Impact on productivity of peri-parturient rise in fecal egg counts in Creole goats in the humid tropics

An insight into the epidemiology of foodborne zoonotic fascioliasis in small ruminants in northwestern region of Bangladesh

Fascioliasis is one of the most common foodborne zoonotic infection of ruminants in Bangladesh. To estimate the prevalence and associated risk factors of fascioliasis and extent of liver damage, 825 livers of sheep and goats were randomly inspected during onsite slaughterhouse visiting in Naogaon, Natore, Rajshahi and Joypurhat districts. The overall prevalence of fascioliasis was 25.09% and significantly (P = 0.008) higher in goats (26.11%) than sheep (24.00%). During gross inspection, Fasciola infected livers were increased in size, fibrosed, fatty, multiple white or reddish necrotic foci on the parietal surface, hard to cut, calcified, and numerous mature and immature flukes were also observed. In histoarchitecture, inflammatory cell infiltration in the hepatic parenchyma and periportal area, fibrous connective tissue proliferation around necrotic area, hyperplastic bile duct, congestion, and primary biliary cirrhosis were seen in acute and chronic fascioliasis. Epidemiological investigations revealed that fascioliasis was higher in goats than sheep. Age, sex, BCS and season were found to have statistically significant associations with fascioliasis in goats. In case of sheep, age (OR = 5.8671; 95% CI: 2.9482-11.6757, P < 0.0001), sex (OR = 3.7317; 95% CI: 1.9052-7.3094, p < 0.0001), BCS (OR = 6.0346; 95% CI: 1.7986-20.2472, p < .0001), and season (OR = 8.2308; 95% CI: 3.9922-16.9693, p =  < .0001) were also found to have statistically significant associations with fascioliasis. Results of the study can help for molecular epidemiology of fascioliasis in small ruminants to plan fluke control programs for safe food production.

Morphometry and genetic diversity pattern of Cysticercus tenuicollis, an important food-borne taeniid metacestode in goats in Bangladesh

Cysticercus tenuicollis is a larval stage of Taenia hydatigena resulting in cysticercosis, and responsible for enormous economic loses, especially in livestock production. Here, we planned to determine the prevalence and explore genetic variation of C. tenuicollis isolated from goats based on small subunit ribosomal RNA (rrnS) and cytochrome oxidase subunit 1 (cox1). To do this, samples were collected from different slaughter houses of municipal areas such as Bramhapalli slaughterhouse, Jubileeghat slaughterhouse and Mesuabazar slaughterhouse at Mymensingh sadar, and tentatively identified by morphological and morphometrical analysis. To study genetic variation, DNA was extracted from C. tenuicollis, and amplified rrnS and cox1 genes using specific primers, and were sequenced. Among 1372 examined animals, 177 (12.9%) were infected with C. tenuicollis. Cysts were recovered from peritoneum (7.9%), liver (4.4%) and urinary bladder (0.6%) of the infected animals. Females (18.9%) and adults (20.7%) were significantly more susceptible than male (8.8%) and young (9.3%), respectively. Genetic analysis defined 8 distinct rrnS genotypes and 9 unique cox1 haplotypes among 20 C. tenuicollis isolates. The nucleotide diversities were 0.00283 and 0.00434 for rrnS and cox1 genes, respectively. Neighbor joining (NJ) trees of rrnS and cox1 gene were constructed and the studied sequences were clustered with reference sequences of T. hydatigena with strong nodal support (100%). To compare Bangladeshi isolates, a median joining network was constructed with the population from other geographical regions and hosts. This led to a clustering pattern, but the clusters were not built with unique geographical regions or hosts. In conclusion, this is the first study that describes the genetic variation of T. hydatigena population and suggests the existence of host-specific variants. Therefore, it is fundamental to dispose infected viscera, restrict dog movement and proper management of slaughter house for the prevention and control of cysticercosis.

An Artemisia cina n-hexane extract reduces the Haemonchus contortus and Teladorsagia circumcincta fecal egg count in naturally infected periparturient goats

The objective of this study was to evaluate an n-hexane extract of Artemisia cina (Acn-h) as a natural anthelmintic treatment for periparturient goats naturally infected with the nematodes Haemonchus contortus and Teladorsagia circumcincta. A total of 200 periparturient Alpine and Nubian goats were used. Deworming criteria were based on the following parameters: fecal egg account (epg), ocular mucosa color (OMC), and body condition (BC). A previous analysis using coprocultures of the flock revealed the presence of H. contortus (80%) and T. circumcincta (20%). The Acn-h contained two new compounds identified by mass spectrometry data as isoguaiacin and norisoguaiacin at 284.14 and 315 m/z. The lethal effects of Acn-h at 0.5, 1, 2, and 4 mg/mL on H. contortus adult stages were 31.6, 66.5, 81.3, and 86.9%, respectively (p < 0.05), showing similar efficacy at 2 and 4 mg/mL with albendazole (positive control group). Then, two experimental groups, with 100 goats in peripartum in each, were distributed randomly and treated at day 0 as follows: group 1 = 4 mg/kg of Acn-h as single oral dose, and group 2 = control group, treated with water (as a placebo). The epg, OMC, and BC parameters were recorded at 0 (periparturient period), 7 (birth period), and 23 (postpartum) days and analyzed using a completely randomized design with Duncan's test for comparison of means and analysis of variance. The following epg reductions were recorded in the Acn-h-treated group as follows: 20.1 ± 34.4 and 31.7 ± 38.2% at days 7 and 23 compared to the control group. During the whole experiment, no significant differences in OMC or BC were observed in relation to the control group, excepting at day 23 (p < 0.05) for BC in the group treated with A. cina. Thus, Acn-h can be a useful natural alternative tool for the control of the nematodes H. contortus and T. circumcincta in periparturient goat flocks.

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 9.5 months, 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.

Effects of creep feeding and its interactions with other factors on the performance of meat goat kids and dams when managed on pasture

Creep feeding and its possible interactions with other influential factors (genetics, litter type, and sex) for weaning traits were studied in meat goat kids and their dams. Kids across 3 yr were creep fed (254 kids; 5 pens) or not creep fed (255 kids; 5 pens) from 30 to 90 d of age. Creep-fed kids had higher (P ≤ 0.05) preweaning average daily weight gain and weaning weights (113.1 ± 13.0 g/d; 15.0 ± 0.8 kg) than kids not creep fed (99.8 ± 13.1 g/d; 14.0 ± 0.8 kg). However, financial returns were not higher (P > 0.05) for creep-fed kids compared with kids not creep fed. There was no difference (P > 0.05) in kid conformation score or survival rates between the treatment groups. The only important interaction among kid traits was treatment × litter type (P < 0.05) for FAMACHA scores. Within noncreep pens, single kids had lower (better; P < 0.05) FAMACHA scores (2.9 ± 0.3) than twin kids (3.9 ± 0.3). There was no litter-type effect on FAMACHA scores for kids within the creep feed pens. Dams of the creep-fed (n = 175) and noncreep (n = 178) kids were also evaluated. Treatment did not affect (P > 0.05) litter weights, dam weight change, gross revenue for weaned litters, or fecal egg counts. Treatment interacted with litter type (P < 0.05) to effect packed cell volume (PCV). In the noncreep group, dams raising singles had higher (better; P < 0.05) PCV (18.7 ± 1.3%) than dams rearing twin kids (15.7 ± 1.3%). The litter-type effect on dam PCV was not evident (P > 0.05) in the creep-fed group. Creep feeding improved some kid growth traits but did not improve dam traits or financial returns. Interactions of creep treatment with other factors were minimal for doe-kid traits.

Biology, Epidemiology, and Control of Gastrointestinal Nematodes of Small Ruminants

Strongylid gastrointestinal nematodes are an important cause of disease and economic loss in small ruminants. These parasites are important in most of the United States, with the bloodsucking parasite Haemonchus contortus being the predominant species of concern. Sheep and goats are infected while grazing, and the biology of infective larvae on pastures is important in the design of parasite management programs. Widespread resistance to anthelmintics requires strategies designed to preserve remaining drug activity; these include combination treatments with multiple classes of anthelmintics and targeted treatments.

Gastro-intestinal nematodes in goats in Bangladesh: A large-scale epidemiological study on the prevalence and risk factors

Goats greatly influence the economic sustainability of rural communities. However, parasitic diseases, especially gastrointestinal nematodes (GINs) are a major constraint on profitable small ruminants' production worldwide. During July- 2015 to June- 2016, we conducted a cross sectional study within seven topographic zones of Bangladesh to explore the level of infection and associated risk factors of GINs infections of goats. The study followed standard flotation and modified McMaster techniques. Among 1998 samples from goats; 1241 (62.1%) were found to be infected with one or more species of GINs by fecal examination for nematode eggs. The identified nematodes were strongyles (51.9%), Strongyloides sp. (19.0%) and Trichuris spp. (2.9%). By coproculture, we identified Haemonchus spp., Oesophagostomum spp., Trichostrongylus spp. and Bunostomum spp. in the different topographic zones. According to univariate analysis; young age, other breed than Black Bengal, animals in poor condition, backyard rearing system, muddy housing, illiterate farmers and rainy season were found significantly associated with GINs infections. Besides, other breed than Black Bengal, animals in poor condition, backyard rearing system, muddy housing and illiterate farmers were identified as the risk factors of GINs infections in goats. This is the first detailed epidemiological investigation of GINs of goats in Bangladesh. The epidemiological findings are expected to help formulate effective control strategies against GINs infections in goats by improving health status of animals, management system and education level of the farmers.

Factors associated with strongyle infection in goats at the individual and farm level

OBJECTIVE To identify factors associated with strongyle infection and parasite reduction strategies associated with low strongyle fecal egg counts (FECs) in goats on farms in North Carolina. DESIGN Cross-sectional study. ANIMALS 631 adult goats on 52 farms in North Carolina. PROCEDURES Participating farms were visited to collect fecal samples from goats and administer a survey regarding goat, environmental, and management factors. The McMaster technique was used to determine strongyle FEC for each sample. Univariate followed by multivariate modeling was performed to identify factors associated with FEC at the farm and individual goat level. RESULTS Multivariate analysis controlling for several other factors and multiple comparisons revealed that farms on which no anthelmintic drugs had ever been used had the lowest mean FECs, compared with farms on which specific strategies for parasite control were used; no other variables were significant. For individual goat FEC, significant variables included goat breed, breed type, owner-defined purpose, daily dietary protein intake, and fecal coccidia score. In particular, companion goats (vs meat or dairy goats) had the lowest FECs. Higher dietary protein intake and coccidia scores were associated with higher FECs. Among females, goats that had kidded in the last 6 weeks had the highest FECs. CONCLUSIONS AND CLINICAL RELEVANCE Various factors were identified that appeared to influence the likelihood of strongyle infection in goats. The finding that farms with no history of anthelmintic use had the lowest mean FECs suggested that a focus on preventative measures could reduce the need for anthelmintic drugs and, by extension, lessen the opportunity for the development of anthelmintic resistance.

Epidemiology and effect of gastrointestinal nematodes on dairy goats in Argentina

The aim of this work was to study the epidemiology and harmful effects of gastrointestinal nematodes (GINs) on dairy goats maintained in an intensive system. Two groups of goats were studied: untreated group (UG) (subdivided into UGjun goats that kidded in June, and UGjul goats that kidded in July) and treated group (TG) (with no subgroups, treated with monepantel: 3.75 mg/kg, orally, monthly). Eggs per gram (epg) in faeces were counted, faecal culture was performed to differentiate nematode genera and milk production was measured. Differences between groups were compared using least squares means analysis of variance (milk production and milking period length) and Kruskal–Wallis test (faecal egg counts). Nematode infection was moderate, with Haemonchus and Trichostrongylus being the dominant genera; the faecal egg counts reached the level of 2000 only once throughout the study. Goats that kidded in June had higher egg count after parturition (UGjun = 1564 epg), with significant differences (p < 0.04) from those that still had not kidded (UGjul = 962 epg). Over the entire trial period, the mean total milk production of TG (399.5 L ± 34.0 L) was significantly higher (p < 0.05) than that of UG (281.6 L ± 37.5 L), representing an increase of 41.8% in total milk yield. The results of this study show a post-partum peak in egg count and a negative effect of GINs on milk yield, even with moderate infections.

Effect of Moxidectin Treatment at Peripartum on Gastrointestinal Parasite Infections in Ewes Raised under Tropical Andes High Altitude Conditions

This study tested the impact of moxidectin at peripartum on nematode fecal egg count (FEC) and clinical parameters on ewes in the high altitude tropical Andes of Colombia. FEC and clinical evaluations were performed on 9 occasions in 43 naturally infected ewes before and during gestation and after lambing. Moxidectin (Mox, 200 µg kg(-1)) was applied at late pregnancy (T 1, n = 15) or 48 hours after parturition (T 2, n = 14). 14 untreated ewes served as controls (C). Suckling lambs (n = 58) remained untreated and underwent four clinical and parasitological evaluations until 8 weeks after birth. Mox efficacy equaled 99.3% (T 1) and 96.9% (T 2). Highest mean FEC value reflecting periparturient nematode egg rise (PPER) was recorded in C ewes at 4-6 weeks after lambing. Significant FEC reductions were found in T 1 (94.8%) and T 2 (96.7%) ewes (p < 0.05). All lambs showed a significant and ewes-group independent increase in FEC before weaning (p < 0.05). Clinical parameters (anemia and diarrhea) showed time- and treatment-related differences (p < 0.05). Monitoring of FEC and clinical parameters linked to gastrointestinal parasite infections allowed demonstrating that postpartum or preweaning are two critical periods to nematode infection for sheep raised under tropical Andes high altitude conditions. Use of Mox as anthelmintic treatment prevented PPER.

Economic values of body weight, reproduction and parasite resistance traits for a Creole goat breeding goal

A specific breeding goal definition was developed for Creole goats in Guadeloupe. This local breed is used for meat production. To ensure a balanced selection outcome, the breeding objective included two production traits, live weight (BW11) and dressing percentage (DP) at 11 months (the mating or selling age), one reproduction trait, fertility (FER), and two traits to assess animal response to parasite infection: packed cell volume (PCV), a resilience trait, and faecal worm eggs count (FEC), a resistance trait. A deterministic bio-economic model was developed to calculate the economic values based on the description of the profit of a Guadeloupean goat farm. The farm income came from the sale of animals for meat or as reproducers. The main costs were feeding and treatments against gastro-intestinal parasites. The economic values were 7.69€ per kg for BW11, 1.38€ per % for FER, 3.53€ per % for DP and 3 × 10(-4)€ per % for PCV. The economic value for FEC was derived by comparing the expected profit and average FEC in a normal situation and in an extreme situation where parasites had developed resistance to anthelmintics. This method yielded a maximum weighting for FEC, which was -18.85€ per log(eggs per gram). Alternative scenarios were tested to assess the robustness of the economic values to variations in the economic and environmental context. The economic values of PCV and DP were the most stable. Issues involved in paving the way for selective breeding on resistance or resilience to parasites are discussed.

Implementation of herd health program to improve survival of Boer goats in Malaysia

A Boer goat breeding farm with 800 heads of breeder females, 50 breeder males, and 400 growing goats of various ages in Sabah, Malaysia was selected to study the effect of implementing herd health program. This included vaccination program against pneumonic mannheimiosis; fecal monitoring for helminthiasis, coccidiosis, and colibacillosis; and introduction of modified feeding regime comprised of day-time grazing and feeding of cut grass and supplemented feed. The herd health program was implemented in September 2007 and the impact was observed on body weight gains, body scoring, and annual mortality among adults and kids. It was found that implementation of herd health program significantly (p < 0.05) increased the average body weight gains in both adults and kids from 1.8 g per kid and 0.6 g per adult in 2006 to 3.7 g per kid and 2.2 g per adult in 2008. The percentage of adults with body scoring of <3 was significantly (p < 0.05) reduced from 82.3% in 2006 to 77.6% in 2007 and 4% in 2008. Similarly, the annual mortality rate was significantly (p < 0.05) reduced from 6.5% among kids and 58.2% among adults in 2006 to 12.1% among kids and 10.4% among adults in 2007, and to 9.1% among kids and 1.1% among adults in 2008. Therefore, it was concluded that implementation of herd health program significantly improved the survival and performance of goats.

Influence of periparturient nutritional demand on resistance to parasites in livestock

Periparturient relaxation of immunity (PPRI) to gastrointestinal nematode parasites may have a nutritional basis, as the increasing nutrient demand at times of nutrient scarcity during late pregnancy and subsequent lactation may result in a penalty on expression of acquired immunity to parasites. This nutritional basis implies that lowering nutritional demand, at constant nutrient supply, should reduce the degree of PPRI. Evidence to support the latter is reviewed through exploration of the effects of reproductive effort on periparturient resistance to parasites. A large body of evidence shows that a lower nutritional demand arising from rearing single rather than multiple lambs and/or kids consistently reduces the degree of PPRI in small ruminants, as manifested by reduced worm burdens and/or nematode egg excretions. Such variation in reproductive effort may also account, at least to some extent, for the often observed between-breed differences in PPRI, which may arise from differences in production potential, and thus nutritional demand. A reduction in nutrient demand can reduce the degree of PPRI in a matter of days. However, host immune responses associated with this nutritional sensitivity of host resistance remain to be elucidated, which may be achieved through a recently established periparturient rodent model.

Nutrition-parasite interactions in goats: is immunoregulation involved in the control of gastrointestinal nematodes?

Compared to sheep, goats seem to develop a low immune response against the parasitic nematodes of the gastrointestinal tract. Nevertheless, some variability in the host response has been observed either at the individual level or depending on internal (genetic) or external (physiological status, nutrition) factors suggesting the possibility to exploit and manipulate this response. There is good evidence from field studies to suggest that a better plane of nutrition might contribute to improve goat resilience. However, the effects on immunoregulation and host resistance remain less clear. Due to their peculiarities in feeding behaviour ('intermediate browser'), goats represent a valuable model to explore the relationships between the three possible strategies to control nematode infection through nutrition: (i) by increasing the immune response; (ii) by avoiding the infective larvae; and (iii) by selecting plants with direct anthelmintic properties (self medication).

Genetic variability in resistance to gastro-intestinal strongyles during early lactation in Creole goats

The study was undertaken in a Creole goat flock at INRA-Gardel in Guadeloupe, to evaluate the opportunity to use artificial selection as a means of controlling gastro-intestinal infection during early lactation. The flock grazed all year on Digitaria decumbens pastures. Faecal and blood samples were taken from kids at 11 months of age and from does at kidding before drenching (week 0) and at weeks 4 and 6 after kidding. Faecal egg counts (FEC) were estimated using a modified McMaster method. Blood samples were used to determine packed cell volume (PCV) and eosinophil concentrations (EOS) values. Haemonchus contortus, Trichostrongylus colubriformis and Oesophagostomum columbianum were the main strongyle species identified in faecal cultures. The data came from 1092 litters obtained from 688 does sired by 142 bucks and 413 dams. Variance and covariance components for genetic and residual effects were estimated with multivariate animal models using the restricted maximum likelihood VCE package. Repeatability and overall heritability for FEC during the post-partum period were 0·17 and 0·10±0·02. The genetic correlations between FEC and PCV were −0·56±0·11 at 4 weeks after kidding and −0·79±0·13 at 6 weeks after kidding. The genetic correlations between FEC and EOS were 0·37±0·15 at 4 weeks after kidding and 0·68±0·17 at 6 weeks after kidding. Hence, does that contributed least to pasture contamination during the postpartum period also had low EOS and high PCV breeding values. The genetic correlations between FEC measured at 11 months of age and FEC during periparturient period ranged from 0·57±0·12 to 0·76±0·16. Therefore, breeding goats for increased resistance during the post-weaning period will lead to a less marked and less persistent rise in doe FEC during early lactation. The epidemiological implications of this selection have to be quantified in terms of lower pasture contamination, lower kid parasitism, and higher milk production of does.