Interrelationships Among Sulfur Amino Acids, Choline and Betaine in the Chicken: Effects on Betaine-Homocysteine Methyltransferase Activity, Homocysteine Utilization and Choline Bioavailability

Chick assays (10 to 22-d-old chicks) were conducted to determine choline bioavailability in fluid lecithin (FL), deoiled lecithin (DL), soybean meal (SBM), canola meal (CM) and peanut meal (PM). A basal diet containing soy protein isolate and 2-amino-2-methyl-1-propanol (an inhibitor of choline biosynthesis) was severely deficient in choline, and weight gain of chicks fed this diet responded to choline, but not methionine or betaine. In Assay 1, weight gain of chicks increased linearly $(P<0.01)$ with increasing concentrations of choline from choline chloride, FL or DL. Multiple linear regression analysis indicated bioavailable choline concentrations of 2.0 and 3.5% for FL and DL, respectively. In Assay 2, weight gain of chicks increased linearly $(P<0.01)$ with increasing concentrations of choline from choline chloride, SBM, CM or PM. Multiple linear regression analysis indicated bioavailable choline concentrations of 1,708, 1,545 and 1,203 mg/kg for SBM, CM and PM, respectively. In Assay 3, similar methodology gave bioavailable choline estimates of 2,002, 1,464 and 1,320 mg/kg for SBM, CM and PM, respectively, and bioavailability was not $(P>0.05)$ affected by severely overheating the oilseed meals. Combined estimates indicated bioavailable choline levels were 87, 27 and 77% of analytically determined total choline levels in SBM, CM and PM, respectively. Three chick assays were conducted to determine effects of dietary changes on hepatic betaine-homocysteine methyltransferase (BHMT) activity. In Assay 1, use of a methionine-deficient purified diet caused a 3-fold increase $(P<0.05)$ in BHMT activity, and addition of choline or betaine further increased $(P<0.05)$ activity. In Assay 2, use of a methionine-deficient corn-peanut meal diet increased $(P<0.05)$ BHMT activity relative to methionine-supplemented chicks, and activity was increased further $(P<0.05)$ by addition of surfeit choline to the basal diet. The additive effect of methionine deficiency and surfeit choline or betaine was observed again in Assay 3. Large increases in BHMT activity occur under methionine-deficient conditions, especially in the presence of excess choline or betaine.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Nutritional Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Emmert, Jason Lee

Contributors dc:contributor

• Baker, David H.

• Biology, Animal Physiology

Language dc:language

eng

Identifier

(MiAaPQ)AAI9717271

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/84972