Effect of gynecological screening on rates of conception and gestation total of Nellore cows submitted to three protocols for fixed-time artificial insemination (TAI)
ABSTRACT. Grillo G.F., Guimarães A.L.L., Soares J.R., Mello M.R.B., Alonso L.S., Abidú-Figueiredo M. & Palhano H.B. [Effect of gynecological screening on rates of conception and gestation total of Nellore cows submitted to three protocols for fixed-time artificial insemination (TAI).] Efeito da triagem ginecológica sobre as taxas de concepção e gestação total de vacas Nelore submetidas a três protocolos de inseminação artificial em tempo fixo (IATF). Revista Brasileira de Medicina Veterinária, 37(3):250-254, 2015. Área de Anatomia, Departamento de Biologia Animal, Instituto de Biologia, Universidade Federal Rural do Rio de Janeiro, Campus Seropédica, BR 465 km 7, Seropédica, RJ 23890-000, Brasil. Email: firstname.lastname@example.org The aim of this study was to assess the rates of total conception and gestation of Nellore cows total, commercial herd in the region of the coastal plains of the state of RJ, subjected to three hormonal protocols for synchronization of ovulation with screening of females for inclusion in the TAI program. Two hundred and six lactating females with multiple calvings history were used (60 to 100 days after parturition), divided into four groups: I - Ovsynch, n = 55, II - Ovsynch + progesterone, n = 55, III - EB. + P4 + eCG, n = 48, IV - EB. + P4 + eCG, n = 48. All females were exposed to bulls of Simmental breed, from 24 hours to pass after TAI. The conception rates and pregnancy rates were 45.5% overall (25:55) and 81.8% (45:55) for group I, 61.8% (34:55) and 87.3% (48 : 55) for group II, 62.5% (30:48) and 87.5% (42:48) for group III, 60.4% (29:48) and 83.3% (40:48) for group IV, respectively. The results, after analysis by the chi- -square showed no significant difference (p> 0.05) among protocols, as compared to the conception and pregnancy rates after transfer with total bulls. Thus, the use of gynecological screening for insertion of cows in the TAI program of the respective property, allows adaptation of the protocols for ovarian function, providing good pregnancy rates independent of the protocol used.