{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,29]],"date-time":"2025-10-29T03:22:27Z","timestamp":1761708147109,"version":"3.38.0"},"reference-count":28,"publisher":"American Veterinary Medical Association (AVMA)","issue":"11","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["javma"],"published-print":{"date-parts":[[2007,12,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n<jats:p><jats:bold>Objective<\/jats:bold>\u2014To determine whether vaccination with a monovalent <jats:italic>Leptospira borgpetersenii<\/jats:italic> serovar Hardjo strain hardjobovis vaccine coupled with parenteral long-acting oxytetracycline treatment would improve the reproductive performance of beef cows.<\/jats:p>\n<jats:p><jats:bold>Design<\/jats:bold>\u2014Randomized controlled field trial.<\/jats:p>\n<jats:p><jats:bold>Animals<\/jats:bold>\u20141,446 Angus-cross beef cows in 8 locations.<\/jats:p>\n<jats:p><jats:bold>Procedures<\/jats:bold>\u2014Cows were given 2 doses, 4 weeks apart, of vaccine (treatment; n = 741) or placebo (control; 705). Cows in the treatment group were also given a single dose of a longacting oxytetracycline formulation (20 mg\/kg [9.1 mg\/lb], SC) at the time of booster vaccination. Estrus synchronization was performed, followed by fixed-time artificial insemination; bulls were introduced 14 days after insemination. Serum and urine samples were obtained on a random subset of cows (n = 194) for detection of serologic titers and leptospiruria, and locations were categorized as positive or negative for leptospirosis on the basis of detection of leptospiruric cows.<\/jats:p>\n<jats:p><jats:bold>Results<\/jats:bold>\u2014No differences in pregnancy and calving rates between treatment and control groups were detected. Pregnancy rate following artificial insemination was lower among cows in locations positive for leptospirosis than among cows in locations negative for leptospirosis; however, overall pregnancy rate, calving rate following artificial insemination, and overall calving rate did not differ between groups when cows were grouped on the basis of location leptospirosis status.<\/jats:p>\n<jats:p><jats:bold>Conclusions and Clinical Relevance<\/jats:bold>\u2014Results suggested that under the conditions of the present study, administration of a monovalent <jats:italic>Leptospira<\/jats:italic> vaccine in conjunction with systemic administration of oxytetracycline did not significantly improve reproductive performance of beef cows.<\/jats:p>","DOI":"10.2460\/javma.231.11.1709","type":"journal-article","created":{"date-parts":[[2007,12,4]],"date-time":"2007-12-04T15:56:44Z","timestamp":1196783804000},"page":"1709-1714","source":"Crossref","is-referenced-by-count":15,"title":["A field study of the effects of a monovalent Leptospira borgpetersenii serovar Hardjo strain hardjobovis vaccine administered with oxytetracycline on reproductive performance in beef cattle"],"prefix":"10.2460","volume":"231","author":[{"given":"Ramanathan","family":"Kasimanickam","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"William D.","family":"Whittier","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jonathan C.","family":"Collins","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"John F.","family":"Currin","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bom","family":"Inman","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"John B.","family":"Hall","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kevin D.","family":"Pelzer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1272","reference":[{"key":"ref1","series-title":"Vet Clin North Am Food Anim Pract","first-page":"463","article-title":"Leptospirosis as a cause of reproductive failure","volume":"10","author":"Ellis","year":"1994"},{"key":"ref2","series-title":"Vet Rec","first-page":"334","article-title":"Effect of vaccination against Leptospira interrogans serovar hardjo on milk production and fertility in dairy cattle","volume":"138","author":"Dhaliwal","year":"1996"},{"key":"ref3","series-title":"Vet Rec","first-page":"110","article-title":"Reduced conception rates in dairy cattle associated with serological evidence of Leptospira interrogans serovar hardjo 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hardjo","volume":"219","author":"Alt","year":"2001"},{"key":"ref21","series-title":"Aust Vet J","first-page":"481","article-title":"Leptospira borgpetersenii serovar hardjo vaccination of pregnant beef cows and subsequent growth rate of progeny","volume":"56","author":"Holroyd","year":"1980"},{"key":"ref22","series-title":"J Clin Microbiol","first-page":"578","article-title":"Restriction fragment length polymorphisms distinguish Leptospira borgpetersenii serovar hardjo type hardjo-bovis isolates from different geographical locations","volume":"31","author":"Zuerner","year":"1993"},{"key":"ref23","series-title":"Vet Rec","first-page":"272","article-title":"Reproductive performance of dairy herds infected with Leptospira interrogans serovar hardjo relative to the year of diagnosis","volume":"138","author":"Dhaliwal","year":"1996"},{"key":"ref24","series-title":"Vet Rec","first-page":"333","article-title":"Genital leptospirosis in bulls","volume":"118","author":"Ellis","year":"1986"},{"key":"ref25","series-title":"Infect Immun","first-page":"7550","article-title":"Protective killed Leptospira borgpetersenii vaccine induces potent Th1 immunity comprising responses by CD4 and JG T lymphocytes","volume":"69","author":"Naiman","year":"2001"},{"key":"ref26","series-title":"N Z Vet J","first-page":"62","article-title":"Leptospirosis vaccination in beef cattle: use of decision tree analysis","volume":"40","author":"Sergeant","year":"1992"},{"key":"ref27","series-title":"Epidemiol Infect","first-page":"29","article-title":"Changing epidemiology of human leptospirosis in New Zealand","volume":"128","author":"Thornley","year":"2002"},{"key":"ref28","series-title":"N Z Vet J","first-page":"73","article-title":"Epidemiology of leptospirosis in dairy farm workers in the Manawatu. Part II. A case-control study of high and low risk farms","volume":"30","author":"MacKintosh","year":"1982"}],"container-title":["Journal of the American Veterinary Medical Association"],"original-title":[],"link":[{"URL":"https:\/\/avmajournals.avma.org\/view\/journals\/javma\/231\/11\/javma.231.11.1709.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/avmajournals.avma.org\/downloadpdf\/journals\/javma\/231\/11\/javma.231.11.1709.xml","content-type":"text\/html","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/avmajournals.avma.org\/downloadpdf\/journals\/javma\/231\/11\/javma.231.11.1709.xml","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,3,7]],"date-time":"2025-03-07T13:52:23Z","timestamp":1741355543000},"score":1,"resource":{"primary":{"URL":"https:\/\/avmajournals.avma.org\/view\/journals\/javma\/231\/11\/javma.231.11.1709.xml"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2007,12,1]]},"references-count":28,"journal-issue":{"issue":"11"},"URL":"https:\/\/doi.org\/10.2460\/javma.231.11.1709","relation":{},"ISSN":["0003-1488"],"issn-type":[{"type":"print","value":"0003-1488"}],"subject":[],"published":{"date-parts":[[2007,12,1]]}}}