Combining the effects of supplementary feeding and copper oxide needles for the control of gastrointestinal nematodes in browsing goats.

The aim was to assess the benefits obtained from combining supplementary feeding and copper needles (COWP), compared to the use of both approaches independently, for the control of gastrointestinal nematode (GIN) infections in browsing kids. Forty-four nematode free Criollo kids were exposed to natural parasite infection. The kids were divided into six experimental groups: not treated, supplemented (NT-S), not treated, not supplemented (NT-NS), moxidectin treated, supplemented (M-S), moxidectin treated not supplemented (M-NS), copper treated, supplemented (COWP-S) and copper treated, non-supplemented (COWP-NS). Copper treated groups received Copinox (2 g capsules) on day 0 and on day 60 of the trial. Moxidectin treated groups received Cydectin (0.2 mg/kg of body weight s.c.) every 28 days. Three of the groups received individual supplementation (100 g of feed/day fresh basis; 74% sorghum: 26% soybean meal; NT-S, M-S and COWP-S) and the other three groups were not supplemented (NT-NS, M-NS and COWP-NS). Animals browsed native vegetation (6.5 h/day) during the wet season (154 days). Kids were weighed every 14 days to determine live weight gain (LWG) and blood and faecal samples were obtained to determine packed cell volume (PCV), haemoglobin (Hb), peripheral eosinophil counts (PEC) and faecal egg counts (FEC). At the end of the trial, four kids of each group were euthanatized (six kids in each COWP treated group). Worm burdens, female worm lengths and prolificacy were determined. Liver samples were used to determine copper concentration and were stained with haematoxylin-eosin to determine microscopic lesions. Animals receiving the combination of supplementary feeding and COWP improved their LWG, PCV and Hb to similar levels of animals with suppressive AH treatment. This was not the case when COWP was used without supplementation. Liver copper concentration in COWP treated groups increased significantly especially in the COWP-NS kids but this was not associated with liver lesions or clinical signs. Post-mortem Haemonchus contortus and Trichostrongylus colubriformis worm counts had a tendency to be reduced in the different groups (66-35% reduction) compared to NT-NS group at the end of the trial (P>0.05). Also, COWP treatment and/or supplementation reduced female worm length of T. colubriformis and prolificacy of H. contortus and T. colubriformis. This study, confirmed the value of nutritional supplementation in the control of GIN in growing kids. The use of COWP in addition to supplementation had a limited contribution on the kids' resilience against GIN. This may be due to the reduced infection of H. contortus during this trial.

Improving resilience against natural gastrointestinal nematode infections in browsing kids during the dry season in tropical Mexico.

The objective was to determine the effect of supplementary feeding on the resilience and resistance of Criollo kids against natural gastrointestinal nematode (GIN) infections, when browsing native vegetation during the dry season in tropical Mexico. Thirty-three two-month-old Criollo kids, raised nematode free, were included at weaning in a 20-week trial. The kids were placed into four groups. Two groups of eight kids were offered 100g/day soybean and sorghum meal (26%:74% respectively fresh basis) (treated/supplemented (T-S) and infected/supplemented (I-S)). Two groups remained with no supplement for the duration of the trial (infected/non-supplemented (I-NS) (n=9) and treated/non-supplemented (T-NS) (n=8)). Kids in groups T-S and T-NS were drenched with 0.2mg of moxidectin/kg body weight orally (Cydectin, Fort Dodge) every 28 days. Groups I-S and I-NS were naturally infected with GIN. The animals browsed native vegetation for an average of 7h/day together with a herd of 120 naturally infected adult goats. Cumulative live weight gain (CLWG), packed cell volume (PCV), haemoglobin (Hb), total plasma protein and plasma albumin were recorded every 14 days as measurements of resilience. Resistance parameters (faecal egg counts (FEC) and peripheral eosinophil counts (PEC)) were also measured. Bulk faecal cultures were made for each group every 28 days. Every month a new pair of initially worm-free tracer kids assessed the infectivity of the vegetation browsed by the animals. Tracer kids and faecal cultures showed that kids faced low mixed infections (Haemonchus contortus, Trichostrongylus colubriformis and Oesophagostomum columbianum). Under conditions of scarce vegetation, such as those in the present study, supplemented groups (I-S and T-S) had higher growth rates compared to the non-supplemented groups independently of the control of GIN infection with anthelmintic (AH) treatment (P<0.001). Supplementary feeding did not affect FEC or PEC. In the absence of supplementation, lack of AH treatment may lead to outbreaks of clinical nematodosis. The supplementary feeding was economically feasible.

The effect of supplementary feeding on the resilience and resistance of browsing Criollo kids against natural gastrointestinal nematode infections during the rainy season in tropical Mexico.

The objective was to determine the effect of supplementary feeding on the resilience and resistance of Criollo kids against natural gastrointestinal nematode (GIN) infections, when browsing native vegetation during the wet season in tropical Mexico. Thirty-four 2-month old Criollo kids, raised nematode free, were included at weaning in a 22-week trial. The kids were placed into four groups. Two groups of 8 kids were offered 100g/day soybean and sorghum meal (26%:74%, respectively fresh basis) (treated/supplemented (T-S) and infected/supplemented (I-S)). Two groups remained with no supplement for the duration of the trial (infected/non-supplemented (I-NS) (n = 10) and treated/non-supplemented (T-NS) (n = 8)). Kids in groups T-S and T-NS were drenched with 0.2mg of moxidectin/kg body weight orally (Cydectin, Fort Dodge) every 28 days. Groups I-S and I-NS were naturally infected with GIN. The animals browsed native vegetation (for an average of 7h/day) together with a herd of 120 naturally infected adult goats. Cumulative live weight gain (CLWG), packed cell volume (PCV), haemoglobin (Hb), total plasma protein and plasma albumin were recorded every 14 days as measurements of resilience. Resistance parameters (faecal egg counts (FEC) and peripheral eosinophil counts (PEC)) were also measured. Bulk faecal cultures were made for each group every 28 days. Every month a new pair of tracer kids assessed the infectivity of the vegetation browsed by the animals. The T-S group had the highest CLWG, PCV and Hb compared to the other three groups (P < 0.001). The I-S and T-NS group had similar mean CLWG and PCV (P > 0.05), while the I-NS group had the poorest CLWG, PCV and Hb (P < 0.001). The PEC of supplemented kids (I-S and T-S) was higher than in the I-NS and T-NS kids (P < 0.05). No effect of supplementary feeding was found in the FEC. Tracer kids and faecal cultures showed that kids suffered mixed infections with Haemonchus contortus, Trichostrongylus colubriformis and Oesophagostomum columbianum. Supplementary feeding improved resilience of browsing Criollo kids against natural GIN infections and was economically feasible. Improved resistance was also suggested by the PEC but was not confirmed in the FEC.