Population genetic structure of Ascaridia galli of extensively raised chickens of South Africa.

Ascaridia galli is one of the most common nematode affecting chickens. This study characterized A. galli parasites collected from South African village chickens of Limpopo (n=18) and KwaZulu-Natal (n=22) provinces using the 510bp sequences of cytochrome C oxidase subunit 1 gene of the mitochondrial DNA. Fourteen and 12 polymorphic sites were observed for Limpopo and KwaZulu-Natal sequences, respectively. Six haplotypes were observed in total. Haplotype diversity was high and ranged from 0.749 for Limpopo province to 0.758 for KwaZulu-Natal province isolates. There was no genetic differentiation between A. galli from Limpopo and KwaZulu-Natal provinces. The six South African haplotypes were unique compared to those published in the GeneBank sampled from Hy-line chickens raised under organic farming in Denmark. The utility of cytochrome C oxidase subunit 1 gene as a potential genetic marker for studying A. galli in village chicken populations is presented.

A study of some infectious causes of reproductive disorders in cattle owned by resource-poor farmers in Gauteng Province, South Africa.

Two hundred and thirty-nine cattle from Gauteng Province in South Africa were tested for various pathogens causing reproductive diseases includingbovine viral diarrhoea/mucosal disease (BVD/MD) virus, infectious bovine rhinotracheitis/infectious pustular vulvovaginitis (IBR/IPV) virus, Neospora caninum and Brucella abortus usingvarious tests. For BVD/MD virus, 49.37% tested positive, 74.47% for IBR/IPV virus, 8.96% for Neospora caninum and 3.8% for Brucella abortus. The result for Brucella abortus is higher than the national average, possibly due to the small sample size. A high seroprevalence of antibodies to both BVD/MD virus and IBR/IPV virus was evident. These 2 viruses should be considered, in addition to Brucella abortus, when trying to establish causes of abortion in cattle. The clinical significance of Neospora caninum as a cause of abortion in Gauteng needs further investigation. One hundred and forty-three bulls were tested for Campylobacter fetus and Trichomonas fetus, and a low prevalence of 1.4% and 2.1% respectively was found in this study. The clinical implications of these findings are discussed.

Parasitic helminths of veterinary importance in cattle, sheep and goats on communal farms in the northeastern Free State, South Africa.

The purpose of the study was to record and determine intensities, seasonal incidence and distribution of helminth parasites of veterinary importance that occur in cattle, sheep and goats in the northeastern Free State. The study was conducted at Harrismith and Kestell and in Qwa-Qwa from March 2000 to May 2001. Cattle of various breeds (including Bonsmara, Simmentaler and Friesian), Merino sheep and Angora goats were sampled. Faecal samples were analysed using the McMaster and Visser sieve techniques for egg counts and faecal cultures for 3rd-stage nematode larvae identification. Haemonchus and Oesophagostomum were the dominant nematode genera found to be infecting the animals. The socioeconomic status of the farmers in the study area was determined through a questionnaire survey aimed at recording their management strategies. It indicated that 81% of farmers take care of their livestock by feeding them with supplements. The low to moderate faecal egg counts from cattle showed that helminth infections in this region are still under control even though helminthosis seems to be a problem in small-stock, since EPG counts of more than > 1000 were found. Cattle farmers in this region are encouraged to continue with good animal husbandry practices that have ensured that helminth infections rates are kept low. Small-stock farmers are, however, encouraged to control helminth infections in their sheep and goats by anthelmintic treatment.