Scientometrics Approach to Research in Ovine Mastitis from 1970 to 2019 (with a Complete List of Relevant Literature References)

Abstract

The present study is a scientometrics evaluation of refereed publications on bacterial mastitis in sheep; the objectives were the evaluation of the relevant papers and the presentation of quantitative characteristics regarding their scientific content and bibliometric details. The Web of Science platform was used with search terms: [mastitis OR *mammary infection*] AND [sheep OR ewe* OR ovine] for papers from 1970 tο 2019; only 'articles', 'reviews', 'proceedings papers', or 'data papers' were evaluated, whilst documents related solely to contagious agalactia, mammary aspects of lentiviral infections, or infections of the teats and the udder skin were excluded. Finally, 580 papers were considered in detail. The number of published papers increased from 8 during the 1970s to 273 during the 2010s. These papers originated from 43 countries (most from Greece or Spain, n = 87 from each) and 240 institutions (145 universities and 95 other establishments), of which 35 produced ≥ 5 papers each. Most papers present original studies (n = 539) with a few reviews (n = 41). The original papers refer to dairy (n = 428), meat (n = 113), or wool (n = 1) production systems and present field (n = 329), laboratory (n = 163), or experimental (n = 67) work; the papers report aetiology (n = 146), risk factors (n = 100), pathogenesis (n = 92), diagnosis (n = 88), effects (n = 66), treatment (n = 50), control (n = 36), or descriptive epidemiology (n = 32) of the disease. Papers related to dairy production present more field and fewer experimental work than papers related to meat production; also, in papers describing work performed in dairy sheep, studies about aetiology, risk factors, and diagnosis of the disease predominate, whilst in papers performed in meat sheep, studies about aetiology, pathogenesis, and effects/diagnosis are reported more often. The papers were published in 175 scientific journals (most in Small Ruminant Research, n = 90, or Journal of Dairy Science, n = 54). On average, the papers received 16.8 total citations and 1.6 yearly citations (h-index = 47). Most papers were published in Scimago classification Q1 (n = 240) or Q2 (n = 230) journals and received 23.4 or 15.4 total citations, respectively. Reviews received more citations than original papers; among the latter, papers with work referring to dairy production received more yearly citations than papers referring to meat production; no differences in citations were seen according to type of work or mastitis aspect covered. Most citations were received by papers from France. Papers published in Journal of Dairy Science or Small Ruminant Research received the most citations. In total, there were 1558 individual authors of the papers, with 24 authors having co-authored > 10 papers each (max: 73 papers); on average, there were 5.2 co-authors per paper (min-max: 1-25). Average number of co-authors progressively increased from 2.1 in the 1970s to 6.3 in the 2010s, with original papers having a higher number of co-authors than reviews: 5.3 and 3.7, respectively. Papers from France had highers number of co-authors (7.9). The findings of this first ever scientometrics study into ovine mastitis indicate that the disease has not been studied as other sheep diseases and that future studies in it should be directed to its control.

Keywords: ewe; intramammary infection; mastitis; meta-research; ovine; scientometrics; sheep; subclinical mastitis.

Figure 1

Number of papers published on mastitis in sheep from 1970 to 2019, classified according to the decade during which they were published.

Figure 2

Average year of publication of papers on mastitis in sheep from 1970 to 2019 from the 11 countries with the most papers published (abbreviations of country names according to International Naming Convention ISO 3166).

Figure 3

Frequency of published papers on mastitis in sheep from 1970 to 2019 according to type and content (top left: types of papers; top right: types of production system to which the original papers referred; bottom left: types of studies in original papers; bottom right: mastitis aspects reported in the original papers—colour legend for each pie diagram to its right).

Figure 4

Association between type of study, production system referred to, and mastitis aspect in papers on ovine mastitis published during the period 1970–2019 (Study type: 1 experimental, 2 field, 3 laboratory; Production system: 1 dairy, 2 meat, 3 wool; Mastitis aspect: 1 aetiology, 2 control, 3 epidemiology, 4 diagnosis, 5 effects, 6 pathogenesis, 7 risk factors, 8 treatment. Size of the spheres reflects number of papers at each point).

Figure 5

Association between journals and countries of origin of papers on ovine mastitis published during the period 1970–2019 (abbreviations of country names according to International Naming Convention ISO 3166; abbreviations of journals from left to right: Journal of Dairy Research, Journal of Dairy Science, Journal of Veterinary Medicine B, Pesquisa Veterinária Brasileira, Small Ruminant Research, The Veterinary Journal, The Veterinary Record, Veterinary Microbiology).

Figure 6

Association between journals and aspect of mastitis covered in papers on ovine mastitis published during the period 1970–2019 (abbreviations of journals from left to right: Journal of Dairy Research, Journal of Dairy Science, Journal of Veterinary Medicine B, Pesquisa Veterinária Brasileira, Small Ruminant Research, The Veterinary Journal, The Veterinary Record, Veterinary Microbiology).

Figure 7

Association between production system referred to in papers, journal classification, and citations in papers on ovine mastitis published during the period 1970–2019 (Production system: 1 dairy, 2 meat, 3 wool; Scimago classification: 1 Q1, 2 Q2, 3 Q3, 4 Q4, 5 not included in the database).

Figure 8

Association between number of co-authors in papers with total citations and yearly citations received by these papers.