 3 aldehy some of these samples had low solubility to water, des, i.e. lauryl, myristyl and stearyl aldehydes , were 0.5% of detergent, Lipon F produced by Lion Yushi Co., was used to make the solution emulsified. All of 1) M. Yoshida, H. Morimoto and R . Oda, Agr. the other samples tested were given orally being mixed Biol. Chem., 34, 1301 (1970). in the diet at 5% level. Procedure of the determina 2) M. Yoshida and H. Morimoto, ibid., 34, 684 tion of digestibility was also the same as that re- (1970). ported in the previous papers) Availability of Energy in Alcohols, Aldehydes and Ketones by Growing Chicks 1309

RESULTS AND DISCUSSION of ethyl alcohol made chicks fell down and sleep overnight, and that one ml of 95% ethyl The data on alcohols were summerized in alcohol made chicks asleep and they never Table I. Chicks can apparently utilize energy in woke up again. According to these prelimina methyl and ethyl alcohols which were given ry findings, all of the test materials were in- into crop as 1000 aqueous solution. Very slight fused as 1000 aqueous solution into crop when symptoms showing that chicks were intoxicated they were expected to be lost by evaporation were observed at this feeding condition, and from the diet. chicks took diet normally as shown by pala Chicks infused one ml of 10°o solution of tability index. Preliminary tests revealed that propyl alcohol were heavily drunken and lost one ml of 25% solution of ethyl alcohol made appetite; growth rate was retarded as shown chicks drunken and they then fell down asleep by negative availability. Chicks infused one for several hours, that one ml of 50%/ solution ml of 10°0 solution of either n- or isobutyl

TABLE I. GROSS ENERGY, AVAILABILITY, PALATABILITY AND DIGESTIBILITY OF ALCOHOLS

a) See text . b) Special: special grade reagent; Reagent: reagent gradec) Dead/total di Can not be estimated because chicks died. 1310 M. YOSHIDA, H. MORIMOTO, M. MATSUI and R. ODA alcohols were intoxicated heavily and lost being 75. These findings on lauryl alcohol appetite; one chick out of 4 of each group were comparable to those on lauric acid re died. As reported previously," chicks can ported previously! ' Contrary to these findings, efficiently utilize 1,2-propanediol and 1,3- Miyazaki" reported that rats could not utilize butanediol, which are relative diols to propyl higher alcohols and detrimental effect of di and butyl alcohols, respectively . Availability etary alcohols was getting severer with the of propionic and butyric acid, on the other increase in carbon chain length of alcohols. hand, was unexpectedly low as reported pre The difference between chicks and rats in the viously.1) With these observations, it is certain- ability to utilize higher alcohols is very in ly interesting to study whether or not propyl teresting and the data shown in Table I should and butyl alcohols, when given by the other be reconfirmed by long-term feeding experi procedures than direct infusion of aqueous ments. solution, can be available to chicks. Low digestibility of cetyl alcohol was certain- Miyazaki" reported that rats could utilize ly main reason of its low availability by ethyl, propyl, butyl and isoamyl alcohols , even chicks. Since digestibility of alcohols higher when these alcohols were mixed at the level than 12 decreased inversely with the increase of 20% in the diet. Rats were reported to be in carbon chain length of alcohols, digestibility normal and no sign of intoxication by the of stearyl alcohol was suspected to be lower alcohols was observed. Since our preliminary than that of cetyl alcohol and low availability studies revealed that about 80% of these of stearyl alcohol with good appetite might alcohols mixed in the diet was lost by evapora be due to low digestibility. The findings again tion within 24 hr," these alcohols have to be are agreeable with those on rats reported by infused directly into crop under the experi Miyazaki," who estimated the digestibility mental conditions of mini-test to avoid the of octyl, cetyl and stearyl alcohol being 99.5, loss by evaporation. Therefore, it may not 52.3 and 19.495, respectively. be reasonable to compare the data on rats Combining the observations on fatty acids with those on chicks. reported in the previous paper," it is certain All of the alcohols other than methyl , ethyl, that young chicks such as used in these mini- propyl, butyl and isobutyl alcohol, were given tests can not absorb completely the compounds orally being mixed in the diet. As shown in of carbon chain length longer than 14 or 16. Table I, chicks apparently can not utilize Alcohols with side chain , i.e. tert-butyl and energy in the alcohols of straight carbon chain 2-ethylhexyl alcohol, were not utilized by between 5 to 9. The findings are quite agree- chicks. The findings were comparable to those able with those reported by Miyazaki" that reported previously that chicks could not utilize rats can not utilize alcohols with carbon chain pivalic acid, (CH3)3C•ECOOH, and 2-ethyl-hex longer than 6. anoic acid. Rats were also reported to be To our great surprize, chicks can utilize unable to utilize tert-butyl alcohol efficiently .4) energy in alcohols with carbon chain length There may be no wonder in that chicks between 10 to 14. Especially, availability and can utilize energy in glycerol, the constituent digestibility of lauryl alcohol was quite satis of natural fat, efficiently. factory, though palatability was slightly low , Trimethylol propane looked like toxic as shown by negative available energy in Table 3) M. Yoshida, H. Hoshii and H . Morimoto, I. 1,2-Dimethylol cyclopropane killed the Japan. Poultry Sci., 6, 73 (1969). chick within 2 days, although only one chick 4) M. Miyazaki, Nippon Nogeikagaku Kaishi, 29,(1955) 497 . was used in the test, since only 5 g of the 5) M. Miyazaki, ibid., 29, 501 (1955) . sample was available. 2,2,6,6-Tetramethylol Availability of Energy in Alcohols, Aldehydes and Ketones by Growing Chicks 1311

TABLE II. GROSS ENERGY, AVAILABILITY, PALATABILITY AND DIGESTIBILITY OF ALDEHYDES AND KETONES

a) See footnotes of Table I.b) First: first grade reagent; BDH: obtained from the British Drug Houses, Ltd. c) See text . d) Chicks lose body weight. cyclohexanol also looked like toxic, as shown The data on aldehydes and ketones were by negative available energy in Table I. summarized in Table II. These methylol compounds depressed the ap- It was hard to understand why chicks died on glycolaldehyde and why the availability petite of the chicks. Chicks could efficiently utilize energy in D- of glyceraldehyde and dihydroxyacetone by sorbitol, which is one of sugar alcohols, with chicks was negative, since glycolaldehyde is .good appetite. one of the simplest carbohydrates, except The chick on vinyl alcohol polymer gained formaldehyde, and glyceraldehyde-3-phosphate body weight in the initial 5 days, but lost and dihydroxyacetone-phosphate are known as body weight at 6th day. The data suggested moieties of fructose-1,6-diphosphate split by that vinyl alcohol polymer might not be toxic aldolase in anaerobic metabolism of carbohy but low palatability of the chick made body drate. However, it was observed that the diet weight lost as glycolic and azelaic acid did." containing 5°0 of glycolaldehyde turned to Although only one chick was used in this brownish yellow after 6 days of experimental mini-test, an information indicating that chicks period. Therefore, it was most likely that have a limited ability to utilize energy in some chemical reaction might take place in the diet, by which these aldehydes themselves polymers, was added to those obtained with together with other dietary nutrients were polymers of ethanediol and propanediol in the decomposed, producing detrimental bypro- previous paper." 1312 M. YOSHIDA, H. MORIMOTO, M. MATSUI and R. ODA

ducts in the diet. and no detrimental effect to the chicks was The suspicion was confirmed by feeding observed. Good appetite on paraacetaldehyde glutaraldehyde to chicks. This sample was and parapropionaldehyde may also rule out obtained and mixed in the diet as 25°o solution. the possibility of such detrimental reaction in Soon after the sample was mixed, the color the diet, since carbonyl groups are masked by of the test diet, usually being creamy white, each other in para-form. However, the data changed into brown, and chicks fed the diet shown in Table II revealed that the avail- died within two days. It is well known, as ability of these aldehydes by chicks was low. Maillard or amino-carbonyl reaction, that car Contrary to these compounds whose carbonyl bonyl group in aldehyde reacts with amino group was masked, acetaldol and diacetone group in protein, resulting in brown product. alcohol, in which one of the two carbonyl Certainly, other possible chemical reactions groups was free, were actually toxic to the may take place in the diet containing free chicks. carbonyl group. The speed of the reactions The data on paraacetaldehyde given in may be different among different chemicals, Table II suggest that acetaldehyde may not and therefore, the detrimental effect to the only be toxic, but also its energy is partially chicks within the experimental period of available by the chicks. The findings are 6 days may be also different among the various agreeable to those reported by Ozaki6) and samples tested. Ashida." Again, energy of propionaldehyde, In the previous paper," it was reported that having carbon chain of 3, was not available

growth retardation and extremely low palata by the chicks. This is just comparable to the bility were observed in chicks fed either data on propyl alcohol in Table I and pro oxalacetic or ƒ¿-ketoglutaric acid, both of pionic acid in the previous paper." which are known as constituent elements of The detrimental effect of free carbonyl group the tricarboxylic acid cycle in aerobic metabo seemed to decrease inversely with the increase lism of carbohydrate, and therefore, expected in carbon chain length of aldehydes. Energy to be utilized by chicks efficiently. Free in aldehydes with carbon chain longer than carbonyl group in these acids must have re- 9 was partially available by chicks, but their acted with the other dietary nutrients, produc low availability, 74°c or less, may be partly ing detrimental product. due to their low digestibility. Low digestibili Only one exception was pyruvic acid, which ty of laurylaldehyde was unexpected since the has free carbonyl group but was utilized well." digestibilities of lauric acid and lauryl alcohol However, the diet containing the acid got were determined to be 83 and 96°c, respec offensive smell and the color changed from tively. creamy white to yellowish brown toward the Ozaki6) already described that nutritive value end of experimental period of 6 days. There- of aldehydes to rats increased with the increase fore, it is most reasonable to expect that the in carbon chain length from 7 to 17. growth of the chicks on the diet will be re Isobutyl aldehyde and paraacetaldehyde tarded if the feeding experiment be continued when infused into crop as 100; aqueous so further. lution made chicks severely intoxicated, and Energy in acetal was available by chicks 3 and 2 chicks, respectively, among 4 chicks in with good appetite. This may be due to the each treatment died within 6 days of experi fact that carbonyl group of acetaldehyde is mental period. However, no symptom of in- masked by two ethoxy groups in acetal. There fore, no reactions might take place in the diet 6) J. Ozaki, Nippon Nogeikagaku Kaishi,3, 977 (1927). between carbonyl group and other nutrients 7) K. Ashida, private communication (1967). Availability of Energy in Alcohols, Aldehydes and Ketones by Growing Chicks 1313 toxication was observed when paraacetaldehyde of saturated fatty acids reported in the previ was mixed in the test diet, and chicks seemed ous paper," although in this case, availability to utilize energy in paraacetaldehyde partially of caproic acid, which has 6-carbon chain, as shown in Table II. was already fairly high. Summarizing, the availability of saturated However, as mentioned at the beginning of alcohols of straight carbon chain, when mixed discussion in the previous paper," the bioassay in the diet and fed to chicks, seemed to in- procedure was miniaturized by sacrificing the crease gradually with the increase in length accuracy of the estimate, although the pro of carbon chain. With carbon chain length cedure was so devised that the confidence longer than 10, the availability became positive interval of the estimates could be calculated reaching the maximum at about 12 or 14, i.e. if necessary. Especially, any chronic influence lauryl or myristyl alcohols, and thereafter, the to the chicks can not be detected by this availability decreased with further increase of mini-test, since the experimental period is cut carbon chain length, mainly because of lower- off to be only 6 days. Therefore, any definite ed digestibility. Similar tendency was observed conclusion should be given after the long-term in the availability of saturated, straight chain feeding experiment to confirm the above dis aldehydes as shown in Table II. Similar cussion. The data on mini-tests indicate only tendency was also suggested in the availability the possibility.