Treatment of tibial shaft fractures by interlocking nailing.

Between 1982 and 1986, 60 tibial shaft fractures were treated by interlocking nailing. Of these, 10 were complicated by a pseudarthrosis. The results were assessed after a minimum follow-up of 2 years and were found to be good both in patients with fresh fractures and with pseudarthroses; in only 3 out of 60 cases was the outcome poor. The advantages of the techniques include: its suitability for virtually all types of shaft fractures ease of surgery early mobilization and weightbearing, with a low risk of infection rapid consolidation. Relative drawbacks are: radiation exposure longer preoperative preparation involvement of the entire shaft if infection develops irritation of the patellar tendon.

Quantitative determination of androstenone in pig adipose tissue.

A simple, cheap and rapid method for the quantitative determination of the boar taint substance, 5 alpha-androst-16-en-3-one, in pig adipose tissue is described. After saponification of the fat the androstenone is extracted, derivatised with o-(pentafluorobenzyl)hydroxylamine hydrochloride in pyridine and analysed by fused-silica open-tubular capillary gas chromatography with electron-capture detection.

Metabolism of leucine by the isolated perfused goat udder.

Seven lactating goat mammary glands from 6 goats were perfused for several hours in the presence of [U-14C]L-leucine (4 experiments) or [2-3H; 1-14C]DL-leucine (3 experiments) and received adequate quantities of glucose, acetate and amino acids. Radioactivity in casein was mainly recovered in leucine and 90% of casein leucine was derived from free plasma leucine. About 64% of the leucine molecules were used for casein synthesis. Up to 12% of the molecules were channelled into lipid synthesis, while the remaining (up to 24%) were metabolized to CO2. From the 3H/14C ratio of casein and casein leucine, it was calculated that 70-80% of the leucine molecules were reversibly transaminated before their incorporation into milk protein. However, only 4-8% of the plasma leucine molecules were transaminated during passage through the udder. Different pools for oxidation and for protein synthesis may be present in the goat mammary gland.

Sensitive and specific post-column fluorimetric determination of diethylstilboestrol residues in extracts of urine and animal tissues at the 1-ppb level.

A rapid method for the selective detection and quantitation of diethylstilboestrol (DES) residues at the 1 ppb level in extracts of urine and animal tissues is described. After selective extraction of the oestrogens, DES is analysed by high-performance liquid chromatography using an in-line specific photochemical reactor followed by oxidation to highly fluorescent products. The reaction products of DES were investigated by thin-layer chromatography (TLC). The specificity of the proposed method was compared with that of a reference TLC method on different extracts of animal origin.

Propionate for fatty acid synthesis by the mammary gland of the lactating goat.

Isolated mammary glands of lactating goats were perfused with heparinized and oxygenated blood for 8 to 15 h. Adequate quantities of glucose, acetate, and amino acid were added to the perfusate. After addition of propionate to the perfusion blood, concentrations of odd-numbered and of monomethyl-substituted fatty acids other than those with iso and anteiso configuration increased in the milk fat. These acids seem to be synthesized de novo in the mammary gland. The increase of C17:0 concentration was weak and problematic. We suggest that propionate is acting as a precursor for monomethyl-substituted fatty acids by way of methylmalonyl-CoA. The activating effect of propionate administration upon milk fatty acid production was largest for odd-numbered followed by monomethyl-substituted fatty acids. No increase of iso acids was observed in milk fat in the propionate-infused glands whereas the increase of anteiso acids was extremely small. This agrees with the conception that iso and anteiso fatty acids are synthesized by rumen bacteria.

Sensitive multi-residue method for detection of anabolics in urine and in tisssues of slaughtered animals.

A routine procedure is described for the dependable detection of various anabolic residues in tissues or urine contaminated at levels as low as 0.5-10 ppb (10 parts per 10(9)). A suitable extraction and clean-up procedure was developed, permitting adequate recovery (60-80%) of various anabolics from tissue samples (50 g) or urine (50 ml). Following two-dimensional thin-layer chromatography, the presence of the anabolic residues are detected by sulphuric acid-induced fluorescence. The detection limit of most anabolics is of the order of 1-10 ng.

Metabolism of ornithine in perfused goat udder.

Four lactating goat mammary glands were perfused for several hours in the presence of ornithine labeled with 1-carbon-14 and delta-nitrogen-15 or 5-hydrogen-3 and received adequate quantities of glucose, acetate, and amino acids. For the first label carbon and nitrogen were incorporated in casein of milk. After isolation of the casein amino acids the carbon-14 was incorporated into proline only while nitrogen-15 was localized in aspartic acid, glutamic acid, alanine, serine, glycine, and the branched-chain amino acids. In the experiments with hydrogen-3 labeled ornithine, no reversible transamination of ornithine could be measured during passage through the udder. After incubation in vitro of goat blood in the presence of the labeled ornithine, no nitrogen-15 could be detected in other free amino acids of plasma. Ornithine is transaminated by the udder itself. The delta-amino group of ornithine contributed nitrogen for the synthesis of several nonessential amino acids in the mammary gland.

Metabolism of [U-14C; 2,3-3H]-L-valine by the isolated perfused goat udder.

Two lactating mammary glands excised from 2 goats were perfused for several hours in the presence of [U-14C; 2,3-3H]-L-valine and received adequate quantities of glucose, acetate and amino acids. In the synthesized milk 96 and 89% respectively of the casein valine was derived from free plasma valine. Valine was extensively catabolized by mammary tissue, resulting in a considerable 14CO2 production and in the incorporation of 14C into milk citric acid and to a lesser extent into casein aspartic acid and glutamic acid. About 30% of the valine molecules which were taken up by the mammary gland were oxidized to CO2 and 70% were incorporated in casein as valine residues. About 10% of the plasma valine molecules were reversibly transaminated during one passage through the udder. An important amount of radioactivity of plasma was present in unknown metabolites. Only 7% of this activity was localized in isobutyrate. The radioactivity of total milk fat was very low. Mainly iso-14:0, iso-16:0 and 15:0 were labelled.

Determination of thiocyanate in tissues and body fluids of animals by gas chromatography with electron-capture detection.

A method for the quantitative extraction of thiocyanate from biological material has been developed. Levels of 0.2-5 ppm of thiocyanate, in the presence of cyanide, were determined by gas-solid chromatography using 2-bromopropane as internal standard. Reliable results can be obtained only after careful deproteinization of the extracts with hot methanol. Cyanide can be eliminated by reaction with alkaline formaldehyde. The reproducibility of the determination of thiocyanate in biological extracts was +/-5%; the recoveries were over 90%. In vivo experiments with KS14CN-treated rats gave good agreement between the analytical results and the amount of thiocyanate determined by isotope dilution.

Quality of the meat after the application of anabolic agents in young calves.

Experiments were carried out to test the effect of implantation of Implix¿ (20 mg estradiol + 200 mg testosterone) or Revalor¿ (140 mg trienbolone acetate + 20 mg estradiol) on growth, feed conversion, slaughter quality, and residue levels in black Friesian bull calves at 4, 8, or 4 and 8 weeks before slaughtering. Weighings and calculations of feed conversion were carried out weekly. The control group of weight gain and feed conversion consisted of 22 calves; the chemical analyses of the control group was restricted to 8 animals. Implantation of the hormones at 4 or 8 weeks before slaughtering resulted in a significant beneficial effect on weight gain, feed conversion and carcass index over the control. This effect was improved (up to 15%) by implanting the hormones at 8 and 4 weeks before slaughter. The effects obtained with Revalor seemed to be superior to those obtained with Implix. In 75% of the treated animals, some remainder of implants was found. No effect was found on water binding capacity and colour of raw meat. Carcass quality was not significantly improved as judged from water, fat, ash, and protein content of the M. Longissimus Dorsi. The collagen content of the animals treated with Revalor was slightly, though not significantly, increased. There is a slight decrease in the relative bone content of the treated animals over the control resulting in higher meat percentages. Residues were determined in meat obtained from rib and neck by biological and chemical methods. Oestrogenic activity was found in only 7 samples from the neck; all samples from the rib were negative. Chemical examination indicates the presence of oestradiol in these samples. No residues of trienbolone could be detected in the meat samples. The Pars Dissiminata of the prostate was examined histologically on frozen and paraffin sections. Although the latter permitted a sharper interpretation, both methods indicated an increased activity of the prostates induced by hormone treatment. Compared to Implix, Revalor treatment provoked a more pronounced mucous activity. In recent years, the administration of estrogens in combination with testosterone or with trenbolone acetate (androst-4,9[10]-11-trien-3-one 17-acetate)2,3,4,17 has been shown to improve the growth rate and feed conversion5,14,17 in farm animals. However, there is a lack of information on carcass quality, which is of interest to the producer as well as to the consumer. Moreover, there are sample data14 about the residue levels remaining in the carcass following hormone implantation. These experiments were carried out to test the effect of the implantation of Implix¿ (20 mg estradiol + 200 mg testosterone) or Revalor¿ (140 mg trienbolone acetate + 20 mg estradiol) on growth, feed conversion, slaughter quality, and residue levels in black Friesian bull calves.