THE INFLUENCE OF ENVIRONMENT ON POTATO HAULM KILL BY DIQUAT AND ON ITS RESIDUES IN THE TUBERS

Summary. The effect of various environments on the degree of desiccation and of residues in King Edward and Majestic potatoes was studied. The higher residues frequently associated with the variety King Edward are ascribed from glasshouse experiments to greater diquat movement; they could not be accounted for by differences in uptake between the two varieties.
In glasshouse experiments, uptake was increased both by high air humidities and reduced light intensities before and after treatment. Since earlier work with cocksfoot and wheat indicated that dry soil conditions markedly increased movement, it is concluded that dull, humid air conditions associated with dry soil would be most conducive to efficient haulm desiccation and also to highest residues in the tubers. Late afternoon or evening treatment often provides thes conditions, and residues were in fact least from morning treatment.
In the field, increases in haulm desiccation were associated with reductions in residues. As they were observed only at light intensities below 5000 lux, they are unlikely to occur in normal dull weather.
Rain falling soon after spraying did not reduce the extent of haulm desiccation or diquat residues.
Influence de I'enviromurtunt sur la destruction des fanes de pomme de terre par le diquat el sur ses     

Acute cortisol responses of calves to four methods of dehorning by amputation

Objective To measure the plasma cortisol response in calves dehorned by four different methods (scoop, guillotine shears, saw, embryotomy wire) for 9 h after dehorning.
Design A physiological study with controls.
Procedure Horn amputation was carried out on calves restrained manually in a race.
Results The four methods of dehorning provoked similarly increased cortisol responses which lasted for 6 h. During the first hour after dehorning the plasma cortisol concentrations were similar to those following ACTH injection. The overall cortisol response to control handling was about 30% of the responses to dehorning.
Conclusions The similarity of the cortisol responses produced by the four methods of dehorning suggests that the distress experienced by calves following dehorning by amputation is similar regardless of method used.     

Effect of Insemination–Ovulation Interval and Addition of Seminal Plasma on Sow Fertility to Insemination of Cryopreserved Sperm

In swine, the use of frozen-thawed (FT) sperm for artificial insemination (AI) is limited because of poor sow fertility, possibly associated with a post-thaw capacitation-like status resulting in fewer fully viable sperm. Sow fertility to AI with FT sperm may improve with deeper deposition of sperm within the female tract, insemination very close to ovulation, or reversal of cryocapacitation by seminal plasma (SP). We performed two experiments to examine these suggestions. In experiment 1, 122 multiparous Yorkshire sows received 600 IU equine chorionic gonadotrophin at weaning and 5 mg pLH 80 h later to control time of ovulation. The predicted time of ovulation (PTO) was 38 h after pLH injection. Thereafter, sows were assigned on the basis of parity to a single AI of FT sperm at 2 h before PTO, or at 12 h before PTO, or FT sperm supplemented with 10% SP at 12 h before PTO. Control sows received fresh semen at 12 h before PTO. All semen doses were adjusted to 3 x 10(9) live cells and deposited into the cervix. Experiment 2 employed 99 multiparous crossbred sows and repeated the treatments of experiment 1 except that all FT inseminations were intrauterine. In both experiments, farrowing rates were lower (p < 0.01) following FT inseminations with no effect of time of insemination or of supplemental SP. In experiment 1, litter size was smaller following FT insemination (p < 0.05), but no effect on litter size was evident in experiment 2. Supplemental SP had no effect on litter size in either experiment. The lack of effect of either SP or timing of FT insemination on sow fertility suggests that the non-lethal sperm cryoinjury affecting fertility involves more than just cryocapacitation.     

Arterial Blood Gases in Dogs with Bacterial Pneumonia

The purpose of this study is to report the aterial blood gas findings in dogs with bacterial pneumonia. Arterial blood gas samples were collected from 62 dogs with culture-confirmed bacterial pneumonia. These results were compared with 46 normal dog arterial blood gas samples. Results demonstrated that respiratory acidosis was not a problem in dogs with pneumonia in this study. Significant evidence of hypoxemia was noted with abnormal mean values in PaO₂ (P<0.001) and the Alveolar-arterial (A-α) gradient (P<0.001).     

Serum chlortetracycline concentrations in parrots fed medicated seed diets

Various seed diets containing chlortetracycline were fed to large and small parrots to evaluate serum chlortetracycline concentrations. The substitution of dehulled sunflower seed for whole sunflower in the seed mix may have resulted in higher chlortetracycline concentrations in cockatoos and parrots. The serum chlortetracycline concentration achieved for all diets was less than the goal of 1 μg/mL, but the concentrations attained may be useful for therapy.     

Amoxycillin as an alternative to dihydrostreptomycin sulphate for treating cattle infected with Leptospira borgpetersenii serovar hardjo

Objective To assess the effect of amoxycillin treatment on urinary excretion of leptospires from cattle infected with Leptospira borgpetersenii serovar hardjo .
Design A chemotherapy trial with controls.
Procedure Fourteen heifers serologically negative to L hardjo were inoculated with L hardjo via the conjunctival route and assessed for evidence of infection by serological, fluorescent antibody and microbiological tests. Two injections (48 h apart) of amoxycillin at a dose of 15 mg/kg were administered intramuscularly to seven heifers 6.5 weeks after infection; the remaining heifers acted as untreated controls. Later, these seven control group heifers were treated with a single dose of amoxycillin (15 mg/kg). Samples of urine were collected before and after amoxycillin treatments; kidneys were collected at slaughter, and examined by fluorescent antibody test and microbiological culture.
Results Leptospires were isolated from the urine of 11 of 14 heifers inoculated with L hardjo . After treatment of six of these with two injections of amoxycillin, leptospires were not isolated. Of the controls, four of the five initially leptospiruric heifers continued to shed leptospires; after a single injection of amoxycillin, no leptospires were detected in the kidneys of these four.
Conclusion Amoxycillin may be an acceptable alternative to dihydrostreptomycin sulphate for the treatment of cattle infected with L hardjo .