Antibiotic residues in goats milk following intramammary treatment

Two lactational intramammary antibiotic preparations (cloxacillin and oxytetracycline) were each used to treat eight goats by intramammary infusion in one half. The rate of release of the antibiotics was monitored by a diffusion assay based on the sensitive organism Bacillus stearothermophilus var. calidolactis. Cloxacillin was still detectable 156 hours after the final treatment while oxytetracycline was undetectable 108 hours following treatment. A small but significant amount of antibiotic was translocated between treated and untreated halves of the udder in both cases.     

Characterization of staphylococci associated with clinical and subclinical bovine mastitis

Attempts were made to identify 900 species of staphylococci or micrococci recovered from samples of bovine milk examined for mastitis pathogens. The presence and identity of haemolysins was recorded together with results of disc diffusion antibiotic sensitivity tests. The occurrence of clinical mastitis was also noted and somatic cell counts (SCC) were performed on milk samples which were normal in appearance. Eight hundred and thirty-one coagulase positive staphylococci were obtained, of which 810 were S. aureus and 21 were S. intermedius. Of 65 coagulase negative staphylococci the species of 19 could not be determined by the identification systems used. The remainder were identified as S. hyicus sub sp. hyicus (1), S. hyicus sub sp. chromogenes (19), S. haemolyticus (17), S. hominis (3), S. epidermidis (4), S. capitis (1) and either S. hominis or S. warneri (1). Four other isolates could not clearly be assigned to the genus Staphylococcus or Micrococcus and were designated irregular strains. No micrococci were identified. The presence of alpha, beta, or delta haemolysins occurring singly or in various combinations was identified in 98.3% of coagulase positive staphylococci and in 60% of coagulase negative staphylococci. Epsilon haemolysin was detected in 47.6% of the coagulase negative staphylococci and in 9.5% of S. intermedius. All staphylococci were sensitive to tetracycline (30 microg), novobiocin (1.6 microg), nafcillin (30 microg), methicillin (10 microg) and cephalothin (30 microg) and variable numbers of each species were sensitive to penicillin (2 iu) and streptomycin (10 microg). One non-identified species of coagulase negative staphylococcus was sensitive to erythromycin (0.4 microg) the remaining staphylococci were resistant. Each of the four irregular strains was sensitive to erythromycin and novobiocin. Clinical mastitis was associated with 30.6% of coagulase positive staphylococci, 15.3% of coagulase negative staphylococci, and two of the four irregular strains (50%). Subclinical mastitis as determined by SCC of 500 x 10(3) or greater was associated with 92.7% of coagulase positive and 37.5% of coagulase negative staphylococci.     

A simple restrainer for sheep for abdominal radiography

The construction of a simple, portable restrainer for holding sheep in either the horizontal or vertical position for abdominal radiography is described. Examples of its use in locating slow-release pellets-and needles are given.     

The pharmacokinetics of fenbendazole and oxfendazole in cattle

The pharmacokinetics of fenbendazole and oxfendazole in cattle are described. The pharmacokinetics of oxfendazole were not significantly different when administered orally and by intra-ruminal injection. At a dose rate of 4.5 mg/kg, administered orally, fenbendazole gave rise to mean peak concentrations in plasma of fenbendazole and oxfendazole of 0.11 and 0.13 g/ml respectively. Oral administration of oxfendazole, at 4.5 mg/kg body weight, gave rise to plasma peak concentrations of fenbendazole and oxfendazole of 0.10 and 0.20 g/ml respectively. Following intra-ruminal administration of oxfendazole, the peak concentrations were 0.11 and 0.18 g/ml respectively.     

A study of the interaction between bromocresol green dye and bovine,ovine and equine serum globulins

In human medicine it has been shown that the bromocresol green (BCG) dye-binding method for the determination of serum albumin is not entirely specific, the dye reacting also with certain human serum globulins. This causes over-estimation of albumin when reaction times are prolonged beyond 30 seconds.In the present study, serum albumin values obtained from three animal species by the immediate, i.e. less than 30 seconds, BCG reaction were compared with those by the 10-minute BCG reaction. Albumin-depleted sera were prepared using an affinity chromatography technique and their reactions and those of purified gamma globulin preparations with the dye were studied.In cattle, sheep and horses, serum albumin values obtained by the 10-minute reaction were higher than those obtained by the immediate BCG reaction, the differences being statistically significant. Purified gamma globulin did not react with the BCG dye after 10 minutes, but other globulins did. There were differences between the species in the magnitude of the reaction of their globulins with BCG dye.     

Equine hydatidosis: a new record for New Zealand

Cysts found in the liver of a horse which had never been out of New Zealand were used to infect two dogs which were slaughtered 35 days after infection. Large numbers of Echinococcus granulosus were recovered. These cestodes were compared with mature dog-sheep cestodes, using light and scanning electron microscopy and identified as the dog-horse strain of E.granulosus.     

Immunization against polyandroalbumin leads to increases in lambing and tailing percentages

A series of 10 farm trials was conducted in which the lambing performance of ewes immunised against polyandroalbumin was compared with that of untreated ewes in the same flock. The trials show that polyandroalbumin treatment is a reliable method of increasing lambing and tailing percentages in New Zealand flocks. An average of 39 extra lambs born per 100 ewes tupped was achieved on farms where ewes were given two treatments about four weeks apart and rams were introduced 18-26 days after the second dose. On farms where rams were introduced less than 12 days after this booster injection an average of 19 extra lambs born per 100 ewes tupped resulted. On farms where rams were introduced at 18-26 days post booster injection an average of 35 extra lambs were tailed for every 100 ewes tupped. The response for immunization increased in direct relation to the liveweight of the ewes at tupping.     

Incompatibility Between the Dimorphic Flowers of Collomia grandiflora, a Cleistogamous Species

The cleistogamous species Collomia grandiflora produces dimorphic cross-incompatible flowers on a single plant. The open or chasmogamous flower has smaller, flask-shaped stigmatic papillae, larger pollen grains, longer styles, and faster pollen tube growth rates down the style than the closed or cleistogamous flower. In intermorph crosses, pollen tube growth rates are greatly decreased and fertilization does not occur.