Prevalence of
Coccidia in French Calves: Results of Several Surveys
A. RICHARD (1),,C. RIZET (2),L.
LARAILLET (3)
(1) Alpharma, Silic 411, 3 Impasse de la Noisette,
91374 Verrières le Buisson,France,
alain.richard@alpharma.com
(2) Cabinet vétérinaire, Rue du Général
de Gaulle, 03130 Le Donjon,France
(3) Centre Lait, 1 Bd du Vialenc , 15000 Aurillac,France
Coccidia are parasites
which have an underestimated economic importance in
ruminants.
The aim of the surveys was to have a better knowledge
of oocyst shedding in dairy calves during weaning
and in sucking calves aged 4 to 7 weeks.
On farms where animals did not show clinical signs
of coccidiosis, faecal samples were taken from 2 to
10 calves. The 4 labs, each of which participating
in one of the 4 surveys, all used an iodomercurate
flotation method. Identification of the different
species of coccidia was carried out by examining the
oocysts.
3 surveys were performed on milk calves.
In 1997, on a total of 338 calves tested on 66 farms
all over France, 94 % of the calves and 61 % of the
farms were positive, Eimeria Bovis being observed
in 25 % of the cases, E.subspherica in 21 %, E.zuernii
in 18 %, and finally auburnensis in12 %.
In 2001, on a total of 54 farms in the Massif Central
region, 51 were positive, 47% of them with an oocyst-per-gram
count between 100 and 1,000 and 6 % with one greater
than 1,000.
In 2002, in a survey carried out in Brittany (western
France) the 18 farms assessed were all positive (96
heifers) with 8 % of the calves shedding between 1,000
and 10,000 oocysts per gram. Eimeria bovis was found
on 18 farms and on 55 % of the calves, followed by
E.alabamensis, then subspherica and finally zuernii
and auburnensis.
The survey on sucking calves was carried out in the
Allier region (central France) using groups of 7 calves
aged 4 to 7 weeks from 10 farms. There again all farms
were positive and the oocyst count was significant
: 14 calves out of 70 shed between 1,000 and 10,000
oocysts per gram of faeces and 5 calves out of 70
shed between 10,000 and 100,000.
The various species of coccidia were frequently associated
on a same animal and on the farms. Thus, in the sucking
calves survey, all farms hosted 3 different species
(up to 5 in heifers in 2002).
These surveys carried out in different regions, by
different laboratories, show that coccidia are present
on the almost total of calves farms.
They provide a better understanding of growth improvements
obtained on several farms with decoquinate (a synthetic
molecule active on certain protozoa: coccidia, cryptosporidia,
toxoplasma…and having no antibiotic action),
and this, even in the absence of clinical signs of
the disease.