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Biomedical subjects

J J Vermunt

Publications and source records attributed to J J Vermunt.

At least 19 recordsLinked to original sources
PubMed2000

Comparative efficacy of three dry-cow antibiotic formulations in spring-calving New Zealand dairy cows.

AIM: To evaluate the efficacy of a dry-cow antibiotic preparation containing cloxacillin plus ampicillin in a formulation that gives a 10-week duration of action, in comparison to products containing cephalonium (10-week action) or cloxacillin alone (7-week action). METHODS: A total of 493 cows were selected from 6 spring-calving dairy herds in the Manawatu region of New Zealand, according to the criteria of the SAMM plan, to receive intramammary antibiotic therapy at the end of lactation (drying off). Cows were randomly allocated to receive 1 of the 3 dry-cow antibiotic products under investigation. Cows were examined twice during the dry period and twice daily during the first 10 days of their subsequent lactation for the presence of mastitis. Milk samples were collected from individual quarters at the time of drying off and at 7 and 28-35 days after calving, for determination of milk somatic cell counts (SCC). Bacteriology was carried out on milk samples taken from cows that developed mastitis during the first 10 days after calving. RESULTS: No cows developed mastitis during the dry period. Sixteen cows developed clinical mastitis within 10 days of calving; there was no difference in incidence between treatments. Streptococcus uberis was the most commonly isolated organism. Mean SCC on Day 7 were lower (p = 0.019) in cephalonium-treated quarters (189.9+/-28.4 x 10(3) cells/ml) than in cloxacillin-treated quarters (388.7+/-71.2 x 10(3) cells/ml); values in quarters receiving cloxacillin plus ampicillin were intermediate (252.0+/-47.0 x 10(3) cells/ml). SCC were similar between treatment groups on Day 28-35. CONCLUSIONS: The use of a combination of cloxacillin plus ampicillin was effective for the prevention of mastitis during the dry and peri-calving-periods in pastured dairy cattle.

Journal Article↗
PubMed2000

Unusual congenital deformities of the lower limb in two calves.

Congenital deformities of the lower limb were observed in 2 calves from different properties. One was a newborn Holstein-Friesian bull calf with polydactyly and polypodia of the right fore-limb. The other was an 8-month-old Friesian/Jersey crossbred heifer calf, which had a mirror image duplication of the plantar/palmar half of the distal portion of the digits. The abnormalities in the second calf have not previously been described in cattle. This paper presents details of the clinical, radiological and necropsy findings in these 2 calves.

Journal Article↗
PubMed1996

Hock angles of dairy heifers in two management systems.

Hock angles were measured in 30 Holstein heifers in one herd housed either indoors on concrete slats or out of doors on dirt. Two examinations were made, i.e. at 12-13 and 24-26 months of age. Overall, the heifers had straight limbs; the mean value of the hock angle was 167.3 degrees +/- 0.7 (SEM) (range 154.3-177.4 degrees). Hock angles decreased with age in each group, but the difference between the first and second examinations was significant only for outdoor-housed heifers (P < 0.05). At the first examination, mean hock angles were not significantly different between the two groups (169.5 degrees +/- 1.6 vs 168.1 degrees +/- 1.6), but at the second examination indoor-housed heifers had significantly greater mean hock angles than heifers housed out of doors (167.4 degrees +/- 1.0 vs 164.2 degrees 1.3) (P < 0.05). Heifers housed indoors on concrete slats appeared to retain their straight-angled hocks.

Age Factors↗
PubMed1996

Sole haemorrhages in dairy heifers managed under different underfoot and environmental conditions.

Sole haemorrhages associated with laminitis were studied in 30 Holstein heifers in one herd housed either indoors on concrete or out of doors on a dry lot. Examinations were at 4-week intervals during a 15-month period from approximately 13 months of age to 2 months after calving. At 13 months of age, sole haemorrhages were present in 77% of the heifers. Five heifers, affected by clinical laminitis shortly after calving, developed early sole ulcers. Indoor-housed heifers had a greater number of and more severe haemorrhages than heifers managed in dry lots (P < 0.001). In both groups, hind claws were more affected than front claws (P < 0.001). Lateral claws were more affected in hind limbs (P < 0.001),whereas medial claws had more sole haemorrhages in front limbs (P < 0.01). Heifers managed in dry lots had more sole haemorrhages in right claws than in left claws (P < 0.01). The number and severity of haemorrhages differed among the six zones of the sole (P < 0.001). Overall, the abaxial white zone (zone 2) had the greatest number of haemorrhages, followed by the white zone at the toe (zone 0), the bulb (zone 5) and the sole-bulb junction (zone 4), respectively. Few haemorrhages occurred in the apex of the sole (zone 1) and the axial groove (zone 3). Zone 0 was more severely affected in heifers managed in dry lots (P < 0.001), whereas zones 2, 4 and 5 had greater numbers of haemorrhages in heifers housed indoors (P < 0.01). Time had no effect on total haemorrhages scores, but the effect of management was significant for zones 0 and 5. Total haemorrhage scores for zone 0 were greater in heifers managed in dry lots (P < 0.05), whereas zone 5 was more affected in indoor-housed heifers (P < 0.01). This study shows that sole haemorrhages do occur in the claws of dairy heifers managed either indoors or in dry lots, and permanent damage to the claws of these young cattle may already have occurred before they reach maturity.

Analysis of Variance↗
PubMed1996

Claw conformation of dairy heifers in two management systems.

A computerized conformation determination system was used to evaluate objectively claw conformation of dairy heifers in two management systems, i.e., housed indoors on concrete slats or out of doors in a dry lot. Examinations were made at 4-week intervals from 12-13 months of age until calving at 24-26 months. Overall, the angle of the dorsal border did not differ between front and hind claws. Length of the dorsal border, heel height, and toe:heel ratio were greater for front claws (P < 0.001). Hind claws were longer than front claws (P < 0.001), but front claws were wider (P < 0.001). On both front and hind limbs, lateral claws were wider than medial claws (P < 0.001). Angles of the dorsal border decreased, but lengths of the dorsal border and heel heights increased over time (P < 0.05). Significant differences in claw conformation were found between the two management groups. Heifers maintained out of doors had longer toes and wider lateral claws than heifers housed indoors (P < 0.05). At time of entry into the respective management group, no significant differences in claw traits were found between the two groups. At calving, however, out-door-housed heifers had hind claws with smaller dorsal angles and longer dorsal borders (P < 0.05).

Animals↗
PubMed1996

The effect of electro-ejaculation on aversive behaviour and plasma cortisol concentration in rams.

Electro-ejaculation is used in rams to collect semen for fertility and bacteriological evaluation. Concern has been expressed about animal welfare implications of EE. Two experiments were carried out to compare the aversiveness of electro-ejaculation, part shearing and free movement, and to determine the changes in plasma cortisol concentration produced by electro-ejaculation, shearing and lateral restraint. In the aversion test, transit time was greater (p<0.003) for rams subjected to part shearing than free movement. There were no major differences in the transit time between the rams subjected to electro-ejaculation and those subjected to part shearing or free movement. In addition, there was no significant difference in the effort required to move rams from the three treatment groups into or through the experimental route. These results suggest that electro-ejaculation is no more aversive than part shearing. There were no significant differences in the cortisol response of the rams subjected to electro-ejaculation, shearing or lateral restraint, indicating that there were no significant differences in the distress caused by the three procedures.

Journal Article↗
PubMed1996

Inefficacy of moxidectin and doramectin against ivermectin-resistant Cooperia spp. of cattle in New Zealand.

Two cases are described in which strains of Cooperia spp. of cattle were found to be resistant to either the oral or the injectable formulations of ivermectin. Injectable moxidectin was not effective against the latter strain and doramectin was not effective against either of the ivermectin-resistant Cooperia isolates. In both cases, the anthelmintic efficacy of oral levamisole was 100%.

Journal Article↗
PubMed1995

Hereditary chondrodysplasia ("spider syndrome") in a New Zealand Suffolk lamb of American origin.

The first case of hereditary chondrodysplasia ("spider syndrome") in a New Zealand Suffolk lamb of American origin is described. An imported Suffolk ram of American origin was test mated to 27 of his daughters. In one of the resulting progeny, found dead at birth, a diagnosis of hereditary chondrodysplasia was made based on the typical radiographical abnormalities of multiple centres of ossification in the anconeal process of the ulna, vertebrae, sternebrae and pelvic bones. These changes were confirmed histopathologically.

Journal Article↗
PubMed1994

The effect of repeated doses of toltrazuril on coccidial oocyst output and weight gain in suckling lambs.

Coccidial oocyst output and liveweight were monitored in 43 pairs of lamb twins over a 10-week period during September-November 1992. One of each set of twins was treated orally with toltrazuril (20 mg/kg) weekly while the other was an untreated control. The oocyst output was significantly lower (P < 0.01) and the weight gain over the trial period was significantly greater (P < 0.05) in the treated group than in the control group.

Journal Article↗