Periparturient Rise Research Articles

Comparative peri-parturient rise in faecal egg counts in divergent lines of sheep at an organized farm in semi-arid Rajasthan

Comparative peri-parturient rise in faecal egg counts in divergent lines of sheep at an organized farm in semi-arid Rajasthan

Parasite dynamics in untreated horses through one calendar year

BackgroundHorses are host to a plethora of parasites. Knowledge of the seasonality of parasite egg shedding and transmission is important for constructing parasite control programs. However, studies describing these patterns are sparse, and have largely been conducted only in the United Kingdom. This study evaluated strongylid egg shedding patterns and transmission dynamics of Strongylus vulgaris in naturally infected and untreated mares and foals through one calendar year in Kentucky, USA. The study also investigated the existence of a peri-parturient rise (PPR) in strongylid egg counts in foaling mares and collected information about Strongyloides westeri and Parascaris spp. in the foals.MethodsThis study was conducted from January to December 2018. A herd of 18 mares, one stallion, and 14 foals born in 2018 were followed throughout the year. Sera and feces were collected biweekly from all horses, and worm burdens enumerated in 13 foals at necropsy. An S. vulgaris ELISA antibody test was run on all serum samples. Fecal egg counts were determined for all horses, and coproculture and qPCR assay were employed to test for the presence of S. vulgaris in the mature horses. Data were analyzed using the proc glimmix procedure in the SAS 9.4 software program.ResultsWe found a general lack of seasonality in strongylid egg shedding throughout the year among the mature horses, and no PPR was demonstrated. Shedding of S. vulgaris eggs displayed a higher abundance during the spring, but findings were variable and not statistically significant. Anti-S. vulgaris antibody concentrations did not display significant fluctuations in the mature horses, but evidence of passive transfer of antibodies to the foals was demonstrated, and foals assumed their own production of antibodies starting at approximately 20 weeks of age. Overall, colts shed higher numbers of strongylid, ascarid, and S. westeri eggs than fillies.ConclusionsThis study demonstrated a lack of seasonality in strongylid egg shedding for the study population, which is in stark contrast to previous studies conducted elsewhere. This strongly suggests that more studies should be done investigating these patterns under different climatic conditions.Graphical

Effects of lambing season on nematode faecal egg output in ewes.

In this study, we assessed the occurrence of a periparturient rise (PPR) in winter and spring lambing ewes in Sweden and where nematode egg excretion patterns were investigated mainly for diagnostic purposes. Gastrointestinal nematodes and Haemonchus contortus presence were monitored in parallel in all animals in each experimental group on four farms in samples that were collected mainly when the animals were stabled. Faecal examinations of the same animals were conducted on four sampling occasions between January and June 2018 Each group consisted of 12 crossbreed ewes of similar genotype. One group's peak lambing was in January or February (early), and the other in March or early May (late). The first (S1) and third samples (S3) were from approximately one to two weeks before parturition in the early (winter lambing) and late (spring lambing) group respectively, whereas the second (S2) and fourth samples (S4) were collected approximately three to five weeks post-parturition in the same groups. During the course of the study, there was a significant rise in faecal egg counts (FEC) in both groups on all farms. On three farms with a substantial amount of Haemonchus, we observed a difference in the egg excretion patterns between the two groups of ewes as revealed by a significant interaction between the sampling point and lambing period. Also, when samples corresponding to each other in relation to the number of weeks that had elapsed post-parturition (three to five weeks post-parturition, S2 for early and S4 for late) were compared, FEC were significantly lower in the early group lambing in winter than the late group lambing in spring. This indicates that besides lambing, the rise in nematode egg count is also influenced by other factors unrelated to the lambing period, such as the increased daylight in spring. Due to study limitations, we cannot provide a more detailed explanation for this, but only state that the rise appeared to be more closely linked to season than physiology as measured by day relative to parturition. Still, our results suggests that when turned out, winter lambing ewes contribute to pasture contamination to a lesser extent than those lambing in spring. These results will be used in stipulating evidence-based advice to farmers in their flock management to reduce use of anthelmintics, and at the same time efficiently produce prime lambs.

Studies on peri-parturient rise phenomenon in faecal egg counts of goats in Jaipur district of semi-arid Rajasthan

The peri-parturient rise (PPR) in faecal egg counts in field goats naturally infected with strongyle (predominantly Haemonchus contortus) worms was investigated. A total of 23 lactating goats reared by farmers in four villages (Nayala, Chaksu, Bassi and Kanota) of Jaipur district (Rajasthan) were monitored for the intensity of strongyle infection at weekly interval during October-November, 2020. On each occasion, fresh faecal samples were collected per-rectum from individual lactating does at weekly interval at 0 day to 8th week post-kidding and from selected non-lactating does (27), bucks (12) and kids (20) at fortnightly intervals during the same period. The faecal samples were subjected to McMaster technique for estimation of faecal egg count (FEC). Overall mean intensity of strongyle infection varied significantly (P<0.001) from 1978.3±132.5 eggs per gram (epg) on day 0 of kidding to 184.2±46.1 epg on 8th week post-kidding. There was a continuous and gradual decline in FECs from the 2nd week post-kidding onwards in all villages, suggesting non-occurrence of PPR in goats naturally infected with strongyles. During the contemporary period, the overall mean intensity of strongyle infection from non-lactating animals in the same flocks showed a similar declining magnitude with advancement of period. Thus, it can be inferred that peri-parturient anthelmintic drench in late winter is not warranted in the area studied and adoption of this practice will reduce selection pressure for anthelmintic resistance in gastrointestinal nematodes.

Correlation of subclinical gastrointestinal nematode parasitism with growth and reproductive performance in ewe lambs in Ontario

Infection with gastrointestinal nematode parasites (GINs) is an important cause of productivity loss on sheep farms in Ontario and worldwide. However, efforts to quantify the effect of GIN infection on growth have demonstrated mixed results. Furthermore, there has been limited investigation of their effect on reproductive performance. This study evaluated the effect of subclinical GIN parasitism on growth and reproductive performance of ewe lambs under Ontario grazing conditions. Rideau cross ewe lambs (n = 140) born in spring 2016 on a farm in central Ontario were followed for two years from before weaning through to November 2017, including their first lambing and lactation. These animals grazed from May to November of each year and were sampled every 6−8 weeks during both grazing seasons and once at mid-gestation in March 2017. At each sampling the ewe lambs were weighed, body condition scores assigned, fecal egg counts (FECs) performed, and pasture samples collected to assess number of infective GIN larvae. Study animals with a FEC of 500 eggs per gram or higher were selectively treated with anthelmintics to prevent morbidity and mortality. Fecal samples were cultured to determine infecting GIN species, and climate data were obtained from a weather station 26 km away from the farm. Precipitation levels and numbers of infective larvae on pasture were low during the first grazing season but were more typical of Ontario conditions in the second grazing season. The three most common GIN species were Haemonchus contortus, Teladorsagia circumcincta, and Trichostrongylus spp. General linear mixed models were generated for weight change over time, litter size at lambing, and weaning weights of offspring. Despite moderate peak GIN burdens in both grazing seasons, FEC was not significantly associated with weight change or litter size, apart from periparturient egg rise in study ewe lambs with larger litters (p = 0.05). Significant positive quadratic and negative linear associations were identified between late lactation FECs and offspring weaning weights; the association between FECs and weaning weights changed from negative to positive at a FEC of 361 eggs per gram. These results indicate that when GIN burdens are moderate as evidenced by fecal egg counts and infection is subclinical, there appears to be low to no impact on growth and reproductive performance in ewe lambs in the first 18 months of life. This suggests that when GIN parasitism is regularly monitored and controlled using targeted selective treatment, animal performance is minimally affected.

The dynamics of ovine gastrointestinal nematode infections within ewe and lamb cohorts on three Scottish sheep farms

Gastrointestinal nematodes (GIN) are a serious concern for sheep producers worldwide. However, there is a paucity of evidence describing the epidemiology of GIN on modern UK sheep farms. The aim of this paper was to understand whether expected seasonal variations of infection are still found in ewes and lambs under varying management strategies in temperate climates. Faecal egg counts (FEC) were conducted on freshly voided samples collected from groups of ewes and lambs every third week for twelve months on three farms in southeast Scotland. The patterns of egg output have been described here in relation to management practices undertaken on the farms. Despite changes in farming practice and climatic conditions, the findings complement historical studies detailing the epidemiology of GIN. Findings include a periparturient rise in ewe FEC on two of the farms, while lambing time treatment appeared to suppress this on the third farm. On the same two farms lamb FEC increased during the summer, reaching a peak in the autumn. The work also highlights how the ad hoc use of anthelmintics does little to impact these patterns.

Strategic vaccination of hair sheep against Haemonchus contortus.

In this study, we evaluated in two trials a protocol designed to protect hair sheep using Barbervax®, a vaccine containing Haemonchus contortus gut membrane glycoprotein antigens. Results indicated that naturally infected vaccinated sheep had significant egg count reductions (90.2 ± 4.03%) compared with controls, although blood parameters remained relatively unchanged probably because the level of challenge was low. Vaccination prevented the periparturient rise in egg shedding of ewes, as well as egg shedding in lambs (37.1%). In the second trial, sheep which were experimentally exposed to higher artificial challenge also showed an efficient response to the vaccine as confirmed by high antibody levels and reduced egg counts and worm burdens (87 ± 5.4% and 79%) respectively. Thus, we believe that the vaccine should be integrated with other management practices for meat hair sheep as it has the advantages of adequate efficacy, reducing anthelmintic utilization and avoiding milk and environmental contamination with chemical residues.

Resistance of ewes to gastrointestinal nematode infections during the peripartum and dry periods and the performance of their lambs

ABSTRACT This study aimed to evaluate the resistance of Texel (Tx) and Ile de France (IF) sheep to gastrointestinal nematode infections in the periparturient period and after weaning, and the performance of their lambs. Fecal samples were collected from 19 IF and 17 Texel ewes to determine fecal egg counts (FEC) and larval cultures were prepared to determine the prevalence of nematodes. The ewes were weighed to determine body weight (BW) and blood samples were taken to determine the packed cell volume (PCV) and plasm protein values (PPV). The ewes were classified into two groups by FEC (heavy and moderate infection). The IF presented higher FECs than Tx 28 and 14 days before parturition; 14, 28, and 56 days after parturition; and 28 days after weaning (P&lt;0.05). In the weaning and dry periods, the IF presented higher PCVs than Tx (P&lt;0.05). The PPV did not differ between the groups (P&gt;0.05). The IF presented a higher BW than Tx 14, 28, and 42 days after parturition, and in the weaning and dry periods (P&lt;0.05). The ewes of both breeds classified as moderately infected had the highest BW at weaning (P&lt;0.05). IF ewes with a moderate infection produced weaning lambs that were heavier than those of Tx with the same level of infection (P&lt;0.05). Overall, Tx ewes presented a better ability to withstand infections during the periparturient period and after weaning. Although the IF ewes presented the highest FEC and more intense periparturient rise, they managed to maintain their level of production.

PSVI-21 Coproantibodies as indicators of the periparturient rise in fecal egg counts in St Croix Sheep.

PSVI-21 Coproantibodies as indicators of the periparturient rise in fecal egg counts in St Croix Sheep.

Galectin Secretion and Modulation in Sheep Blood

Galectins (GAL) are &amp;beta;-galactoside binding proteins that can modulate both pregnancy and the response to pathogens. Increased susceptibility to infection by pathogens is linked to periparturient immune suppression and a periparturient rise (PPR) in parasite eggs on pasture. The possible role of GAL in periparturient immune relaxation and PRR needs definition. &amp;nbsp;The objective of this study was to evaluate galectin secretion and its relationship to measures of the immune relaxation and PRR in periparturient sheep. Samples were collected from pregnant St. Croix sheep (n=6) weekly at days -21 to + 21 relative to lambing. Fecal samples were collected and evaluated for strongyle and coccidia parasite eggs. The concentration of IgA and IgE coproantibodies, total microbial DNA, Bifidobacteria and Lactobacillus levels in fecal samples were used as indicators of gut health.&amp;nbsp; Blood samples were collected by jugular venipuncture and assessed for Packed Cell Volume (PCV), total and differential white blood cell counts. Total protein concentrations and protein profile were evaluated in serum. Secretion of GAL 1, 3, 9 and 14 were evaluated using ELISAs. Data were analyzed by one-way ANOVA and statistical significance was declared at P &amp;lt;0.05. Galectins tested were secreted in sheep blood. Differential modulation of GAL secretion and correlation with periparturient immune suppression and parasite infection was observed. Galectin secretion was modulated by the periparturient period, type and status of parasite infection. This first insight into a possible role of secreted galectins in periparturient immune relaxation and PRR improves the understanding of the immune response, informs development of management programs and therapeutics and presents Galectin profiles as biomarkers with diagnostic potential.

Periparturient rise in the Cryptosporidium oocyst count in Beetal goats and evaluation of infection in new born kids

In cryptosporidial infection, very scarce literature is available about periparturient pattern of oocyst excretion in goats and its implications in the epidemiology of disease in kids; thus the present investigation was done. Faecal samples (160) were examined from 20 pregnant goats, collected at weekly interval, commencing from 4 weeks before kidding up to 3 weeks after kidding. Faecal sample examination by Sheather’s floatation sedimentation technique followed by modified Ziehl-Neelsen staining technique revealed an overall positivity of 26.25% for Cryptosporidium oocysts. Prevalence of oocysts excretion was high around parturition and the number of oocysts shed oscillated between 20–400 oocysts/g (OPG) of faeces. Examination of 60 faecal samples of 20 kids born to studied goats from 1 to 3 weeks of age revealed 40% samples positive for Cryptosporidium oocysts and 65% kids became infected by the end of the 3 weeks. The OPG of kids ranged from 100 to 1,560. Molecular characterization by PCR-RFLP of 18S small subunit (SSU) rRNA gene showed that 73.80% and 26.19% goat samples, and 87.5% and 12.5% kids samples were positive for C. parvum and C. ubiquitum, respectively. The study indicated periparturient transmission of Cryptosporidium spp. from pregnant goats to their new born kids.

Genetic parameters for ewe reproductive performance and peri-parturient fecal egg counts and their genetic relationships with lamb body weights and fecal egg counts in Katahdin sheep.

This study estimated genetic parameters for ewe reproductive traits [number of lambs born (NLB) and weaned (NLW) per ewe lambing] and fecal egg counts (FEC) during the peri-parturient rise (PPR) for use in genetic evaluation of Katahdin sheep. Data included NLB and NLW for 23,060 lambings by 9,295 Katahdin ewes, 1,230 PPR at lambing (PPR0) for 750 ewes, 1,070 PPR at approximately 30 d postpartum (PPR30) for 611 ewes, BW at birth, weaning, and (or) post-weaning for 12,869 lambs, and FEC at weaning and (or) post-weaning for 4,676 lambs. Direct additive, permanent environmental, and residual (co)variances were estimated in univariate and bivariate animal models. Fixed effects included effects of ewe management group and ewe age for all traits, and, for PPR, a continuous effect of days between lambing and measurement. Effects of litter size on PPR0 and number of lambs suckled on PPR30 were included in univariate models but excluded from bivariate models for PPR and NLB or NLW. Heritability estimates in univariate models for NLB, NLW, PPR0, and PPR30 were 0.09 ± 0.01, 0.06 ± 0.01, 0.35 ± 0.06, and 0.24 ± 0.07, respectively. Estimates of permanent environmental variance as a proportion of total phenotypic variance were 0.02 ± 0.01 for NLB, 0.03 ± 0.01 for NLW, 0.05 ± 0.06 for PPR0, and 0.13 ± 0.07 for PPR30. Direct additive, phenotypic, permanent environmental, and residual correlations between NLB and NLW were 0.88 ± 0.03, 0.74 ± 0.004, 0.54 ± 0.15, 0.74 ± 0.003, respectively; corresponding correlations between PPR0 and PPR30 were 0.96 ± 0.07, 0.46 ± 0.03, 0.98 ± 0.50, 0.18 ± 0.05, respectively. The additive genetic correlation (rd) between ewe reproductive traits and PPR ranged from 0.12 to 0.18. Estimates of rd between lamb BW and subsequent ewe NLB and NLW ranged from 0.07 to 0.20, and those between PPR and lamb BW ranged from -0.03 to 0.29. The rd between ewe reproductive traits and lamb FEC ranged from 0.27 to 0.40, and those between PPR and lamb FEC ranged from 0.56 to 0.77. Correlations between maternal additive effects on BW and direct additive effects on PPR were low (-0.08 to 0.10), and those between maternal additive effects on BW and direct additive effects on ewe reproductive traits were variable (-0.36 to 0.11). We conclude that FEC in growing lambs and peri-parturient ewes are controlled by similar genes and that modest, but manageable, genetic antagonisms may exist between FEC and ewe productivity.

Periparturient rise in strongyle and coccidian egg/oocyst counts in beetal goats

Periparturient rise in strongyle and coccidian egg/oocyst counts in beetal goats

Factors affecting fecal egg counts in periparturient Katahdin ewes and their lambs.

Selection for low fecal egg counts (FEC) can be used to genetically enhance resistance to gastrointestinal nematode parasites in growing lambs, thereby reducing the frequency of use of anthelmintics, facilitating marketing of organic lamb, and reducing the risk of development of anthelmintic resistance by the parasite. Recording of FEC in lambs has, therefore, been incorporated into several national sheep genetic evaluation programs. Ewes in late gestation and early lactation are also vulnerable to parasite infection and commonly experience a periparturient rise in FEC. This study was designed to assess factors associated with the periparturient rise in FEC in Katahdin ewes and associated changes in FEC in their lambs. Data came from 1,487 lambings by 931 Katahdin ewes from 11 farms in the Eastern United States. Fecal egg counts were measured in ewes at approximately 0, 30, and 60 d postpartum and in their lambs at approximately 60, 90, and 120 d of age. Approximately 1,400 lambs were evaluated at each measurement age. Data were analyzed separately for ewes and lambs and also initially analyzed separately for each measurement time. Repeated-measures analyses were then used to evaluate responses across measurement times. In ewes, FEC peaked at approximately 28 d postpartum, and we concluded that informative periparturient FEC could be obtained from 1 wk before until approximately 5 wk after lambing. Yearling ewes had higher FEC than adult ewes ( < 0.01), and ewes that nursed twin or triplet lambs had higher FEC than ewes that nursed single lambs ( < 0.01). In lambs, FEC increased through approximately 120 d of age. Lambs from yearling ewes and lambs nursed in larger litters were, like their dams, at greater risk of parasitism ( < 0.05). Ewes and lambs in these groups would benefit from enhanced monitoring of parasite loads at lambing and in early lactation. Correlations () between FEC in lambs at 90 d of age and FEC in ewes at 0, 30, and 60 d postpartum of 0.05 to 0.09 ( ≤ 0.05) support the presence of a genetic relationship between these 2 indicators of parasite resistance.

Patterns of faecal nematode egg shedding after treatment of sheep with a long-acting formulation of moxidectin

Much of the current information on the effects of long-acting anthelmintics on nematode populations derives either from research farms or mathematical models. A survey was performed with the aim of establishing how moxidectin is currently being used on sheep farms in the south-east of Scotland. A study was undertaken on a subsection of the surveyed farms to examine the effects of long-acting moxidectin treatments in both spring and autumn on faecal nematode egg output. The survey showed that whole flock treatments of injectable 2% moxidectin were used to control sheep scab on 21% of farms. Injectable 2% moxidectin and oral moxidectin were used to control the periparturient rise in faecal nematode egg shedding by ewes on 13% and 55% of farms respectively. The effects of injectable 2% moxidectin treatment on faecal nematode egg shedding post-treatment in both the autumn and spring were investigated by faecal nematode egg counts at the time of treatment and at 2-weekly interval thereafter on eight and six farms in the autumn and spring, respectively. Faecal egg shedding recommenced at 8 weeks (autumn) and 4 weeks (spring) post-treatment. Counts increased to a peak and then declined. The mean (95% confidence interval) peak counts post-treatment were 2.8 (0.6, 5.1), 3.6 (1.7, 5.5) and 53.5 (25.1, 82.0) eggs per gram (EPG) for autumn-treated ewes, autumn-treated lambs and spring-treated ewes respectively. The spring treated sheep showed a statistically significantly earlier return to faecal egg shedding (p=0.0125, p=0.0342) compared to both other groups, statistically significantly higher peak in egg counts than the autumn treated sheep (p<0.001) and a statistically significantly longer period of positive egg counts (p=0.0148). There was no statistically significant difference in the timing of the peak FECs between autumn and spring (p=0.211). The FECs of all groups of sheep treated with an injectable long-acting formulation of moxidectin became positive earlier than would be expected from the period of persistence given on the datasheet, but post-treatment FECs were very low compared to pre-treatment counts.

Dynamics of epidemiological intelligence for exploitation in effective worm management in sheep - A Rajasthan experience

Being of ubiquitous nature and omnipresence of the gastrointestinal (GI) parasites, their management presents a difficult challenge following wide-spread emergence of anthelmintic resistance. Anthelmintics have a definite role to play in worm management but their frequency of use should be minimised to the extent possible and the available resources of anthelmintics could be used judiciously by exploiting the knowledge of parasite epidemiology. The present communication discusses different aspects of worm biology and their interaction with environment, host and managemental practices. The bioclimatographs suggested existence of suitable conditions for translation of exogenous stages of Haemonchus contortus from late May to late September in semi-arid region and from mid June to late August / September in arid region. Based on real-time observations, different strategies were developed and tested for efficient management of GI nematodes in sheep flocks of Rajasthan. The agro-climatic conditions and lambing pattern do not favour the development of strongyle larvae during December-June, resulting in absence of typical peri-parturient rise in faecal egg counts (FECs). However, the epidemiology of strongyle worms showed the possibility of hypobiosis. An initial rising trend in FECs in June could be probably due to resumption of development of hypobiotic worms within the host, giving peak of infection in July and providing the source of pasture contamination during monsoon. The decline in FECs in the following months may be due to spontaneous occurrence of “self-cure” phenomenon. The GI parasite populations in small ruminants are highly aggregated and over-dispersed, with around 80% of the worms found in only 20-30% of the host. Thus, requirement for treatment is a reflection of the genetic basis of host variation in either innate or acquired resistance to parasites or resilience. The over-dispersion phenomenon was used in the form of targeted selective treatment and for breeding for resistance / resilience to parasites ultimately with the aim to increase the size of refugia, maintain anthelmintic efficacy and cost-effective worm management.

The Occurrence and Seasonal Magnitude of the Periparturient Rise in Trichostronglyid Nematode Egg Output in Breeding Yankasa Ewes in a Sub Humid Climate

Investigations were carried out on the occurrence of a periparturient rise in Trichostrongyle egg counts in breeding ewes grazing natural pastures. The first study using ewes in the last month of gestation and non-pregnant ewes as controls, showed that a significantly (p<0.05) greater increase in egg counts (EPG) occurred in the lambing ewes when compared with the non-pregnant ewes. Peak EPG was 357.1±94 four weeks after lambing while it was 190±162 in non pregnant ewes. A second study using ewes grazing a separate pasture showed an exponential increase in mean EPG from 187±124 pre lambing to 1589±429 two weeks post lambing. A third study investigated the effects of season on the magnitude of the periparturient rise. Ewes whose lambings were timed to coincide with four seasons (late dry, early wet, late wet and late dry seasons) were monitored from 4 weeks pre to 5 weeks post lambing. The periparturient rise occurred irrespective of season of lambing but the magnitude was influenced by the season. The highest periparturient rise occurred in the late wet season (peak of 4201±1813) four weeks post lambing while the lowest occurred when lambing coincided with the late dry season (peak of 1800±765). Packed cell volume values in lambing ewes declined with increased egg counts but total protein values did not show appreciable changes. The periparturient rise in helminth egg counts is an important epizootiologic consideration in the study area and tactical treatment in its elimination will reduce infection for lambs, lower mortality and increase productivity of ewes.

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.

Efficacy of targeted anthelmintic treatment for suppression of the peri-parturient egg rise in ewes and impact on 50-day lamb weights

This study was conducted to determine whether targeted anthelmintic treatment of peri-parturient ewes lambing in the winter, spring and/or autumn would suppress the peri-parturient egg rise (PPER) and improve 50-day lamb weights. Three farms in Ontario, Canada, that practiced out-of-season lambing were enrolled in 2010 and sampled for three consecutive lambing seasons (winter, spring and autumn). For each lambing season, all farms were visited three times. On the first visit, all ewes due to lamb that season were randomly allocated to treatment with ivermectin, fenbendazole or levamisole at the recommended dosage, or left untreated. Among these treated ewes, 40–60 animals (10–15 ewes per treatment group) were randomly selected for fecal sampling during the 3 sampling visits and processed individually to measure gastro-intestinal nematode (GIN) fecal egg counts (FECs). Ewe and lamb productivity data, including approximate 50-day lamb weights, were collected for all ewes lambing in each season, where available. A Fecal Egg Count Reduction Test was performed on all three farms to determine the ivermectin, fenbendazole and levamisole resistance status. Both farms A and B had fenbendazole resistance, while farm C had ivermectin and fenbendazole resistance; levamisole was effective on all three farms. The effect of targeted treatment on the subsequent PPER depended on the farm, possibly a partial surrogate variable for the different anthelmintic resistance levels on each farm, lambing season and sampling time-point. On farm A, during the winter and autumn lambing seasons, ivermectin and levamisole were more effective at reducing the FECs, compared to fenbendazole. In contrast, during the spring lambing season, treatment of ewes with ivermectin, fenbendazole or levamisole had no effect on the FECs. On farm B, all anthelmintic treatments were associated with a reduction in the FECs during the spring lambing season, while no reduction was observed during the winter and autumn lambing seasons. On farm C, the FECs decreased in ewes treated with levamisole in both the winter and spring lambing seasons, while ivermectin only reduced the FECs in ewes treated in the winter lambing season. Litter size was positively associated with FECs. Anthelmintic treatment was not associated with approximate 50-day lamb weights, although the power to detect significant difference was lower than anticipated due to only having relevant weight data from farm A. These results suggest that the efficacy of targeted treatment for the suppression of the PPER depends on the anthelmintics’ efficacy and time of treatment in relation to the grazing period.

Sainfoin - new data on anthelmintic effects and production in sheep and goats

Gastrointestinal nematodes (GIN) are one of the most important problems affecting health and therefore performance and welfare in small ruminant husbandry. The control of these parasites in the past strongly relied on the repeated use of anthelmintic drugs. This has led to nematode populations which are resistant to most of the currently available anthelmintics. Furthermore customer's demands for organic and residue free animal products are increasing. The aforementioned problems have given a strong impetus for the development of new non-chemical strategies to control GIN. Previous research has pointed out the anthelmintic potential of sainfoin (Onobrychis viciifolia, cv. Visnovsky) and other tanniferous (CT) feed sources in goats and lambs infected with GIN. A recent Swiss experiment focussed on the use of sainfoin and field bean (Vicia faba, cv. Scirocco) as single CT sources as well as in combination for additional synergic effects, to reduce periparturient GIN egg rise of ewes in late gestation and early lactation. Another experiment with Alpine goats concentrated on the influence of sainfoin on milk performance and cheese quality. The results of these experiments will be presented and discussed in connection with previous knowledge on (i) anthelmintic effects of sainfoin and (ii) the influence of sainfoin administration on performance.