Prevalence and sequence-based identity of rumen fluke in cattle and deer in New Caledonia

An abattoir survey was performed in the French Melanesian archipelago of New Caledonia to determine the prevalence of paramphistomes in cattle and deer and to generate material for molecular typing at species and subspecies level. Prevalence in adult cattle was high at animal level (70% of 387 adult cattle) and batch level (81%). Prevalence was lower in calves at both levels (33% of 484 calves, 51% at batch level). Animals from 2 of 7 deer farms were positive for rumen fluke, with animal-level prevalence of 41.4% (29/70) and 47.1% (33/70), respectively. Using ITS-2 sequencing, 3 species of paramphistomes were identified, i.e. Calicophoron calicophorum, Fischoederius elongatus and Orthocoelium streptocoelium. All three species were detected in cattle as well as deer, suggesting the possibility of rumen fluke transmission between the two host species. Based on heterogeneity in ITS-2 sequences, the C. calicophorum population comprises two clades, both of which occur in cattle as well as deer. The results suggest two distinct routes of rumen fluke introduction into this area. This approach has wider applicability for investigations of the origin of rumen fluke infections and for the possibility of parasite transmission at the livestock-wildlife interface

Comparison of tick resistance of crossbred Senepol × Limousin to purebred Limousin cattle

International audienceThe comparison of resistance to natural tick infestation by Rhipicephalus microplus (Canestrini, 1887) of crossbred Senepol × Limousin and purebred Limousin cattle was investigated. The Senepol breed, originated from St Croix Island in the Caribbean is considered as a Bos taurus breed adapted to tropical conditions. Despite its B. taurus genetic background, it is believed to have a good tick resistance, but this resistance has never been assessed previously. Tick counts under natural infestation were carried out to investigate the difference of susceptibility between crossbred Senepol × Limousin and purebred Limousin cattle. Mixed-effect models were used to assess the effect of the breed on the number of ticks. Results show that Senepol × Limousin are five times less infested by ticks than purebred Limousin. These results underline the opportunity to use Senepol cattle for crossing with susceptible B. taurus breeds in tick infested areas, to combine tick resistance with beef production abilities

Binomial general linear mixed model animal-level data output (i).

<p>Binomial general linear mixed model animal-level data output (i).</p

Binomial general linear mixed model rumen fluke-level data output (i).

<p>Binomial general linear mixed model rumen fluke-level data output (i).</p

Geographical distribution of inspected cattle and deer herds in New Caledonia.

<p>Pie charts indicate the inter-herd prevalence of paramphistomes in cattle for each municipality, where the size of the pie chart is proportional to the number of herds inspected from that municipality. Stars indicate municipalities with deer and colour indicates whether or not paramphistomes were observed in deer from that municipality.</p

Animal-level prevalence for cattle slaughtered in New Caledonia in 2013.

<p>Animal-level prevalence for cattle slaughtered in New Caledonia in 2013.</p

Phylogenetic tree showing the topological relationship between mtDNA rRNA-Thr/Cox1 fragments of <i>Calicophoron calicophorum</i> from cattle (white dots, C) and deer (black dots, D) using <i>Calicophoron daubneyi</i> as outgroup.

<p>Numbers along branches indicate bootstrap support (values over 50 shown). Where available, data on region of origin is included (N = North; NE = North-East; E = East; SW = South West; W = West; NW = North West).</p

Batch-level prevalence for cattle slaughtered in New Caledonia in 2013.

<p>Batch-level prevalence for cattle slaughtered in New Caledonia in 2013.</p

Distribution of animal-level prevalence of paramphistomes in batches of cattle at slaughter by age group and observation period.

<p>Animal-level prevalence is shown in categories, where by the first value of the range is excluded and the last value is included. Negative batches are shown as a separate category at animal-level prevalence of zero.</p