Associations between Theileria orientalis Ikeda type infection and the growth rates and haematocrit of suckled beef calves in the North Island of New Zealand
| Autor: | Kevin Lawrence, W.E. Pomroy, Rebecca Hickson, Kristene Gedye, Lisanne M Fermin, B L Lawrence, C A Hewitt |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Male
Veterinary medicine General Veterinary 040301 veterinary sciences Incidence (epidemiology) 0402 animal and dairy science food and beverages 04 agricultural and veterinary sciences General Medicine Biology 040201 dairy & animal science Animals Suckling Theileriasis 0403 veterinary science Hematocrit Theileria Theileria orientalis parasitic diseases Animals Cattle Female Longitudinal Studies Prospective Studies New Zealand |
| Zdroj: | New Zealand Veterinary Journal. 67:66-73 |
| ISSN: | 1176-0710 0048-0169 |
| DOI: | 10.1080/00480169.2018.1547227 |
| Popis: | AIMS: The principle aim of this study was to examine the association between infection with Theileria orientalis Ikeda type and growth rates of suckled beef calves on four beef farms. In addition, associations between calf sex, sampling time, and individual farm and T. orientalis Ikeda type infection intensity and haematocrit (HCT) were investigated. METHODS: The study was a prospective longitudinal study in which 240 calves from four purposively selected beef farms in the North Island of New Zealand were blood sampled and weighed in late spring, mid-summer and early autumn. Two farms were from high-risk (A and B) and two from low-risk (C and D) tick areas. Blood samples were analysed to determine HCT, and the number of T. orientalis Ikeda type organisms/µL of blood (infection intensity) using a quantitative PCR assay. A calf was defined as infected if >415 organisms/µL were detected in a blood sample. Linear mixed models were used to examine associations between infection intensity, mean daily liveweight gain (MDG), HCT, calf sex and time of sampling on the four farms. RESULTS: On Farms A and B nearly all calves were infected at each sampling time, on Farm C T. orientalis Ikeda type infection in suckled beef calves. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|