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Biomedical subjects

B Gustafsson

Publications and source records attributed to B Gustafsson.

At least 235 records · Page 13Linked to original sources

Identification and quantitative determination of steroids in bovine corpus luteum during oestrous cycle and pregnancy.

Neutral steroids in bovine corpus luteum were isolated by liquid-gel chromatography on hydrophobic Sephadex, and were analyzed by computerized gas chromatography-mass spectrometry. The presence of progesterone and 20beta-hydroxy-4-pregnen-3-one was confirmed. In addition, 3beta-hydroxy-5-pregnen-20-one, 5-pregnene-3beta,20beta-diol, 3beta-hydroxy-5alpha-pregnan-20-one and 5alpha-pregnane-3beta,20beta-diol were fully identified, and 3-hydroxy-4-pregnen-20-one, 4 pregnene-3,20-diol, 22-hydroxycholesterol and 20,22-dihydroxycholesterol were partially characterized. Steroid sulphates were not detected. Quantification of the six fully identified steroids was based on peak areas in specific fragment ion current chromatograms constructed by the computer. During the 4th-19th day of the oestrous cycle the steroid concentrations varied as follows: progesterone 6.0-36.7 mug/g wet luteal weight, 20beta-hydroxy-4-pregnen-3-one 0.8-5.5 mug/g, 3beta-hydroxy-5-pregnen-20-one 1.0-7.1mug/g, 5-pregnene-3beta,20beta-diol smaller than 0.2-0.9 mug/g, 3beta-hydroxy-5alpha-pregnan-20-one 1.7-8.6 mug/g, and 5alpha-pregnane-3beta,20beta-diol smaller than 0.2-1.2 mug/g. The concentrations of progesterone and 3beta-hydroxy-5-pregnen-20-one seemed to vary in parallel and were low during days 11-17. During this period the concentrations of 5-pregnene-3beta,20beta-diol and 5alpha-pregnane-3beta,20beta-diol were highest as was the relative contribution of all three 20beta-hydroxysteroids to the total amount of steroids. The relative amount of 3beta-hydroxy-5alpha-pregnan-20-one seemed to be highest during days 4-6. The total steroid concentration in corpora lutea taken in early pregnancy (75-105 days) was 18-47 mug/g. In the period 75-90 days, progesterone constituted only 35-42% of the total steroids, 3beta-hydroxy-5alpha-pregnan-20-one as much as 23-40% and the total 20beta-hydroxysteroids 18-30%. The total steroid concentration in corpora lutea taken in midterm and late pregnancy was 21-77 mug/g. In this period progesterone was by far the predominant steroid and constituted about 80-90% of the total steroids in corpora lutea taken between days 150 and 240. Possible correlations between luteal growth, steroid oxidoreductases and steroid concentrations are discussed.

Animals↗

Prostaglandin induced parturition in swine with some aspects on prevention of the MMA (metritis, mastitis, agalactia) syndrome.

The effect of PGF2alpha to induce parturition in sows was studied in two herds. In one herd with a total number of 150 sows and with a good health status 12 sows were injected intramuscularly with 12.5 mg PGF2alpha during late pregnancy (110--114 days). During the same period 12 sows were treated intramuscularly with saline solution at corresponding gestation stage. The results are given in Tables I and II. The mean age calculated as number of litters was 2.6 in the experimental group and 4.3 in the control group. All sows treated with PGF2alpha farrowed within 30 hours after injection at an average time of 25.4 hours. The controls farrowed at an average 80.2 hours after injection. The mean farrowing time was 4.4 hours for the PG-treated sows while the corresponding figure for the controls was 6.6 hours. The litter size at birth, after 3 weeks and at weaning was somewhat higher in the experimental group. The same applies to the litter weight at the age of 3 weeks. The course of parturition was normal in all sows and the health condition during lactation was good. In another herd -- numbering 18 sows -- all sows which hade farrowed during the last 4 months before the present investigation, had developed the Mastitis-Metritis-Agalactia syndrome (MMA). The symptoms were a prolonged gestation length (116--117 days), fever, mastitis and agalactia. During the present study 3 sows were left untreated while 5 sows were given an intramuscular injection with 12.5 mg PGF2alpha during late pregnancy (112--114 days). Four of the five PG-treated sows farrowed within 32 hours, while the fifth sow farrowed 100 hours after injection. The sow not responding to the PG-treatment and the untreated sows all developed MMA while the four sows responding to treatment remained healthy. The gestation length in treated sows responding to treatment was 113--115 days. In the sows developing MMA the gestation length was 116--117 days. The potential effect for prevention of MMA of shortening the gestation length in this herd is discussed.

Animals↗

[Fertility and fertility problems in some beef herds in Sweden (author's transl)].

The purpose of the study was to investigate the fertility level, some factors affecting fertility and problems of infertility in selected Swedish beef herds. The investigation included 31 herds, 19 of which had Herefords, 13 Charolais, 2 Aberdeen Angus and 1 Limousins. The total number of mature females was 703, including 147 feifers of breeding age. Most data were collected at personal visits to the herds. The results are presented in Tables I--XV and Figures 1--2. The service period coincided roughly with the grazing period and lasted usually 4--5 months. Seventyfive per cent of the females calved during the period February-May. The fertility levels were comparatively good. The percentage of pregnancy at rectal examination performed at the end of the service period was 89.5; however the average calving percentage was only 87.5. The highest calving percentages were recorded for Aberdeen Angus and crossbreds. Also the calf crop, it is the number of calves born alive and surviving 24 hours per mature female was the highest for these two groups; 0.91 and 0.90 respectively. The mean interval from calving to conception was 80.3 days in Herefords, 83.4 days in Aberdeen Angus, 85.6 days in crossbreds and 92.3 days in Charolais. The percentage of animals pregnant within 90 days after calving was on an average slightly more than 50 per cent. The interval from calving to conception rose gradually when the interval from calving to expoure to bull exceeded 40 days. Mean percentages of still born calves were 5.9 in cows and 13.7 in heifers. As far as the fertility level is concerned there does not seem to be any disadvantage in keeping the bull together with the females during the calving period. However, in this case the next calvings will occur over an extended period of time. If the intention is to concentrate 50 per cent of the calvings within the period of one month then the females should be exposed to the bull from 41--60 days after calving at the earliest. In case the females were exposed to the bull from 41--60 days after calving and onwards, 95 per cent of the females finally pregnant had conceived at the end of a 3 months service period. Under such conditions a bull may be able to serve two groups of females within the same grazing period. Cows calving during July-September had the lowest pregnancy rate and those calving during October-December the highest at the following service period. The incidence of ovarian cysts was very low. About 1/3 of those buls serving at least 10 females each obtained calving percentages less than or equal to 80. Herds recording low calving percentages had to a great extent used young bulls, 12--15 months of age at the beginning of the service period. Only for two groups of females out of eleven which had been served by young bulls calving percentages greater than 80 were noted. A more efficient control of the fertility of the bulls could markedly improve the fertility of some herds.

Abortion, Veterinary↗