Evaluation of three strip tests for measuring electrolytes in mares' pre-partum mammary secretions and for predicting parturition

Three strip test kits which measure calcium and/or magnesium in mares' mammary secretions were compared and assessed for their accuracy in:- 1) measuring these electrolytes compared to standard laboratory measurements, and 2) predicting the time of parturition. Daily samples of mammary secretions were obtained pre-partum from 35 Thoroughbred mares and allocated a score. Measurement of mammary secretion calcium and/or magnesium by the strip tests and laboratory methods correlated significantly (P less than 0.001). The results obtained for prediction of parturition were analysed by two methods. Method i) indicated that the majority of mares had a maximum score on the day of birth. However, the second method of analysis included all prepartum scores and this demonstrated that maximum scores occurred on more occasions prior to the day of birth than on the day of birth itself. The number of nights spent attending mares, and the percentage of occasions when foaling was missed, were also calculated for given strip test scores. The results indicate that the test kits are not particularly accurate in predicting time of parturition although they are a reliable means of measuring mammary secretion calcium and/or magnesium. It is suggested that the test kits may be more helpful by indicating when it is not necessary to attend mares at night.     

Ultrastructure of sarcocysts from water buffalo in India

The ultrastructure of sarcocysts of macro- and microscopic species of Sarcocystis was compared from naturally infected water buffalo from India. Grossly visible sarcocysts had walls consisting of cauliflower-like villar protrusions, typical of S. fusiformis. The sarcocyst wall of the microscopic species of Sarcocystis was 6.4 microns thick and consisted of tightly packed conical villar protrusions that were 9.6 microns long and 3.7 microns wide at the base. At approximately 3 microns above the base, the distal two-thirds of the villar protrusion became conical shaped and was bent laterally at an angle of 45 degrees to the sarcocyst surface. The granular layer beneath the villar protrusions was 0.9 microns thick. In S. levinei the granular layer was 1.9 microns thick, the villar protrusions were narrow and it had a highly undulating primary cyst wall. Whether the microscopic S. levinei-like sarcocysts of Indian and Malaysian water buffalo are distinct species of Sarcocystis will require further investigation.     

Effect of pelleting and beta-glucanase supplementation on the ileal and fecal digestibility of a barley-based diet in the pig

The influences of pelleting and beta-glucanase supplementation on the digestibility of dietary components in a barley-based diet were investigated in pigs fitted with cannulas in the terminal ileum. The diet contained 49.0% starch, 18.9% crude protein and 14.8% dietary fiber, with arabinoxylans (4.9%), mixed-linked beta-glucans (3.4%) and cellulose (3.3%) as the main fiber components. Pelleting increased mixed-linked beta-glucan solubility from 45 to 62%. Neither treatment influenced the ileal or fecal apparent digestibilities of dry matter (64 and 80%, respectively), energy (62 and 79%), crude protein (53 and 75%), crude fat (26 and 27%) or dietary fiber (58 and 72%). However, pelleting increased (P less than .01) the pre-ileal apparent digestibility of starch from 91.5 to 95.3% and decreased (P less than .03) that of ash from -10 to -23%, while increasing (P less than .005) the fecal apparent digestibility of starch from 98.6 to 99.7%. The solubility of mixed-linked beta-glucans in ileal digesta was lower (P less than .001) in pelleted (26%) than in unpelleted (58%) diets. beta-glucanase supplementation also increased (P less than .05) the ileal apparent digestibility of starch, from 92.6 to 94.3%, and of mixed-linked beta-glucans, from 95.7 to 97.1%. Significant between-pig differences in the apparent digestibility of dietary components were observed. In conclusion, treatments that disrupt the endosperm cell walls in barley can increase the proportion of the diet digested prior to the large intestine.     

Epidural analgesia with 0.75% bupivacaine for laparotomy in goats

Epidural nerve block with 0.75% bupivacaine (1 ml/4 kg of body weight) was performed in 17 goats tranquilized by IM administration of acetylpromazine (0.07 mg/kg). For comparison, epidural nerve block with 2% lidocaine containing 1:100,000 epinephrine (1 ml/5 kg) was performed in 7 goats. Transient signs of CNS stimulation were observed during injection of bupivacaine in 5 goats and of lidocaine in 2 goats. Analgesia of the flank was inadequate for laparotomy in 4 goats given bupivacaine (including 1 goat given a two-thirds dose) and in 2 goats given lidocaine. Analgesia for these goats was provided by local infiltration of the operative site with lidocaine. With bupivacaine, the onset of analgesia was up to 40 minutes, and the duration of analgesia was several hours; most goats were unable to stand for at least 11 hours. In comparison, epidural nerve block with lidocaine had a more rapid onset and much shorter duration. For both anesthetic drugs, despite adequate analgesia for laparotomy, response to manipulation of abdominal viscera was observed in 12 goats. Arterial blood pressure and blood gas tensions were measured in 8 goats given bupivacaine; 3 goats had mean arterial blood pressure less than 70 mm of Hg. Seven goats had normal PaCO2 but 2 goats had low PaO2; 1 goat sedated with xylazine had increased PaCO2 and hypoxemia.     

Lipid mobilization by obese and lean pigs infused with the beta-adrenergic agonist isoproterenol

Generally obese and lean pigs in both the fed and fasted states were anesthetized and then acutely infused with increasing concentrations of the beta-adrenergic agonist isoproterenol. Plasma free fatty acid (FFA), blood glycerol, glucose and lactate, and heart rate were monitored during the infusion period. Data were reduced by estimating the parameters of the generalized logistic function (minimum, maximum, ED50 and slope) and subsequently analyzed to compare the lean and obese genotypes within nutritional state. Lactate data could not be fitted to this function because the upper asymptote was not approached during the experiment. The minimum plasma concentration of FFA tended (P less than .1) to be less in obese than in lean pigs. The maximum, ED50 and slope for the responses of FFA were similar for obese and lean pigs in fed pigs and in fasted pigs. In fed pigs, the minimum glycerol concentration was greater in obese than in lean pigs, and the ED50 for heart rate tended to be lower in lean than in obese pigs. All other estimated parameters for the variables were similar in fed obese and lean pigs. In fasted pigs, the maximum glucose concentration was greater in obese than in lean pigs. All other parameters for the variables were similar in fasted obese and lean pigs. The results suggest that there was no major defect in lipid mobilization in these obese pigs (only a lower minimum FFA concentration was detected) and that an increased maximum blood glucose concentration in the fasting state might contribute to the obesity.     

Prevalence of Dirofilaria immitis and Dipetalonema reconditum in greyhounds

Blood samples from 331 greyhounds in the Hunter Valley and nearby coastal areas of New South Wales were examined for microfilariae using a filtration technique. Species were identified by histochemical staining; 10.9% of the greyhounds were infected with Dirofilaria immitis and 3.6% with Dipetalonema reconditum. The prevalence of infection of both species was significantly greater in summer than in winter (p = less than 0.05). Infection with D. immitis was correlated with differences in age, sex, bodyweight and coat colour, and a reported lack of stamina and the presence of a cough. No significant association was found. Diethylcarbamazine citrate was used for prophylaxis in 8.8% of all the greyhounds examined.     

Molecular epidemiology of Pasteurella multocida in turkeys.

Pasteurella multocida isolated from turkeys during an outbreak of fowl cholera was characterized by serotype and heterogeneity of genes encoding rRNA (ribotype) to investigate the epidemiology of the organism. Isolates were collected between October 1985 and July 1986. The M9 or Clemson University fowl cholera vaccine-like strain was detected in 17% of the flocks with fowl cholera. One particular strain, isolated only from breeder flocks, was recovered from 7 of the 10 breeder flocks examined in this study. Intracompany transmission appeared to be common, implying a failure in biosecurity. Circumstantial evidence indicated that in the field; the incubation period of P multocida in a turkey flock may be between 2 to 7 weeks. Wildlife did not appear to be an important reservoir of P multocida for turkeys during this study period. Ribotyping results tended to discount several of the possible interflock transmissions, as suggested by examination of serotyping results alone; however, serotyping in combination with ribotyping proved helpful in understanding the epidemiology of P multocida in turkeys.