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Plasma Progesterone Profile in Ovariectomized Beef Cows after Intra‐vaginal Insertion of New, Once‐used or Twice‐used CIDR
Author(s) -
Long ST,
Yoshida C,
Nakao T
Publication year - 2009
Publication title -
reproduction in domestic animals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.546
H-Index - 66
eISSN - 1439-0531
pISSN - 0936-6768
DOI - 10.1111/j.1439-0531.2007.01000.x
Subject(s) - ovariectomized rat , endocrinology , medicine , chemistry , luteal phase , zoology , plasma concentration , estrogen , biology , hormone
Contents Objective of this study was to show plasma progesterone concentrations in ovariectomized beef cows after treatment with new, once‐used and twice‐used controlled internal drug‐releasing devices (CIDRs). Four ovariectomized beef cows were used for the experiment. Plasma concentrations of progesterone were quantified using a validated ELISA. The CIDR was inserted into vagina of cows by using a standard CIDR applicator and then removed 7 days after insertion. One week later, once‐used CIDR was inserted and removed on day 7. Twice‐used CIDR was, then inserted at an interval of 7 days. Mean plasma concentrations of progesterone 24 h after new CIDR insertion was 4.0 ± 0.1 ng/ml, which thereafter decreased gradually to 1.4 ± 0.1 ng/ml at day 7. In cows treated with once‐used CIDR or twice‐used CIDR, mean plasma progesterone concentrations at day 1 were 2.4 ± 0.2 or 1.8 ± 0.2 ng/ml and 1.0 ± 0 or 0.9 ± 0.1 ng/ml at day 7 respectively. The results suggest that once‐used CIDR may be still effective to produce luteal phase progesterone concentrations in plasma in non‐suckling beef cows.