Lower Faecal Egg Counts Research Articles

Increase in dairy production of goats with subclinical nematode infection using injectable eprinomectin.

The effect of the treatment with an injectable product containing eprinomectin on milk yield, milk composition, and somatic cell count (SCC) was investigated in naturally infected dairy goats with low gastrointestinal nematode faecal egg and pulmonary larval counts. The study involved 394 lactating goats and was conducted on a farm in southern Spain. Before treatment, faeces from all animals were analysed to establish two homogeneous groups according to the gastrointestinal nematode egg counts (185 treated and 209 untreated). On day 0, each goat in the treatment group received a single subcutaneous injection of 12 mg of eprinomectin (0.6 ml of Eprecis®, CEVA, Spain). The control goats were left untreated. Faecal egg counts and coprocultures were performed on days 0, 30, 60, and 90 post-treatment. Milk samples were taken on days 0, 30, 60, 90, and 120 and analysed to determine individual production and milk composition parameters, including fat (F), protein (P), lactose (L), total dry extract (TDE), and SCC. Examination of faecal samples indicated that the goats were mainly infected with gastrointestinal strongylids of the genera Teladorsagia and Trichostrongylus and Muellerius lungworms. The percentage reduction of gastrointestinal nematode faecal egg counts on days 30, 60, and 90 was 97.55 % (90 % CI = 95.1 % - 99.9 %), 90.65 % (90 % CI = 83.7 % - 97.6 %) and 87.5 % (90 % CI = 79.5 % - 95.5 %), respectively, and that of lung larval counts in faeces was 98.48 % (90 % CI = 96.3 % - 100 %), 96.91 % (90 % CI = 84.2 % - 98.9 %), and 82.05 % (90 % CI = 66.9 % - 97.2 %), respectively. Milk yield was consistently and significantly higher in the treated group than in the control group (p = 0.004). The treated goats showed a 4 % increase in daily milk yield (60 ml/day) compared with the untreated goats. There was a significant decrease in F and TDE in the treated goats compared with the untreated goats, but eprinomectin did not affect P, L, and SCC. The estimated economic benefit of using injectable eprinomectin was around 6.46€ per goat over the 120-day period. In conclusion, treatment with injectable eprinomectin has an economical positive effect on milk yield in goats, even those infected with a low burden of gastrointestinal and pulmonary nematodes.

Effect of feeding a blackseed meal-sericea lespedeza leaf meal pellet on gastrointestinal nematode and coccidia infection and animal performance in young goats

Gastrointestinal nematode (GIN) infection poses the most significant obstacle to the sustainable development of small ruminant (sheep and goat) farming globally. Resistance of GINs to synthetic anthelmintic drugs has led to rising interest in exploring alternative methods for parasite control, such as the utilization of bioactive plants with anti-parasitic properties. In this investigation, black seed (Nigella sativa), a shrub high in secondary antioxidant compounds, and sericea lespedeza (Lespedeza cuneata), a perennial legume high in tannins with anti-parasitic properties were combined to determine if two bioactive plants containing different types of secondary compounds can provide a stronger anti-parasitic effect than sericea lespedeza alone. In a 49-day trial, naturally parasitized 6–7-month-old intact male Spanish goats (n = 15/treatment) were fed pelletized feeds encompassing sericea lespedeza leaf meal (SL), a combination of black seed meal (BS) and sericea lespedeza leaf meal (BS-SL - 75 % SL, 25 % BS), or alfalfa (Medicago sativa, control parasitized; CONP), with an additional group of dewormed kids given the alfalfa pellets (Control treated; CONT). Weekly measurements of animal weights and samples of blood and feces were collected to determine the packed cell volume (PCV), GIN fecal egg counts (FEC), and coccidia fecal oocyte counts (FOC), respectively. All animals were processed at the end of the trial (60 total), with adult Haemonchus contortus worms recovered from the abomasum of each goat for counting and sex determination. Carcass weights were recorded after processing. Goats given the SL and BS-SL treatments had lower FEC (P<0.05) than the parasitized alfalfa (CONP) goats. At the end of the study, the SL and BS-SL groups' FOC values were lower (P < 0.05) than the CONT and CONP groups. A rise in PCV values was seen over time for all groups; SL, BS-SL, and CONT animals exhibited higher PCV values (P < 0.05) in comparison to the CONP goats. The parasitized goats fed SL-only pellets showed greater feed intake and animal body weights (P < 0.05) compared to goats fed BS-SL or alfalfa pellets. However, the treatments had no effect on the weight of the goats' carcasses. Although the H. contortus adult worm counts in the CONT goats (alfalfa-dewormed) were lower (P < 0.05) than in the CONP goats (alfalfa-parasitized), they did not differ from the SL or BS-SL animals. This study indicates that sericea lespedeza leaf meal pellet diet, either by itself or in combination with black seed meal, showed promising results as an anthelmintic and may prove to be an effective alternative to exclusive use of conventional deworming drugs. The addition of black seed did not appear to enhance the effectiveness of sericea lespedeza in this study.

Association of SERPING1 gene single nucleotide polymorphism with resistance to natural strongyle infection among native goats in humid tropical Kerala

Strongylosis poses a significant threat to goat populations, particularly in humid tropical regions like Kerala, a southern peninsular state in India. This study aimed to compare breed differences in host resistance and resilience to natural strongyle infection between Attappady Black and Malabari goats reared under semi-intensive systems. Additionally, we analyzed the association of a potential single nucleotide polymorphism (SNP) in the Serine Proteinase Inhibitor Clade G member 1 (SERPING1) gene with these traits. Faecal egg count (FEC) and volume of packed red cells (VPRC) were employed as indicators of host resistance and resilience, respectively. Over the course of one year, fortnightly phenotypic data on FEC and VPRC were collected from 109 native goats, including 58 Malabari and 51 Attappady Black goats. The Malabari goats exhibited greater resistance and resilience to strongylosis, evidenced by significantly lower FEC (p≤0.01) and higher VPRC (p≤0.05) compared to Attappady Black goats. Pearson correlation analysis revealed a highly significant negative correlation between FEC and VPRC (r= −0.41, p<0.01). Genotyping of the −312-C>T SNP in SERPING1 gene was conducted using modified bidirectional PCR amplification of specific alleles (Bi-PASA). While the association between SERPING1 genotypes and FEC was not significant, a significant association was observed between SERPING1 genotypes and VPRC (p<0.05). These findings underscore the importance of breed-specific differences in goat resilience to strongyle infection and highlight the potential role of SERPING1 gene polymorphism in modulating host resilience traits.

Strongyle egg shedding and egg reappearance periods in horses with pituitary pars intermedia dysfunction

Pituitary pars intermedia dysfunction (PPID) is the most common endocrine disorder of older horses. Immune dysfunction in horses with PPID could increase susceptibility to infectious diseases, including strongyle infections; however, few data are available. The aim of this study was to determine if horses with PPID had increased strongyle faecal egg counts (FEC) compared with control horses, over a fourteen-week period in Victoria, Australia. Clinical signs and plasma adrenocorticotropic hormone (ACTH) concentrations were used to categorise horses into PPID (n=14) or control (n=31) groups. Faecal samples were collected for FEC determination prior to anthelmintic treatment, and fortnightly post-treatment for each horse. Generalised linear mixed modelling, using a gamma distribution, was used to compare differences between groups in the repeated measures study. The confounding variable of age was controlled for as a fixed effect. Following anthelmintic treatment, mean FEC was greater for the PPID group compared to the control group on day 56 (405 ± 756 eggs per gram [EPG] vs 40 ± 85 EPG, p=0.05) and day 70 (753 ±1598 EPG vs 82 ±141 EPG, p=0.04). There were no differences in mean FEC between groups on days 84 and 98. Cumulative FEC (day 14 to day 98) was significantly greater for the PPID horses than control horses (2118 ± 4016 EPG vs 798 ± 768 EPG, p<0.0001). Group egg reappearance period was shorter for PPID horses (day 56 post-anthelmintic treatment) compared to control horses (day 70) and 30% of the PPID horses reached a FEC threshold of >200 EPG on day 42, compared to 0% of control horses (p=0.02). These results suggest that the rate of a re-established patent infection between groups could be different due to a comprised immune response in PPID horses or differences in the host-parasite relationship regarding encysted stage larvae. However, despite differences between groups, some horses with PPID consistently had no detectable or low FEC (<200 EPG) during the study period. These findings highlight the importance of individual FEC monitoring to determine if anthelmintic treatment is required, in line with sustainable parasite management practices.

Immune markers in goats selected for reduced gastrointestinal nematode egg count under artificial infection conditions

This study aimed to further investigate the mechanisms responsible for inhibition of gastrointestinal nematode egg production in a line of Scottish Cashmere Goat selected for low faecal egg count. Animals were chosen as the lowest egg producers from a line selected for low egg output (selected group) with a second group from the wider herd based on high faecal egg count as controls. All animals were artificially infected with Teladorsagia circumcincta and Trichostrongylus vitrinus, then treated with anthelmintic and challenge infected prior to euthanasia and post mortem sampling.There was no effect on body weight between groups at any point in the study. Mean faecal egg count was reduced by 68 % in the selected group when compared with the controls. Circulating eosinophil counts were consistently elevated in the selected group, but this was only marginally significant (P = 0.045). Most of the circulating and tissue antibodies (IgG, IgA and IgE) measured were slightly elevated in the selected group but not significantly. Mucosal mast cells, eosinophils and globule leukocyte levels were higher in the abomasal and intestinal tissues in selected animals. Following challenge infection there was no difference in numbers of parasites, however there were more early stage parasite larvae and fewer late stage larvae in the both the abomasum and duodenum of the selected group compared with the unselected group, indicating some inhibition of parasite development.Overall, the study further demonstrated that selection based on low egg count has resulted in a line of goats producing significantly fewer parasites under identical infection with no effect on bodyweight. This appears to be associated with elevation in antibody and effector cells. Some evidence of host inhibition of parasite development was observed in the selected animals.

Integration of ITS-2 rDNA nemabiome metabarcoding with Fecal Egg Count Reduction Testing (FECRT) reveals ivermectin resistance in multiple gastrointestinal nematode species, including hypobiotic Ostertagia ostertagi, in western Canadian beef cattle

A large-scale Fecal Egg Count Reduction Test (FECRT) was integrated with ITS-2 rDNA nemabiome metabarcoding to investigate anthelmintic resistance in gastrointestinal nematode (GIN) parasites in western Canadian beef cattle. The study was designed to detect anthelmintic resistance with the low fecal egg counts that typically occur in cattle in northern temperate regions. Two hundred and thirty-four auction market-derived, fall-weaned steer calves coming off pasture were randomized into three groups in feedlot pens: an untreated control group, an injectable ivermectin treatment group, and an injectable ivermectin/oral fenbendazole combination treatment group. Each group was divided into six replicate pens with 13 calves per pen. Individual fecal samples were taken pre-treatment, day 14 post-treatment, and at monthly intervals for six months for strongyle egg counting and metabarcoding. Ivermectin treatment resulted in an 82.4% mean strongyle-type fecal egg count reduction (95% CI 67.8–90.4) at 14 days post-treatment, while the combination treatment was 100% effective, confirming the existence of ivermectin-resistant GIN. Nemabiome metabarcoding of third-stage larvae from coprocultures revealed an increase in the relative abundance of Cooperia oncophora, Cooperia punctata, and Haemonchus placei at 14 days post-ivermectin treatment indicating ivermectin resistance in adult worms. In contrast, Ostertagia ostertagi third-stage larvae were almost completely absent from day 14 coprocultures, indicating that adult worms of this species were not ivermectin resistant. However, there was a recrudescence of O. ostertagi third stage larvae in coprocultures at three to six months post-ivermectin treatment, which indicated ivermectin resistance in hypobiotic larvae. The calves were recruited from the auction market and, therefore, derived from multiple sources in western Canada, suggesting that ivermectin-resistant parasites, including hypobiotic O. ostertagi larvae, are likely widespread in western Canadian beef herds. This work demonstrates the value of integrating ITS-2 rDNA metabarcoding with the FECRT to enhance anthelmintic resistance detection and provide GIN species- and stage-specific information.

Comparison of Three Diagnostic Methods to Detect the Occurrence of Fasciola Species in Communally Grazed Cattle in the North West Province, South Africa.

Fasciolosis causes significant economic losses in commercial cattle herds in South Africa, but its prevalence is unknown in most communal areas. A cross-sectional study was conducted with the aim of determining the occurrence of bovine fasciolosis using three different diagnostic methods in Moretele Local Municipality in Bojanala District, North West Province. Faecal samples were collected from 277 cattle of different breeds, ages, sex and faecal condition scores and examined using the sedimentation technique, quantitative real-time polymerase chain reaction (qPCR) and faecal antigen enzyme-linked immunosorbent assay (coproELISA). All samples were negative for bovine fasciolosis using coproELISA. A total of 73 (26.4%) samples were positive using the qPCR, while 36 were positive using the sedimentation technique, with low faecal egg counts (1 to 20 eggs per gram). The qPCR detected the highest positivity (26.4%, 95% CI 21.3, 32.0) followed by the sedimentation test (13.0%; 95% CI 9.3, 17.5). Location, breed, sex, age and faecal consistency score were not associated with positive qPCR results (p > 0.05). There was also no significant agreement (kappa = −0.011, p = 0.843) between qPCR and the sedimentation technique for the detection of Fasciola spp. The qPCR appeared to be the most sensitive method for detection of Fasciola spp. Further studies are required on the characterisation of Fasciola spp. in communal cattle in South Africa.

Characterization of interferon gamma gene in relation to immunological responses in Haemonchus contortus resistant and susceptible Garole sheep.

Garole sheep exhibits within-breed difference in resistance to natural gastrointestinal nematode infection predominated by Haemonchus contortus. In the present study, interferon gamma gene (IFN-γ) was characterized in relation to parasitological, haematological, and immune response against H. contortus in resistant and susceptible Garole sheep. Resistant and susceptible Garole sheep were selected from the field based on consistent low faecal egg counts (FEC) for one year and single nucleotide polymorphisms (SNPs) in the IFN-γ gene. The partial amplification of IFN-γ gene (1282bp) revealed 4 SNPs exclusively in resistant sheep and 3 SNPs were shared between resistant and susceptible Garole sheep. The selected resistant and susceptible Garole sheep were challenged with H. contortus infection. The parasitological, haematological, immunological responses, and expression of IFN-γ gene were compared between the resistant and susceptible Garole sheep. The FEC of resistant sheep was significantly (P < 0.05) lower than the susceptible sheep infected with H. contortus. There was spontaneous elimination of H. contortus from 28 to 33days post infection (DPI) in resistant sheep. Haemoglobin and packed cell volume were significantly (P < 0.05) higher in resistant sheep than the susceptible sheep. The serum concentration of immunoglobulin (Ig)G1 and IgA and cytokine IFN-γ activity and also the expression of IFN-γ gene were significantly (P < 0.05) higher in the infected resistant sheep from 14 to 28 DPI compared to the susceptible sheep. In resistant sheep, IgA and IgG1 and cytokine IFN-γ positively correlated with expression of IFN-γ gene, and the SNPs recorded in the resistant sheep only might play an important role in conferring resistance against H. contortus. Further studies are required to elucidate the role of IFN-γ gene in H. contortus resistance in Garole sheep.

The impact of sire fecal egg count estimated breeding values on indicators of offspring gastrointestinal nematode infection, and relative impact of lamb estimated breeding values on sale value of ram lambs

Genetic selection of sheep for resistance to gastrointestinal nematodes (GIN) has become a priority for pasture-based production of lambs to minimize the need for deworming. The objective of this experiment was to determine the impact of sire weaning or post-weaning fecal egg count (FEC) estimated breeding value (EBV; WFEC and PFEC, respectively) from the National Sheep Improvement Program (NSIP) on GIN infection in Katahdin lambs born in fall (Oct – Nov; n = 459) or winter (Jan – Feb; n = 378) of 2018 through 2021 at the USDA Agricultural Research Service (ARS). FAMACHA scores were determined, and blood samples and feces were collected from the lambs to determine packed cell volume (PCV), and FEC at 60, 90, 120, and 150 days of age, and lambs were selectively dewormed if anemic. Data were analyzed using mixed models containing fixed effects of year, sex, age at sampling (fitted as a repeated measure), and their interactions, and continuous effects of sire FEC EBV. The FEC and PCV of offspring was positively (P < 0.001) and negatively (P < 0.001), respectively, related to the sire WFEC and PFEC. A second objective was to examine effects on sale prices of breeding-quality ram lambs from four farms, including ARS, of lamb EBV for WFEC and a ewe productivity trait (EPT) designed to identify ewes with superior maternal ability. Sale price effects were dominated by sale type with a premium of $1086/head relative to direct sales from the farm for animals in NSIP or Katahdin Hair Sheep International Expo sales. Producers likewise assigned a premium of $107/head to animals retained for use in their own breeding herds. The next most impactful variable was the EPT EBV. A 1-SD increase of 2.3 units in EPT yielded an extra $39/head whereas a similar 1-SD decrease in EPT resulted in a $32/head discount. Lambs born in fall were discounted by $6/head relative to those born in winter. Lambs that were not dewormed received a $29/head premium over lambs that were dewormed and was presumably taken as a phenotypic signal that the lamb was resistant. A ± 1-SD change in WFEC had no effect on sale value, which changed by less than $0.01/head. This result may have been confounded with whether or not the lamb had been dewormed. Thus, while more parasite-resistant sires produced offspring with lower FEC, the sale value of these ram lambs appeared to have been more strongly associated with other EBV such as EPT or with a desire to obtain ram lambs with balanced EBV rather than elite EBV for parasite resistance.

Within Breed Resistance to Naturally Occurring Gastrointestinal Nematodoses in Garole Sheep of West Bengal, India

Background: Gastrointestinal (g.i.) nematodoses is the main constrain in sheep husbandry and control of g.i. nematodes is challenging due to anthelmintic resistance. Exploitation of host resistance could be an alternative approach to nematodes. Methods: Within breed resistance of Garole sheep to g.i. nematodoses was determined in terms of monthly faecal egg count (FEC), Hb concentration and PCV% in 4- 6-months-old Garole sheep (n=80) in South 24 Parganas district from April, 2018 to March, 2019. On the basis of 6 months’ FEC data sheep were divided into resistant and susceptible group and Hb and PCV were measured in 15 animals from each group at monthly interval. Result: The prevalence of g.i. nematodes was 70 per cent and Haemonchus contortus was the predominant species. The overall FEC in Garole sheep was 360.67 in terms of eggs per gram (EPG) of faeces. Among the 80 Garole sheep 28 sheep showed persistent low FEC. The mean EPG of resistant group were 97.62 whereas, mean EPG of susceptible group were 502.31. In resistant sheep Hb and PCV did not vary whereas, in susceptible Hb and PCV reduced significantly (P less than 0.05) than the resistant sheep. Within breed resistance was present in Garole sheep and that could be utilized in selection of resistant breed.

Effects of supplementation of different indigenous species of browses to Arsi-Bale yearling goats on feed intake, growth performance, and helminthes loads

This study was conducted to evaluate the effects of browse tree leaves meals on growth performance and parasite load of naturally parasitized yearling goats. Thirty-six Arsi-Bale yearling bucks which were naturally parasitized with helminths were randomly allocated to one of the following feeding treatments; T1 = Chloris gayana grass hay ad lib + 100g concentrate, T2 = T1 + dried 100g of Acacia tortilis leaves, T3 = T1 + dried 100g of Acacia seyal leaves, T4 = T1 + dried 100g of Acacia senegal leaves, T5 = T1 + dried 100g of Millettia ferruginea leaves and T6 = T1 + dried 100g of Vernonia amygadalina leaves. Goats were fed on corresponding diets for 70 days. Fecal egg count and body weight changes were recorded every 14 days. Higher feed conversion efficiency was observed in goats supplemented with dried browse tree leaves of Acacia seyal (T3), Millettia ferruginea (T5), and Vernonia amygadalina (T6). All supplemented goats had significantly (p&lt;0.05) lower fecal egg count (FEC) at day 70 and grew significantly (p&lt;0.05) faster than the control group. Goats supplemented with dried browse tree leaves of Acacia seyal, Millettia ferruginea, and Vernonia amygadalina grew faster than goats supplemented with other dried browse tree leaves. A rapid and significant reduction of FEC was observed in goats supplemented with Millettia ferruginea starting from day 14 and the lowest (p&lt;0.05) value was attained at day 70 after treatment. Similarly, goats supplemented with Vernonia amygadalina showed an accelerated reduction of FEC starting from day 28 and attained the lowest (p&lt;0.05) value at day 70 after treatment. Goats supplemented with Millettia ferruginea (T5) and Vernonia amygadalina (T6) had the lowest (p&lt;0.05) FEC at all times after supplementation and grew faster than the other groups. The rapid and accelerated reduction of FECs and fastest growth rate observed in goats supplemented with Millettia ferruginea and Vernonia amygadalina indicated that these browse tree leaves could be effective to control helminths parasite and improve the growth performance of parasitized goats.

Inclusion of Sainfoin in the Diet Might Alter Strongyle Infection in Naturally Infected Horses.

It is increasingly difficult to control equine strongyles with synthetic drugs, as resistance is commonly observed. Here, we investigated the possible anthelmintic effect of sainfoin (Onobrychis viciifolia), a polyphenol-rich legume, in naturally infected horses. On Day 0 (D0), 17 horses were allocated to three different homogenous groups in terms of fecal egg count (FEC): the control group (CONT) received a diet composed on a DM basis of 83% hay and 17% wheat bran, while in the sainfoin 1 (SF1) and sainfoin 2 (SF2) groups, half or all wheat bran, respectively, was replaced by dehydrated sainfoin pellets. The infection dynamics were monitored by weekly FEC, from D0 to D84. On D28, all horses were treated with fenbendazole. Larval motility was assessed from coprocultures at D0, D28, D56 and D84. Horses in Group SF2 had lower FEC from D7 to D28. After fenbendazole treatment, no effect of the diet was measured on FEC. Both before and after anthelmintic treatment, larvae from horses consuming sainfoin were less motile than larvae from the CONT group. These results suggest that sainfoin has an in vivo anthelmintic activity in naturally infected horses, although this effect appears to be context-dependent.

Variants Within Genes EDIL3 and ADGRB3 are Associated With Divergent Fecal Egg Counts in Katahdin Sheep at Weaning.

Gastrointestinal nematodes (GIN) pose a severe threat to sheep production worldwide. Anthelmintic drug resistance coupled with growing concern regarding potential environmental effects of drug use have demonstrated the necessity of implementing other methods of GIN control. The aim of this study was to test for genetic variants associated with resistance or susceptibility to GIN in Katahdin sheep to improve the current understanding of the genetic mechanisms responsible for host response to GIN. Linear regression and case-control genome-wide association studies were conducted with high-density genotype data and cube-root transformed weaning fecal egg counts (tFEC) of 583 Katahdin sheep. The case-control GWAS identified two significant SNPs (P-values 1.49e-08 to 1.01e-08) within introns of the gene adhesion G protein-coupled receptor B3 (ADGRB3) associated with lower fecal egg counts. With linear regression, four significant SNPs (P-values 7.82e-08 to 3.34e-08) were identified within the first intron of the gene EGF-like repeats and discoidin domains 3 (EDIL3). These identified SNPs were in very high linkage disequilibrium (r 2 of 0.996–1), and animals with alternate homozygous genotypes had significantly higher median weaning tFEC phenotypes compared to all other genotypes. Significant SNPs were queried through public databases to identify putative transcription factor binding site (TFBS) and potential lncRNA differences between reference and alternate alleles. Changes in TFBS were predicted at two SNPs, and one significant SNP was found to be within a predicted lncRNA sequence with greater than 90% similarity to a known lncRNA in the bovine genome. The gene EDIL3 has been described in other species for its roles in the inhibition and resolution of inflammation. Potential changes of EDIL3 expression mediated through lncRNA expression and/or transcription factor binding may impact the overall immune response and reduce the ability of Katahdin sheep to control GIN infection. This study lays the foundation for further research of EDIL3 and ADGRB3 towards understanding genetic mechanisms of susceptibility to GIN, and suggests these SNPs may contribute to genetic strategies for improving parasite resistance traits in sheep.

Heather (Calluna vulgaris) supplementation does not reduce trapping ability of Duddingtonia flagrans in faeces of Haemonchus contortus infected lambs

Infection with gastro-intestinal nematodes (GIN) seriously impairs productivity and health of grazing animals. Due to the considerable rise in anthelmintic resistance and the increasing popularity of organic farming, alternative control strategies will replace or complement traditional anthelmintics. The efficacy of two potential alternatives (i) feeding the tanniferous forage heather (Calluna vulgaris) and (ii) the nematophagous fungus Duddingtonia flagrans (isolate FiBL-DF-P14), was tested in a feeding experiment with lambs artificially infected with Haemonchus contortus. Animals received hay supplemented with heather or with a late cut hay (ecohay) as a control feed ad libitum for three weeks. Two doses (1 × 105 and 5 × 104 chlsp/kg LW) of D. flagrans chlamydospores (chlsp) were administered to animals of each roughage treatment and H. contortus larval recovery from faecal cultures was compared with an untreated control (6 animals per D. flagrans-heather combination). Protein, crude fiber and energy contents of ecohay and heather were similar but heather contained approximately twice more fat, four times more lignin and ten times more of all condensed tannin fractions. Heather contained 17.3 mg Proanthocyanidin per g dry matter (DM) while contents of ecohay were 1.7 mg/g DM. Daily average feed intake across both treatments was 1.5 kg DM/animal/day, of which heather/ecohay intake accounted for 0.17/0.19 kg. Overall, there was no significant effect of heather on faecal egg counts (FEC). There was a tendency for a significant interaction between feed supplement and time and a significantly (p = 0.030) lower FEC of nominally 1799 EPG in the heather treatment at the end of the heather feeding period compared with the ecohay treatment. Lambs in this study consumed less heather than grazing sheep in other studies, even though condensed tannin contents were comparably low. Heather supplementation did not affect larval recovery in faecal cultures and trapping ability of D. flagrans. As compared with the untreated control, both doses of D. flagrans reduced larval recovery by 96.2 % and 95.5 %, respectively (p < 0.001), with no significant difference between the doses. The isolate FiBL-DF-P14 was at least as effective as isolates tested in other studies and achieved over 95 % reduction at a low dosage of 5 × 104 chlsp/kg LW. In conclusion, our results confirm the potential of and indicate no negative interactions between both alternative GIN control methods.

Long-Acting Moxidectin for the Control of Gastrointestinal Nematodes in Preweaned Beef Calves in Tropical Areas

Gastrointestinal nematodes (GINs) in beef calves in the preweaning period can be an underestimated problem, and an adequate control program can result in increased productivity. In the current scenario of anthelmintic resistance, clinical studies with highly effective molecules with a prolonged period of action can contribute to the development of technologies applied in the field. The objective of this study was to evaluate the effects of a 10% moxidectin formulation (10%MOX), administered to calves aged 4–5 months, in the control of gastrointestinal nematodes and weight gain until the time of weaning. The study was divided into 2 stages. The first stage was carried out on a farm, with a randomized block design based on fecal egg counts (FEC), live weight, number of calvings of the mother, breed of the calves, and pickets. In the second stage, the study was repeated on 10 other farms, following a completely randomized design, to confirm the results obtained in the first stage. In all experiments there was a treated group and a placebo group. In the first stage, the effectiveness of 10%MOX in the FECRT performed on the 38th day post-treatment was 98.49%, and the treated animals still had lower FEC averages and a 9.4 kg increase in weight at weaning compared to those from the placebo group. In the second stage, the average increase in weight gain was 6.1 kg, confirming the results of the first stage. The study demonstrated effective control of GINs and improvement in the productive performance of calves treated in the preweaning phase, using 10% moxidectin.

PSXIV-18 Genetic improvement for resistance to gastrointestinal parasitism in growing meat goats and hair sheep through a centralized performance test in the southcentral USA

Abstract Progress from selecting meat goats and hair sheep from different farms in the southcentral United States for resistance to internal parasitism during three consecutive central performance tests was evaluated. Tests entailed 7–10 wk of data collection after artificial infection of growing males with Haemonchus contortus larvae. There were 44, 50, and 50 Boer, Kiko, and Spanish goats and 54, 55, 34, and 47 Dorper, Katahdin-farm-A, Katahdin-farm-B, and St. Croix sheep, respectively. In year 1, males were randomly selected and in years 2 and 3 were progeny of sires and females classified as highly and moderately resistant. Criteria for males was average daily gain and residual feed intake during the performance test and means of fecal egg count (FEC) and packed cell volume after artificial infection and for females was FEC and FAMACHA on-farm. There were interactions in FEC of breed×year (P &amp;lt; 0.001) for both species (1,046; 1,134; and 2,630 for Boer; 3,781; 1,239; and 1,216 for Kiko; 1,303; 1,357; and 1,464 for Spanish; 3,288; 1,956; and 1,315 for Dorper; 1,528; 1,759; and 2,241 for Katahdin-A, 2,414; 3,874; and 1,793 for Katahdin-B; and 1,371; 1,160; and 1,175 eggs/g for St. Croix in years 1, 2, and 3, respectively) and year×resistance group (RG; P = 0.005) for goats (1,359; 610, and 552 for high; 1,951; 1,268; and 1,440 for moderate; 2,821; 1,852; and 3,118 eggs/g for low RG in years 1, 2, and 3, respectively) but not for sheep (P = 0.639). In conclusion, resistance appeared greatest for Spanish and St. Croix within species and was increased by selection of Kiko and Dorper. For highly resistant goats, lower FEC in year 2 and 3 vs. 1, compared with no year differences for moderate and low RG, indicates selection progress, and the lack of similar differences for sheep may reflect their relatively greater resistance.

Evaluation of resistance to gastrointestinal helminth nematodes in two naturally infected indigenous Nigerian goat breeds.

Tropical goat breeds often have at least modest resistance to gastrointestinal nematode parasites (GIN), but enhancement of GIN resistance is important for breed improvement. This study compared changes in fecal egg count (FEC), packed cell volume, and body weight in Red Sokoto (RS) and Sahelian (SH) male and female weaner kids and adult goats. The RS is found throughout Nigeria, but the SH is found only in the arid Sahel. Goats were evaluated fortnightly for 20 times (MT) under normal grazing conditions and natural GIN infection over 9.5months, beginning in the dry season (November) and ending at the end of the subsequent wet season (August). Animals were dewormed at the start of the study and during the rainy season (MT 18). Breed differences in FEC and PCV were not observed in weaners. Weaner females had lower FEC than males but were rapidly re-infected after deworming, perhaps in association with attainment of puberty. Adult SH goats of both sexes had lower FEC than RS goats in MT 8 through 17, suggesting a stronger acquired immune response. The FEC in lactating females of both breeds increased rapidly after deworming, to ≥ 3000 eggs per gram of feces at MT 19 and 20. The optimal time to evaluate GIN resistance in weaners was during the early rainy season, but the decision to focus on the initial high FEC near MT 15 or wait until mobilization of the acquired immune response near MT 17 requires further consideration.

Is selection for resistance and resilience to Haemonchus contortus possible in Morada Nova sheep?

Gastrointestinal nematodes (GIN) are a major constraint for sheep production. Selection of animals resistant to GIN infection is an effective and sustainable control strategy. In this study, the possibility of selection for resistance and resilience, as well as potential correlated responses, were evaluated. A total of 256 lambs and 123 ewes were submitted to two consecutive independent artificial infections with 4,000 infective larvae (L3) of Haemonchus contortus. Records of faecal egg count (FEC), packed cell volume (PCV), and body weight (BW) were taken serially until day 42 after infection in both challenges. Estimates of genetic parameters were obtained for individual records (in lambs) and for overall traits (in lambs and ewes) using mixed models. Phenotypic and genetic correlations were estimated between traits in lambs, with genetic correlations being based on estimated breeding values (EBVs). In addition, correlations between FEC in lambs and FEC in ewes, as well as PCV in lambs and ewes, were calculated. Heritability estimates for FEC in the first and second parasite challenge were, respectively, 0.25 ± 0.18 and 0.46 ± 0.19 for lambs, and 0.00 ± 0.09 and 0.20 ± 0.16 for ewes. For PCV, heritability estimates were 0.23 ± 0.14 and 0.32 ± 0.16 for lambs and 0.13 ± 0.11 and 0.37 ± 0.18 for ewes. For the overall daily weight gain (DWG), the heritability estimate was 0.70 ± 0.21. No significant genetic correlation was found between DWG and the other traits, while there was a negative genetic correlation between FEC and PCV (-0.70 ± 0.03). Genetic correlations of FEC and PCV between lambs and ewes were 0.36 ± 0.08 and 0.42 ± 0.08, respectively. The results of the present study suggest that selection for low FEC, high PCV and high BW/DWG is possible in Morada Nova lambs. Furthermore, selection for low FEC should have a correlated response on PCV (leading to higher PCV), while no correlated response is expected on DWG. Selection for low FEC in lambs would, in future generations, lead to higher resistance of lambs and also of ewes. Simultaneous selection for all three traits is possible in Morada Nova lambs, which would increase performance, decrease losses due to parasite infection and reduce the need for anthelmintic treatments, with beneficial consequences regarding selection pressure on parasite populations and productivity.

Ovine β-globin gene: A new qPCR for rapid haplotype identification and association with susceptibility to Haemonchus contortus infection

Two β-globin allelic haplotypes (A and B) were identified in domestic sheep, wherein animals which are homozygous for βB allele (BB haplotype) have a deletion of pre-adult βC-globin and consequently are less tolerant to anemia and hypoxia. Since Haemonchus contortus infection, is associated with severe anemia, studies performed from 1960s to 1990s investigated the association between β-globin haplotype and resistance against this parasite. However, the findings were controversial, pointing out from increased resistance in animals harboring the βA allele to inexistence of association. Thus, our study aimed to develop a qPCR for β-globin haplotype identification, and to evaluate the association between β-globin haplotype and resistance against H. contortus in a group of sheep submitted to artificial infection with this parasite. A total of 286 lambs of Morada Nova breed were experimentally challenged with 4000 H. contortus L3 and monitored for 112 days from weaning. Significantly improved (p < 0.05) phenotypic profiles (lower fecal egg counts, higher packed cell volume and birthweight) were observed for AA haplotype animals, especially when compared to BB animals, while AB animals were similar to BB. This is the first report of a qPCR assay for ovine β-globin haplotype identification. In view of significant differences of phenotypic profiles between haplotype groups, the developed qPCR may constitute an important tool for sheep producers to improve genetic selection of parasite resistant animals.

Prevalence and Faecal Egg Counts of Gastrointestinal Parasites of Merino Sheep in Lesotho

The present study aimed to evaluate the effect of the agroecological zone, host age, and gender on the prevalence and faecal egg load of gastrointestinal parasites (GIPs) for six months (July to December) in the Maseru and Quthing districts, Lesotho. A total of 1919 faecal samples were examined using the McMaster technique. The data were analyzed through generalized estimating equations (GEE) under the binary logistic regression model to determine the significant differences for the GIPs prevalence. Moreover, faecal egg counts (FEC) data were analyzed for repeated measures using GEE. In total, three types of GIPs, namely nematodes, coccidia, and cestodes were identified in this study. The overall prevalence rates of nematodes, coccidia, and cestodes were 53.9%, 46.5%, and 4.3% in the Maseru district, respectively. Furthermore, the Quthing district indicated the prevalence rates of 65.0%, 38.2%, and 0.9% for nematodes, coccidia, and cestodes, respectively. In the Maseru district, the overall faecal egg counts for nematodes, coccidia, and cestodes were within the ranges of 0-20.3, 0-90, and 0-600 eggs per gram, respectively. Additionally, the faecal egg counts in the Quthing district ranged from 0 to 8.000, 6.700, and 2.000 eggs per gram for nematodes, coccidia, and cestodes, respectively. The majority of the Merino sheep (&gt;69%) in both districts had lower faecal egg counts (100-800) per gram. The agroecological zone affected the nematode infestation in both districts. Coccidia in the Quthing was higher in the mountain areas. In the Maseru district, the nematode infestation was not age-dependent; however, in the Quthing district, the prevalence was higher in juveniles, compared to adults. Age and gender did not affect the prevalence and faecal egg counts of nematodes and coccidia. The coccidian faecal egg loads were higher in females, compared to males. Merino sheep in Lesotho are mostly infected with gastrointestinal nematodes and protozoal coccidia, which could have a tremendous impact on their health and productivity. It is, therefore, of significant importance to develop the deworming strategy for sheep of different age and gender groups in different agroecological zones.