Nematode Parasites of Vertebrates: Their Development and Transmission

A brief report is given of the 4th Network for Animal Health and Welfare in Organic Agriculture (NAWHOA) workshop at Wageningen in the Netherlands, held in March 2001. The workshop focussed on breeding (especially dairy, pigs and poultry) and feeding, as opposed to yield and productivity, with the emphasis on food quality. Feeding was discussed from two angles: feeding for production, and feeding to protect the animal from disease or parasitic infection.

A vision of the future was described, in which higher prices are gained for fewer animals, better housed and with a regional approach to breeding, processing and marketing.

Animal Health and Welfare in Organic Agriculture

A questionnaire survey was undertaken on sheep farms in Denmark to obtain information on sheep management and worm control practices. The questionnaires were inserted in the June and July, 1993 issue of the Danish Sheep Breeders Journal, circulated monthly to approximately 1200 sheep breeders nationwide. A total of 183 (11%) questionnaires were returned. A second questionnaire was posted to 50 of the 183 responding farmers to examine the repeatability of responses to the first questionnaire. The majority (97%) of the 183 farmers used anthelmintics. The mean number of doses per year for lambs (< 12 months old) and adult sheep (> 12 months old) were 1.9 and 2.3, respectively. Only 42% of the farms followed predetermined drenching programmes. Live weights were determined by visual appraisal on 45% and 84% of the farms for lambs and adult sheep, respectively. In calculating anthelmintic doses for groups of lambs and adult sheep, the recommended weights of the heaviest animals were only used on only 18% and 27% of the farms respectively. Benzimidazoles were the most commonly used anthelmintics from 1986 to 1993. Eighty one percent of 94 responding farmers had been using the same class of anthelmintic for 3 or more consecutive years. Information from this study indicated lack of knowledge about worm control strategies, anthelmintic use and the problem of anthelmintic resistance among the majority of Danish sheep farmers. The majority of responses to the questionnaire were repeatable at least to a fair degree except when farmers were asked to recall anthelmintics used in past years.

Worm control practices on sheep farms in Denmark

A series of 2-Arylidene-4-(methoxyphenyl)but-3-en-4-olides were screened against Pheretima posthuma earthworm for anthelmintic activity. The in vitro effects of compounds were evaluated at a concentration of 2mg/mL and time taken by the compounds to paralyze and subsequently kill the worms was recorded. Butyrolactone derivatives exhibited moderate to good anthelmintic activity but among all tested compounds, compound II, 2-(3,4,5-trimethoxy-benzylidene)-4-(methoxyphenyl)but-3-en-4-olide, was found to be the most potent against Pheretima posthuma. The anthelmintic activity of compound II was observed to be comparable with positive control albendazole in terms of paralytic and lethal time. Keywords: Furnaone, Butyrolactone, Pheretima posthuma, Anthelmintic.

https://jbpr.in/index.php/jbpr/article/download/225/215

Biological evaluation of 2-arylidene-4-(methoxyphenyl)but-3-en-4-olides

Synthesis and biological study of Pyrazoles, Amino- Pyrimidines and Malononitriles derived from Cyclic Imides

This study was focused on in vitro screening of 15 selected plant species identified to have anthelmintic traits for their individual activity at three concentrations on mixed L3 larvae of goats and sheep grazing contaminated Kikuyu grass (Pennisetum clandestinum). It comprised of three sub-studies, based on major bioactive anthelmintic principles from extensive body of research. Sub-study (1) was based on alkaloids and tannins plant species, including Crinum macowanii, Gunnera perpensa, Nicotiana tabacum, Sarcostema viminale, Vernonia amygdalina, Zingiber officinale and Zizyphus mucronata. Sub-study (2) was based on flavonoid plant species and consisted of Trema orientalis, Urtica dioica and Zanthozylum capense. Ultimately, sub-study (3) was based on proteases and nitrogen compounds containing plant species including Allium cepa, Ananas comosus, Bidens pilosa, Carica papaya, and Ricinus communis. Oven-dried leaf samples (40g; 20g; 10g) of each species were extracted in 70% ethanol, and concentrated to 100ml; constituting 4×, 2× and 1× crude extract concentration. Rectal faecal material from 10 Merino sheep and 25 Nguni goats, pooled within species and hand-mixed. Dung samples (5g) were weighed and cultured for 12 days at 27°C. On day 13, four plates were watered, and others (4) treated with 70% ethanol to correct for solvent effect on mortality. Sub-study (1), had 2 (animal species) x 7 (plant species) x 3 (extract concentrations) factorial design. Sub-study (2), 2 (animal species) x 3 (plant species) x 3 (extract concentration) factorial design. Sub-study (3) had 2 (animal species) x 5 (plant species) x 3 (concentrations) factorial design. In each run, three plates were treated with each crude extract concentration. L3 larvae isolated on day 14, larval counts done, and mortality adopted as indices of percentage dose anthelmintic efficacy. The study was re-run three times. In substudy (1), animal species (P= 0.0107) and concentration (P= 0.0005) affected efficacy. Increases in crude extract concentration from 1x to 2x and 4x resulted to efficacies of 71.2±2.62%, 88.0±1.88% and 97.9±0.91% for goats, and 93.8±2.62%, 96.0±1.88 % and 98.0±0.91 % for sheep. Interaction between extract concentration and animal species affected efficacy (P= 0.0127). In sub-study (2), concentration affected (P< 0.0001) efficacy. Animal

Sylvester Werekeh. Fomum

Papers

Plant-plant combination: an important option in the phase of failing anthelmintics to control nematodes in small ruminants.