17 research outputs found
Ostertagia spp., rumen fluke and liver fluke single- and poly-infections in cattle: an abattoir study of prevalence and production impacts in England and Wales
This study aims at investigating the occurrence, risk factors and production impacts on beef carcassparameters of three of the most important cattle helminth infections in England and Wales. Abomasa, reticulorumens and livers from healthy cattle were collected and examined post-mortem quarterly over a one year period in an abattoir in South-West England. Specific viscera from 974 cattle were collected,examined and scored for Ostertagia spp., adult rumen fluke and liver fluke lesions/presence. A total of89%, 25% and 29% of the carcasses had lesions/presence of Ostertagia spp., rumen fluke and liver fluke, respectively, and 39% had presence of helminth co-infection. Animal demographic and carcass parameters associated with helminth infections were investigated using multi level multinomial and multilevel linear mixed models respectively. After adjusting for other factors, significant differences in the distribution of helminth infections were observed among cattle by type of breed, animal category (cow, heifer, steer and young bull), age, season and concurrent helminth infections. Compared to carcasses free of helminths, carcasses presenting solely Ostertagia Spp. lesions or adult rumen fluke had significantly lower cold carcass weight (coef.: −30.58 [−50.92;−10.24] and −50.34 [−88.50;−12.18]) and fat cover-age (coef.: −3.28 [−5.56;−1.00] and −5.49 [−10.28;−0.69]) and carcasses presenting solely liver flukelesions had significantly lower conformation grade (coef.: −3.65 [−6.98;−0.32]). Presence of helminth poly-infections was negatively associated with cold carcass weight
What is the global economic impact of Neospora caninum in cattle - the billion dollar question
Neospora caninum is regarded as one of the most important infectious causes of abortions in cattle worldwide, yet the global economic impact of the infection has not been established. A systematic review of the economic impact of N. caninum infections/abortions was conducted, searching PubMed with the terms ‘cattle’ and ‘Neospora’. This yielded 769 publications and the abstracts were screened for economically relevant information (e.g. abortion prevalence and risk, serological prevalence). Further analysis was restricted to countries with at least five relevant publications. In total, 99 studies (12.9%) from 10 countries contained data from the beef industry (25 papers (25.3%)) and 72 papers (72.8%) from the dairy industry (with the remaining two papers (2.0%) describing general abortion statistics). The total annual cost of N. caninum infections/abortions was estimated to range from a median US 546.3 million impact per annum in the US dairy population. The estimate for the total median N. caninum-related losses exceeded US 2.380 billion. Nearly two-thirds of the losses were incurred by the dairy industry (US 1,600.00, while on beef farms these costs amounted to just US 20.00 for dairy and less than US 110.00 and US $40.00, respectively, for N. caninum-infected pregnant dairy and beef cows. This estimate of global losses due to N. caninum, with the identification of clear target markets (countries, as well as cattle industries), should provide an incentive to develop treatment options and/or vaccines.Michael P. Reichel, M. Alejandra Ayanegui-Alcérreca, LuÃs F.P. Gondim, John T. Elli
Gamma interferon production correlates negatively with plasma levels of pregnancy-associated glycoprotein-1 (PAG-1) during gestation in dairy cows naturally infected with Neospora caninum
Gamma interferon (IFN-γ) production has been ascribed a role in protecting cows infected with Neospora caninum against abortion. The present study analyzes the interaction between IFN-γ production and levels of plasma pregnancy-associated glycoprotein-1 (PAG-1), as a marker of placental/fetal well-being, throughout gestation in naturally Neospora-infected dairy cows. Data were obtained from 88 pregnant cows from two herds: 62 seropositive and 26 seronegative for the parasite. Blood sample collection was performed on days 40, 90, 120, 150, 180 and 210 of gestation.
Plasma was tested for antibodies against N. caninum, PAG-1 and IFN-γ. Twenty five (28.4%) pregnancies were recorded after AI using Holstein-Friesian semen (19 in seronegative and 6 in seropositive animals), and 63 (71.6%) after AI using Limousin semen (7 in seronegative and 56 in seropositive animals). Gamma interferon was detected in the plasma of 14 (22.6%) of the 62 Neospora-seropositive cows and could not be detected in any of the 26 seronegative animals. All 14 cows producing IFN-γ became pregnant by using Limousin semen. Our GLM repeated measures showed no effect of herd, lactation number, milk production at the time of pregnancy diagnosis and Neospora-seropositivity on plasma PAG-1 concentrations. Significant positive effects of both the day of gestation (P<0.0001) and interaction between day of gestation and breed of sire (P = 0.001) on PAG-1 values were registered. Cows carrying twins had higher (P = 0.002) PAG-1 concentrations throughout gestation than cows carrying singletons. Interactions between breed of sire and Neospora-seropositivity (P<0.0001), and between IFN-γ production and Neospora-seropositivity (P = 0.04) were also detected. Thus, Neospora-seronegative cows inseminated with Limousin and Neospora-seropositive cows with no IFN-γ production, exhibited higher PAG-1 concentrations throughout gestation than seropositive cows inseminated with Limousin semen and producing IFN-γ, respectively. Our data indicate that production of IFN-γ correlates negatively and, the production of antibodies against N. caninum is uncorrelated with plasma PAG-1 concentrations during gestation in Neospora-infected dairy cows. Our results also suggest that augmented Th1 cell-mediated immunity is related to a lower risk of abortion and therefore higher resistance to the parasite in cows inseminated with Limousin versus Holstein-Friesian semen
Different humoral mechanisms against Neospora caninum infection in purebreed and crossbreed beef/dairy cattle pregnancies
The antigen-specific IgG subclass response may be a convenient indicator of the underlying
nature of T helper cell regulation. The aim of the present study was to identify possible
differences in Neospora caninum-specific total plasma IgG, IgG1 and IgG2 antibody levels
in purebreed and crossbreed pregnancies throughout gestation in beef and dairy cattle
chronically infected with N. caninum. Comparisons were also made between aborting and
non-aborting dams. The population examined comprised 96 pregnant parous cows seropositive
for N. caninum. Plasma antibodies were determined on Days 90, 120, 150, 180 and 210
of gestation or until abortion. Of the 96 pregnancies examined, 12 ended in abortion. None
of the 14 Holstein-Friesian (HF) cows inseminated with HF semen (HF–HF group) aborted,
whereas 6 (11.0%) of the 54 HF cows inseminated with Limousin semen (HF-L group) and
6 (21.4%) of the 28 Rubia Gallega (RG) beef cows inseminated with RG semen (RG–RG
group) aborted. In the 84 non-aborting cows, a significant positive effect of gestation day
was observed on total IgG, IgG1 and IgG2 antibodies levels (P < 0.0001 for the three variables).
In RG–RG cows, significantly higher levels of IgG (P = 0.003; d.f. = 2; F-value = 6.41),
IgG1 (P < 0.001; d.f. = 2; F-value = 10.55) and IgG2 (P = 0.004; d.f. = 2; F-value = 5.82) antibodies
against N. caninum were recorded throughout gestation compared to the other groups,
whereas the levels of these antibodies were significantly lower in HF–HF on Days 180 and
210 of gestation. In aborting cows, significantly lower IgG (P = 0.001; d.f. = 1; F-value = 25.21)
and IgG2 (P = 0.001; d.f. = 1; F-value = 20.39) antibody levels were observed in the RG–RG
cows compared to the HF-L cows, whereas no significant effect on IgG1 antibody levels was
detected in the two groups with aborting animals (RG–RG and HF-L). Our findings indicate
that humoral mechanisms against N. caninum infection and abortion differ in purebreed
pregnancies and crossbreed pregnancies in beef/dairy cattle
Seroprevalence and risk factors of Neospora caninum
This study aimed to determine the frequency of antibodies to Neospora caninum in domestic sheep raised in Henan province, central China. Serum samples from 779 domestic sheep were collected from March 2015 to May 2016, and antibodies to N. caninum were evaluated using an enzyme-linked immunosorbent assay (ELISA). The results showed an overall IgG positive rate of 7.32% (57/779). The risk factors significantly related to seropositivity to N. caninum in sheep were the age, the presence of dogs, and the rearing system. This is the first report of N. caninum infection and associated risk factors in domestic sheep in central China
First detection of anti- Besnoitia spp. specific antibodies in horses and donkeys in Italy
Dynamics of anti-Neospora caninum antibodies during gestation in chronically infected dairy cows
The dynamics of antibody production against Neospora caninum during the gestation period was examined in chronically
infected dairy cows. Data were obtained from 86 pregnant parous dairy cows, 21 of which had suffered abortion. The cows belonged
to two herds in which a diagnosis of N. caninum infection had been previously confirmed in aborted foetuses. Pregnancy diagnosis
and blood collection were performed on post-insemination Days 40, 90, 120, 150, 180, 210, and at parturition or until the time of
abortion detection. Blood plasma was tested for antibodies against N. caninum using ELISA. The non-aborting cows were divided
into two groups according to whether their antibody values in the second half of gestation had increased or not, while aborting cows
were classified as those showing an antibody peak before abortion or those not showing a pre-abortion peak. Differences in antibody
values throughout pregnancy in each group of non-aborting and aborting cows were analysed by GLM repeated measures of
analysis of variance. While 32 non-aborting cows (49%) showed a significant and consistent increase in anti-Neospora antibody
values during the second half of gestation, antibody values in the remaining 33 non-aborting cows were practically constant
throughout gestation. An antibody peak around abortion was observed in 11 aborting cows (52%), while antibody values in the
remaining 10 aborting cows were similar before and at abortion. Seroprevalence fluctuations, defined as seronegative blood samples
at some point during the gestation period, were, furthermore, observed in 2 aborting and 11 non-aborting cows. Our results indicate
two clearly distinguishable types of humoral immune dynamics throughout gestation: an increased or flat production of antibodies
during the second half of gestation in non-aborting animals and before abortion in aborting cows. The observation that some
Neospora-infected dams can exhibit negative antibody values at any time during gestation, particularly at parturition or abortion,
prompts future studies designed to explore the use of new ELISA strategies at the farm level