Epidemiology and effect of gastrointestinal nematodes on dairy goats in Argentina

Abstract

The aim of this work was to study the epidemiology and harmful effects of gastrointestinal nematodes (GINs) on dairy goats maintained in an intensive system. Two groups of goats were studied: untreated group (UG) (subdivided into UGjun goats that kidded in June, and UGjul goats that kidded in July) and treated group (TG) (with no subgroups, treated with monepantel: 3.75 mg/kg, orally, monthly). Eggs per gram (epg) in faeces were counted, faecal culture was performed to differentiate nematode genera and milk production was measured. Differences between groups were compared using least squares means analysis of variance (milk production and milking period length) and Kruskal–Wallis test (faecal egg counts). Nematode infection was moderate, with Haemonchus and Trichostrongylus being the dominant genera; the faecal egg counts reached the level of 2000 only once throughout the study. Goats that kidded in June had higher egg count after parturition (UGjun = 1564 epg), with significant differences (p < 0.04) from those that still had not kidded (UGjul = 962 epg). Over the entire trial period, the mean total milk production of TG (399.5 L ± 34.0 L) was significantly higher (p < 0.05) than that of UG (281.6 L ± 37.5 L), representing an increase of 41.8% in total milk yield. The results of this study show a post-partum peak in egg count and a negative effect of GINs on milk yield, even with moderate infections.

Prevalence, effects and alternative control methods of Haemonchus contortus in small ruminants: A review

“…According to Suarez et al (2009), anthelmintic treatment positively affects the length of the milking period with regard to the length of the milking period of untreated dairy sheep. The same way, Suarez et al (2017) revealed, in goats instead, a significant negative effect of the GIN infections on the milking period length of the goats after kidding (262.3±9.8 days and 223.3±10.8 days respectively for treated and untreated goats). These different results could explain the positive correlation between the GINs infections treatment and the persistence increase in milk yield in dairy goats, ranging from 7.4 to 18.5% with respect to control values observed by Rinaldi et al (2007).…”

“…Indeed, in Italy, a study involving untreated naturally infected and anthelminthic-treated animals has revealed significantly effect of GINs infections on milk production, with the highest milk yield recorded in the treated goats (Rinaldi et al, 2007). More recently, in Argentina, Suarez et al (2017) reported a significant difference in the mean total milk production between treated (399.5 L ± 34.0 L) and untreated goats (281.6 L ± 37.5 L), amounting to 41.8% increase in total milk yield. The same study also revealed a post-partum peak in egg count and a negative effect of gastrointestinal nematodes (GINs) on milk yield, even with moderate infections.…”

Kinetics of IgA and eosinophils following a low‐dose, predominantly Haemonchus contortus infection of Boer goats

“…Although H contortus infection generally occurs together with other gastrointestinal nematodes, it consistently dominates the infection among livestock in tropical or subtropical countries . For example, milk production in Saanen goats naturally infected with H contortus and Trichostrongylus colubriformis and subsequently treated with anthelmintic is significantly higher (399.5 L ± 34.0 L; P < .05) when compared to untreated goats (281.6 L ± 37.5 L) …”

Problemas sanitarios de las majadas caprinas en los sistemas familiares de los valles calchaquies (Payogasta, Salta)

“…A partir de estos resultados se podría inferir que la mayor infestación se registraría al inicio del otoño cuando el desarrollo de los NGI se vería favorecido por las lluvias estivales. A pesar de que los muestreos de heces no mostraron los niveles de infestación descritos en las explotaciones comerciales de los valles templados de altura de Salta y Jujuy (Suarez et al, 2017c), las principales especies presentes coincidieron con las de esa región. En otros muestreos en otras regiones áridas también se observó la presencia en bajo número de los géneros Trichostrongylus spp.…”