Morbidity Parameters Associated with Gastrointestinal Tract Nematodes in Sheep in Dabat District, Northwest Ethiopia

Genetic variations of Toll-like receptor 4 gene in exon 2 of South African Dorper sheep

Objective

The study was conducted to identify the sequence variation of Toll-like receptor 4 (TLR4) in exon 2 of South African Dorper sheep.

Materials and Methods

Blood samples were collected from fifty (n = 50) South African Dorper sheep aged between 3 and 4 years. The Deoxyribonucleic acid (DNA) was extracted, amplified, and sequenced for the TLR4 gene. DNA sequencing was used to identify the sequence variations of the TLR4 gene in South African Dorper sheep.

Results

The results showed that one synonymous single nucleotide polymorphism (SNP) of the TLR4 gene in exon 2 position T2249C was identified. Two genotypes (TT and TC) were discovered from the identified SNP. The dominant genotype was TT (0.60) over TC (0.40), with the dominant allele T (0.80) over C (0.20). The results also indicated that the used population was in the Hady-Weinberg Equilibrium. Polymorphism genetic analysis findings suggest that the identified sequence variation of TLR4 in exon 2 of South African Dorper sheep was moderate polymorphism.

Conclusion

TLR4 gene at exon 2 of South African Dorper sheep had the SNP (T>C) at position 2249 bp with two genotypes (TT and TC).

Assessing periparturient ewe characteristics and nemabiome composition to guide targeted selective treatment for sustainable gastrointestinal nematodes control in sheep

Gastrointestinal nematodes (GINs) are a significant threat to the sustainability of global sheep production. Periparturient ewes play a key role in GIN epidemiology, with increased GIN faecal egg counts (FECs) in these ewes resulting in heavy pasture contamination that facilitates parasitic gastroenteritis in immunologically naïve lambs later during the grazing period. Traditionally, blanket anthelmintic treatment would suppress GIN egg outputs in these ewes and subsequent pasture contamination. However, farmers are now advised to implement targeted selective treatment (TST) to reduce anthelmintic use and subsequent anthelmintic resistance development, yet, there is currently limited evidence to determine optimal TST strategies in ewes. In this study, the characteristics of 226 ewes on seven Welsh farms were assessed postlambing to identify factors associated with their individual strongyle FECs using negative binomial mixed model analysis. Nemabiome analysis was conducted on 34 ewes across two study farms using the Oxford Nanopore MinIon platform with an aim of identifying factors associated with variations in ewe nemabiome composition within flocks. The best-fitted model of ewe FEC incorporated ewe body condition score, dag score, breed, and an interaction effect between ewe age and litter size as fixed factors. The addition of a mean FEC value for ewes of a specific litter size on each farm further improved model fit and reduced between-farm variance in the model. Nemabiome analysis revealed significant variation in within flock nemabiome diversity on individual farms, with significantly reduced nemabiome diversity recorded in ewes exhibiting dags and in twin-bearing ewes on respective farms, whilst T. circumcincta was present as a significantly higher proportion of the nemabiome in Suffolk ewes and twin bearing ewes (P < 0.05) in respective flocks. Our data demonstrate that commonly recorded ewe characteristics can be exploited to predict individual periparturient ewe FEC and subsequently may be used as a guide for TST strategies on sheep farms once specific TST thresholds are identified to deliver the optimal balance between minimal pasture contamination and maximal GIN refugia. This study is the first to utilise Oxford Nanopore MinIon sequencing to evaluate the nemabiome of sheep, and to molecularly assess the nemabiome of individual ruminants within a flock/herd, with results indicating that significant within flock variations in nemabiome composition which may have implications for TST and flock management strategies.

Assessment of the Epidemiology of the Gastrointestinal Tract Nematode Parasites in Sheep in Toke Kutaye, West Shoa Zone, Ethiopia

Introduction

Gastrointestinal tract nematodes are considered to be the most significant and underestimated problems that hinder sheep productivity.

Objective

This study aimed to evaluate the epidemiology of gastrointestinal tract nematode infestation of sheep in the Toke Kutaye District of West Shoa Zone, Ethiopia.

Methods

A cross-sectional study was conducted to determine the prevalence and risk factors associated with gastrointestinal tract nematode parasite infestation in sheep. Faecal samples were collected from 384 sheep and subjected to coprological examination, including direct smear, flotation techniques, and Baermann techniques for screening and identifying gastrointestinal nematodes.

Results

The overall prevalence of gastrointestinal tract nematode parasite infestation in sheep in the study area was 284 (73.96%). From the total positive cases, males and females were 97 (82.91%) and 187 (70.04%), respectively. The predominantly detected gastrointestinal tract nematodes of sheep in the study area were Trichostrongylus 111 (28.91%), Oestartagia 55 (14.32%), Haemonchus 42 (10.94%), Oesophagostomum 48 (12.50%), and Trichuris 23 (5.99%). Mixed nematode eggs were noticed in some of the sheep beside the single type of nematode eggs, with a prevalence of 85 (22.14%). The relationship in the occurrence of parasites between sex, age groups, body conditions, and seasons was statistically significant (P = 0.008, P = 0.014, P = 0.001 and P = 0.003), respectively.

Conclusion

The present study is of great importance to add to the existing knowledge of the epidemiology of gastrointestinal tract nematodes of sheep, and the findings are very important to apply the proper control and prevention strategies for gastrointestinal tract nematodes of sheep in the area.

Immunoprotection Efficacy of Con A-Purified Proteins against Haemonchus contortus in Goats

Parasitic nematodes are important pathogens that infect animals, causing significant economic losses globally. Current repeated treatments have led to widespread anthelmintic resistance in nematode populations, so vaccine development offers an alternative control approach. However, only one effective vaccine (named Barbervax) has been developed to protect animals against one of the most pathogenic nematodes of ruminants—Haemonchus contortus (the barber’s pole worm). This vaccine contains a dominant component, Concanavalin A (Con A) purified H11 antigen, which has been shown to induce high levels (>85%) of immune protection in sheep breeds, but in goat breeds, the immunoprotection test of this native protein is still lacking. Here, we evaluated the protective efficacy of low-dose Con A-purified proteins for controlling the H. contortus infection in goats. Four-month-old Boer goats were equally divided into two vaccinated groups of 5 μg and 10 μg native proteins, and one adjuvant control. Each goat was immunized subcutaneously thrice and then challenged with 7000 infective third-stage larvae (L3s). The fecal egg count (FEC), degree of anemia, antibody levels of serum and abomasum mucosa, as well as worm burdens, were detected in experimental goats. Our results showed that both 5 μg and 10 μg vaccinated groups induced the effective protection in goats, reduced mean FEC by 71.8% and 68.6%, and mean worm burdens by 69.8% and 61.6%, respectively, compared to the adjuvant control. In addition, we detected that the serum antibody responses to the Con A-purified proteins were dominated by the IgG subtype, but the mucosal antibody responses were not detected. These data demonstrate Con A-purified proteins induced effective immunoprotection in goats, and underline their significance for controlling this widespread parasite.

Differences in burden of gastrointestinal nematode infestations in indigenous does foraging in grassland and forestland vegetation types

Gastrointestinal nematode (GIN) infestations remain a major challenge to the health, productivity and reproductive performance of small ruminants. A longitudinal study was conducted to assess the effect of vegetation type, season and parity on the burden of GIN in indigenous does that were foraging in grassland and forestland vegetation types. Body condition scores (BCS), packed cell volume (PCV), FAMACHA score and faecal egg counts (FEC) were determined in Xhosa lob-eared does (n = 165) during the cool-dry, hot-wet and post-rainy seasons in both vegetation types. Faecal samples were collected from the rectum and analysed using the modified McMaster technique. There was a significant association between vegetation type and season on the recorded BCS, body weight (BW), FEC, PCV and FAMACHA scores. Xhosa lob-eared does in the forestland had higher (P < 0.05) BCS as compared to those in grassland. Higher FEC (P < 0.05) were observed in Xhosa lob-eared does in the grassland vegetation compared to those in forestland. Body condition scores, FEC and FAMACHA scores were significantly higher in the hot-wet season than cool-dry and post-rainy seasons, while PCV was significantly higher during the cool-dry compared to hot-wet season in forestland. Strongyles and Strongyloides eggs were higher in does grazing in the grassland than those in the forestland during the hot-wet season. Strategies for the effective control of GIN in goats should consider that infestation levels differ with vegetation type, season and parity. Controlling of GIN in goats, therefore, requires an integrated control strategy that should consider the vegetation type that the goats are reared on.

Epidemiology and spatio-temporal distribution of gastrointestinal parasites infection and accuracy of FAMACHA test in sheep in traditional farming systems in Burkina Faso

Blood and faecal samples from 2086 Sahelian and Djallonke sheep have been collected to assess the epidemiology and spatio-temporal distribution of gastrointestinal parasites. A survey with a questionnaire allowed collecting data on individual animal and farms. Faecal samples were analysed using the McMaster technique, while anaemia was assessed using FAMACHA score test and packed cell volume. The overall prevalence of gastrointestinal parasites was 91%, and strongyles (70.7%), Eimeria sp. (60.4%), Moniezia sp. (5.7%), Stronyloides sp. (0.9%) were identified. There was no significant association between the region and strongyles infection (P ˃ 0.05). Animals sampled during the rainy season (n = 565; P = 82.2%, mean EPG = 154.8 ± 12.02) were mostly and heavily infected than those from the hot dry (n = 518; P = 74.2%; mean EPG = 97.7 ± 17.4) and the cold dry season (n = 392; P = 55.5%; mean EPG = 24.5 ± 19.5) (P ˂ 0.05). Females (n = 1027; P = 72.1%; mean EPG = 77.6 ± 17) were most infected than males (n = 448; P = 67.7%; mean EPG = 61.6 ± 19.5) (P ˂ 0.05). Animals that were treated, at most 3 months before sampling (n = 166; P = 61.5%; mean EPG = 41.7 ± 21.4), were less infected than those, which received this treatment after three months before sampling (n = 199; P = 74.8%; mean EPG = 89.1 ± 15.8) (P ˂ 0.05). Data from blood samples indicate that 6.5% of sheep was anaemic (PCV ≤ 19%), while 59.7% was noted anaemic regarding FAMACHA scores. PCV values varied significantly for FAMACHA scores, and the highest mean value was noted for score 1 (27.6) (P ˂ 0.05). The Cohen's kappa score between FAMACHA and PCV was 0.02. These findings suggest that strongyles infections are significantly associated with season, and heavier infections were noted during rainy season.

An epidemiological study of gastrointestinal nematode and Eimeria coccidia infections in different populations of Kazakh sheep

This is an epidemiological study on the gastrointestinal nematode (GIN) and Eimeria coccidia infections in Kazakh sheep and the F1 and F2 generations of Kazakh × Texel sheep crosses. A total of 7599 sheep fecal samples were collected from the Zhaosu County and Nilka County in Ili Kazakh Autonomous Prefecture in the four seasons-spring, summer, autumn, and winter of 2019. The parasite causing the infection was identified by the saturated saline floating method, and the infection intensity was calculated by the modified McMaster method. SPSS19.0 was used to evaluate the differences in the fecal egg count (FEC) of for GIN and the fecal oocyst count (FOC) value of for coccidia per sample. The results showed that there were nine types of sheep GIN infections and Eimeria coccidia in these two counties of Ililocations, with the dominant parasite species of Haemonchus contortus, Trichostrongylus spp., and Ostertagia spp as the predominant parasites in the sheep. Most of the GIN and coccidia infections in these two regions were mild and moderate. The mean log (FEC) of GIN infection in the Zhaosu area was significantly higher than that in the Nilka area, whereas the mean log (FOC) of coccidia infection in Zhaosu was significantly lower than that of Nilka. The mean log (FEC) of GIN infection in the four seasons was the highest in spring, followed by in summer, then in autumn, and the lowest in winter. The mean log (FOC) of coccidia infection was the highest in spring, followed by in autumn, and was the lowest in summer and winter. The mean log (FEC) of GIN infection and log (FOC) of coccidia infection of Kazakh sheep was significantly higher than the F1 generation, which was then significantly higher than the F2 generation of summer. A positive correlation was found between the EPG and OPG levels in the sheep. These results showed that the GIN and coccidia infection intensities of the F1 generation sheep of Kazakh ×Texel crosses were significantly lower than that of Kazakh sheep paving the way for marker-based resistance selection.

Anthelmintic resistance and prevalence of gastrointestinal nematodes infecting sheep in Limpopo Province, South Africa

Background and Aim:

Previous studies recorded the prevalence of gastrointestinal nematodes (GIN) in Limpopo Province. However, the studies did not address the seasonal patterns of infection and did not cover all districts of Limpopo Province, namely; Capricorn, Sekhukhune, Waterberg, Mopani, and Vhembe. It is, therefore, important to provide up to date information on the prevalence and seasonal occurrence data of GIN in all districts of Limpopo province. The present study was conducted to determine the occurrence of anthelmintic resistance (AR) and document the prevalence of GIN infecting sheep in five districts of Limpopo Province, South Africa.

Materials and Methods:

Forty animals in each district were used for fecal egg count reduction test (FECRT) to determine AR against ivermectin (0.2 mg/kg), levamisole (LEV) (5 mg/kg), and albendazole (7.5 mg/kg). Egg hatch test (EHT) was used to determine AR against thiabendazole (TBZ) and micro-agar larval development test (MALDT) was used for both TBZ and LEV. Naturally, infected sheep (n=780) were sampled for prevalence across five districts of Limpopo. FAMACHA^© eye-color score estimations were also performed for each study animal.

Results:

FECRT showed occurrence of AR in most of the districts and a few with suspected resistance. EHT results showed AR development against TBZ for all districts, while the MALDT showed no AR against LEV in all districts, but detected AR against TBZ in Sekhukhune, Capricorn, and Waterberg. Haemonchus contortus was the most resistant species. A high nematode prevalence (88-100%) and 1210-1861 eggs per gram (EPG) was observed in all districts during the hot wet season, decreasing to 75-80% (453-1202 EPG) during the cold dry season. The sheep revealed a FAMACHA^© mean score of 3, indicating mild anemia during the hot wet season except for Vhembe district that revealed a FAMACHA^© mean score of 4 during the hot wet season, indicating anemia.

Conclusion:

AR recorded in Limpopo Province may be due to under-dosing caused by lack of weighing equipment and high treatment frequencies due to lack of proper training on anthelmintic use. The detection of AR in Limpopo is an important finding because it will help in outlining effective management systems against GIN.

Iceberg Indicators for Animal Welfare in Rural Sheep Farms Using the Five Domains Model Approach

Simple Summary

Animal welfare is difficult to quantify, especially among farmers, in extensive rural sheep farms where there is a low level of animal interaction and a lack of technology. In this study, we searched for iceberg indicators of animal welfare using the Five Domains Model approach, and studied the relationship among sheep flight distance, sheep handling training and job satisfaction in extensive rural sheep systems. A structured survey was used to obtain socio-demographical, job satisfaction and sheep handling training data. A full animal welfare evaluation was performed on all farms; furthermore, a health status examination was also made in which blood and stool samples were taken. Four iceberg indicators were found with the potential to predict overall animal welfare scores on farms, and one to study state of mind in extensive rural sheep systems, as well as interactions among job satisfaction, training in sheep handling and sheep mind state.

Abstract

Animal welfare for sheep in extensive rural farms is difficult to quantify among rural farmers due to several factors, including the lack of technology and the low level of interaction they have with the animals. The purpose of this study was to search for animal-based iceberg indicators using the Five Domains Model approach and study the relationship between sheep reactive behavior (flight distance), sheep handling training and farmers job satisfaction. Thirteen extensive commercial dual-purpose sheep farms (n = 520 animals) were evaluated in Marulanda, Caldas (Colombia, South America). On-farm Animal Welfare Indicators (AWIN) were assessed using an adapted version of this protocol. Socio-demographic characteristics, sheep handling training and job satisfaction were evaluated using a structured interview. Blood and stool samples were taken to determine Fecal Egg Count and Packed Cell Volume. Bivariate regression models were used to find animal-based indicators that predicted Nutrition, Ambience, Health and Behavior welfare domains, and a Qualitative Behavior Analysis was used for mind state domain analysis. Body condition score (BCS) (p = 0.001), fleece cleanliness (p = 0.03), FAMACHA© Score (p = 0.05), and flight distance in meters (p = 0.19) were found to be indicators, and were useful for predicting overall welfare assessment (R2 = 0.85) on theses farms. Regarding mind welfare domain, Qualitative Behavioral Assessment found two principal components (PC) that explained 82% and 67% of the variance, and described emotional valence and energy levels of sheep, respectively. Sheep handling training (β = −8.75, p = 0.004) and job satisfaction (β = −7.5, p = 0.013) had a negative association with the average flock flight distance. Spearman’s rank correlations were significant (p < 0.001) between Fecal Egg Count, Packed Cell Volume, FAMACHA© Score (FS), Body Weight (BW) and, BCS. The strongest association was observed between Packed Cell Volume (PCV) and Fecal Egg Count (FEC) (r = −0.43), also FS was correlated with PCV (r = −0.28) and FEC (r = 0.21), and BCS was correlated with weight (r = 0.32). We suggest that these animal-based indicators could be useful as iceberg indicators for extensive sheep production systems and may set the ground for more research in small extensive sheep farms to develop strategies to find welfare problems and solutions.

Evaluating the relationship between fecal egg count, FAMACHA score, and weight in dewormed and non-dewormed Katahdin rams during a parasite challenge

The objective of this study was to evaluate and to estimate the relationship between fecal egg counts (FECs) and FAMACHA score and the body weight of growing Katahdin rams during a parasite challenge. One of the largest factors negatively influencing reproduction and economics in the sheep industry is gastrointestinal nematode (GIN) parasites. Due to anthelmintic resistance of these parasites, animals are selected for parasite resistance using FEC and FAMACHA scores. Data were used from the Virginia Tech Southwest Agricultural Research and Extension Center Ram Test in Glade Spring, VA, from the year 2012 to 2018 in which animals were tested in 14-d intervals for 70 d. Mixed models for repeated weight measurements were made from backward stepwise selection to evaluate the relationships between weight and GIN FEC. A total of 576 animals within 23 contemporary groups derived from test year and pasture group were analyzed. Ram, contemporary group, and consignor were considered random effects, and fixed effects were birth type, test day, age, age squared, starting weight, FEC, and FAMACHA score. Pairwise contrasts were used in the statistical analysis of parameters and their interactions. Weight and age were found to have a quadratic relationship. Increased FEC was associated with weight loss at a rate of 0.00030 kg/FEC (P < 0.0001). Animals dewormed at any point during the trial weighed less than those that were not and increased with test day to a maximum difference of 4.66 kg (P < 0.001). FAMACHA score was found to be significant (P < 0.05), but a direct relationship with weight was not conclusive. Overall, rams with severe enough parasite load to require deworming had lesser weights, which could impact the profitability of sheep production and reinforced the need to select animals that had greater innate parasite resistance.

Effects of Feeding Garlic Powder on Growth Performance, Rumen Fermentation, and the Health Status of Lambs Infected by Gastrointestinal Nematodes

Simple Summary

Non-chemical strategies to control gastrointestinal nematodes (GINs) infection are urgently needed to support the sustainable development of the livestock industry. The potential anti-parasitic properties in garlic powder to control sheep GINs was investigated in this study. The key finding of this study was that feeding garlic powder increased growth performance of lambs infected with GINs by decreasing fecal egg counts and improving feed digestion, rumen fermentation, and the health status of lambs.

Abstract

For the study, forty lambs were weighed and assigned into two treatments to determine the effects of feeding garlic powder on growth performance, rumen fermentation, and the health status of lambs infected with gastrointestinal nematodes (GINs). The lambs were fed with a basal diet without or with 50 g/kg garlic powder for 84 d. Data were analyzed by a general linear or mixed model of SAS software and differences were considered statistically significant if p ≤ 0.05. Results showed that garlic powder supplementation increased the lambs’ average daily gain (p = 0.025), digestibility of dry matter (p = 0.019), and crude protein (p = 0.007). No significant changes were observed on the dry matter intake, feed conversion ratio, as well as the apparent digestibility of lipid and fiber. An interactive effect between treatment and feeding day was observed on ruminal pH (p < 0.001) and ammonia nitrogen concentration (p < 0.001). Ruminal pH (p < 0.001) and ammonia nitrogen concentration (p < 0.001) decreased with garlic powder supplementation, while ammonia nitrogen concentration increased (p = 0.001) with the extension of the feeding period. Garlic powder supplementation increased the total volatile fatty acid concentration (p < 0.001) in the rumen fluid, the molar proportion of acetic acid (p = 0.002), propionic acid (p < 0.001), and isovaleric acid (p = 0.049), but it decreased the ratio of acetic acid to propionic acid (p = 0.015). The lambs’ fecal egg count decreased (p < 0.001), but the packed cell volume and body condition scores of lambs increased (p < 0.001) with garlic powder supplementation. In conclusion, feeding garlic powder increased growth performance, feed digestion, rumen fermentation, and the health status of lambs infected with GINs.