These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Effect of progesterone and/or estradiol treatments prior to induction of ovulation on subsequent luteal lifespan in anestrous Nelore cows.
    Author: Sá Filho OG, Thatcher WW, Vasconcelos JL.
    Journal: Anim Reprod Sci; 2009 May; 112(1-2):95-106. PubMed ID: 18468816.
    Abstract:
    Three experiments evaluated effects of estradiol (E(2)) and/or progesterone (P(4)) prior to induction of ovulation with GnRH on subsequent luteal lifespan in anestrous Nelore cows. In Experiment 1, cows (25-65 days post-partum [DPP]; n=114) were assigned randomly to receive a 6-day treatment with an intravaginal P(4) device (CIDR) and/or 1mg i.m. injection of 17beta-E(2) (4 groups; 2x2 factorial design) prior to ovulation. Blood samples were collected on days 0, 5, 7, 9, 12, 15 and 19 for evaluation of luteal function. Pre-treatment with P(4) reduced occurrence of premature luteolysis (PL; 79.2% in non-treated vs. 13.5% in treated cows; P<0.01), but there was no effect of treatment with 17beta-E(2) on percentage of PL. In Experiment 2, cows (30-40 DPP; n=35) were assigned randomly to receive either 0.5mL i.m. injection of cottonseed oil (placebo) or 1mg i.m. injection of E(2) cypionate. Blood samples were collected on days 0, 5, 9 and 15 for evaluation of luteal function. Incidence of PL (83.0% in Control Group vs. 75.0% in ECP Group; P>0.1) and mean serum P(4) did not differ between treatment groups. In Experiment 3, cows (30-60 DPP; n=109) were randomly assigned to receive either a 6-day (6-d Group) or a 3-day (3-d Group) treatment with CIDR. Blood samples were collected on days 0, 5, 7 and 9 for luteal function evaluation. Incidence of PL (5.5% in 6-day vs. 5.5% in 3-day groups; P>0.1) and mean serum P(4) did not differ between treatment groups. In conclusion, both 3- and 6-day treatments with P(4) prior to induction of ovulation in anestrous Nelore cows increased percentage of normal luteal lifespan, while administration of 1mg of 17beta-E(2) or E(2) cypionate failed to prevent occurrence of PL.
    [Abstract] [Full Text] [Related] [New Search]