Gastrointestinal nematode infections in German sheep

The objective of the present study was to determine the prevalence and variation of natural gastrointestinal nematode (GIN) infections in lambs according to birth type, gender and breed based on individual faecal egg counts (FEC) from various regions in Germany. A total of 3,924 lambs (3 to 15 months old) with different genetic backgrounds (Merinoland, German Blackhead Mutton, Rhoen, Texel and Merino long-wool) were individually sampled during the grazing period between 2006 and 2008. Furthermore, pooled faecal samples from each of the farms were cultured in order to differentiate the third-stage larvae of the nematode spp. Sixty-three percent of the lambs were infected with GIN. The infections were mostly low to moderate and involved several nematode species. The Trichostrongylus spp. was the predominant species based on the percentage of larvae in faecal cultures. Only 11.4% of the lambs were free of Eimeria oocysts. Tapeworm eggs were encountered in 13.2% of all samples. The prevalence of GIN infections varied significantly (P < 0.001) among farms. A significantly higher FEC (P < 0.05) was observed in multiple-born lambs when compared with singletons. Moreover, male lambs were more susceptible to infection than females (P < 0.001). No significant differences (P > 0.05) were observed between breeds regarding FEC. Inter-individual variations were higher than inter-breed differences, which may indicate the possibility of selection within these breeds for parasites resistance as described in earlier studies

Early pregnancy detection by real-time ultrasonography in Boer goats

Early pregnancy detection in goats was not practicable until recently. The present investigation evaluated the use of transrectal and transabdominal real-time ultrasonography for this purpose in a flock of Boer goats. Measurements were conducted by both the transrectal and transabdominal routes. A rectal 7.5 MHz linear array transducer enabled the reliable recognition of uterine fluid accumulation, indicating early pregnancy, from day 19.5 (S.E.M. 0.3) of pregnancy onwards; fetal heartbeat could be detected from day 22.9 (S.E.M. 0.7). With an abdominal 3.5 MHz transducer, the corresponding times for the first reliable detection of pregnancy were from day 24.7 (S.E.M. 0.4) onwards for uterine fluid accumulation and from day 27.0 (S.E.M. 0.6) for fetal heartbeat. No false positive pregnancy diagnoses occurred with either transducer in non-pregnant does. For maximum reliability, the rectal transducer approach is recommended and observation of the fetal heartbeat as conclusive evidence of the presence of a live fetus. Real-time ultrasonography is recommended as a reliable means of pregnancy detection as early as 26 days after conception. (c) 2004 Elsevier B.V. All rights reserved

Ovsynch synchronization and fixed-time insemination in goats

This study assessed the efficacy of an Ovsynch protocol (vs. the classical cronolone containing vaginal sponge + eCG treatment) to generate fixed-time insemination in goats during the breeding season. Each regimen was applied to 24 Boer goat does. Onset and duration of estrus were determined with an aproned male and follicular development was monitored by ultrasonography. Ovulation and quality of the corpora lutea were established from progesterone concentrations. In 10-11 goats per group, LH concentrations were determined throughout the preovulatory period. Does were inseminated at pre-determined times (16 It after the second GnRH injection and 43 It after sponge removal). Estrus was identified in 96% of the Ovsynch-treated goats (at 49 It after prostaglandin injection) and in 100% of the goats synchronized with sponges (at 37 It after sponge removal). Low progesterone concentrations at the time of AI were observed in 21/24 and 24/24 goats synchronized by Ovsynch and sponges, respectively. Synchronization of the LH surge was tighter following Ovsynch compared to sponge treatment. Kidding rates (at 58 and 46% in the Ovsynch and sponge groups, respectively) and prolificacy (at 1.86 and 1.83 in the Ovsynch- and sponge-treated goats) were similar for both groups, as were the number of ovulations (2.9 and 3.3) and the proportion of does with premature corpus luteum regression (29 and 17%). When excluding does with premature luteal regression and those with low progesterone levels when receiving prostaglandins, kidding rate reached 87.5% (14/16) after Ovsynch. During the breeding season, the Ovsynch protocol may thus be an useful alternative to the sponge-eCG treatment. (c) 2008 Elsevier Inc. All rights reserved

Fixed-time deep uterine insemination in PGF(2 alpha)-synchronized goats

The aim of this investigation was to optimize fixed-time insemination in goats by clustering ovulations in prostaglandin F-2 alpha-synchronized goats either with gonadotropin releasing hormone (GnRH) or human chorionic gonadotropin (hCG). The underlying intention was to reduce the incidence of short cycles by providing a more sustained stimulation of the corpus luteum by substituting the commonly used GnRH with longer-acting hCG. It was conjectured that this might render the corpus luteum less prone to premature regression. Sixty pluriparous does were administered 5 mg of the prostaglandin F-2 alpha preparation dinoprost (Dinolytic; Pharmacia and Upjohn, Erlangen, Germany) during the luteal phase of the estrous cycle. Twenty of these does were administered 0.004 mg of the GnRH analog buserelin (Receptal; Intervet, Unterschleissheim, Germany) 48 hours later; another 20 does received 500 IU hCG (Chorulon; Intervet, Unterschleissheim, Germany) instead. Sixteen hours later the does were inseminated with frozen-thawed semen. The remaining 20 does served as controls and were inseminated 16-18 h after the onset of detected estrus. All 60 treated goats displayed estrous symptoms, the time of onset being similar for all groups (42.6, 37.6, and 40.5 hours after treatment for GnRH-treated, hCG-treated, and control does, respectively). The duration of estrus in the GnRH-treated group was 10 h less than in the other groups (45.1 vs. 56.4 and 54.4 h, P 0.05). Monitoring of serum progesterone revealed that the incidence of corpus luteum insufficiency was significantly higher in GnRH-and hCG-treated does than in the control group (40% and 35% vs. 5%, P 0.05). When disregarding does with corpus luteum insufficiency, pregnancy rates would have been 83%, 54%, and 63%, and kidding rates 67%, 54%, and 63%, respectively. The average number of kids born was 1.88, 1.71, and 1.83, respectively (P > 0.05). It may be concluded that fixed time insemination of cycling does treated with prostaglandin F-2 alpha, during the luteal phase, followed by ovulation induction with GnRH or hCG, would be an effective management tool if it were possible to control the high incidence of corpus luteum insufficiency. The attempt to achieve this by substituting GnRH with hCG, was not met with success. Until a solution for the problem has been found, it is advisable to inseminate prostaglandin-synchronized does 16-18 hours after the onset of detected estrus. (C) 2011 Elsevier Inc. All rights reserved

Establishment of gastro-intestinal helminth infections in free-range chickens: a longitudinal on farm study

The objective of this study was to monitor establishment and development of gastro-intestinal helminth infections in chickens over two production years (PY) on a free-range farm in Lower Saxony, Germany. The data were collected between July 2010 and June 2011 (PY1) and July 2011 and January 2013 (PY2), respectively. During PY1, Lohmann Brown classic (LB classic, N =450) was tested, while in PY2 two different genotypes (230 LB classic, 230 LB plus) were used. The hens were kept in two mobile stalls that were moved to a new position at regular intervals. In both PY1 and PY2, 20 individual faecal samples per stall were randomly collected at monthly intervals in order to calculate the number of internal parasite eggs per gram of faeces (EPG). At the end of the laying periods, approximately 10% (N = 42) or more than 50% (N = 265) of hens were subjected to post-mortem parasitological examinations in PY1 and PY2, respectively. No parasite eggs were found in the faecal samples during PY1, whereas almost all of the hens (97.6%) were infected with Heterakis gallinarum (36 worms/hen) at the end of the period. In PY2, nematode eggs in faeces were found from the third month onwards at a low level, increasing considerably towards the final three months. There was no significant difference between the two genotypes of brown hens neither for EPG (P = 0.456) or for overall prevalence (P = 0.177). Mortality rate ranged from 18.3 to 27.4% but did not differ significantly between genotypes or production years. Average worm burden was 207 worms/hen in PY2. The most prevalent species were H. gallinarum (98.5%) followed by Ascaridia galli (96.2%) and Capillaria spp. (86.1%). Furthermore, three Capillaria species, C. obsignata, C bursata and C. caudinflata were differentiated. In conclusion chickens kept on free-range farms are exposed to high risks of nematode infections and have high mortality rates with no obvious link to parasite infections. Once the farm environment is contaminated with the nematode eggs, establishment and further spread of nematodes to the hens is a matter of time. This will latest be the case in the second production period, even if the hens are kept in a rotation system and in small herd sizes. This underlines the importance of nematode infections in all free-range systems.Chandrakasem Rajabhat University, Bangkok, Thailan

The Constitution and Conflict-of-Laws Treaties: Upgrading the International Comity

BACKGROUND: Classical faecal egg counts (FEC) provide less reliable diagnostic information for nematode infections in chickens. We developed an ELISA based on Ascaridia galli antigens and tested two hypotheses, as follows: (i) IgY antibodies developed against A. galli will also be useful to identify Heterakis gallinarum infections, and (ii) circulating antibodies stored in egg yolks are as good as plasma samples, so a non-invasive diagnosis is possible. The aim of this study, therefore, was to compare the diagnostic accuracy of the ELISA system with FEC, using both plasma and egg yolks from experimentally infected hens. In addition, naturally infected animals were evaluated to validate the assay. RESULTS: The assay quantified large differences (P &lt; 0.001) in plasma or in egg-yolk IgY concentrations between infected and uninfected animals in two experiments, each performed with either of the nematode species. The assay performed with high accuracy as quantified with the area under the ROC curve (AUC) values of &gt; 0.90 for both nematodes using either plasma or egg yolks. Sensitivity of the assay was 94 and 93% with plasma and egg yolk samples, respectively, whereas FEC yielded in a sensitivity of 84% in A. galli experiment. Total test accuracy of the assay with plasma samples (AUC = 0.99) tended to be higher (P = 0.0630) than FEC (AUC = 0.92) for A. galli, while the assay with either sample matrix performed similar to FEC (AUC ≥ 0.91) for H. gallinarum. Among the three tests, the FECs correlated better with A. galli burden than the ELISA. Although 90% of naturally infected hens were correctly identified by the ELISA, 45% of the infected hens tested negative with FEC, indicating the validity of the higher test accuracy of the ELISA. CONCLUSIONS: Antigens of A. galli can be used successfully to identify H. gallinarum-infected animals, indicating that chickens develop cross-reactive antibodies against the two closely related species. Egg yolks are as informative as plasma samples, so that animal welfare-friendly sampling is possible. Although the assay with plasma samples reveals qualitative information of higher quality than FECs on the infection status of naturally infected birds, the latter is still a better tool to assess the intensity of A. galli but not of H. gallinarum infections

Egg production dynamics and fecundity of Heterakis gallinarum residing in different caecal environments of chickens induced by fibre-rich diets

In modern husbandry systems, feed rations for laying hens may contain high levels of dietary fibre, which may only be fermented intestinally. Depending on fermentation properties, the type of dietary fibre may influence the intra-caecal environment constituting the predilection site of Heterakis gallinarum. We investigated egg production dynamics and fecundity of H. gallinarum residing in different caecal environments induced through different types of dietary fibre. Growing layers were fed a standard (CON) or an insoluble(I-) or soluble- (S-) non-starch polysaccharides-(NSP) supplemented diet for the first 11 weeks (wk) of life in a twice-replicated experiment. At 3 wk of age, the birds were infected with 200 embryonated eggs of H. gallinarum. Starting from 3 wk post-infection (p.i.), individual daily total excreta were collected. The number of eggs per gram of faeces (EPG) was determined (N = 2240), and the number of eggs per day (EPD) were estimated. The birds were necropsied 8 wk p.i. and the worm burdens were quantified. The nematode began to lay eggs as early as 23 d.p.i. and thereafter laid on average 436 eggs/d. I-NSP- and S-SNP-supplemented diets expedited the onset of patency by approximately 5 days, and increased total egg excretion by 110% and 185%, respectively, due to higher worm counts. The latter diet (S-SNP) additionally increased total egg excretion by 94% due to enhanced fecundity. Longitudinally collected data showed that fecundity of the nematode (EPD/female) was relatively stable starting from the second week of the patent phase. Results suggest that NSP-induced enlargement of caeca favoured establishment of the nematode while effects of an intensified microbial fermentation through S-NSP were crucial for an enhancement in the worm fecundity. Based on the long-term data obtained from daily collections of total excreta in experimentally H. gallinarum-infected chickens, it is concluded that a diet enriched with pea bran as source of insoluble NSP increased worm egg production merely through elevated worm counts, whereas a diet supplemented with chicory root meal as source of soluble NSP elevated worm egg production through both increased worm counts, and more profoundly through enhanced fecundity. (C) 2014 Elsevier B.V. All rights reserved

Helminth infections in laying hens kept in organic free range systems in Germany

This study describes the spectrum and intensity of helminth infections in laying hens kept in organic production systems in Germany. A total of 740 laying hens from 18 organic free range farms were collected between 2007 and 2010. The hens were sacrificed and the gastrointestinal tracts were examined for the presence and intensity of helminth infections with standard parasitological methods. Three nematode (Ascaridia galli, Heterakis gallinarum, Capillaria spp) and four cestode (Raillietina cesticillus, Hymenolepis cantaniana, Hymenolepis carioca, Choanotaenia infundibulum) species were found. Almost all hens (99.6%, N=737) harboured at least one helminth species. Average worm burden per hen was 218.4 (SD=218.3) worms. The most prevalent species were the nematodes Heterakis gallinarum (98%) followed by Ascaridia gall (88%) and Capillaria spp. (75.3%). The overall prevalence of the cestodes was 24.9%. Total worm burden was significantly higher during the summer season when compared with animals slaughtered during winter season (254 vs. 191, P<0.0001). The most dominant helminth species was Heterakis gallinarum averaging 190 (SE = 9.8) worms per hen in the summer and 129 (SE = 8.7) in the winter season (P<0.0001). Average Ascaridia gall burden was 25 (SE = 2.0) in summer and 26 (SE = 1.7) in winter (P=0.1160). Risk of infection with any of the nematodes was 50% higher in summer compared to winter (Psi = 1.49, P<0.0319). Probability of infection with any of the tapeworm species was 3.5 times higher in summer than in winter (P<0.0001). It can be concluded that the vast majority of hens are subclinically infected with at least one helminth species. The prevalence as well as intensity of the helminth infections, particularly with tapeworms, considerably increases in summer. The results indicate that it is essential to adopt alternative control strategies in order to lower infection risk in organic production systems which are gaining popularity. (C) 2011 Elsevier B.V. All rights reserved