title: Individual and combined effects of anovulation and cytological endometritis on the reproductive performance of dairy cows.
abstract: The objective was to evaluate the individual and combined effect of anovulation and cytological endometritis (CTE) on the reproductive performance of dairy cows. A total of 1,569 cows from 3 data sets were used. In data set 1, 403 Holstein cows from 5 dairies in New York were used. In data set 2, 750 Holstein cows from 2 dairies, one in Florida and one in California were used. In data set 3, 416 dairy cows, 165 Holsteins, 36 Jerseys, and 215 Holstein-Jersey crossbreeds from a grazing dairy in Florida were used. Cyclicity and CTE was determined at 35±3 (data set 2) or 49±3 d in milk (data sets 1 and 3). A variable (VarCycCTE) containing all 4 possible permutations between cyclicity (cyclic = Cyc; anovular = Anov) and CTE (present = CTE; absent = Healthy) was created. In the combined data set (sets 1, 2, and 3), pregnancy per artificial insemination (P/AI) diagnosed at 30 to 38 d after first AI was affected by VarCycCTE, with AnovCTE cows having decreased P/AI compared with CycHealthy cows (21.3 vs. 46.7%), whereas AnovHealthy (37.9%) and CycCTE cows (36.0%) had intermediate P/AI. Pregnancy per artificial insemination for the individual data sets and for pregnancy diagnosed at 63 to 74 d after artificial insemination followed a similar pattern. Pregnancy loss was not affected by VarCycCTE. Hazard of pregnancy up to 300 d in milk was affected by VarCycCTE in the combined data sets 1 and 2, with AnovCTE [hazard ratio (HR)=0.55], AnovHealthy cows (HR=0.71), and CycCTE (HR=0.8) having decreased hazard of pregnancy compared with CycHealthy cows. Median days open were 200, 159, 145, and 121 for AnovCTE, AnovHealthy, CycCTE, and CycHealthy, respectively. Hazard of pregnancy for the individual data sets followed a similar pattern. In summary, both anovulation and CTE were negatively associated with reproductive performance and, when combined, they had an additive negative effect.
authors.affiliation: Departamento de Medicina Veterinária, Universidade do Estado de Santa Catarina, Lages, SC 88520, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Vieira-Neto
authors.affiliation: Department of Clinical Sciences, Cornell University, Ithaca, NY 14853.
authors.forename: R O
authors.initials: RO
authors.lastname: Gilbert
authors.affiliation: Department of Animal Science, Cornell University, Ithaca, NY 14853.
authors.forename: W R
authors.initials: WR
authors.lastname: Butler
authors.affiliation: Department of Animal Sciences, University of Florida, Gainesville 32610.
authors.forename: J E P
authors.initials: JE
authors.lastname: Santos
authors.affiliation: Department of Animal Sciences, University of Florida, Gainesville 32610.
authors.forename: E S
authors.initials: ES
authors.lastname: Ribeiro
authors.affiliation: Department of Farm Animal Health, Utrecht University, 3508 TD Utrecht, the Netherlands.
authors.forename: M M
authors.initials: MM
authors.lastname: Vercouteren
authors.affiliation: School of Veterinary Medicine, University of California-Davis, Tulare 93274.
authors.forename: R G
authors.initials: RG
authors.lastname: Bruno
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville 32610.
authors.forename: J H J
authors.initials: JH
authors.lastname: Bittar
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville 32610; D.H. Barron Reproductive and Perinatal Biology Research Program, University of Florida, Gainesville 32610. Electronic address: galvaok@ufl.edu.
authors.forename: K N
authors.initials: KN
authors.lastname: Galvão
mesh_terms: D000818:Animals; D000858:Anovulation / Q000662:veterinary*; D002140:California; D002417:Cattle; D002418:Cattle Diseases / Q000503:physiopathology*; D004032:Diet / Q000662:veterinary; D004716:Endometritis / Q000662:veterinary*; D005260:Female; D005431:Florida; D006799:Housing, Animal; D007315:Insemination, Artificial / Q000662:veterinary; D008892:Milk; D009518:New York; D011247:Pregnancy; D012098:Reproduction; D012189:Retrospective Studies
keywords: cyclicity; cytological endometritis; dairy cow; reproductive performance