Persistent effect of ivermectin against Haemonchus contortus in goats.

A study on the efficacy of ivermectin in goats and its persistent effect against H. contortus is presented. Eighteen goats naturally infected with H. contortus were used in the study.Ten goats were given a single sc injection of ivermectin at a dose rate of 200 micro g/kg, while the remaining 8 goats acted as untreated controls. Faecal samples were taken 2 days prior to treatment and for several days after treatment for up to 33 days. The ova counts of treated goats were reduced to zero 24 h after treatment. This ova count remained zero until day 29 post- treatment when only one goat had H. contortus ova in its faeces. The other treated goats did not show evidence of worm burden up to 33 days post-treatment

Abiotic and biotic control of Argulus sp. among goldfish (Carassius auratus)

Argulus spp. are branchiuran crustaceans with a direct life cycle, therefore current aquaculture practice with a high density of potential hosts provides ideal conditions for effective transmission of this obligate ectoparasite. Chemicals are usually used to treat parasite infestation of fishes. However chemical treatments result in side-effects including environmental pollution, parasite resistance, alteration of zooplankton ecosystem, changes in certain hematological parameters and contamination of host organs. Thus there is a need for alternative measures to control parasitic diseases in the aquaculture industry. To date, there are no studies reported on biological control of fish lice, in particular the use of Thai silver barb (TSB) (Pontius gonionotus) to control Argulus population. In this study, the effectiveness of abiotic and biotic control methods for an ectoparasite infestation was examined. Therefore, an abiotic study was designed firstly to examine the effect of water current on parasite abundance and incidence of the fish lice, Argulus sp. among captive goldfish (Carassius auratus). Secondly, in a biotic study, the effectiveness of using TSB to reduce the parasite number was investigated and thirdly, to compare both the abiotic and biotic control methods in their effectiveness to reduce parasite number. The mean abundance and incidence of the ectoparasite, Argulus sp., on goldfish was measured. In the abiotic study goldfish infected with Argulus sp. was mixed with other susceptible goldfish hosts and kept in tanks with fast flowing or stagnant water. There was no difference in the parasite mean abundance and incidence between fast flowing and stagnant water. Thai Silver Barb which is a predator of the Argulus was introduced to the parasite infected goldfish for the biotic study. The mean parasite abundance was significantly lowered (P<0.05) after introducing the predator TSB into the tanks. Combination of both control methods did not further improve the effectiveness in reducing Argulus population. Hence this study showed that utilizing this method of biotic control among goldfish is definitely a future control solution. This study also showed that water current seemed to reduce Argulus transmission and population. The predator effect of TSB was lessened by the fast flowing current. The major finding in this study indicated that TSB was a very effective biological control where with only two TSBs, 96% of Argulus was removed in less than 24 hours. The number of TSB used in the biotic control did not affect the predator efficiency. It is suggested that the biological control tested in this study can be used to reduce Argulus population among goldfish in aquaculture settings

Status and effect of fascioliasis in buffaloes kept extensively in a farm in Sabah, Malaysia

This study was carried out to determine the status and possible effect of fascioliasis among buffaloes kept extensively in the Buffalo Breeding and Research Centre at Telupid, Sabah, Malaysia. Forty adult four-year old buffaloes from a herd of 250 animals were selected for the study. Faecal samples were obtained from the animals and subjected to sedimentation technique to determine the presence of Fasciola sp. ova. Blood sample from each animal was collected into a plain tube and serum obtained for determination of AST and albumin concentrations. The helminth burden was determined in these animals to obtain information on the prevalence of gastrointestinal helminthiasis in the farm. None of the faecal samples had Fasciola sp. ova. However, the serum ALT concentrations in these animal were significantly (p<0.05) higher than the upper limit of the reference range. The study suggests that that the buffaloes may have been exposed to diseases that caused liver damage

Management practices affecting helminthiasis in goats

The study was conducted to investigate the effects selected management practices have on worm burden in goats as reflected by faecal egg counts. The faecal examination of six goat farms for the quantitative presence of strongyles was conducted in Terengganu. A questionnaire was developed and directed to six farmers on the management practices adopted on their farms. The management practices selected in the study were grazing time, mineral block supplementation, type of drug used, breed, and source of animal, grass type, additional feed, and drenching personnel. The data analysis was done through systematic approaches using t-test, Spearman correlation and ANOVA. Afternoon grazing reduced the mean FEC nearly five-fold compared to morning grazing and mineral block supplementation reduced FEC two-fold compared to unsupplemented goats (P<0.05)

Epidemiology of Trypanosoma evansi Infection in Crossbred Dairy Cattle in Malaysia

An investigation into the epidemiology of Trypansoma evansi infection in crossbred dairy cattle was conducted for a period of 12 months on a dairy cattle farm in Penninsular Malaysia. The prevalence of parasitaemia was highest in lactating animals (13.4%), followed by those in the dry herd (8.8%), late pregnant animals (8.1%), early pregnant animals (4.7%), calves (0.3%) and heifers (0.2%). The prevalence of antigenaemia was highest in the lactating animals (54.7%), followed by that in dry animals (53.7%), heifers (51.1%), late pregnant animals (47.7%), early pregnant animals (46.5%) and calves (24.2%)

Helminth control for small ruminants in Malaysia

This paper reviews gastrointestinal helminths present in small ruminants in Malaysia and their pathogenic effects, studies on resistance to anthelmintics and worm control options which include grazing management, anthelmintics, medicated feed blocks, medicinal plants, breeding and biological control

Control of haemonchosis in Malaysian goats with closantel

The therapeutic and prophylactic effects of closantel on natural infections with Haemonchus contortus were studied in goats in Peninsular Malaysia. Closantel was highly effective against H. contortus, either at a subcutaneous (s.c.) injection of 5.0 mg kg- ~ body weight (100%), or in an oral drench mixture with mebendazole at a dose of 10.0 mg kg-(99.2%), as indicated by faecal egg counts. H. contortus larvae were absent from faecal cultures for 5, 6 and 7 weeks following treatment with s.c. injections of closantel at doses of 2.5 mg kg- 1, 5.0 mg kg- ~ and 10.0 mg kg- 1 respectively, and for 6 weeks after treatment with closantel at 10.0 mg kg -1, given orally. Through its sustained activity, closantel not only prevented reinfection with H. contortus but also caused a dramatic reduction in pasture contamination. The potential utility of closantel in the strategic control of haemonchosis in goats, and as an alternative treatment for benzimidazoles and levamisole resistant H. contortus strains, is discussed

Anthelmintic resistance in goats in Peninsular Malaysia

Ninety-six randomly selected farms, located throughout peninsular Malaysia, were surveyed for goat nematodes resistant to benzimidazoles (BZ). On 33 farms BZ resistance was demonstrated by means of an egg hatch assay. Haemonchus contortus was found to be the main species involved in anthelmintic resistance. There was a positive association between the frequency of anthelmintic treatments on a farm and the presence of benzimidazole resistance. To assess the value of the egg hatch assay, faecal egg count reduction (FECR)tests were also performed on 20 farms. On six farms the LD50 of thiabendazole (TBZ)was less than 0.10/~g ml- 1 and the FECR higher than 95% and on ten farms with an LD50 TBZ of over 0.10/tg ml- ~ a FECR of less than 95% was measured. On four farms the FECR was less than 95%, although the egg hatch assay showed LD50 TBZ values of less than 0.10 ~g ml- t and on two of these three farms a controlled efficacy test confirmed the presence of BZ resistant H. contortus. From these results it can be concluded that the egg hatch assay underestimated the true incidence of benzimidazole resistance. Levamisole resistance was detected with a FECR test on two of ten farms investigated

Presence of parasite larvae in goat manure for use as fertiliser

Some livestock farmers utilise goat manure to fertilise grasses grown for animal feed, which may lead to parasitic diseases caused by strongyle infection. Therefore, the presence of strongyle larvae in manure needs to be determined. In this study, goat faeces containing strongyle eggs were deposited into five replicates for daily sampling throughout 23 days and subjected to faecal egg count, larvae identification and enumeration. Absence of eggs was detected on Day 4 when the infective larvae of Haemonchus contortus, Trichostrongylus sp. and Oesophagostomum sp. were found. Larvae counts reached a maximum of 164 larvae on Day 8 and were negligible by Day 14, by which time the manure can be used as fertiliser to grow forage crops for animal feed