Controlling gastro-intestinal nematodes of goats with plant extracts

Gastro-Intestinal Nematodes (GIN) impact on health of goats. In response to increasing problems with anthelmintic resistance, farmers opt for other strategies to control GIN. Amongst these, the use of plant preparations receives renewed interest. In the south of France where the production of medicinal plants is economically important, goat farmers traditionally use commercially available plant essential oils (EO) to cure and alcoholic plant extracts (AE) to prevent infection with GIN. We performed a series of on-farm trials with adult goats where the effect of (i) a specific EO mixture and (ii) an AE of various plants (Table 1) were tested on GIN. Three goat farms, each with> 40 adult animals were enrolled in the study. Faecal egg count (FEC) were performed for every animal individually and all goats with EpG> 1000 were selected for the study. For each farm, the study animals were randomly distributed to either a treatment or a control group, which resulted in 10 to 12 animals per group and farm. EO was dissolved in paraffin (7 ml per treatment unit and day) and administered to all animals of the treatment group per os for 3 consecutive days (Table 1).

Tab. 1: Composition of essential oil (EO) and alcoholic (AE) extracts and administered doses

Essential oil	Daily dose (ml)	Total dose (ml)*	Plant part
Cinnamomum cossio	0.1	0.3	-
Origanum compact	0.1	0.3	-
Eugenia aromaticum	0.1	0.3	-
Thymus vulgaris	0.1	0.3	-
Peumus boldus	0.17	0.5	-
Laurus nobilis	0.43	1.3	-
EtOH/H2O**
Artemisia absinthium	0.5	5	Aerial part
Juglans regia	0.5	5	Leaves
Rubus fructicosus	0.5	5	Leaves
Allium sativum	0.5	5	Bulb
Tanacetum vulgare	0.5	5	Flowers
*Total treatment period was 3 days for EO and 10 days for AE **Ethanol contents of different plant extracts varied between 20% and 60%

Fig. 1: Efficacy of essential oil mixture on FEC as measured by eggs per gramm faeces (EpG), before and 7 and 14 days post treatment. Grey squares represent treated animals (n = 12), open circels represent control animals (n = 11), black bars indicate group means. NS = not significant, *= significant at α= 0.05

Control animals received paraffin only. AE treatment was done on only one goat flock. In order to examine the preventive potential of AE, all animals were treated with a short acting anthelmintic in order to assure GIN naïve conditions. The experimental animals were then treated for 10 consecutive days with AE and were allowed to pasture from the beginning of the treatment procedure. FEC were performed at day 0, 7 and 14 for the EO treatment and at day 0, 23 and 33 of the AE treatment. Compared to controls, EO treatment did result in a significantly reduced FEC in one herd 7 days after treatment onset (Figure 1). No further effects of EO treatment were found for the other farms, neither at day 7 or day 14 after EO treatment. AE treatment did not lead to FEC differences between the control and the treatment group.