9 research outputs found
PCR diagnosis of tick-borne pathogens in Maharashtra state, India indicates fitness cost associated with carrier infections is greater for crossbreed than native cattle breeds
Tick-borne pathogens (TBP) are responsible for significant economic losses to cattle production, globally. This is particularly true in countries like India where TBP constrain rearing of high yielding Bos taurus, as they show susceptibility to acute tick borne disease (TBD), most notably tropical theileriosis caused by Theileria annulata. This has led to a programme of cross breeding Bos taurus (Holstein-Friesian or Jersey) with native Bos indicus (numerous) breeds to generate cattle that are more resistant to disease. However, the cost to fitness of subclinical carrier infection in crossbreeds relative to native breeds is unknown, but could represent a significant hidden economic cost. In this study, a total of 1052 bovine blood samples, together with associated data on host type, sex and body score, were collected from apparently healthy animals in four different agro-climatic zones of Maharashtra state. Samples were screened by PCR for detection of five major TBPs: T. annulata, T. orientalis, B. bigemina, B. bovis and Anaplasma spp.. The results demonstrated that single and co-infection with TBP are common, and although differences in pathogen spp. prevalence across the climatic zones were detected, simplistic regression models predicted that host type, sex and location are all likely to impact on prevalence of TBP. In order to remove issues with autocorrelation between variables, a subset of the dataset was modelled to assess any impact of TBP infection on body score of crossbreed versus native breed cattle (breed type). The model showed significant association between infection with TBP (particularly apicomplexan parasites) and poorer body condition for crossbreed animals. These findings indicate potential cost of TBP carrier infection on crossbreed productivity. Thus, there is a case for development of strategies for targeted breeding to combine productivity traits with disease resistance, or to prevent transmission of TBP in India for economic benefit
Mean (+/- standard error) body condition of female cattle of different breed types (cross breeds upper panel, native breeds lower panel) in relation to apicomplexan and <i>Anaplasma</i> spp. infection status.
<p>The graph shows crossbreeds in the upper panel and native breeds in the lower panel.</p
Output from MCMCglmm testing the impact of infection status, age and breed type on body condition in female cattle.
<p>Data came from subset of female cattle where native and crossbreeds cohabited the same farms.</p
PCR screening results for different parasites in four different agro-climatic zones of Maharashtra state, India.
<p>Nb. Column totals for each individual TBP include all types of infections (e.g. 7 positive T annulata may have occurred singly, or in co-infections with other parasites).</p
Output from logistic regression of factors impacting prevalence of different parasites in cows in Maharashtra.
<p>Output from logistic regression of factors impacting prevalence of different parasites in cows in Maharashtra.</p
Proportion of female cattle (+/- standard error) infected with any apicomplexan parasite according to acaricide treatment.
<p>The data for this analysis comes from a subset of farms where both breed types were kept.</p
Proportion of TBP co-infections (+/- standard error) in female cattle by age class and breed type (crossbred upper panel, native breed lower panel).
<p>The data for this analysis comes from a subset of farms where both cattle breed types were kept.</p
Mean (+/- standard error) body condition of female cattle of different breed types (cross breeds upper panel, native breeds lower panel) in relation to apicomplexan and <i>Anaplasma</i> spp. infection status.
<p>The graph shows crossbreeds in the upper panel and native breeds in the lower panel.</p
List of number of samples collected from various district and zone.
<p>List of number of samples collected from various district and zone.</p