João Jacob-Ferreira

Dr. João Jacob-Ferreira

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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14 June 2023 in Pathogens
Verified
Journal Article
Open access
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João Jacob-FerreiraJoão Jacob-Ferreira
João Jacob-Ferreira
Ana Cláudia CoelhoAna Cláudia Coelho
Ana Cláudia Coelho
AVAna Grau Vila
Ana Grau Vila
Delia LacastaDelia Lacasta
Delia Lacasta
Helder QuintasHelder Quintas
Helder Quintas
Small ruminant lentiviruses (SRLVs) are transmitted among ovine and caprine species. This disease is a severe problem for small ruminant production, not only for animals’ well-being but also for flocks’ efficiency. The main aim of this research was to quantify the seroprevalence and associated risk factors for SRLV infection in the northern region of Portugal. Samples were collected from a total of 150 flocks, of which 129 (86.0%; 95% CI: 80.67%–91.33%) had at least one seropositive animal. Out of 2607 individual blood samples, 1074 (41.2%) were positive for SRLVs. Risk factors associated with SRLV infection were species (caprine), age (>2 years old), flock size (>100 animals), production system (intensive), food production system (milk), type of activity (professional), participation in livestock competitions (yes), replacement young ewe bought (yes), and natural feeding management (yes). This knowledge empowers the implementation of effective preventive measures. Overall, biosecurity measures should be promoted and implemented with the main aim of reducing viral transmission and reducing the prevalence of this disease. We recognise that government authorities should promote and audit voluntary control and eradication programs in small ruminant flocks in the region studied.

26 May 2023 in Preprints.org
Verified
Preprint
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João Jacob-FerreiraJoão Jacob-Ferreira
João Jacob-Ferreira
Ana Cláudia CoelhoAna Cláudia Coelho
Ana Cláudia Coelho
AVAna Grau Vila
Ana Grau Vila
Delia LacastaDelia Lacasta
Delia Lacasta
Helder QuintasHelder Quintas
Helder Quintas
Small ruminant lentivirus (SRLV) are infected and transmitted among ovine and caprine species. This disease is a severe problem for small ruminant production, not only for animals’ wellbeing but also for the herd’s efficiency. The main aim of this research was to quantify the seroprevalence and associated risk factors for SRLV infection in the north region of Portugal. Collected samples from a total of 150 herds, of which 129 (86.0%; 95% CI: 80.67% - 91.33%) had at least one seropositive animal. Out of 2607 individual blood samples, 1074 (41.2%) were positive for SRLV. The risk factors associated with SRLV infection were: specie (caprine), age (> 2 years old), herd size (> 100 animals), production system (intensive), production aptitude (milk), type of activity (professional), participation in livestock competitions (yes), buy replacement young ewe (yes) and rearing (natural). This knowledge empowers the implementation of effective preventive measures. Overall, biosecurity measures should be promoted and implemented to aim reducing viral transmission, with the main goal of reducing the prevalence of this disease. Completely, we understand that government authorities should promote and audit voluntary control and eradication programs in small ruminant herds in the region studied.

1 January 2025 in Veterinarski glasnik
Verified
Journal Article
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RMRafaela S S Moreira
Rafaela S S Moreira
João Jacob-FerreiraJoão Jacob-Ferreira
João Jacob-Ferreira
LSLiliana Santos
Liliana Santos
RVRamiro Valentim
Ramiro Valentim
PCPaulo Cortez
Paulo Cortez
Helder QuintasHelder Quintas
Helder Quintas
The Preta de Montesinho goat is an autochthonous Portuguese breed classified as endangered. Autochthonous breeds should be preserved because they are usually well adapted to their specific regional conditions, exhibit resistance to certain diseases, and serve as important reservoirs of unique genetic diversity. For a breed like the Preta de Montesinho, maintaining the health of the animals to ensure their reproduction and increase their numbers is essential. Therefore, understanding the hematological reference interval is particularly important. This study aimed to determine the hematological reference interval for the Preta de Montesinho breed and assess the potential influence of age, sex, and seasons on these intervals. A total of 136 blood samples were collected from healthy animals. The samples were analyzed using the Mindray BC?5000 Vet? automatic hematology analyzer, and reference intervals for 23 blood parameters were established applying the Reference Value Advisor v2.1 software. JMP? was utilized to determine statistically significant differences between the established groups. Regarding age, statistically significant differences (p < 0.05) between young and old goats were detected in 15 parameters. Sex significantly influenced eight parameters, six of which were erythrocyte indices. The annual season (summer or winter) affected seven parameters and six erythrocyte indices. The reference intervals described here can serve as a tool to identify sick animals, evaluate responses to therapies, and select healthy animals for reproduction, thus contributing to the breed?s preservation.

18 April 2026 in Animals
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Journal Article
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João Jacob-FerreiraJoão Jacob-Ferreira
João Jacob-Ferreira
Ana Cláudia CoelhoAna Cláudia Coelho
Ana Cláudia Coelho
AVAna Grau Vila
Ana Grau Vila
Delia LacastaDelia Lacasta
Delia Lacasta
RVRamiro Corujeira Valentim
Ramiro Corujeira Valentim
Helder QuintasHelder Quintas
Helder Quintas
Small ruminant lentiviruses are longstanding viral infections affecting sheep and goats worldwide, resulting in reduced efficiency and economic losses. In Portugal, updated epidemiological data are scarce. The aim of this study was to assess the seroprevalence and risk factors for SRLV in Portugal. The study was conducted in Portuguese flocks of ovine and caprine species. Flocks were randomly chosen, and producers were invited to answer a questionnaire. The indirect ELISA test, ID Screen® MVV/CAEV Indirect, was made to detect infection. We collected samples from 59 flocks, of which 55.93% (CI 95%: 43.26–68.60%) had at least one positive animal. Of these flocks, 1302 individual samples presented a seroprevalence of 32.95% (CI 95%: 30.08–35.81%). Regarding the risk factor analysis, the multivariable mixed-effects logistic regression model at the individual level identified variables with increased odds of SRLV seropositivity. Caprine species (OR = 2.47; CI 95%: 1.01–6.03), non-autochthonous breed (OR = 2.95; CI 95%: 1.23–7.06), animals older than two years old (OR = 1.95; CI 95%: 1.29–2.94), dairy aptitude (OR = 8.15; CI 95%: 2.53–26.24), unknown serostatus of newly acquired animals (OR = 9.41; CI 95%: 2.93–30.23) and participation in livestock competitions (OR = 4.25; CI 95%: 1.42–12.73) were significantly associated with increased odds of seropositivity. SRLV has been confirmed in both regions of Portugal studied, with a significant regional disparity that is likely attributable to differences in management practices. The identification of risk factors specific to each production system is crucial for the development and implementation of voluntary control programs.

6 November 2024 in Veterinarska stanica
Verified
Journal Article
Open access
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Helder QuintasHelder Quintas
Helder Quintas
JBJúlio Benavides
Júlio Benavides
João Jacob-FerreiraJoão Jacob-Ferreira
João Jacob-Ferreira
PAPaulo Afonso
Paulo Afonso
ACAna Cláudia Coelho
Ana Cláudia Coelho
Paratuberculosis, also known as Johne’s disease, is a granulomatous enteritis in both domestic and wild ruminants caused by the bacterium Mycobacterium avium subsp. paratuberculosis. Understanding the prevalence of this disease in small ruminants is essential for disease control and prevention strategies. A systematic review of the literature was conducted using the PubMed, ScienceDirect and Scopus databases to identify all articles reporting Mycobacterium avium subsp. paratuberculosis (MAP) seroprevalence in sheep and goats in Europe, published from January 2006 to December 2023. The initial search for existing publications reporting systematic reviews and primary studies was carried out by searching the available databases. For the final selection of studies, an initial screen for basic eligibility and a detailed appraisal of quality were performed. After the study selection, the relevant data was extracted. The detailed appraisal generated 21 publications that reported 55 studies, 22 (40.0%) from sheep (12 at the animal-level and 10 at the flock-level) and 28 (50.9%) from goats (17 at the animal-level and 11 at the flock-level), and 5 (9.1%) from mixed small ruminant species at the animal level. In total, 34 (61.8%) were animal-level studies and 21 (38.2%) were flock-level studies. Population and inclusion criteria were highly variable among studies. Sample sizes ranged from 291 to 15,585 animals. Most studies reported testing adult animals (over 24 months of age). Commercial ELISA kits were used in most studies. The highest prevalence was obtained in sheep (100%) in Türkiye, and the lowest was found also in sheep (0.7%) in Austria. Overall, the results suggest that MAP antibodies have been frequently detected among small ruminants in some countries and there is a need for standardisation of case definitions to improve the accuracy of prevalence estimates. Further research is needed to understand the risk factors associated with MAP infection in small ruminants and to develop effective control and prevention strategies.

13 March 2023 in Animal - science proceedings
Verified
Journal Article
Closed access
João Jacob-FerreiraJoão Jacob-Ferreira
João Jacob-Ferreira
ACA.C. Coelho
A.C. Coelho
DLD. Lacasta
D. Lacasta
RVR. Valentim
R. Valentim
HQH. Quintas
H. Quintas