Enfriamiento artificial y tasa de concepción de vaquillas Holstein con estrés térmico

Translated title of the contribution: Cooling and conception rate in Holstein heifers with heat stress

A. Correa-Calderón, G. des Santos, L. Avendaño, F. Rivera, D. Alvarez, F. Ardon, R. Diaz, R. Collier

    Research output: Contribution to journalArticlepeer-review

    6 Scopus citations


    The objective of this study was to evaluate the effect of a timed artificial insemination protocol plus a period of artificial cooling on conception rate and physiologic response of heifers under heat stress. Ninety Holstein heifers were randomly allotted into one of three treatments: A control treatment (T1) with visual heat detection and insemination morning-evening (n=30), a second treatment (T2) under a timed artificial insemination protocol and a third treatment (T3) with the same protocol than T2 plus an artificial cooling period beginning 11 d before and ending 21 d after insemination. The experiment was divided in two periods: the first period was from June 25 to July 26, and the second one from August 15 to September 16. In period 1, heifers in T3 had a lower (p<0.01) rectal temperature (39.35°C) compared to T1 (39.68°C) and T2 (39.67°C); respiration rate (breaths/min) was more reduced (p<0.01) in T3 (72) in comparison to T1 (85) and T2 (84). Conception rate was not different between T3 (64.3%) and T1 (46.7%) but both showed a tendency to be different (p<0.10) to T2 (13.3%). During the period 2, the rectal temperature in T3 (39.24°C) was lower (p<0,01) than T1 (39.61°C) and T2 (39.62°C). Respiration rate also was decreased (p<0,01) in T3 (77) with respect to T1 (87) and T2 (94), being T1 and T2 different (p<0.01). Conception rate was similar between T3 (40%), T1 (13%) and T2 (13%). The pregnancy rate including both periods had a tendency to be increased (p<0,10) in T3 (51.7%) compared to T2 (13.3%) and T1 (30.0%). The artificial insemination to fixed time plus artificial cooling may be an alternative to increase the fertility of Holstein heifers during the summer.

    Translated title of the contributionCooling and conception rate in Holstein heifers with heat stress
    Original languagePortuguese
    Pages (from-to)231-239
    Number of pages9
    JournalArchivos de Zootecnia
    Issue number222
    StatePublished - Jun 2009


    • Estrus synchronization
    • Fertility
    • Fogging
    • Ventilation

    ASJC Scopus subject areas

    • Animal Science and Zoology


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