Effects of copper, zinc and selenium status on performance and health in commercial dairy and beef herds: Retrospective study.

A retrospective study using analysis of plasma copper and zinc, and erythrocyte glutathione peroxidase from 2 080 dairy and beef cow herds was conducted to evaluate the relationship between trace-element status and production, reproduction and health in cows and their calves. Classification of the herd status as deficient, marginal, low-adequate or high-adequate was based on the lower tercile of individual values. Odds ratios for each disorder in herds were calculated by multivariable stepwise logistic regression. Inadequate copper status was not associated with adult disorders, but was an important risk factor for poor calf performance or health. Selenium deficient status was associated with most studied disorders in cows, and both deficient and marginal herd status were strongly associated with poor health of calves, particularly with increased risks of myopathy and infectious diseases. Zinc insufficiency was strongly associated with low milk production and impaired locomotion in dairy herds, and was also associated with diarrhoea and poor growth in calves. Because a low-adequate status increased the risk of many disorders in adults and calves, we propose to classify herds as deficient and marginal when the lower terciles of plasma zinc concentration are below 12 and between 12 and 14 mumol/l respectively.

Effects of copper supplementation on the copper status of peripartum beef cows and their calves.

The effects of copper supplementation on the copper status of 40 late-pregnant Aubrac beef cows grazing a copper-deficient pasture and later fed a marginally deficient diet were studied for five months. They were divided into four equal groups; the control group received no copper supplement, groups 1 and 2 received copper as copper sulphate at 10 and 30 mg/kg of diet dry matter (DM), respectively, for five months, and group 3 received 120 mg/kg of diet dry matter for 10 days. Plasma copper concentration and the activity of erythrocyte superoxide dismutase (eSOD) were measured at the beginning of the experiment, in the cows and calves during weeks 1 and 3 after calving, and in the calves before they were turned out to pasture at a mean (sd) age of 51 (26) days. In spite of the low dietary copper content (4.2 mg/kg of DM), the plasma copper concentration of the control cows increased during the winter. All the copper supplements resulted in normal and similar plasma copper concentrations in the cows after calving, but the concentration decreased slightly between weeks 1 and 3 after calving in the group supplemented for 10 days. The treatments did not affect the eSOD of the cows. The calves born to the four groups showed the same patterns of plasma copper and eSOD. Compared with the cows, the calves had low plasma copper concentrations at week 1 and values in the normal range at week 3; their eSOD was high at weeks 1 and 3 but decreased after week 3.

Effects of pre- or postpartum selenium supplementation on selenium status in beef cows and their calves.

The effect of Se supplementation before or after calving on Se status in deficient cows and their calves was studied using 72 beef cows in two experiments. In Exp. 1, cows calving in February or March 1997 were supplemented orally for 15 d in late pregnancy with 13.0, 32.5, or 45.5 mg of Se/d as sodium selenite. Glutathione peroxidase (GSH-Px) activities were measured in red blood cells (RBC) or plasma of cows and calves at d 15 and between d 17 and 88 after calving. In Exp. 2, cows calving in January 1997 were supplemented orally with .0, 13.0, or 32.5 mg of Se/d for 15 d postpartum, and calves were injected with 1.38 mg of Se when 2 d old and at an average age of 49 d. The GSH-Px activities were measured in 30-d-old calves and in cows and calves between d 77 and 115 after calving. In both experiments, Se supplementation resulted in adequate Se status for the dams. The increase in RBC GSH-Px activity was faster with 45.5 mg of Se/d, and GSH-Px activities remained high for up to 98 d after the end of supplementation. The improvement in Se status in calves as a result of maternal supplementation was greater in Exp. 1 than in Exp. 2, suggesting that the placental transfer of Se is more efficient than milk transfer. Prepartum oral Se supplementation of deficient beef cows with 13.0 mg of Se/d for 15 d allowed adequate Se status of dams and calves, and 45.5 mg of Se/d resulted in a faster improvement of Se status. Parenteral administration of 1.38 mg of Se to newborn calves did not sustain normal Se status in calves issued from deficient cows.

[Contribution of autologous blood transfusion in cardiac surgery in the adult]. / Apport de l'autotransfusion sanguine en chirurgie cardiaque de l'adulte.

The use of autologous blood transfusion in cardiac surgery is still controversial. This study was prospectively designed to evaluate the haemodynamic and haematological benefits of this method, with special attention to its impact on reducing bank blood requirements. Between November 1983 and October 1984, 160 patients underwent cardiac surgery with extracorporeal circulation and were randomly assigned to two groups: group I (81 patients) was the control group and group II (79 patients) received autologous transfusion following extracorporeal circulation. Blood was withdrawn immediately after the induction of anaesthesia via a jugular catheter and stored in CPD solution at room temperature. The volume of blood removed was replaced with gelatin solutions; after bypass, blood was returned to the patient. There was no difference in systolic, diastolic or mean blood pressures between the two groups. Right atrial pressure and heart rate were not statistically different in both groups. Myocardial perfusion and myocardial oxygen consumption remained unchanged in group II compared with group I. Complete haematological evaluation was carried out before and during bypass, and thereafter daily for the first twelve days of the postoperative period. There was no significative difference between the two groups in platelet counts, fibrinogen levels, prothrombin and partial thromboplastin times. During extracorporeal circulation, mean haematocrit was 22.9 +/- 0.4% in group II and 25.3 +/- 0.5% in group I (p less than 10(-3)). The mean haematocrit time course was similar in both groups during the postoperative period and returned to preoperative value at discharge.(ABSTRACT TRUNCATED AT 250 WORDS)

[Investigation of the immunity status towards tetanus of a population of mechanics at the car-factory "Renault" (author's transl)]. / Etude de l'immunité antitétanique d'une population d'ouvriers des usines Renault: influence de différents facteurs dont celle de la contamination des liquides d'usinage par Clostridium tetani.

Tetanus immunity has been studied in a population of mechanics working at the car-factory "Renault". For the study, 283 individuals were divided into 3 groups. The first group consisted of non-vaccined individuals, the second of vaccinated individuals and the third of individuals who had been boostered. The influence of different parameters on tetanus immunity status was considered, i. e. the age of the subjects, the time at which boostering was given, the serotherapy (when it was administered) and the contact with machine lubricating and cooling fluids. Clostridium tetani bacilli and spores were frequently found in aqueous machine fluids. Their presence is a potential hazard for non-vaccinated mechanics coming to contact with the fluids. Tetanus antibody levels in the sera of the tested population were determined in vivo by the toxin neutralization test. The influence on tetanus immunity of the different parameters considered in this paper was subjected to statistical analysis. From the whole population, 27% of the individuals were found to have no protection against tetanus. When age was taken into account, 53% of the individuals over 45 years old and 10% of those under 45 years old were shown to be devoid of tetanus immunity. It could be shown that younger individuals were better protected than older ones, because the formers had been immunized with adsorbed tetanus toxoid and most of the latters with fluid toxoid. Of the individuals in the third group who had received a booster injection within 15 years after primo-vaccination, 98% showed protective tetanus antibody levels in their sera in contrast to 25% when boostering had occurred more than 15 years after primo-vaccination. Contact with machine fluids was found to influence the degree of immunity of only those individuals whose boostering dated back to more than 25 years. Unexpectedly, 3 mechanics seemed to develop immunity after coming into contact with machine fluids. From the results reported here, it is concluded that tetanus immunity in vaccinated individuals should be renewed by a compulsory booster injection given every 5, 10 or, at the minimum, 15 years. Moreover, high-risk populations such as that represented by the mechanics should be immunized or boostered on commencing employment.