BIANCHI CP, BRUNO S, VIDELA DORNA I, RODRÍGUEZ E, ABA MA. Effect of short-term artificial light and transvaginal progesterone device on first ovulation in late transitional mares.
J Equine Sci 2022;
33:1-6. [PMID:
35510073 PMCID:
PMC9018460 DOI:
10.1294/jes.33.1]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Accepted: 02/08/2022] [Indexed: 11/07/2022] Open
Abstract
In study I, plasma progesterone concentrations were evaluated in anoestrous mares that
received an intravaginal progesterone release device (IPRD) for 10 days. Mares were
divided into 3 groups based on the dosage of progesterone (0 g, n=3; 1.38 g, n=5; and 1.9
g, n=5). No statistical differences were found in plasma progesterone concentrations
between the two doses tested. In study II, the effects of a protocol based on a short
program of artificial light combined with an IPRD containing 1.38 g of progesterone on
oestrous behaviour and onset of ovulation were evaluated. IPRDs were inserted into 31 late
transitional mares (10 days of treatment). The mares were divided into a control group
(n=9, IPRD with 0 g of progesterone) and two treatment groups (T1, n=10, IPRD with 0 g of
progesterone and artificial light; T2, n=12, IPRD with 1.38 g of progesterone and
artificial light). The percentages of mares in heat within the first 14 days after
treatment were 100%, 70%, and 100% in the control, T1, and T2 groups, respectively
(P=0.097), and their ovulation rates were 44%, 60%, and 100%, respectively (P≤0.01). In
conclusion, a protocol based on artificial light and an IPRD containing 1.38 g of
progesterone for 10 days could be considered to advance the first ovulation of the year in
late transitional mares, as it ensures a higher rate of ovulation within the first 14 days
after treatment.
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