Quarter milk samples were taken from 150 cows from three dairy farms in south-east Queensland at drying off, two, four and six weeks after drying off, at calving, and one, two and three weeks after calving. In each of the herds, the cows were randomly allocated to three groups of approximately equal size. One group had all the quarters of all the cows treated at drying off with a dry cow antibiotic infusion containing cloxacillin; the second group was given no treatment, and the third group had selected quarters treated on the basis of their high activity of N-acetyl-beta-D-glucosaminidase at drying off. Dry cow treatment resulted in a marked reduction in the number of infected quarters at two and four weeks after drying off, so that the comprehensively treated group had significantly less infected quarters at these times (P<0.02). Twelve dinical cases of mastitis were detected two weeks after drying off in the untreated groups, 10 in the untreated quarters of the selectively treated groups, and no cases in the comprehensively treated groups. These cases were due mainly to Streptococcus uberis and Streptococcus dysgalactiae. The number of infected untreated quarters increased markedly between drying off and two weeks later, but in all three groups there was a marked decrease in the number of infected quarters between six weeks after drying off and calving, suggesting that the mammary glands were more able to overcome infections at this time.
A trial was conducted to compare the efficacy of intranasal vaccination in protecting goats against pneumonic pasteurellosis with intramuscular vaccination using an oil adjuvant vaccine, and a combination of the two methods. Forty goats were divided into four equal groups. Group 1 was vaccinated twice intranasally with formalin-killed Pasteurella haemolytica A2, group 2 was vaccinated twice intramuscularly with an oil adjuvant vaccine containing P haemolytica A7, and group 3 was initially vaccinated intranasally with the formalin-killed P haemolytica A2 followed by intramuscular vaccination with the oil adjuvant vaccine. In each group the two vaccinations were carried out four weeks apart. Group 4 was the unvaccinated control group. All goats were challenged intratracheally with 4 ml of an inoculum containing live P haemolytica A2 at a concentration of 1.3 x 10(7) colony forming units/ml two weeks after the last vaccination and were killed 14 days after the challenge. Although group 2 showed the highest clinical score following the challenge, deaths were observed only in group 3. Three goats in group 1 had pneumonic lung lesions, compared with six goats in group 2 and all the goats in groups 3 and 4. The lung lesions in group 1 were significantly (P < 0.05) less severe than in groups 3 and 4. Similarly, the lesions in group 2 were markedly less severe than in groups 3 and 4, although the differences were not significant. The difference between the extent of the lung lesions in the goats in groups 1 and 2 was not significant. Antibody against P haemolytica A2 in group 1 reached peak levels and was significantly (P < 0.01) higher than in the control group one week after the second vaccination, before declining.
Fourteen goat kids of the local indigenous breed naturally infected with Eimeria species were divided into two equal groups. The first group was superinfected with 500,000 Eimeria species oocysts and the second group was treated with amprolium. Sixty days later both groups were infected with 5000 third-stage caprine Haemonchus contortus larvae. The goats experimentally superinfected with eimeria shed more H contortus eggs and gained weight more slowly.
The superovulatory response to gonadotrophin treatment during different months of the year was investigated in Kambing kacang goats, a tropical breed, in Malaysia. Sixty-three cycling does, fitted with progesterone impregnated intravaginal sponges for 17 days, received two days before sponge withdrawal, an intramuscular injection of either 10, 15 or 20 mg of follicle stimulating hormone (FSH) or 500, 1000 or 1500 iu of equine chorionic gonadotrophin (eCG). The dose of FSH was divided into four decreasing daily doses and each daily dose was subdivided into two and administered at 07.00 and 19.00. Fifty-four does detected in oestrus were mated with fertile bucks. The ovarian response was determined by laparoscopy and eggs were recovered surgically five or six days after oestrus. The ovulatory response (mean +/- standard deviation) based on corpora lutea was higher in the FSH (13.4 +/- 8.4 corpora lutea per doe, n = 20) than the eCG-treated groups (6.4 +/- 5.1 corpora lutea per doe, n = 25) but the difference was not significant (P greater than 0.05). Does responded to gonadotrophins throughout the year with more than 50 per cent of does responding during the rainy months compared with less than 35 per cent responding during the dry months. This difference was statistically significant (P less than 0.05). Egg recovery was better in the FSH (6.8 +/- 5.3 per doe, n = 20) than the eCG groups (3.0 +/- 3.8 per doe, n = 21) but the difference was not significant (P greater than 0.05).
A total of 764 adult dogs were examined for microfilariae and adult worms of D immitis and 197 (25-8 per cent) were found to be infected. Direct blood examinations revealed only 47-2 per cent of the infected dogs whereas the blood serum examination detected 57-8 per cent of them. These results showed that the absence of circulating microfilariae could not be relied upon to be an accurate indication of the absence of patent heartworm infection. The average number of heartworms per dog was 5-5 with a range of one to 50.
The liver fluke Fasciola hepatica is a parasitic trematode that has a major impact on livestock production and human health. Control of F hepatica is difficult and relies on anthelmintics, particularly triclabendazole, due to its efficacy against both adult and juvenile stages of the parasite. Emergence of triclabendazole-resistant F hepatica populations has been reported in a number of countries, including the UK, but the overall prevalence and distribution of triclabendazole resistance is unknown. In this study, the authors established the presence of reduced efficacy of triclabendazole in sheep flocks in England and Wales, using a validated composite faecal egg count reduction test. Seventy-four sheep farms were sampled from Wales, southwest, northwest and northeast England between Autumn 2013 and Spring 2015. F hepatica eggs were detected in samples from 42/74 farms. Evidence of a lack of efficacy of triclabendazole was detected on 21/26 farms on which the faecal egg count reduction test was completed, with faecal egg count reductions ranging from 89 per cent to 0per cent. Regression analysis suggested that both prevalence of F hepatica and lack of efficacy of triclabendazole were spatially correlated, with higher faecal egg counts and lower percentage reductions on farms located in the northwest of England, and Wales. Overall, the results show that reduced efficacy of triclabendazole is present across England and Wales, with a complete lack of therapeutic efficacy observed on 9/26 farms.