Evaluation of Available Energy of Aliphatic Chemicals by Rats

Abstract

Bioassy procedure to evaluate biologically available energy of chemicals applicable to rats was established, and available energy of 36 chemicals was determined and compared with that estimated by chicks previously. Rats can utilize energy of propionic and butyric acids and n-hexyl propionate and butyrate well, while chicks cannot. Succinic acid, lauryl alcohol and dilauryl succinate at 5% dietary level were available by rats, though at 10% level lauryl alcohol was toxic. Ethyl lactate, octyl and decyl acetates and 1,2-propanediol dilaurate were available by both rats and chicks. Availability of other 6 esters including ethyl succinate and citrate was low. Availability and digestibility of aldehydes by rats were also low. Growth response of chicks on aliphatic chemicals reported previously1•`5) revealed some difference between chicks and rats in certain chemicals, though most of the chemicals available by chicks are also available by rats.

Conversion of 1,3-Butanediol or Acetaldol to β-Hydroxybutyric Acid in Chicks

“…Perhaps this may indicate that 1,3-butanediol was metabolized completely, and Gessner proposed in the paper that 1,3-butanediol would be metabolized after its conversion to ,B-hydroxybutyrate. Stoewsand et al/ 3 ) and Mehlman et af.1 4 ) observed that total lipids contents in carcass of the rats fed diets containing 20 ~ 30 % of 1,3-butanediol tended to decrease, while lipids contents in the liver to increase. Furthermore, Mehlman et al 14) observed the increase in plasma level of free fatty acids, being followed by the increase in liver triglycerides in the rats fed 1,3-butanediol.…”

Methionine substitute. 4-Methylthiobutane-1,2-diol

“…Among these references, particularly noteworthy is the comment by Laug et al (1939) that 1,2-propanediol may be converted into a normal body constituent. This comment is at odds, however, with the results reported by Yoshida and Ikumo (1971) who demonstrated that chickens receiving about 5% of 1,2-propanediol excreted significant amounts of propionic acid. Their experiments do not support our working hypothesis, which predicated that the diol 1 might be converted in animals by normal metabolic oxidation of the primary hydroxyl group to a carboxyl group, resulting in the transformation of compound 1 to methionine hydroxy analog.…”

“…That example stimulated us to conceive the possibility that a hitherto unknown compound, 4-methylthiobutane-l,2-diol (1), could also be ch3sch.,ch,chch,oh OH 1 metabolized to methionine. This concept is supported by several literature references to the assimilation, toxicology, and metabolism of various vicinal glycols (Bayley et al, 1967; Bowen and Waldroup, 1969;Hanzlik et al, 1939a,b;Huff, 1961; Laug et al, 1939;Persons et al, 1968;Rudney, 1954;Scholz, 1950; Waldroup and Bowen, 1968;Yoshida et al, 1969;Yoshida and Ikumo, 1971). Among these references, particularly noteworthy is the comment by Laug et al (1939) that 1,2-propanediol may be converted into a normal body constituent.…”

Evaluation of Nutritive Value of Glycol Esters as Energy Source for Growing Chicks and Rats

“…The standard diets fed to the rats were the same as reported previously. 2 Cellulose powder in the low energy standard diet was replaced by a certain percent of the sample, in the preparation of various test diets. The content of the sample in the test diet is shown in Table III with the data of the rats.…”