Effect of cleaning /disinfection strategies on helminth infections in finishing pigs

Ascaris suum is the most prevalent helminth on organic pig farms (Carstensen et al., 2002) and is transmitted mainly via the faeces. The use of anthelmintics does not fit in the organic principles and preventive measures are promoted. This project focused on assessing the efficacy of a cleaning protocol for the dunging area of pens on Ascaris s. transmission to pigs. In 4 batches with 8 identical pens for 15 pigs each (n=480 pigs) 6 pigs per pen were orally infected with Ascaris s. The other pigs can be earliest infected at 10 weeks and half of the pens were thoroughly cleaned at that time. Affected livers and egg counts in the manure had to show if this cleaning protocol keeps the non infected animals free of Ascaris s. The results show no effect of the cleaning protocol on the non infected pigs. These pigs had 57% damaged livers in both treatment and 50% had positive egg counts in the manure. The conclusion is that pen hygiene does not contribute to a reduction of Ascaris s. infections

Effect of rooting area and drinker in the outdoor run on behaviour and Ascaris infection of organic pigs

Hygiene is often a problem on the outdoor runs of growing organic pigs. Manure and urine are mainly excreted outside, but spread all over the run. Reduc-ing the dirty surface may improve well being, reduce ammonia emission, improve hygiene and reduce labour and parasite infections. The presence of a rooting area and of a drinker on the outdoor run were tested in a 2x2 factorial design. The pens with the rooting areas had a higher number of pigs on the outdoor run than the pens without a rooting area (1.6 vs 1.2 pigs). This was caused by more pigs in area 2 and 3. At higher temperatures there were more pigs outside, except in the root-ing area: this was popular at all temperatures. A rooting area resulted in a cleaner outdoor area, however in some cases the root-ing area became a dunging area. An extra outdoor drinker leads to a cleaner area around the drinker, but to a dirtier indoor area. No difference in Ascaris infection was found between the four treatment combinations

Ixodes ricinus ticks are reservoir hosts for Rickettsia helvetica and potentially carry flea-borne Rickettsia species

Rickettsia specie

The use of outdoor runs with rooting areas and drinkers by organic pigs

Hygiene is often a problem on the outdoor runs of growing organic pigs. Manure and urine are mainly excreted outside, but spread all over the run. Reducing the dirty surface may improve well being, reduce ammonia emission, improve hygiene and re-duce labour. The presence of a rooting area and of a drinker on the outdoor run were tested in a 2x2 facto-rial design. The pens with the rooting areas had a higher number of pigs on the outdoor run than the pens without a rooting area (1.6 vs 1.2 pigs). This was caused by more pigs in area 2 and 3. At higher temperatures there were more pigs outside, except in the rooting area: this was popular at all temperatures. A rooting area resulted in a cleaner outdoor area, however in some cases the rooting area became a dunging area. An extra outdoor drinker leads to a cleaner area around the drinker, but to a dirtier in-door area

The efficacy of an ivermectin/closantel injection against experimentally induced infections and field infections with gastrointestinal nematodes and liver fluke in cattle. Vet

Abstract Three studies were performed to test the efficacy of an ivermectin/closantel injection (200 mg/kg À1 ivermectin and 5 mg/kg À1 closantel) in cattle. Two were experimentally induced infections of Ostertagia ostertagi, Cooperia oncophora and Fasciola hepatica in calves, and the third had natural field infections in cattle with several species of gastrointestinal nematodes and F. hepatica. In the two studies with artificial infections, four groups of 8 calves were used. All calves were infected with metacercariae on Day 0. Infection with the nematodes took place on Day 33 in groups 1 and 2 and on Day 54 in groups 3 and 4. Treatment was given to calves of group 1 on Day 63 and to calves of group 3 on Day 84. Calves of groups 2 and 4 served as untreated control groups. Calves of groups 1 and 2 were sacrificed on Day 84, calves of groups 3 and 4 on Day 105. The field study was carried out on a commercial farm in the Netherlands. Six groups of cattle were used. Groups A and B consisted of 10 parasite free calves, introduced to the farm and grazed for four weeks on pastures naturally infected with gastrointestinal nematode larvae and liver fluke metacercariae. Group C were the farmers own calves (15), group D heifers (10), group E dry cows (6) and group F milking cows (20). Treatment was given to animals of group A, C, D and E 10 weeks after housing of group A and B. Animals of groups B and F served as untreated controls. Calves of groups A and B were sacrificed 14 days after treatment. The efficacy of the treatment was calculated on basis of the post-mortem fluke and nematode worm counts in the first two studies and on a combination of post-mortem fluke and nematode worm counts and faecal egg output in the field study. In the two experimental studies, the efficacy of the treatment against F. hepatica was 99.2% and 94.5% for 9-week-old flukes and 98.4% and 99.5% for 12-week-old flukes. For O. ostertagi in both studies efficacy was 100% and against C. oncophora in both Groups 1 efficacy was 84.9% and 99.0% and in Groups 3 85.0% and 99.4%. In the field study, based on the post mortem fluke and nematode worm counts in groups A and B, efficacy against F. hepatica was 98.4%, O. ostertagi 100%, C. oncophora 99.4%, C. punctata 100%, Nematodirus helvetianus 60.8%, Trichuris spp. 100% and against larval intestinal nematodes 100%. The results of the faecal examinations 14 days after treatment confirmed the post-mortem results with 100% reduction of egg output for O. ostertagi, C. punctata, Trichostrongylus spp. and Trichuris spp. and low egg output of C. oncophora and N. helvetianus.

Molecular analysis of selection for benzimidazole resistance in the sheep parasite Haemonchus contortus

The molecular basis for the resistance of the sheep parasitic nematode Haemonchus contortus to the benzimidazole (BZ) group of anthelmintics was investigated. Three BZ-susceptible and three resistant populations from different geographical locations were characterized with respect to the egg-hatch assay with thiabendazole (TBZ), mebendazole (MBZ) binding tests and restriction fragment length polymorphism (RFLP) after Southern blotting. Cloned H. contortus α- and β-tubulin genes were used as probes to analyze the RFLPs of genomic DNA prepared from mixtures of infectious larvae (L3) or adults. The susceptible populations showed, with both α- and β-tubulin probes, 2 to 6 different fragments, depending on the restriction enzyme used. The three resistant populations showed as many fragments with the α-tubulin probe as the susceptible populations, but when probed with β-tubulin only 1 or 2 fragments were visible, but always less than in the susceptible populations. An in vitro selection experiment was carried out using a susceptible population that was isolated in the laboratory before BZ came on the market. The results showed that after two selections with increasing amounts of TBZ, the population had become resistant, according to the egg-hatch assay values and MBZ binding assay. Using RFPL, the number of β-tubulin probe reactive DNA fragments was reduced from 5 to 1. Analysis of the DNA of individual male adults of susceptible populations indicated a heterogeneity among the individual worms regarding the number of β-tubulin probe reactive fragments (1 to 4) and frequency of the specific fragments. Usually, only one specific fragment (9 kb) was found in the resistant individuals. This 9-kb fragment was already present in some individuals in the susceptible population although it was in combination with other fragments. This would imply that genes conferring BZ resistance were present in H. contortus populations before BZ came on the market, and could explain the fast selection for BZ resistance in the field.</p

Longitudinal Analysis of Tick Densities and Borrelia, Anaplasma, and Ehrlichia Infections of Ixodes ricinus Ticks in Different Habitat Areas in The Netherlands

From 2000 to 2004, ticks were collected by dragging a blanket in four habitat areas in The Netherlands: dunes, heather, forest, and a city park. Tick densities were calculated, and infection with Borrelia burgdorferi and Anaplasma and Ehrlichia species was investigated by reverse line blot analysis. The lowest tick density was observed in the heather area (1 to 8/100 m(2)). In the oak forest and city park, the tick densities ranged from 26 to 45/100 m(2). The highest tick density was found in the dune area (139 to 551/100 m(2)). The infection rates varied significantly for the four study areas and years, ranging from 0.8 to 11. 5% for Borrelia spp. and 1 to 16% for Ehrlichia or Anaplasma (Ehrlichia/Anaplasma) spp. Borrelia infection rates were highest in the dunes, followed by the forest, the city park, and heather area. In contrast, Ehrlichia/Anaplasma was found most often in the forest and less often in the city park. The following Borrelia species were found: Borrelia sensu lato strains not identified to the species level (2.5%), B. afzelii (2.5%), B. valaisiana (0.9%), B. burgdorferi sensu stricto (0.13%), and B. garinii (0.13%). For Ehrlichia/Anaplasma species, Ehrlichia and Anaplasma spp. not identified to the species level (2.5%), Anaplasma schotti variant (3.5%), Anaplasma phagocytophilum variant (0.3%), and Ehrlichia canis (0.19%) were found. E. canis is reported for the first time in ticks in The Netherlands in this study. Borrelia lusitaniae, Ehrlichia chaffeensis, and the human granylocytic anaplasmosis agent were not detected. About 1.6% of the ticks were infected with both Borrelia and Ehrlichia/Anaplasma, which was higher than the frequency predicted from the individual infection rates, suggesting hosts with multiple infections or a possible selective advantage of coinfection

Performance of organic and low input livestock systems: a matter of sound design?

The QLIF project has targeted a variety of issues to make organic animal production (dairy cattle, pig, poultry) more safe, develop alternative methods to promote animal health and improve product quality. This workshop will discuss these aims as well as the QLIF achievements to date. It will also address our way of assessing the quality of our organic farms. We ask the question what the advantages are of doing this by looking at the output of a farm, such as yield, animal welfare and environmental issues. Alternatively, we also want to know what benefits there are in looking at how the farm is organised, via input factors such as housing design, nutrition, management quality. Two invited speakers will state their preference. Legislation, certification and consumer perceptions wil be addressed