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Ha H.J.,Massey University | Banda M.,Massey University | Banda M.,Zambia Institute of Animal Health | Howe L.,Massey University | Gartrell B.D.,Massey University
Avian Diseases

Blood samples were collected from 65 free-ranging birds from six species in the southern North Island of New Zealand. Sera from the birds were tested for the presence of avipoxvirus (APV) antibodies by enzyme-linked immunosorbent assay (ELISA), and blood cells from 55 birds were also tested for Plasmodium spp. by PCR. Forty-five birds (69.2%) tested seropositive to APV. Song thrushes (Turdus philomelos) presented the highest seroprevalence at 100% (4/4), followed by Eurasian blackbirds (Turdus merula) (96.86%, 31/32), chaffinches (Fringilla coelebs) (54.55%, 6/11), starlings (Sturnus vulgaris) (25%, 3/12), greenfinches (Carduelis chloris) (25%, 1/4), and European goldfinches (Carduelis carduelis) (0%, 0/2). Plasmodium spp. DNA was detected in 15/55 birds (27.3%), including 11 Eurasian blackbirds, one song thrush, and three starlings. Eight Eurasian blackbird isolates (73%) grouped within the subgenus Novyella. Two Eurasian blackbird isolates and the song thrush isolate clustered within a different group with previously reported lineages LINN1 and AFTRU5. In addition, all three starling isolates clustered within the well-characterized lineage Plasmodium (Huffia) elongatum GRW06. All Plasmodium-positive Eurasian blackbirds and the song thrush were seropositive to APV, whereas only 67% of Plasmodium-positive starlings showed evidence of previous exposure to APV. A significant relationship between birds seropositive to APV and birds infected by Plasmodium spp. was observed (χ2 = 5.69, df = 1, P = 0.0086). To the authors' knowledge this is the first report describing the seroprevalence of APV and its association with Plasmodium spp. infection in introduced bird species in New Zealand. © American Association of Avian Pathologists. Source

Mizutani F.,The Lolldaiga Institute | Kadohira M.,Obihiro University of Agriculture and Veterinary Medicine | Phiri B.,Zambia Institute of Animal Health
Animal Science Journal

This study aimed to examine livestock-wildlife interactions at the micro level and to quantify how resources are shared in joint land use by comparing the monitoring records collected on the Lolldaiga Hills ranch in Laikipia, Kenya from 1990s onwards. Livestock and wildlife distributions together with existing water points were geo-referenced; by air and road census total animal biomass densities were estimated. Through 38-h observation at a water point, livestock-wildlife interaction was recorded. During this period, water decline has been identified as an acute factor for farming and ranching. It was found that distributions of livestock and wildlife were related to water and pasture availability during the severe drought in 2009. Although there is seasonality in densities of both livestock and wildlife populations, results of air census indicated that the stable resident populations of wildlife have resided on the ranch. In this paper, we describe how livestock and wildlife interact at a water point and on pastures on the ranch in terms of biomass density. Such resources shared at different times need to be investigated further as a key factor to improve productivity of livestock-wildlife joint land use. © 2011 The Authors. Animal Science Journal © 2011 Japanese Society of Animal Science. Source

Phiri B.J.,Zambia Institute of Animal Health | Phiri B.J.,Massey University | Benschop J.,Massey University | Stevenson M.,Massey University | And 3 more authors.
Tropical Animal Health and Production

A combination of survival and spatial analyses was applied to a dataset containing cattle mortalities on smallholder dairy farms in two separate regions (Tanga and Iringa) of Tanzania. Cattle mortality data for the year 1998 were collected retrospectively during the period January to April 1999. The objectives of the current study were, firstly, to quantify the hazard of mortality and, secondly, to investigate whether there was a spatial pattern in the variation that was unaccounted for in the hazard of mortality. A Cox regression model with farm as a frailty term was used to quantify the hazard of mortality. Geostatistical techniques were used to explore the first- and second-order spatial distribution of the farm frailty term. A total of 1,790 cattle from 400 randomly sampled smallholder dairy farms were included in the study. The overall mortality incidence rate for the study was 11.8 per 100 animal years (95% CI 10.0-13.8). The hazard of mortality for male cattle was 2.4 (95% CI 1.7-3.4) times higher than that of female cattle. There was evidence of a first-order spatial pattern, i. e., a tendency for farms with higher frailty to aggregate. © 2011 Springer Science+Business Media B.V. Source

Phiri B.J.,Massey University | Phiri B.J.,Zambia Institute of Animal Health | Benschop J.,Massey University | French N.P.,Massey University
Preventive Veterinary Medicine

This article presents the first systematic review of the causes and factors associated with morbidity and mortality, on smallholder dairy farms in Eastern and Southern Africa. It was conducted in August 2007. Primary studies on causes of morbidity and mortality on smallholder dairy farms in the region were identified, examined and descriptive information extracted. Electronic (CAB Abstracts, PubMed, ScienceDirect and Web of Science) and non-electronic databases were used to identify and retrieve the primary studies. The retrieval process included all types of study designs with no restriction on the year of publication and language. Mastitis, tick-borne diseases (TBDs), tick infestation and diarrhoea were among the most commonly documented causes of morbidity. TBDs, diarrhoea and trypanosomiasis were among the most commonly documented causes of mortality; however, a substantial number of mortalities with undiagnosed causes were also reported. Factors ranked as most negatively associated with mastitis were residual calf suckling and increased water availability on the farm while use of common udder towel was the factor most positively associated with mastitis. Zero-grazing was ranked as the factor most negatively associated with TBDs while age was most positively associated. More intervention studies are recommended in the region to better identify animal health constraints and their associated risk factors. © 2010 Elsevier B.V. All rights reserved. Source

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