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The effect of various environmental temperature changes on the antibody production of chickens were examined. Chronic cold exposure significantly increased the antibody titers. Birds exposed to 32.2 degrees C. and above had significantly depressed agglutinin levels. Short term cold exposures 2 or 4 times following the antigen injection enhanced the agglutinin and hemolysin response. Thirty minute cold exposures for 2 or 4 times significantly increased IgM antibody production and markedly reduced the IgG antibody. The data suggest the elevation of antibody titers are in relation to time of the cold treatment and antigen injection. Observed differences of antibody production may be due to cold induced changes in the metabolic activity of antigen reactive cells and antibody producing cells.

Residues of estradiol-17 beta (E2 beta) in the kidney fat of one milk-fed calf were studies using radiometric methodologies. A three-month old Friesian male veal calf was injected intramuscularly daily for 3 d with 333 mg of [6,7(n)-3H]-E2 beta (specific activity: 7.55 MBq mmol-1) dissolved in 2 ml of propylene glycol and slaughtered 3 h after the last administration. Total estrogens were about 280 ng g-1 in perirenal fat. After a de-lipidation step, the relatively polar metabolites that were extractable with dichloromethane represented the main fraction of the metabolites, which accounts for almost 50% of the total radioactivity of the tissue, of which E2 beta was the major metabolite (19.7%) and E1 and E2 alpha represented only 7.7 and 3.2%, respectively. Conjugated estrogens accounted for only 15.2% of the total estrogen content. Non-polar estrogens (about 25% of total estrogens) were removed specifically with isooctane during the de-lipidation step and were further purified on silica and alumina columns before being chromatographed by normal-phase HPLC. The radioactive metabolites were eluted as estrogen-17 esters. The HPLC analysis of the estrogens released following hydrolysis of the esters indicated that E2 beta was the main estrogen acylated by long-chain fatty acids in the fraction of lipoidal estrogens. The presence of such a class of estrogens in fat could be of interest for the detection of estrogens a considerable time after estradiol administration.

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