Dairy goat doe-kid rearing systems: Farmers' motivations and a description of practices, benefits and drawbacks.

In French dairy goat systems, kids are generally separated from their mother does shortly after birth. The main drivers of this practice are related to health-especially the prevention of the Caprine Arthritis Encephalitis Virus (CAEV) transmission-and economics. However, the separation of young ruminants from their does is being increasingly questioned by society and has raised concerns about the satisfaction of their behavioral needs. Some farmers choose to leave their female kids with their does. The aims of this study were to understand their motivations for leaving kids with their does, to describe how kids are reared in this case and how farmers perceive different aspects of the impacts of this practice. Individual semi-structured interviews were carried out with 40 farmers who had implemented the kids-with-does practice for at least one year. Compared with the national database describing the French population of dairy goat farmers, the characteristics of the interviewed farmers differed from those of the general population. They were younger and had done longer studies. Their farms were smaller, mainly with rare breeds and milk was mainly processed on-farm under an organic certification system. They chose to implement this practice for different reasons: ethical considerations, improving integration of kids within the herd, saving time and increasing comfort at work or improving the kids' growth, welfare, and health. The doe-kid rearing contact practices varied greatly between farms, with some kids staying with their does from a period of 45 d to never being separated; furthermore, some kids remained with their does all day, while others remained together part of the day or for a limited time, and daily contact evolved over time. Overall, farmers were satisfied as the benefits quoted were coherent with their motivations to implement this rearing practice. Most have decided to continue the practice, though usually with changes. However, as 40% of them had only 3 years or less of experience of doe-kid rearing, some had not sufficient hindsight into long-term issues such as the transmission of CAEV. It is crucial to tackle challenges associated with this practice, i.e., potentially wild kids, health issues, and economic consequences stemming from a reduction in marketable milk.

Cross-resistance to moxidectin and ivermectin on a meat sheep farm in France.

Resistance to ivermectin and moxidectin was explored by a faecal egg count reduction test in two sheep flocks with suspected anthelmintic resistance. The FECRT confirmed one suspicion, with a mean percentage of reduction in egg excretion within the treated groups of 0% for ivermectin (CI 95%: -228 to 58) and 13% for moxidectin (CI 95%: -152 to 70). This was further explored by a controlled efficacy test. An experimental infection of 18 naïve lambs was set up using infective larvae isolated from this flock (5000 L3/lamb). Compared to the control group, abomasal worm burdens (Teladorsagia circumcincta) were reduced by 90% [CI 95%: 81.5-94.8] and 85% [CI 95%: 72.4-92.2] after ivermectin (p<0.05) and moxidectin (p<0.05) treatment respectively. Again, compared to the control group, there was a reduction for intestinal strongyles (Trichostrongylus colubriformis) of 100% and 99% [CI 95%: 97.5-99.7] for ivermectin and moxidectin respectively. No difference was found between the efficacy of moxidectin and ivermectin. Pharmacokinetic values indicated that the strongyles were submitted to anthelmintic concentrations usually lethal to them. This trial demonstrated the first multiple resistance of ovine strongyles in France.

Cryptosporidium parvum infection and associated risk factors in dairy calves in western France.

This study was conducted to determine the prevalence and risk factors for Cryptosporidium infection in calf neonates on dairy farms in Normandy. Fecal samples were randomly collected between July 2010 and September 2011 from 968 calves (7-21 days old) on 97 farms. Up to 10 calves were selected and sampled per farm, and feces examined for oocysts by microscopy. C. parvum oocyst shedding was scored semi-quantitatively (0-5). A questionnaire about calf-level care and management was completed, and mortality rates were obtained from the French national registration database (BDNI). Bivariable and multivariable analyses of potential risk factors for C. parvum oocyst shedding were conducted using generalized estimating equation (GEE) models (family=Binomial).Overall, 402 out of 968 calves (41.5%) were positive for oocysts, and 25.1% of animals had a shedding score >2. Seven of the 97 farms (7%) were negative for oocysts in all fecal samples. At the time of collection, 375 calves (39%) had diarrhea, and its prevalence strongly correlated with the score for C. parvum oocyst shedding (p<0.0001). The mortality rate at 90 days was significantly greater for calves with high combined scores of diarrhea and shedding. Factors associated with the shedding of C. parvum were the Normande breed (odds ratio=1.49; 95% confidence interval (CI): 0.93-2.37), dispensing of colostrum using a bucket (odds ratio=1.37; 95% CI: 1.00-1.89), treatment with halofuginone (odds ratio=0.46; 95% CI: 0.19-1.15) and feeding with fermented milk (odds ratio=0.32; 95% CI: 0.17-0.63). C. parvum is widespread among calves under 21 days old in dairy herds of western France. Shedding of C. parvum is associated with a high incidence of diarrhea and increased risk of mortality in young calves. This study identified some associated calf-level factors, although further investigations are necessary to determine appropriate measures that farmers and veterinary practitioners should take to reduce the prevalence of C. parvum.

High excretion of Cryptosporidium ubiquitum by peri-parturient goats in one flock in western France.

Cryptosporidium spp. is an important agent of neonatal diarrhoea in goat kids. Little is known about its molecular characterization in adult goats. A longitudinal study was set up to identify the species excreted by adult goats around parturition. Individual faecal samples were collected from 20 pregnant adult goats between 1 and 5 years old in one flock. Samplings began 3 weeks before the estimated kidding date and were done weekly until kidding and for 2 weeks after kidding. Cryptosporidium oocysts were concentrated from 15 g of faeces using a caesium chloride (CsCl) method. Oocyst output was determined using a direct immunofluorescent antibody test (IFAT). Genomic DNA was extracted from each CsCl-concentrated faecal sample positive by IFAT and submitted to a nested PCR-RFLP on the SSU rDNA gene followed by sequencing to identify the isolates at species level. According to their kidding date, goats were sampled between 4 and 8 times. Sixteen goats, out of the eighteen which kidded, were found positive at least at one sampling date. Infection was asymptomatic. Prevalence of excretion was maximal 14 days before kidding with half of the goats excreting oocysts at this date. Excretion was higher before kidding than after kidding. Unexpected levels of excretion were observed with individual oocyst excretion ranging from 6 to 2.5 × 10(5) oocysts per gram of faeces. All isolates were identified as Cryptosporidium ubiquitum.

Molecular characterization of Cryptosporidium isolates from high-excreting young dairy calves in dairy cattle herds in Western France.

Ninety-two Cryptosporidium sp.-positive fecal samples of dairy diarrheic or non-diarrheic calves from 30 cattle herds in Normandy (France) were selected. Here, the aim was to investigate the species of Cryptosporidium excreted as well as the subtypes of Cryptosporidium parvum found in 7-17-day-old dairy calves. Excretion levels were comprised between 2 × 10(4) and 4 × 10(7) oocysts per gram of feces. Here, a nested 18S SSU rRNA PCR associated with sequencing was performed for identification of Cryptosporidium species and revealed the presence of C. parvum in most cases (80/82), except for two animals which were infected with Cryptosporidium bovis. Then, C. parvum samples were submitted to gp60 PCR. For 39 samples from 24 different herds, a multilocus analysis based on four mini-microsatellites loci (MM19, MM5, MSF, and MS9-Mallon) were conducted. These results were combined with sequence analysis of the gp60 to obtain multilocus types (MLTs). Here, C. parvum gp60 genotyping identified three subtypes in the IIa zoonotic allele family: IIaA15G2R1 (88%), IIaA16G3R1 (10%), and IIaA19G2R1 (2%), and we identified 12 MLTs. The MS9-Mallon locus was reported as the most polymorphic (five alleles). The most common MLT was MLT 1 with 15 samples in 10 farms: (MS9-M: 298, MSF: 165, MM5: 264, MM19: 462, and gp60 subtype: IIaA15G2R1). When comparing diarrheic and non-diarrheic fecal samples, no difference was seen for distribution of Cryptosporidium species, C. parvum gp60 subtypes, and MLTs. Here, in a range of oocyst excretion of 10(4)-10(7) opg, both in diarrheic and non-diarrheic calves, infection was mainly due to C. parvum and to the zoonotic subtype: IIaA15G2R1.

Detection of Cryptosporidium oocysts in fresh calf faeces: characteristics of two simple tests and evaluation of a semi-quantitative approach.

The objective of the present study was to evaluate the characteristics of two rapid tests, namely, a faecal smear staining method (Heine staining) and a commercially available immunochromatographic (IC) assay, against a direct immunofluorescent antibody test (IFAT) for the diagnosis of Cryptosporidium infections in 917 faecal samples from calves aged <3 weeks. These rapid tests were performed on non-concentrated faeces using a semi-quantitative approach using a 6-point scale (0-5) for Heine staining according to the number of oocysts per microscopic field, and a 4-point scale (0-3) for the IC assay reflecting the intensity of the positive line compared to the control line. Direct IFAT was performed following a diethyl ether concentration and results were expressed as oocysts per g of faeces (opg). Heine staining showed a sensitivity of 76.7% and a specificity of 90.7%. For faecal samples with ≥ 10,000opg, sensitivity increased to 90.0%. The sensitivity of the IC assay was lower (61.8%) but the specificity was 100%. For faeces with ≥ 100,000opg, the sensitivity of the IC assay reached 81%, indicating some limitation for clinical cryptosporidiosis diagnosis. Additional scoring (1-5) of the Heine staining correlated with the corresponding direct IFAT results, particularly for ranges of 1000 to >1,000,000opg. Additional scoring from 1 to 3 according to the thickness of the sample line for the IC test correlated with increasing levels of Cryptosporidium opg measured by IFAT in the range of 10,000 to >1,000,000opg. In conclusion, both Heine staining and the IC test can be reliably used through a simple semi-quantitative scale for grossly quantifying oocyst output in calf faecal samples.

Multicentric evaluation of a new real-time PCR assay for quantification of Cryptosporidium spp. and identification of Cryptosporidium parvum and Cryptosporidium hominis.

Cryptosporidium is a protozoan parasite responsible for gastroenteritis, especially in immunocompromised patients. Laboratory diagnosis of cryptosporidiosis relies on microscopy, antigen detection, and nucleic acid detection and analysis. Among the numerous molecular targets available, the 18S rRNA gene displays the best sensitivity and sequence variations between species and can be used for molecular typing assays. This paper presents a new real-time PCR assay for the detection and quantification of all Cryptosporidium species associated with the identification of Cryptosporidium hominis and Cryptosporidium parvum. The sensitivity and specificity of this new PCR assay were assessed on a multicentric basis, using well-characterized Cryptosporidium-positive and -negative human stool samples, and the efficiencies of nine extraction methods were comparatively assessed using Cryptosporidium-seeded stool samples and phosphate-buffered saline samples. A comparison of extraction yields showed that the most efficient extraction method was the Boom technique in association with mechanical grinding, and column extraction showed higher binding capacity than extraction methods based on magnetic silica. Our PCR assay was able to quantify at least 300 oocysts per gram of stool. Satisfactory reproducibility between laboratories was observed. The two main species causing human disease, Cryptosporidium hominis and Cryptosporidium parvum, were identified using a duplex real-time PCR assay with specific TaqMan minor-groove-binding ligand (MGB) probes for the same amplicon. To conclude, this one-step quantitative PCR is well suited to the routine diagnosis of cryptosporidiosis since practical conditions, including DNA extraction, quantification using well-defined standards, and identification of the two main species infecting humans, have been positively assessed.

Dynamics of excretion and molecular characterization of Cryptosporidium isolates in pre-weaned French beef calves.

Studies on excretion and molecular characterization of Cryptosporidium have been mostly conducted in dairy calves, both diarrhoeic and non-diarrhoeic. Little is known about Cryptosporidium in beef calves, especially in non-diarrhoeic ones. This study was conducted in a herd of Parthenais beef cattle (France) with no history of clinical cryptosporidiosis. Twenty-five calves were sampled once a week from birth to one month of age (age range: 5-34 days). At each sampling date, presence of clinical signs of cryptosporidiosis (diarrhoea) was recorded. Oocyst excretion was assessed using the Heine staining method and a direct immunofluorescence method (Merifluor(®) C/G) which allowed quantification (oocysts per gram of faeces, opg). All samples were subjected to a two-step nested PCR protocol to amplify the 18S rRNA gene and amplification products were sequenced. None of the calves presented diarrhoea. Twenty-three of them excreted oocysts at least one sampling date. Prevalence of excretion was maximal when calves were 27-34 days old, with a percentage of excretion of 85% in this age category [95% CI: 70; 100]. Mean excretion was maximal when calves were 20 to 26 days old, with a mean excretion of 7.6×10(5) opg (range: 0-8×10(6) opg). 32 isolates were successfully identified: 27 as Cryptosporidium bovis, 4 as Cryptosporidium ryanae and 1 as Cryptosporidium parvum. C. bovis was isolated from samples of calves between 11 and 33 days old. C. ryanae was isolated from samples of calves between 17 and 34 days old. C. parvum was isolated from one calf aged 13 days. This survey demonstrated the high infection rate of non-diarrhoeic beef calves by Cryptosporidium species other than C. parvum.

Administration of the nematophagous fungus Duddingtonia flagrans to goats: an evaluation of the impact of this fungus on the degradation of faeces and on free-living soil nematodes.

The environmental impact of Duddingtonia flagrans, a potential biological control agent for nematode parasites, was tested in a 2-year-plot study using goat faeces. The trial assessed the impact of fungal presence on the disintegration of faeces and on non-target, free-living soil nematode populations. Three groups of goats experimentally infected by Trichostrongylus colubriformis received three different doses of D. flagrans chlamydospores (0 chlamydospores/kg body weight (BW), 0.5 × 10(6) chlamydospores/kg BW or 5 × 10(6) chlamydospores/kg BW). One hundred grams of faeces containing T. colubriformis eggs and D. flagrans chlamydospores at three different concentrations were deposited on pasture plots on four different occasions: May 2003, September 2003, June 2004 and September 2004. Faeces were weighed 2, 4, 6, 8, 10, 12, 14, 16, 18 and 20 weeks after deposit and immediately afterwards replaced to their initial positions. In addition, soil samples were taken just below faecal deposits to evaluate the impact of fungal presence on non-target free-living nematodes. Results showed that there was no treatment effect on the pellet degradation rate. Analysis of soil nematode fauna failed to demonstrate any effect of the dose rate of 0.5 × 10(6) chlamydospores/kg BW, while a reduction of the number of free-living nematodes was seen for the maximal chlamydospore concentration at autumn sets.

Cryptosporidiosis in small ruminants.

Cryptosporidiosis is an infection caused by protozoan parasites belonging to the genus Cryptosporidium which is responsible for a potentially severe disease in new-born ruminants. This infection is highly prevalent in small ruminants throughout the world, especially in pre-weaned animals. The clinical expression is different between goat kids and lambs, the infection being generally more severe in the former. Molecular data demonstrate geographical variations in the species of Cryptosporidium infecting small ruminants. They also support the possibility of transmission of zoonotic species from these hosts to humans. Studies are still needed on molecular epidemiology, especially in goats, and on ways to control infection.

Control of cryptosporidiosis in neonatal goat kids: efficacy of a product containing activated charcoal and wood vinegar liquid (Obionekk®) in field conditions.

Many compounds have been screened for their potential anti-cryptosporidial activity in ruminants but none of them has been totally efficient in controlling the disease. A product containing activated charcoal and wood vinegar liquid demonstrated a good efficacy in controlling clinical signs and oocyst excretion in calves experimentally infected. This product (Obionekk(®), Obione, Charentay, France) was given to goat kids in field conditions. The product was administered in a preventive way at the dose rate of 3.75 g/day/kid of Obionekk(®) from the age of 3 days to the age of 17 days in suspension in milk replacer twice or three times a day. A significant reduction of oocyst excretion was observed when the product was given 3 times a day when compared to control group. The clinical signs (diarrhoea) were significantly reduced whatever the rhythm of distribution when compared to control group. These results demonstrated the efficacy of Obionekk(®) in preventing cryptosporidiosis in goat kids in field conditions.

Evaluation of oral tilmicosin efficacy against severe cryptosporidiosis in neonatal kids under field conditions.

Many compounds have been screened for their potential anti-cryptosporidial activity in ruminants but none of them has been totally efficient in controlling the disease. Macrolide antibiotics have demonstrated some activity against Cryptosporidium spp. in humans. Tilmicosin is a macrolide antibiotic, available in France in an oral form (Pulmotil AC, Lilly France). The preventive efficacy of tilmicosin was evaluated in a goat farm experiencing severe clinical cryptosporidiosis in kids. Twenty-two kids were separated from their dams just after birth and placed in a separated pen. They were divided into 3 groups: an untreated group (10 kids), group 1 (6 kids) receiving tilmicosin at 25mg/kg BW/day and group 2 (6 kids) receiving tilmicosin at 50mg/kg BW/day. Tilmicosin was individually given by oral route from day 2 of age for 10 days. Three times a week, individual faecal samples were performed to assess the oocyst output. Clinical data, i.e. diarrhea and mortality, were recorded. In control kids, the highest prevalence and intensity of excretion were observed between day 6 and day 16 of age and mortality reached 90%. Excretion dynamic and clinical consequences were similar in both treated kid groups. Finally, tilmicosin did not demonstrate any activity against severe kid cryptosporidiosis in field conditions.

Efficacy of oxyclozanide against the rumen fluke Calicophoron daubneyi in experimentally infected goats.

Paramphistome infections are very common in ruminants and may induce clinical signs, but little is known about effective treatments. In this study, the efficacy of oxyclozanide against Calicophoron daubneyi was studied in goats and its activity tested against immature stages (10 days post-infection) at a dose of 22.5mg/kg bodyweight (BW) and against adult stages using two doses (15 and 22.5mg/kg BW). There was a reduction (82%) in the number of immature worms (compared to controls) but the result was not statistically significant. When tested against adult stages, however, oxyclozanide reduced the worm burdens by 95.6% and 95.9% at doses of 15 and 22.5mg/kg BW, respectively, with no significant difference between the two doses. The experiment demonstrated that oxyclozanide is highly effective in reducing the number of adult paramphistomes in goats.

Efficiency of feeding Duddingtonia flagrans chlamydospores to control nematode parasites of first-season grazing goats in France.

A field trial, conducted over two consecutive years, was aimed at assessing the efficacy of the administration of spores of the nematophagous fungus Duddingtonia flagrans to young goats for the control of nematode parasite infections on a French commercial dairy goat flock. For both years, the first-year grazing kids were divided into two similarly managed groups (fungus and control groups): in 2003 a daily dose rate of 5 x 10(5) spores/kg body weight was given to the fungus-group animals, while in 2004 a daily dose rate of 10(6) spores/kg body weight was used; the other half of the kids, acting as control, did not receive the spores. Parameters measured every 3 weeks included nematode egg excretion, larval development in faecal cultures and pasture larval counts. Additionally, at the beginning, the middle and the end of each grazing season, the goats were weighed and blood samples for pepsinogen determination were collected. In 2003, similar results were recorded for all the measured parameters in the control and fungus groups. In contrast, in 2004, the kids receiving the spores showed lower faecal egg counts and pepsinogen levels at the end of the season and higher growth rate compared to kids of the control group.

Comparative efficacy of the nematode-trapping fungus Duddingtonia flagrans against Haemonchus contortus, Teladorsagia circumcincta and Trichostrongylus colubriformis in goat faeces: influence of the duration and of the temperature of coproculture.

Amongst the alternative strategies to the use of anthelmintics, the administration of Duddingtonia flagrans spores has already proved its efficacy in reducing the number of developing larvae of several nematode species in goat faeces. In this trial, the efficacy of this fungus against the larvae of the three major nematode species of goats was compared in various conditions of coproculture. Twelve strongyle free goats were experimentally infected with either Trichostrongylus colubriformis, Teladorsagia circumcincta or Haemonchus contortus larvae. Half of the animals received an oral dose of 5x10(5) Duddingtonia chlamydospores/kg BW daily for 27 days, whereas the remaining was kept as control goats. From the 7th day of administration onwards, individual coproscopical examinations as well as coprocultures, which were incubated 4, 7, 10 or 14 days at 21 or 28 degrees C, were performed. The reduction in developing larvae due to the activity of Duddingtonia ranged from 62.8 to 99.5% compared to control. The trapping efficacy depended on temperature (better activity of the fungus at 21 than at 28 degrees C) and on duration (larval reductions lower after 4 days than after 7, 10 and 14 days of coproculture). Teladorsagia larvae were the least trapped, and Haemonchus larvae were the most trapped.

Impact of the nematophagous fungus Duddingtonia flagrans on Muellerius capillaris larvae in goat faeces.

The small lungworm Muellerius capillaris is very prevalent in goats and causes production losses. Its control is particularly difficult. The nematophagous fungus Duddingtonia flagrans has been shown to be effective in trapping a large range of gastro-intestinal nematode larvae but its trapping activity against small lungworm remains to be assessed. The purpose of this work was firstly, to evaluate the ability of first-stage larvae of M. capillaris (L1) to induce trap formation in in vitro conditions and secondly, to determine the effect of D. flagrans on the L1 infectivity to snails. In experiments on agar, the presence of L1 failed to induce any D. flagrans traps whereas in the same conditions, gastro-intestinal third-stage larvae induced 44-135 traps/cm(2) depending on the species. Moreover, when the traps were pre-induced by Haemonchus contortus larvae, the L1 of M. capillaris were not trapped. For the in vivo trial, two goats naturally infected with M. capillaris received D. flagrans chlamydospores at the daily dose rate of 5x10(5) spores/kg BW for 8 days. Faeces were collected individually before, during and 11 days after spore administration. On each day of harvest, the initial larval output was determined. The remaining faeces were subjected to coproculture at 21 degrees C for 7 days. At the end of this period, L1 were collected and used to infect snails (30 snails per goat isolate each snail given 40 L1 by direct deposit of the larvae on the foot of the snail). These snails were artificially challenged in contrast to others that were exposed to natural infection by exposure to faeces carrying first-stage M. capillaris larvae. The natural infection used the same number of snails, i.e. 30 snails deposited on the faeces of each goat. After 3 weeks at room temperature, the infective larvae present in the snail foot were counted. There was no difference in the survival of the L1 in faeces after coproculture whether the faeces contained D. flagrans or not. The infectivity of the extracted larvae from the two goats before and after fungal administration was the same. The number of infective larvae per snail obtained after "natural" infection showed variations that were not related to the presence of D. flagrans mycelium in faeces. These trials clearly indicate that D. flagrans was unable to trap or to alter the infectivity of M. capillaris first-stage larvae and thus cannot be considered as a non-chemotherapeutic alternative approach to the control of the small lungworm in goats.

Biological control of infective larvae of a gastro-intestinal nematode (Teladorsagia circumcincta) and a small lungworm (Muellerius capillaris) by Duddingtonia flagrans in goat faeces.

The high prevalence of benzimidazole-resistant nematodes in French grazing dairy goat flocks led to a search for nematode-control schemes based on integrated approaches with non-chemical options, like vaccination, grazing management, or biological control using nematophagous fungi. The effect of the daily feeding of goats with spores of the nematophagous fungus Duddingtonia flagrans on third-stage larvae (L3) of Teladorsagia circumcincta was examined in faecal cultures. In addition, the effect of D. flagrans on the survival of first-stage larvae (L1) of Muellerius capillaris was tested. Twenty-two culled dairy goats previously raised in a zero-grazing system were twice infected at monthly intervals with 5,000 and then 7,500 T. circumcincta L3. Eight animals were infected with a benzimidazole-susceptible (BZs) strain while the remainder received a benzimidazole-resistant one (BZr). Six culled goats naturally infected with M. capillaris were purchased from private farms. All the goats were divided in two groups, one group receiving daily 5 x 10(5) chlamydospores of D. flagrans/kg body weight per goat for seven consecutive days in the food, the other group acting as control. For T. circumcincta-infected goats, individual egg counts and coprocultures (13 days, 25 degrees C) followed by L3 extraction with the Baermann method were performed. For M. capillaris-infected goats, extraction of L1 with the Baermann apparatus was individually performed on day 0 and after coprocultures on days 7, 10 and 14. Reductions in percentage development of T. circumcincta L3 in fungus groups compared with control groups ranged from 84% (BZs strain) to 90% (BZr strain). A decrease in M. capillaris L1 recovery was noted on days 7 and 10 (a reduction of 70% compared with day 0) and on day 14 (85%), but this pattern was similar in both groups, whether receiving the fungus or not. At the dosage of 5 x 10(5) spores/kg body weight, D. flagrans was highly effective in reducing the larval development of T. circumcincta in goats faeces. In contrast, the fungus did not reduce M. capillaris L1 survival in faeces in our conditions.