Seroprevalence of Major Pasture-Borne Parasitoses (Gastrointestinal Nematodes, Liver Flukes and Lungworms) in German Dairy Cattle Herds, Association with Management Factors and Impact on Production Parameters.

Andrea Springer,Daniela Jordan,Bettina Schneider,Christina Strube,Alina Kirse,Amely Campe,Kerstin E Müller,Gabriela Knubben-Schweizer,Martina Hoedemaker

doi:10.3390/ani11072078

Abstract

Simple SummaryPasture-borne worm infections impact cattle health and productivity worldwide. The present study assessed exposure of dairy cattle herds to the three most important pastural parasites, i.e., gastrointestinal worms, liver flukes and lungworms, in three parts of Germany by measuring antibodies in bulk tank milk samples. The results show a high level of exposure to gastrointestinal worms, while antibodies against liver flukes were less frequently detected and lungworm-positive herds were rare. Regional and breed differences regarding parasite exposure were detected. In addition, the presence of antibodies was associated with access to fresh grass, access to hay, silage quality and deworming frequency. Furthermore, parasite exposure was significantly associated with a poor body condition across all regions. Parasite-exposed cows of high-performance breeds also produced on average less milk per year than dual-purpose breeds. Pasture-borne parasites adversely affect bovine health and productivity worldwide. In Europe, gastrointestinal nematodes, especially Ostertagia ostertagi, the liver fluke Fasciola hepatica and the lungworm Dictyocaulus viviparus represent the most important parasites of dairy cattle. The present study assessed exposure towards these parasites among 646 cattle herds in three parts of Germany during 2017–2019 via antibody detection in bulk tank milk (BTM). Overall, O. ostertagi levels indicative of production losses were detected in 41.2% (266/646; 95% confidence interval (CI): 37.4–45.1%) of BTM samples, while F. hepatica seroprevalence amounted to 14.9% (96/646; 95% CI: 12.2–17.9%). Only 2.3% (15/646; 95% CI: 1.4–3.9%) of samples were D. viviparus antibody-positive. Significantly lower O. ostertagi as well as F. hepatica seroprevalence was detected in dual-purpose breeds compared to high-performance breeds from the same region. Management factors related to parasite exposure included access to fresh grass and hay, silage quality and anthelmintic treatment. Furthermore, F. hepatica and O. ostertagi seropositivity was significantly associated with suboptimal herd-level body condition. Interestingly, the relationship between seropositivity and productivity differed between breed types. Negative impacts on milk yield were detected only in high-performance breeds, while O. ostertagi seropositivity was associated with a lower milk fat content in dual-purpose herds.

Highlights

Pasture-borne parasites represent a major global problem for bovine health and productivity
O. ostertagi levels indicative of production losses were detected in 41.2% (266/646; 95% confidence interval (CI): 37.4–45.1%) of bulk tank milk (BTM) samples, while F. hepatica seroprevalence amounted to 14.9% (96/646; 95% CI: 12.2–17.9%)
Anthelmintic treatment of young cattle was positively associated with O. ostertagi seropositivity in the North and the South, probably because farms with known Gastrointestinal nematodes (GIN) problems increase their use of anthelmintics

Summary

Introduction

Pasture-borne parasites represent a major global problem for bovine health and productivity. Infections are often subclinical in dairy cows, studies in several European countries have shown a significant negative correlation between O. ostertagi antibody levels and cow productivity, especially in terms of milk yield [5,6]. A lower milk protein content has been observed in animals with patent GIN infections [7]. The liver fluke Fasciola hepatica and the lungworm Dictyocaulus viviparus are less prevalent than GIN, but represent significant economic burdens [1]. Liver fluke infections mostly cause chronic disease in cattle, resulting in reduced milk yield, impaired fertility, and condemnation of affected livers [8,9,10]. Patent D. viviparus infections are associated with a lower average daily milk yield [13]. Negative effects on milk fat and milk protein content have been observed [14,15]

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