The worm burden of tracer kids and lambs browsing heterogeneous vegetation is influenced by strata harvested and not total dry matter intake or plant life form.

This study assessed the effect of total dry matter intake (DMI), plant life form and strata harvested on the gastrointestinal nematode (GIN) worm burdens of tracer kids and lambs browsing heterogeneous vegetation during the rainy season (August-November). The rainy season was divided into 6 2-week periods (P1-P6), and environmental conditions (rainy days, rainfall, temperature and humidity) were recorded daily. Five pairs each of tracer kids and tracer lambs raised free of GIN infections were used. Every 15 days, different pairs of kids and lambs were introduced to a 2.2-ha plot and co-grazed with a flock of 30 sheep and 70 goats for a period of 3 weeks. Feeding behaviour of each pair of tracers was measured in weeks 2 and 3. The continuous bite monitoring method was used to estimate total DMI, DMI of plant life forms and DMI from plants of different strata. After each 3-week period, the tracer pair was maintained indoors for 28 days and necropsied on day 29 to recover the worm burden. The feeding behaviour of the tracers was compared between periods (P2-P6) and between kids and lambs. The differences in the worm burdens of the tracers between periods were not associated with total DMI or DMI from plant life forms. Worm burdens were highest during P5 and P6 in tracer kids and lambs (P < 0.05), suggesting a build-up of infective larvae in the tropical deciduous forest (TDF). The lower worm burdens of tracer kids compared with lambs (P < 0.05) seemed to be associated with less low- and more medium-stratum ingestion.

Supplementation with dry Mimosa caesalpiniifolia leaves can reduce the Haemonchus contortus worm burden of goats.

Gastrointestinal nematodes (GINs) cause considerable economic losses in grazing goat herds. At present, GIN control cannot rely on conventional anthelmintic (AH) drugs because parasites have developed resistance against such drugs. Thus, alternative control methods are being sought to reduce the dependence on AH. Many tannin-rich plants exhibit AH activity and may be used as alternatives for GIN control. Mimosa caesalpiniifolia is a tannin-rich shrub consumed by small ruminants in Brazil. This study evaluated the in vivo AH effect of M. caesalpiniifolia leaf powder supplementation on GIN egg fecal excretion and worm burden in goats. Plant leaves were harvested, dried and ground to obtain a powder. Twenty-four castrated male goats, aged six to eight months, with a mean body weight of 15.0 ±â€¯2.5 kg were used in the experiment. Animals were infected orally with 16,000 larvae comprising 50% Haemonchus spp., 41% Trichostrongylus spp. and 9% Oesophagostomum spp. Once the infection was patent, the goats were distributed into four groups of six animals. The control group received concentrate without condensed tannins (CTs) and did not receive any drench against GINs. The monepantel group received concentrate without CTs and were drenched once with monepantel. The other two groups received the M. caesalpiniifolia leaf powder in two periods of seven consecutive days (days 1-7 and 14-21), with one of the groups also receiving 10 g of polyethyleneglycol (PEG)/day. The animals were weighed weekly, and individual fecal eggs counts (FECs) were performed daily. After 28 days, the animals were humanly slaughtered, and the worm burden was estimated. Although live weight gain and FECs did not differ among the groups (P > 0.05), post-mortem worm counts showed a reduction in Haemonchus contortus adult worm burden (57.7%) in goats of the CT group compared to control goats (P < 0.05). The addition of PEG did not diminish AH activity in the CT + PEG group (66.9% reduction compared to the control). No AH effect against other GIN species was found. The result for the addition of PEG suggested that the observed AH activity was associated with plant secondary compounds, as opposed to CTs. As expected, no AH effect against Oesophagostomum columbianum was found for the monepantel group showed. Thus, feeding dry leaves of M. caesalpiniifolia represent a promising alternative for the control of GIN infections in goats.

Efeito anti-helmíntico dos extratos aquosos e etanólicos da Annona squamosa L. (fruta-do-conde) sobre o nematóide Ascaridia galli / Anthelmintic effect of aqueous and ethanolic extracts from Annona squamosa L. (sweetsop) on the nematode Ascaridia galli

As plantas são fontes importantes de produtos naturais biologicamente ativos. Dentre as plantas usadas na medicina popular a Anonna squamosa conhecida como fruta-do-conde é citada como tendo várias ações medicinais, dentre elas a atividade inseticida e anti-helmíntica. Dentro desta perspectiva, objetivou-se determinar a atividade anti-helmíntica dos extratos aquosos (EA) e etanólicos (EE) das folhas da fruta-do-conde sobre o nematóide de aves Ascaridia galli, in vitro e in vivo. No primeiro, os nematóides foram colocados em placa de Petri contendo diferentes concentrações dos extratos e no segundo foram utilizadas seis galinhas poedeiras por grupo, as quais foram administrados10 mL Kg-1 dos extratos. No teste in vitro o EA da A. squamosa nas concentrações 2,4 e 9,6 mg mL-1 foi capaz de matar 63,33 por cento e 53,33 por cento dos nematóides, respectivamente. O EE não produziu efeito significativo. No teste in vivo, o percentual de eliminação do EA foi de 39 por cento e do EE de 20 por cento. Estes dados sugerem que neste caso a substância responsável pela mortalidade dos parasitos esteja em maior concentração na fração aquosa. Desta maneira, acredita-se que o EA de A. squamosa apresenta uma atividade anti-helmíntica potencial sobre o A. galli.

Plants are important sources of biologically active natural products. Among the plants used in popular medicine, Annona squamosa, known as sweetsop, is reported to have several medicinal actions such as insecticidal and anthelmintic activity. Therefore, this study aimed to assess the anthelmintic activity of aqueous (AE) and ethanolic (EE) extracts from sweetsop leaves on the chicken roundworm Ascaridia galli, both in vitro and in vivo. In the former, nematodes were placed on a Petri plate containing different concentrations of the extracts; in the in vivo test, six egg-laying chickens per group received 10 mL Kg-1 of the extracts. In vitro results indicated that A. squamosa AE at the concentrations 2.4 and 9.6 mg mL-1 could kill 63.33 percent and 53.33 percent nematodes, respectively. However, EE did not have any significant effect. According to the in vivo test, the elimination percentage for AE was 39 percent and for EE, 20 percent. These data suggest that the substance responsible for parasite mortality was present at a higher concentration in the aqueous fraction. Thus, A. squamosa AE is believed to have a potential anthelmintic activity on A. galli.