Average Faecal Egg Counts Research Articles

Evaluation of a refugia-based strategy for gastrointestinal nematodes on weight gain and fecal egg counts in naturally infected stocker calves administered combination anthelmintics

Refugia-based strategies associated with a combination of anthelmintic drugs belonging to different drug classes are becoming more common management practices to mitigate anthelmintic resistance (AR) in gastrointestinal nematodes (GIN) in small ruminants. Though refugia-based strategies have been largely demonstrated in small ruminants, cattle veterinarians and producers are considering such management strategies in grazing cattle production systems. Implementing refugia-based strategies lowers the amount of anthelmintics used in the herd and therefore slows the progression of AR by allowing a proportion of worms to escape drug selection pressure. The objective of this study was to observe the effect of a refugia-based strategy on body weight (BW), average daily gain (ADG) and fecal egg counts (FEC) of trichostongyle-type nematodes in naturally infected beef calves over a 131-day grazing season when compared with a whole herd treatment strategy, using the same combination of drugs. Stocker calves (n = 160) were ranked by body weight within sex then allocated to 16 paddocks, which were randomly assigned to one of two treatment groups. All calves in Group 1 (n = 80) were administered treatment, while in Group 2 (n = 80) the steer with the highest FEC in eggs per gram (EPG) within the paddock was left untreated. Treated calves received an extended release injectable 5 % eprinomectin (LongRange®, Boehringer Ingelheim Animal Health USA Inc.; 1 mL/50 kg of BW) and a 22.5 % oxfendazole oral suspension (Synanthic®, Boehringer Ingelheim Animal Health USA Inc.; 1 mL/50 kg of BW). Fecal egg counts and BW were recorded on days (D) −35, 0, 21, 131, and 148 to calculate the average fecal egg count reduction (FECR) and ADG for both groups. Linear mixed models, with paddock as the experimental unit, were used for analyses. The EPG differed on D21 (p < 0.01) and D131 (p = 0.057) with Group 2 having a higher average FEC (15.2 EPG D21; 57 EPG D131) compared with Group 1 (0.4 EPG D21; 37.25 EPG D131). However, there was no significant difference in average BW or ADG between treatment groups throughout the study. Results suggest refugia-based strategies could be implemented without significant negative impacts on average BW and ADG across other calves in the herd.

159 Evaluation of Supplemental Feeding Behavior and Growth Performance in Katahdin Lambs Divergently Selected for Fecal Egg Count Estimated Breeding Value

Abstract Nutritional supplementation and genetic selection are potential methods to mitigate the impact of parasitism in sheep. Understanding feeding behavior of growing lambs divergently selected for parasite resistance using the fecal egg count (FEC) estimated breeding value (EBV) may help quantify the impact of supplementation and genetic selection on parasitism. The C-Lock, Inc Super SmartFeed system (feeder) allows measurement of individual lamb feed intake. The objective of this study was to evaluate the effect of FEC EBV selection on daily supplemental intake, average daily gain (ADG), supplemental feed:gain (S:G), frequency of feeder visits, and FEC. Over two years (Y1, Y2), Katahdin lambs divergently selected for FEC EBV (Y1: LowFEC, n = 27; HighFEC, n = 24. Y2: LowFEC, n = 37; HighFEC, n = 40) were fed for 8 weeks in Y1 and 5 weeks in Y2 at the Southwest Virginia Agricultural Research and Extension Center. Pasture-raised lambs were supplemented with a concentrate pellet (16% CP) ad libitum using the feeder with free choice hay in a dry lot post-weaning. Data analyses were performed by sampling period which was approximately every two weeks. Statistical analyses were performed using PROC Mixed SAS (SAS Institute, Cary, NC). In Y1, LowFEC lambs had less average FEC than HighFEC lambs (405.25 vs. 771.23 epg; P &amp;lt; 0.05). LowFEC lambs in Y2 tended to have less average FEC compared with HighFEC lambs (1,191.75 vs. 2,028.30 epg; P = 0.1). In Y1, LowFEC lambs had greater intake compared with HighFEC lambs (1.45 vs. 1.27 kg; P &amp;lt; 0.05). LowFEC lambs tended to have greater intake in Y2 (1.64 vs. 1.16 kg; P = 0.1). While ADG was not affected by FEC EBV type in Y1 (P &amp;gt; 0.70), LowFEC lambs in Y2 had increased ADG compared with HighFEC lambs (0.27 kg vs. 0.21 kg; P = 0.05). In both years, LowFEC lambs had numerically greater S:G compared with HighFEC lambs, but these differences were not significant (P &amp;gt; 0.1) due to greater variation around these means. Over both years, the number of feeder visits did not differ between LowFEC and HighFEC lambs (P &amp;gt; 0.1). Selection of sires for LowFEC EBV resulted in progeny with less FEC that had increased supplemental intake, but no difference in S:G compared with HighFEC progeny. In addition to improvements in parasite resistance, selection for FEC EBV may impact lamb feeding behavior in the post-weaning period.

Farmers' Views and Tools Compared with Laboratory Evaluations of Parasites of Meat Goats in French West Indies.

Gastrointestinal nematodes (GINs) are a major health problem in tropical goat husbandry. The control of GIN has been nearly exclusively reliant on the use of anthelmintic treatments. Their wide use has provoked the appearance and diffusion of anthelmintic resistance. Therefore, there is a need to use anthelmintics only when they are really needed. This strategy of targeted selective treatment (TST) has been recommended. The selection of animals to be treated has been based either on the objective measures of GIN intensity (fecal nematode egg counts) performed in the laboratory or on indirect assessment such as anemia (FAMACHA©), diarrhea score or weight gains, particularly in sheep. The roughness of hair has also been proposed in goats. These indicators can be handled by the farmer. Their opinion on the importance of GINs, and the indicators that they are ready to accept and use have very rarely been studied. Goat for meat production is important in the French West Indies (especially in Guadeloupe) and GIN infection may significantly alter this production. Eighteen farmers participated in semi-directive interviews in order to appreciate their relation to goat GIN infection and the solutions they considered. Seventeen farms were investigated for fecal nematode egg counts, FAMACHA©, body score, and roughness of hair. The average infection by GINs was high (average fecal egg count 1562 and standard deviation 2028) with a wide range from one farm to another (from 0 to 25,000 eggs of GIN per gram of feces). The Haemonchus genera was predominant (54%), followed by Trichostrongylus (37%) and Oesophagostomum (9%). Young goats were less infected than adult goats since they were not yet grazing; males were more infected than females; and the Creole breed was more infected than the other breeds. Among the farming types, the professional ones were less infected compared with the traditional or mixed agriculture and husbandry farms. Those using targeted selective treatment did not have a significantly higher GIN infection than those treating the whole herd. Most of the characteristics were related and multivariate analysis could not match the intensity of GIN infection with any parameter. The frequency of anthelmintic treatments was negatively related to the use of body score, FAMACHA©, and hair roughness. The use of semi-directive interviews provided a wider understanding of the strategies and problems of farmers. The farmers valued their animals very much and diseases, in general, were a preoccupation, whereas parasites were not a major issue for traditional farmers. This is due to the important use of indicators and the belief in their value that gives comfort to the farmers that the parasites are being controlled. The extension services have well diffused the practice of indicators to the goat farmers of Guadeloupe, with some depending less on anthelmintics to control the gastrointestinal nematodes by using targeted selective treatments.

Anthelmintic Potency of Garlic (Allium sativum) and Neem (Azadirachta indica) combination As Herbal Anthelmintic in Lactating Karan Fries Cows

Gastro-intestinal parasites affect the health and production performance of dairy cows under tropical and sub-tropical conditions. This study was conducted to evaluate the anthelmintic efficacy of herbal anthelmintic (Neem and Garlic combination) as an effective alternative for chemical dewormers which has chemical toxicity and resistance problems in dairy cows. For this, EPG count for gastrointestinal parasites, body weight and BCS of cows were studied. Freshly calved crossbred KF (n=28) cows were selected and divided into 4 groups (T1, T2, T3, T4), each having 7 cows. The cows of T1 were used as control; in T2, cows were provided the commercial (synthetic) dewormer; in T3 cows were provided with a dose of combination of garlic and neem in the ratio of 1:5 @ 4g/kg body wt. at 7 days after parturition and in T4, in addition to first dose at 7 days, a second dose was also supplemented at day 60. Sampling for fecal sample was done on 0, 1, 2, 3, 4, 5, 6, 7, 8 fortnights relative to the deworming treatment. The EPG counting was done by using McMaster counting chamber. The average fecal egg count (FCE) reduction was significantly (P&lt;0.05) maximum in T2 (83.20%) group followed by T4 (77.48%). The BCS and FCE were found significantly (P&lt;0.05) better in all the anthelmintic treated groups compared to control group. However, the FCE was significantly (P&lt;0.05) better in herbal treated groups (T3 and T4) compared to the synthetic anthelmintic treated group (T2). Based on the findings, it could be concluded that Garlic and Neem combination is effective herbal dewormer/anthelmintic and might be used against nematodes in dairy cattle as an effective alternative of synthetic anthelmintics drugs.Â

363 Relationship Between Parasite Load and Performance in Goat Kids at Weaning and Early Post Weaning

Abstract Goats are small ruminants that have enormous potential to boost the economy and be a major source of income especially to marginal farmers and landless laborers. A very common and economically important condition, which affects domestic livestock species worldwide, is Gastrointestinal (GI) parasitism. Haemonchus contortus is the gastrointestinal parasite most common in small ruminants. To better understand the impact of GI parasitism, a study was conducted to research the relationship between parasite load and performance in goat kids at weaning and 60 d post-weaning. Fecal samples were collected at weaning and 60 d post-weaning and egg counts were performed using the modified McMasters technique. Data collected included weights, Fecal Egg Count at weaning, and at 60 d post-weaning. The average fecal egg count at weaning was 830 eggs per gram and 1103 eggs per gram 60 d post-weaning for H. contortus. Egg count at weaning was significantly related to weight at both weaning and 60 d post-weaning (P &amp;lt; .0001 and P = .0003 respectively), but not to ADG (P &amp;gt; .05). Fecal egg count at 60 d post-weaning was not significantly related to either weight or ADG (P &amp;gt; .05). Egg counts at weaning and 60 days post-weaning were not related (P = .0708). The results indicate that early parasite infection can influence animal weights. The lack of a significant correlation between egg counts at weaning and 60 d post weaning indicates a need to evaluate parasite load at later ages in kids when selecting for resistance.

Anthelmintic effect of Indigofera tinctoria L on Haemonchus contortus obtained from sheep in Indonesia.

Background and Aim:Hemonchosis has resulted in huge economic losses for sheep farmers worldwide. Secondary metabolite compounds from Indigofera tinctoria L. can be used as anthelmintics. This study aimed to evaluate the in vitro and in vivo effects of I. tinctoria L. aqueous extract (IAE) as an anthelmintic against adult Haemonchus contortus isolated from sheep.Materials and Methods:Ten active adult worms were placed in each Petri dish containing 25 mL of IAE, each having a different concentration of IAE (at concentrations 100, 120, 140, 160, 180, 200, and 220 mg/mL). Each experiment was repeated. The positive control used 1% albendazole, and the negative control used 0.62% saline water. The number of immobile worms and the time of mortality were recorded after 2, 4, 6, and 8 h. The dead worms were subsequently tested using scanning electron microscopy (SEM) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In the in vivo study, 15 sheep with an average fecal egg count (FEC) of 1000 eggs per gram were treated with IAE for 9 days: Group A (negative control, saline water 0.62%), Group B (21 mg/mL), Group C (41 mg/mL), Group D (62 mg/mL), and Group E (positive control, albendazole 100 mg/mL). Measurements of the body weight, FEC reduction test, and hematology testing were performed on days 0, 7, and 14. SEM was performed using worms found from the abomasum of slaughtered sheep.Results:The leaves of I. tinctoria L. contained a number of secondary metabolites, including total tannins, saponins, flavonoids, and alkaloids. The most effective concentration that killed the adult H. contortus worms was 220 mg/mL (93.33% mortality) after 8 h of treatment. The electrophoresis results showed that the protein band at a dose of 22% was less than that of the control. The highest FECR value of the treatment group on the 14th day after treatment was at a dose of 62 mg/mL. The highest weight gain as well as the highest increased hemoglobin (Hb), packed cell volume (PCV), and total erythrocyte count (TEC) values on the 14th day after treatment were at a dose of 41 mg/mL. The SEM results showed that IAE treatment caused the worms’ anterior parts to become wrinkled with thick creases and cuticle abrasion (in vitro) and the anterior part to shrink along with the presence of aggregates in the worm cuticle (in vivo).Conclusion:The aqueous extract of I. tinctoria contains tannins, saponins, flavonoids, and alkaloids and has an anthelmintic effect with decreased FEC, increased weight gain, Hb, PCV, and TEC, causing damage to the worms’ body and reducing the protein profile of adult H. contortus worms.

PSX-20 Internal parasite resistance measured on pasture and in confinement of young Kiko bucks

Abstract Resistance to internal parasites (IP) is important in the sustainability of a meat goat enterprise. Langston University (LU) and the American Kiko Goat Association conducted a SecondGeneration Buck Performance Test in 2019. The performance test measured fecal egg count (FEC) and packed-cell volume (PCV) in a natural challenge of 6 wk on pasture (PAS) and in an artificial challenge in dry-lot confinement (CON). Seventy-seven Kiko bucks less than 1 yr of age completed both PAS and CON. The PAS was conducted on a 23-ha pasture with native grasses and forbs. Bucks were supplemented at 0.5% BW (25.8±0.18 kg) daily to facilitate visual inspection of animals. CON was conducted at LU’s testing facility. Bucks were sampled every 2 wk in PAS. In CON, bucks were sampled on d 29, 34, and 38 following an artificial challenge with each buck receiving 7,000 L3 Haemonchus contortus larvae. Average FEC and PCV for each buck for PAS and CON were analyzed. The correlation between FEC-PAS and PCV-PAS was -0.283 (P &amp;lt; 0.05), which is almost identical to the correlation between FEC-CON and PCV-CON (r=-0.280, P &amp;lt; 0.05). The Spearman rank correlation between FEC-PAS and FEC-CON was 0.069 (P &amp;gt; 0.50). However, the Spearman rank correlation between PCV-PAS and PCV-CON was 0.376 (P &amp;lt; 0.01). Using mixed model methods, the means for FEC-CON and FEC-PAS were similar (1,428 vs 1,698±169 epg for CON and PAS, respectively). However, PCV were different (P &amp;lt; 0.01), with 28.3 vs. 20.7±0.34 for CON and PAS, respectively. Pasture PCV was a predictor of PCV in confinement and vice versa; however, that was not true for FEC, indicating that FEC in PAS and in CON may be two separate traits. Future buck performance tests should incorporate pasture and confinement phases to more precisely identify superior bucks for IP resistance.

Sample size needed to make decisions about measuring FEC in a contemporary group of lambs

Faecal egg count (FEC) is used in sheep to decide when to drench. It is also used in genetic evaluations, in which case FEC should be recorded when the parasite burden is large enough so that variation among animals can be expressed. Another requisite is that the fraction of animals with zero FEC should be below 0.1. In order to decide the appropriate moment for drenching, or FEC recording in the whole group in the case of genetic evaluations, FEC is monitored in a random sample of animals from the group. Two questions arise: (i) what is the appropriate sample size to determine if the average FEC has reached a threshold? and (ii) what is the sample size needed to determine that the fraction of animals with a FEC of zero is 0.1 or less? In this paper we calculate the number of animals to be sampled for a range of FEC means and standard deviations, as well as for different fractions of animals with a zero FEC. Regarding FEC, we found that sample size was greater than the recommended 10 to 20 animals. With respect to fraction of animals with a FEC of zero, sample size was even greater than for FEC. Given the insufficient sample size currently used, we recommend a revision of the topic and a statistically based reformulation of sampling guidelines.

An Insight into the Potential Parasitological Effect ofSchistosoma mansoniAntigens in Infected Mice: Prophylactic Role of Cercarial Antigen

Schistosomiasis is a multifactorial disease that includes environmental, behavioral, parasitic, vector, and host factors. This study aimed to assess the protective effect of single and polyvalent antigens from cercarial antigen preparations (CAPs), soluble worm antigen preparations (SWAPs), and soluble egg antigens (SEAs) which were used as candidate vaccines in an experimental model of Schistosoma mansoni-infected mice. The efficiency of the antigens was tested by determining their effects on fecal egg count, egg viability analysis, and tissue egg counts. Histological and morphometric analyses of granulomas in liver and intestine tissues were performed. In the present study, all immunized groups showed a significant reduction in the average fecal egg count and tissue egg load compared with infected mice. The most substantial reduction in fecal egg count was observed in the combined vaccinated group (23.23 ± 3.2). The group vaccinated with CAP before infection showed the highest reduction in tissue egg load (liver and intestine: 85.22 and 91.70%, respectively). Immunized animals showed a highly significant reduction in the numbers of hepatic granulomas compared with the infected non-immunized group. In conclusion, combining these different antigens (CAP, SWAP, and SEA) augments the protective immunity compared with other immunized groups.

Gastrointestinal nematode infections do not hinder the development of Simmental X Nellore crossbred calves raised with a nutritionally enhanced diet.

An evaluation was made of the effect of anthelmintic treatments on the performance of Simmental X Nellore crossbred calves before and after weaning. To this end, the calves were divided into three groups: (1) treated monthly with a low efficacy anthelmintic drug, ivermectin; (2) treated monthly with a highly effective anthelmintic drug, albendazole; and (3) untreated control group. All the groups in this experiment showed an average fecal egg count of less than 400 eggs per gram (EPG), and no clinical signs of parasitic gastroenteritis. The blood variables were within the normal range and no calf presented anemia. In most of the samplings, mean EPGs were significantly lower (P<0.05) in the group treated with albendazole. The calves received dietary supplementation before and after weaning, which enabled them to gain weight in every month of the experiment and reach a body weight of about 250 kg on the last sampling date, before turning one year old. The anthelmintic treatments did not affect body weight gain, leading to the conclusion that, when fed with suitable dietary supplements, Simmental X Nellore crossbred calves are not affected by gastrointestinal nematode parasites acquired by grazing.

Efficacy of single topical treatment of Selamectin (Revolution®) against Ancylostoma ceylanicum in experimentally infected cats.

Ancylostoma ceylanicum, a species of hookworm, is a common parasite of dogs and cats in the Asia-Pacific region. The objective of this study was to determine the efficacy of a single topical treatment of selamectin (Revolution®) against A. ceylanicum in experimentally infected cats. 12 kittens were injected with 300 infective stage larvae (L3) of A. ceylanicum by the subcutaneous route. Faecal samples were examined daily (days 7-15) for the presence of hookworm eggs. On day 18 kittens were stratified by faecal egg count and randomly allocated in equal numbers to control (n = 6) and treatment (n = 6) groups. Faecal egg counts were then performed daily (days 14-27) or every 3 days (days 28-51) until the end of the study and compared between the treated and control groups. Kittens in the treatment group were administered a single topical dose of selamectin (Revolution®), per label recommendations (6 mg/kg), on day 19. Kittens in the control group were not treated. At 4 days post-treatment, no hookworm eggs were detected in the treated group. Faecal samples from this group remained negative throughout the study, the treatment efficacy was 100% egg reduction (P < .0001). Average faecal egg counts remained high (558 ± 231 eggs per gram) in the untreated control group until the end of the study period. In conclusion, a single topical treatment of selamectin (Revolution®) at the recommended dose was highly efficacious against infection with A. ceylanicum in cats.

Can the strategies for endoparasite control affect the productivity of lamb production systems on pastures?

ABSTRACT The objective of this study was to evaluate the productivity and carcass traits of unweaned Suffolk lambs finished on pasture and subjected to three strategies for endoparasite control: prophylactic treatment of all animals every 28 days; treatment of animals with a cut off number of nematode fecal egg count (FEC) ≥ 700; and treatment of animals using the FAMACHA scores ≥ 3. Average daily weight gain (ADG) and FEC were evaluated every 14 days for 112 days. Body condition [...]

Rhythmicity in thermal humidity index and regulation of Haemonchus contortus in sheep of semi-arid tropical Rajasthan

ABSTRACTOver the period (2012–18) at Avikanagar, the average monthly thermal humidity index (THI) varied significantly (p < 0.001) from 15.62 ± 0.19 (January) to 32.76 ± 0.14 (June), revealing that for sheep flocks the periods of non-stress and extreme stress were from November to February and April to October, respectively. Under modified worm management programme (MWMP), the monthly average faecal egg counts (FECs), Haemonchus contortus (adult and L4) counts in abomasum varied significantly (p < 0.001) from 251.52 ± 20.72 (January) to 2763.54 ± 162.07 (July), from 18.21 ± 1.21/sheep in February to 1510.41 ± 66.87/sheep in September and from 0.24 ± 0.02/abomasi (July) to 46.82 ± 1.41/abomasi (January), respectively. Over the years, the monthly interaction between THI and parasitological observations exhibited almost similar relation among parameters. Both FECs and abomasal worm count showed a positive relation with THI while a reverse pattern was exhibited for L4 counts. Overall on Pearson correlation a significant (p < 0.001) positive correlation was found between FEC and adult worm counts (r2 = 0.411) and FECs and THI (r2 = 0.253). The significantly negative correlation between FECs and L4 counts during December to March supports the occurrence of hypobiosis in H. contortus. However, significant positive correlation between FECs and L4 count during July to September suggested acquisition of fresh infection from environment. A positive correlation between FECs and THI during April to June and October to December indicated resumption of development in hypobiotic larvae could be due to stressful environment for host and initiation of hypobiosis due to non-stressful status of host, respectively.

Meta-analysis of the parasitic phase traits of Haemonchus contortus infection in sheep

BackgroundThe parasitic nematode Haemonchus contortus shows highly variable life history traits. This highlights the need to have an average estimate and a quantification of the variation around it to calibrate epidemiological models.MethodsThis paper aimed to quantify the main life history traits of H. contortus and to identify explanatory factors affecting these traits using a powerful method based on a systematic review and meta-analysis of current literature. The life history traits considered are: (i) the establishment rate of ingested larvae; (ii) the adult mortality rate; (iii) the fertility (i.e. the number of eggs laid/female/day); and (iv) fecundity of female worms (i.e. the number of eggs per gram of faeces).ResultsA total of 37 papers that report single experimental infection with H. contortus in sheep and published from 1960 to 2015, were reviewed and collated in this meta-analysis. This encompassed 115 experiments on 982 animals. Each trait was analysed using a linear model weighted by its inverse variance. The average (± SE) larval establishment rate was 0.24 ± 0.02, which decreased as a function of the infection dose and host age. An average adult mortality rate of 0.021 ± 0.002) was estimated from the literature. This trait varied as a function of animal age, breed and protective response due to prior exposure to the parasite. Average female fertility was 1295.9 ± 280.4 eggs/female/day and decreased in resistant breeds and previously infected hosts. Average faecal egg count at necropsy was 908.5 ± 487.1 eggs per gram of faeces and varied as a function of infection duration and host resistance. The average sex ratio of H. contortus was 0.51 ± 0.006.ConclusionThis work is the first systematic review to summarise the available information on the parasitic phase of H. contortus in sheep. The results of the meta-analysis provide robust estimates of life history traits for parametrization of epidemiological models, their expected variation according to experimental factors, and provides correlations between these.

Strongyle egg reappearance period after moxidectin treatment and its relationship with management factors in UK equine populations

Parasitic nematodes, particularly cyathostomins, are ubiquitous in grazing horses world-wide. Considerable burdens of cyathostomin larvae can encyst in the large intestinal wall. The most recommended treatment against these pathogenic stages is moxidectin. Information is required on how effective moxidectin is against cyathostomin populations in different regions. The objectives here were to determine the efficacy of moxidectin treatment and estimate the strongyle egg reappearance period (ERP) after treatment in several equine populations, to confirm the type of strongyle nematodes present and to identify other (i.e. management) factors associated with shortened ERP. Eight yards were recruited and moxidectin in combination with praziquantel administered to all horses (n=261). Faecal egg count (FEC) analysis was performed at weeks 0, 2, 6, 10 and 12 after treatment to determine efficacy and ERP. The ERP was estimated using two previously published methods. Morphological identification of cultured third stage larvae from the sample population was compared to a Strongylus vulgaris-specific end-point PCR to examine the presence of S. vulgaris in samples before and after treatment. Strongyle egg shedding patterns were also compared to worm management practices at each site. At 2 weeks post-treatment, moxidectin was highly effective (faecal egg count reduction range, 99.9–100%). The strongyle ERP ranged from 6 weeks to >12 weeks depending on the calculation method applied. Only cyathostomin larvae were detected by morphological identification. The results from the coprocultures and PCR showed that S. vulgaris was absent before and after treatment. Analysis revealed that regular faecal removal from pasture was associated with lower average FEC and lower prevalence of egg shedding.

Productive performance and parasitological control of kids supplemented with umbu fruits (Spondias tuberosa Arruda)

Summary Native fruits from Caatinga vegetation can be an important alternative to improve the productive performance of kids in the semi-arid region of Brazil. This work aimed to evaluate the effect of supplementation with Umbuzeiro fruits in natura over the weight gain and anthelmintic control of kids kept in Buffel grass pasture in the semi-arid zone of Pernambuco, Brazil. Twenty-four castrated, crossbreed kids were allocated into three treatments: 1) Control (n = 8) fed exclusively with Buffel grass; 2) Umbu 1x (n = 8) fed with fruits once a week and 3) Umbu 3x (n = 8) fed with fruits for three times a week. The following parameters were evaluated: variation of body weight, faecal egg counts (FEC) and coproculture. Overall, the average consumption of Umbu fruits in natura was 1.48 kg/animal/day, which corresponded to 133.5 g daily dry matter intake (DMI/animal/day). There were no significant difference (P&gt;0.05) for any parameters evaluated. During the experimental period, the overall daily weight gain was variable between 108.75 to 116.70 g/animal/day and the average FEC was 436 eggs. In the present study, the goat kids supplemented with fresh umbu fruits showed a good productive performance, however the supplementation with umbu did not control the infestation of gastrointestinal nematodes in kids.

Economic assessment of FEC-based targeted selective drenching in horses

In the face of an increased prevalence of drug-resistant cyathostomin populations, a targeted selective treatment (TST) strategy based on Faecal Egg Counts (FECs) has been proposed as an alternative management strategy. However, associated costs may be a barrier to the uptake of this strategy. Our study aims to provide an economic assessment of FEC-based TST. FECs were determined in a Welsh pony herd thrice a year from 2010 to 2014. This database was used to explore the impact of FEC price, sampling strategy (individual or pooled) and labour-associated costs. Drug price was set at the cheapest level, hence providing a conservative framework to determine the maximum viable FEC price in the context of a cost-driven horse industry. The maximum viable FEC price for a cost-efficient individual based strategy was determined by an in silico bootstrap approach consisting of randomly sampling 1000 virtual pony herds of various sizes (1 to 100 ponies) from the available database and estimating the associated costs (FEC price ranging from €1 to €10, anthelmintic costs and labour-associated costs). The costs and benefits of the pooling strategy that consists of basing the decision to treat on group FEC values were also investigated. This is thought to reduce FEC-based costs but may result in highly infected individuals being left undrenched, i.e. in false-negatives, as a result of FEC overdispersion. For various pool-sizes (1–20 ponies) and various cut-off thresholds (50–200eggs/g), we sampled 1000 pony herds in silico to estimate the associated costs and determine the number of positive ponies within a negative pool. Following these simulations, pool-based FECs of various sizes were performed on 40 ponies to compare predictions with real data. Within 4 years, anthelmintic costs were cut by 80%, albeit with free FECs. In silico estimations suggested that an individual FEC-based TST would not be cost-efficient in this context for an FEC price above €5. With a pooled FEC strategy, the proportion of false-negatives never exceeded 15% of the pool size. The combination of a 14-pony pool and a cut-off value of 150eggs/g minimized total costs while keeping the number of false negatives to a reasonable level. Real data obtained from infected ponies however, suggested that pool size should not exceed 10 individuals, since the inhomogeneous mixing of faeces of larger pools probably reduced the correlation between average pooled FECs and the mean of individual FECs. Our study provides an economic framework that could be valuable for emphasizing the use of FEC-based approaches in the field.

Identification of novel loci associated with gastrointestinal parasite resistance in a Red Maasai x Dorper backcross population.

Gastrointestinal (GI) parasitic infection is the main health constraint for small ruminant production, causing loss of weight and/or death. Red Maasai sheep have adapted to a tropical environment where extreme parasite exposure is a constant, especially with highly pathogenic Haemonchus contortus. This breed has been reported to be resistant to gastrointestinal parasite infection, hence it is considered an invaluable resource to study associations between host genetics and resistance. The aim of this study was to identify polymorphisms strongly associated with host resistance in a double backcross population derived from Red Maasai and Dorper sheep using a SNP-based GWAS analysis. The animals that were genotyped represented the most resistant and susceptible individuals based on the tails of phenotypic distribution (10% each) for average faecal egg counts (AVFEC). AVFEC, packed cell volume (AVPCV), and live weight (AVLWT) were adjusted for fixed effects and co-variables, and an association analysis was run using EMMAX. Revised significance levels were calculated using 100,000 permutation tests. The top five significant SNP markers with - log10 p-values >3.794 were observed on five different chromosomes for AVFEC, and BLUPPf90/PostGSf90 results confirmed EMMAX significant regions for this trait. One of these regions included a cluster of significant SNP on chromosome (Chr) 6 not in linkage disequilibrium to each other. This genomic location contains annotated genes involved in cytokine signalling, haemostasis and mucus biosynthesis. Only one association detected on Chr 7 was significant for both AVPCV and AVLWT. The results generated here reveal candidate immune variants for genes involved in differential response to infection and provide additional SNP marker information that has potential to aid selection of resistance to gastrointestinal parasites in sheep of a similar genetic background to the double backcross population.

Effects of supplementation with dietary green tea polyphenols on parasite resistance and acute phase protein response to Haemonchus contortus infection in lambs

The objective of this study was to determine the effects of supplementation with dietary green tea polyphenols (GTPs) on parasite resistance and acute phase protein (APP) response to Haemonchus contortus infection in lambs. Thirty male Ujumqin lambs were randomly assigned to five treatment groups for an 8-week feeding period. Treatments included: (1) uninfected as control, (2) infected but not given GTP (INFGTP0) and (3)–(5) infected and fed 2, 4, or 6g GTP/kg feed (dry matter basis; INFGTP2, INFGTP4, and INFGTP6, respectively). Fecal and blood samples were collected to determine fecal egg count (FEC), packed cell volume (PCV), and APP concentrations. Live weight was measured once every 2 weeks. At the end of the feeding period, lambs were slaughtered to determine the adult H. contortus burden. The results demonstrated interaction effects between treatment and sampling time on the average daily gain (ADG; P=0.0005), FEC (P<0.0001), PCV (P=0.0005), and concentrations of serum amyloid A (SAA), haptoglobin (Hp), lipopolysaccharide binding protein (LBP), and α1-acid glycoprotein (α1AGP) (P<0.0001). From days 0 to 56, the ADG values for all infected lambs were lower than that of uninfected lambs, but the ADG values for all GTP-fed lambs were higher than that of INFGTP0 lambs, especially from days 28 to 42. The FECs of all GTP-fed lambs were higher than those of uninfected lambs but lower than that of INFGTP0 lambs. The PCVs of all infected lambs were lower than those of uninfected lambs, but PCV increased with increasing amounts of GTP supplementation. Furthermore, supplementation with different concentrations of GTP significantly reduced the numbers of adult H. contortus, including both males and females (P<0.0001), and the H. contortus burden in INFGTP6 lambs was reduced to uninfected levels. Overall, the SAA, Hp, LBP, and α1AGP concentrations of all infected lambs were higher than those of uninfected lambs from days 0 to 56. Two peaks in expression were observed from days 0 to 3 and at day 28, and APP concentrations of all GTP-fed lambs were lower than those of INFGTP0 lambs, except for SAA in INFGTP6 lambs. In conclusion, quantitative measurements of APP responses to H. contortus infection provide valuable diagnostic information for monitoring infection progression and treatment responses in lambs. An appropriate dose of dietary GTP supplementation can increase host resistance by reducing H. contortus burden and weight loss and suppressing blood APP expression.

Effects of stocking rates on gastrointestinal nematode infection levels in a goat/cattle rotational stocking system

Gastrointestinal nematodes (GIN) are increasingly resistant to anthelmintic drugs worldwide, so integrated control methods are more and more needed for the sustainability of small ruminant farming. Such methods rely on knowledge in epidemiology, physiology, and genetics. Ecological studies have highlighted the effect of host density on parasite populations, and in the humid tropics, rotational grazing systems were designed according to the survival of GIN free-living stages. This study aimed to assess the effects of mixed stocking and host stocking rate on host GIN infection level.Four groups of 15–17 Creole male kids were raised on irrigated pasture from weaning (about 3 months) until the age of 7 months, at four partial stocking rates (pSR): 100% (control), 75% (G75), 50% (G50), and 25% (G25) of the total stocking rate of the pasture. The last three groups were associated with weaned Creole heifers to obtain the same overall stocking rate as the control. Animals grazed in a ‘leader’ goat and ‘follower’ cattle design: the G25, G50, and G75 paddocks were split into six plots; each plot was grazed by goats for 1 week and by heifers the following week. The pasture then rested for 4 weeks before the animals were returned for a new grazing sequence. Five control plots were grazed rotationally for 1 week, and rested for 4 weeks. This design was repeated three times a year for a total of 10 repetitions. Average faecal egg counts (FEC) decreased according to a power function of the pSR: FEC=1829pSR3.7. The observed death rate decreased significantly with the pSR (27.6%, 16.4%, 11.9%, and 12.2%). The kids grew faster in G25 (51gd−1) than in G50 (43gd−1) and G75 or control (32gd−1, p<0.05). Heifers were not significantly infected with GIN and grew normally (about 0.48kgd−1).Reducing the pSR by associating a non-host species in a rotational stocking system may be a very promising component of integrated GIN control, at least for the humid tropics.