Reduced gastrointestinal worm burden following long term parasite control improves body condition and fertility in beef cows

Welfare on Dairy Cows in Different Housing Systems: Emphasis on Digestive Parasitological Infections

The aim of this research was to assess welfare indicators in different dairy cow management systems, determine the prevalence of parasitic infections, and examine the impact of these infections on welfare indicators. This study was conducted in 2024 on 45 Holstein-Friesian cows aged 2 to 6 years (first to third lactation) in Northern Serbia. Monitoring was carried out in tie stall, loose, and pasture-based systems, covering three production phases: late dry period, clinical puerperium, and peak lactation. Cow welfare was evaluated using the Welfare Quality® protocol, and parasitological diagnostics from fecal samples. Identified welfare issues included a low body condition score (BCS), dirtiness of udders, flanks, and legs, integument alterations, nasal and ocular discharge, lameness, and diarrhea. Cows in the pasture-based system had significantly higher scores for dirtiness (p < 0.001), while those in tie stalls showed more integument alterations (p < 0.001). Loose-housed cows had higher nasal discharge scores (p < 0.001). Parasites identified included Eimeria spp., Buxtonella sulcata, gastrointestinal strongylids, Moniezia spp., Dicrocoelium dendriticum, Fasciola hepatica, and Paramphistomum spp. Significant correlations (p < 0.001) were found between certain welfare indicators and parasite infections, such as a low BCS with Eimeria oocysts and nasal discharge and hairless patches with Buxtonella sulcata and Dicrocoelium dendriticum. These data indicate needs for improving dairy cows' welfare and the implementation of effective parasite control measures in all housing systems.

Gastrointestinal nematodiasis of goats in Somali pastoral areas, Ethiopia

Livestock, mainly goats, are crucial for animal protein, household income, economic security, and wealth creation in the pastoral areas of eastern Ethiopia. However, gastrointestinal parasitosis poses a substantial challenge in this sector. A cross-sectional study was conducted in the Gursum district of the Somali region, Ethiopia, to investigate the prevalence and intensity of gastrointestinal nematodes in goats and their associated risk factors. A total of 384 goat fecal samples were collected and examined using flotation and McMaster egg counting techniques for GIT nematodes. Coprological cultures have also been conducted for nematode identification. Fecal samples showed an overall parasite prevalence of 54.17%, with identified nematodes including Haemonchus (24%), Strongyloides (10.4%), Trichostrongles (6.5%), Nematodirus (6%), Oesophagostomum (5.5%) and Trichuris (1.87%). Older and poor body condition animals had higher chances of hosting nematodes than younger (OR = 0.245; CI = 0.144-0.417) and good body condition animals (OR = 0.069; CI = 0.030-0.157), according to multivariate logistic regression analysis. Quantitative examination of eggs revealed light 75(36.06%), moderate 99(47.60%), and heavy infection (n = 34, 16.35%). Analysis of the different study variables indicated that the age and body condition of the animals and the season of the year had a statistically significant association with the prevalence of GIT nematode infections (P-value <0.05). The high prevalence and intensity of GIT nematodiasis in goats from the study area warrants immediate attention and the implementation of strategic control and prevention measures.

The Economic Impact of Parasitism from Nematodes, Trematodes and Ticks on Beef Cattle Production

Global human population growth requires the consumption of more meat such as beef to meet human needs for protein intake. Cattle parasites are a constant and serious threat to the development of the beef cattle industry. Studies have shown that parasites not only reduce the performance of beef cattle, but also negatively affect the profitability of beef agriculture and have many other impacts, including contributing to the production of greenhouse gases. In addition, some zoonotic parasitic diseases may also threaten human health. Therefore, ongoing cattle parasite research is crucial for continual parasite control and the development of the beef cattle industry. Parasitism challenges profitable beef production by reducing feed efficiency, immune function, reproductive efficiency, liveweight, milk yield, calf yield and carcass weight, and leads to liver condemnations and disease transmission. Globally, beef cattle producers incur billions (US$) in losses due to parasitism annually, with gastrointestinal nematodes (GIN) and cattle ticks causing the greatest economic impact. The enormity of losses justifies parasitic control measures to protect profits and improve animal welfare. Geographical differences in production environment, management practices, climate, cattle age and genotype, parasite epidemiology and susceptibility to chemotherapies necessitate control methods customized for each farm. Appropriate use of anthelmintics, endectocides and acaricides have widely been shown to result in net positive return on investment. Implementing strategic parasite control measures, with thorough knowledge of parasite risk, prevalence, parasiticide resistance profiles and prices can result in positive economic returns for beef cattle farmers in all sectors.

Eprinomectin 5% w/v extended-release injection for the treatment of larval and/or adult Bunostomum phlebotomum, Haemonchus contortus, H. placei, Nematodirus helvetianus, Oesophagostomum radiatum, and Trichostrongylus colubriformis infections in cattle

In an effort to generate data for regulatory purposes on the therapeutic efficacy of eprinomectin 5% w/v extended-release injection (Eprinomectin ERI) (LongRange®, Boehringer Ingelheim) against infections of immature and adult stages of some nematode species (or stages) which are generally less common or predominantly seen in younger cattle, nine studies (minimum two per parasite and stage) were conducted in the USA and Germany. A total of 218 young cattle were included in seven experimentally induced infection studies (180 animals) and two studies with naturally acquired nematode infections (38 animals), which were compliant with WAAVP and VICH guidelines. In each study, cattle were randomly assigned into groups which received 1 mL per 50 kg body weight of either saline (controls) or Eprinomectin ERI (equivalent to 1 mg eprinomectin per kg body weight) via subcutaneous injection when the parasites were developing fourth-stage larval (L4) or adult nematodes. Following necropsy and parasite recovery, percentage efficacy was calculated based on the comparison of geometric mean nematode counts of the Eprinomectin ERI- vs. the saline-treated animals. Eprinomectin ERI-treated cattle had significantly (p < 0.05) lower counts of each species and stage of nematodes than the controls. Eprinomectin ERI treatment was demonstrated to be efficacious (> 90%) against L4 and adult Bunostomum phlebotomum and Nematodirus helvetianus; against L4 Haemonchus placei, Oesophagostomum radiatum, and Trichostrongylus colubriformis; and against adult H. contortus. Percentage efficacy against L4 H. contortus was variable (69.6 to 100%). All treatments were well accepted, and no treatment-related health problems were observed in any study.

Association of gastrointestinal parasite burden, serum cytokines and hormones concentrations, and pregnancy in Angus-cross beef cows

The objective was to elucidate the relationships among gastrointestinal (GI) parasite load, serum cytokines (Th 1 - Interleukin (IL) 2, Interferon (IFN) γ and Tumor necrosis factor (TNF) α; Th 2- IL4, IL6, and IL10) levels, hormones (progesterone, cortisol, 8-epi-prostaglandin F2 alpha (isoprostane), prolactin, substance-p, and prostaglandin F metabolites) concentrations, and pregnancy in beef cattle. Angus-cross beef cows (n = 700; age, 3-8 y) were blocked by age and body condition score (BCS, 1-9), and were randomly assigned to treatment (n = 350, TRT, 50 mg of eprinomectin/50 kg BW, im) or control (n = 350, CON, no treatment) on Day -30. Cows were synchronized using Controlled Internal Drug Release insert (CIDR) + CO-Synch protocol and artificially inseminated at a fixed time on Day 0 (66 h after CIDR removal). Fecal samples were collected to determine fecal egg count per gram (FEG, McMaster method) on Days -30, -23, -16, -7, 7, 0, 16 and 23, and blood samples were collected on Days -7, 0, 7, 16 and 23. Serum cytokines were determined on Days -7, 0, 7, 16 and 23, and circulating hormones were measured on Day 16. BCS were recorded on Day 16 following artificial insemination (AI), and pregnancy status was diagnosed on Day 30 and 60. Pregnancy/AI varied among treatment groups on Day 30 [TRT, 62.0% (217/350); CON, 54.9% (192/350) (P = 0.05)] and Day 60 [TRT, 60.9% (213/350); CON, 51.7% (181/350) (P < 0.05)]. Pregnancy loss between 30 and 60 days for TRT and CON groups were 1.8% (4/217) and 5.7% (11/192), respectively (P < 0.05). The BCS on Day 16 did not differ among treatment groups (P> 0.1). Four groups of 40 cows were selected based on their pregnancy status and treatment: pregnant, TRT; non-pregnant, TRT; pregnant, CON; and non-pregnant, CON to compare the mean FEG, cytokines, and hormones levels. The FEG and cytokine concentrations were significantly (P < 0.05) influenced by treatment, pregnancy status, day, treatment by pregnancy status, and treatment by day. Day 16 hormone concentrations were considerably influenced by treatment, pregnancy status, and treatment by pregnancy. Although FEG on Day -30 did not differ among the groups (P> 0.1), it was lower in treated, pregnant cows compared with cows in other three groups from Day -23 onwards (P < 0.05). Overall and pairwise comparisons showed that serum concentrations of Type 1 cytokines, IL2, IFNγ, and TNFα were lower (P < 0.05) from gestational Day 7 onwards in treated, pregnant cows compared with cows in other three groups. In contrast, serum concentrations of Type 2 cytokines, IL4, IL6 and IL10 were greater (P < 0.05) from gestational Day 7 onwards in treated, pregnant cows compared with cows in other groups. Serum concentrations of progesterone was greater and other hormones were lower for pregnant cows in TRT group compared to cows in other groups on gestational Day 16. In conclusion, GI parasite load was reduced; Th 1 cytokines levels were decreased; Th 2 cytokines concentrations were increased; progesterone level was increased; and cortisol, substance-P, prolactin, isoprostane, and PGFM were decreased in pregnant, TRT cows. These changes also resulted in an increase in P/AI. It is plausible that direct and bidirectional host-parasite interactions mediated by cytokines and hormones may have promoted maternal tolerance of an immunologically diverse conceptus and the establishment of pregnancy.