RESUMO
The aim of this study was to identify modifications in the feeding behaviour of goats browsing a tropical deciduous forest (TDF) when natural gastrointestinal nematode (GIN) infection was suppressed. Continuous bite monitoring through direct observation was implemented in 12 Criollo goats (adults, non-pregnant) foraging for 4 h per day during the rainy season. In the first Period (P1, one observation point) all goats were maintained with natural GIN infection. In the second Period (P2, three observation points), goats were equally distributed into 2 groups: i) moxidectin treated group (TG) used in a suppressive scheme; and ii) naturally infected group (IG). For each observation point, goats were monitored at three timepoints per day (80 min each), for three consecutive days, to estimate their intake of dry matter (DM), condensed tannins (CT), crude protein, metabolizable energy and digestible DM. Live weight (LW), faecal samples and blood samples were obtained every 28 days to determine LW change, faecal egg counts (FEC) and packed cell volume (PCV). During P1 and P2, the TG and IG had similar LW change and PCV. During both periods, the intake of DM, CT and all macronutrients were similar for TG and IG. The suppression of GIN infection did not modify the feeding behaviour of goats. Therefore, a therapeutic self-medicative behaviour was not identified in Criollo goats browsing a TDF.
Assuntos
Comportamento Alimentar , Doenças das Cabras/psicologia , Infecções por Nematoides/psicologia , Animais , Fezes/parasitologia , Feminino , Doenças das Cabras/parasitologia , Cabras , Macrolídeos/uso terapêutico , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/veterinária , Contagem de Ovos de Parasitas/estatística & dados numéricos , AutomedicaçãoRESUMO
This study evaluated the status of anthelmintic resistance against the three available classes of commercial drugs in seven sheep farms in the hot humid tropics of Mexico. Drug classes included benzimidazole (BZ), ivermectin (IVM) and levamisole (LV). Respective faecal egg count reduction tests (FECRT) were performed in each farm. Faecal samples were obtained from the rectum of >100 sheep in each farm. Adult sheep shedding >150 eggs per gram of faeces (EPG) were included. In each farm, animals were allotted to one of four groups with similar mean EPG: Control Group (untreated), BZ group (albendazole sulfoxide 5mg/kg LW), IVM group (ivermectin, 0.2mg/kg LW) and LEV group (levamisole 7.5mg/kg LW). Drugs were administered subcutaneously. A second faecal sampling was performed on the same animals of each farm 14days post-treatment. The GIN genera obtained from faecal cultures were identified for each group in different farms. Percentage faecal egg count reduction (%R) and 95% confidence intervals were estimated using the RESO© software. A questionnaire was applied to farm owners to describe anthelmintic management practices. All sheep farms had GIN populations with multiple resistance to the three anthelmintic classes tested. The %R ranged from 0 to 48% for BZ, 29 to 82% for IVM and 1 to 88% for LEV. Haemonchus spp. and Trichostongylus spp. were found in all treated groups of the study farms. Resistant Oesophagostomum spp. larvae (BZ or IVM) were found in respective farms. Treatment practices in study farms included frequent mass treatment every two months with extra treatments applied individually in the presence of clinical signs. Drug dosage used visual estimation of body weight rather than the exact weight of each animal. Quarantine anthelmintic treatment of incoming stock was used but efficacy was not confirmed.
RESUMO
This trial evaluated the effect of maize supplementation on the ingestive behavior, nutrient intake and the resilience against gastrointestinal nematode (GIN) infection of hair sheep in a silvopastoral system containing tropical grasses and legume trees. In addition, it attempted to determine the metabolic cost of the natural GIN infection in supplemented and non-supplemented animals. Twenty-nine 3-month-old lambs (male and female), raised nematode free, were allocated to four groups: I-NS (infected, not supplemented, n = 8), I-S (infected, supplemented with maize at 1.5% live weight (LW), n = 7), T-NS (treated with moxidectin 0.2 mg/kg LW every 28 days, and not supplemented, n = 7) and T-S (treated with moxidectin and supplemented with maize at 1.5% LW, n = 7). During the 70-day trial, fodder intake, fodder selection, LW change (LWC), red blood cell counts (RBC), hemoglobin (Hb), hematocrit (Ht) and eggs per gram of feces (EPG) were measured every 14 days. Supplement consumption was recorded daily. Metabolizable energy (ME) and protein (MP) consumption from the feeds were estimated. Maize supplementation helped to improve the resilience of hair sheep lambs against GIN infections. The I-S and T-NS groups showed similar LWC, RBC, Hb and Ht (P > 0.05) and both were higher than those in the I-NS group (P < 0.05). No difference was found in EPG between the I-NS and the I-S groups (P > 0.05). No effect of sex was observed in the different variables. Although all groups showed low dry matter intake (DMI) (< 2% LW), supplemented groups (T-S and I-S) showed higher total DMI (fodder + maize; P < 0.05), hence higher ME and MP intakes than the non-supplemented groups (T-NS and I-NS). All groups showed similar fodder selection patterns. The estimated metabolic cost of parasitism was ME = 0.70 MJ/day and MP = 9.2 g/day in the I-S animals. Meanwhile, the cost in the I-NS animals was ME = 1.46 MJ/day and MP = 12.71 g/day. Maize supplementation was an economically viable strategy to control GIN compared with no intervention.
Assuntos
Ração Animal/normas , Gastroenteropatias/veterinária , Infecções por Nematoides/veterinária , Doenças dos Ovinos/prevenção & controle , Zea mays , Ração Animal/classificação , Criação de Animais Domésticos/métodos , Animais , Antinematódeos/administração & dosagem , Peso Corporal , Cynodon , Suplementos Nutricionais , Ingestão de Alimentos , Metabolismo Energético , Fabaceae , Feminino , Gastroenteropatias/parasitologia , Gastroenteropatias/prevenção & controle , Macrolídeos/administração & dosagem , Masculino , México , Infecções por Nematoides/parasitologia , Infecções por Nematoides/prevenção & controle , Ovinos , Doenças dos Ovinos/parasitologia , Organismos Livres de Patógenos EspecíficosRESUMO
The aim was to determine the persistent efficacy of copper oxide wire particles (COWP) against Haemonchus contortus in sheep, using the harmonization guidelines protocol. Thirty-six male lambs (2 months old) reared free of gastrointestinal nematodes were used (average body weight of 10.8±3.8kg). Before and for the duration of the study, lambs were kept in raised cages with slatted floors and were offered ad libitum a complete mixed diet. Animals were divided into six groups (n=6): one non-treated control group (G0) and five groups treated with one COWP capsule (1.7g of copper oxide; Copinox(®)). Animals in each group were treated on pre-defined dates before the artificial infection was applied: days -35 (G1), -28 (G2), -21 (G3), -14 (G4) and -7 (G5). On day 0 animals were infected with 3700 H. contortus infective larvae per animal. Animals were humanely slaughtered between days 22 and 23 post-infection. The abomasums were individually washed to obtain the contents. These organs were subjected to separate artificial digestions. Adult parasites were counted from the abomasum contents and the larvae from the digested material. Worm burden geometric means were calculated for each group. A significant worm burden reduction in either of the treated groups (G1, G2, G3, G4, and G5) compared to the control (G0) was considered as persistence of the anthelmintic effect. Copper levels were determined from individual liver samples of each animal. The geometric mean worm burden of the control group (G0) was 1959. Compared to the control, worm burdens geometric means were significantly reduced in groups G1 (1108), G4 (528) and G5 (1063) (P<0.03). Efficacies in G1, G4 and G5 were 43.4%, 73.0% and 45.7% respectively. No significant reduction was found for G2 (1342) and G3 (1430). A larger quantity of Cu was found in the livers of treated animals compared to the control group (P<0.05) except for G3 (P=0.06). A negative association between Cu liver content and worm burdens was found (r=-0.42, P<0.05). Live weight gain was similar in all groups and no clinical or post-mortem manifestations of Cu toxicity were recorded in treated animals.