Vie CONG. INTERN. REPROD. ANIM. INSEM. ARTIF., PARIS, 1968, VOL. II

SYNCHRONISATION OF OESTRUS IN AYRSHIRE HEIFERS BY THE USE OF
PROGESTINATED INTRA-VAGINAL SPONGES

P. G. HIGNETT and H. BOYD
Department of Veterinary Reproduction,
University of Glasgow Veterinary Hospital,
Bearsden Road, Bearsden, Glasgow, Scotland.

INTRODUCTION. Robinson (1965) described the use of polyurethane
sponges for the intra-vaginal administration of progestogens to
obtain synchronisation of oestrus in ewes. A similar technique
has been used in cattle in which, although the numbers have been
small, the results have been similar to those obtained with sheep
(Mauléon and Rey, 1966; Shimizu, Toyoda , Takeuchi, Kawai &
Adachi, 1967; Carrick & Shelton, 1967).

During the summer of 1967, we had the opportunity to
investigate the use of spoBges containing one of two synthetic
progestogens, l7a-acetoxy- a-fluoro-llb-hydroxy—quregnene—
3,20 dione , and l7a-ethyl-hydroxynorandrostenone’ .

MATERIALS AND METHODS. Forty virgin heifers between 15 and 13
months old were brought together on June 16th. Each heifer was
examined per rectum to ensure that the genitalia were palpably
normal, and each was fitted with a KaMaR heatmount detector
(Boyd & Hignett, 1968).

They were divided at random into four treatment groups.

Group 1. Cronolone (200 mg.) sponges inserted SO s
removed 21.8.67.

Group 2. & 0 tt inserted 10.7.67.,
; removed 31.7.67.

The above two groups were injected intramuscularly with
750 i.u. mare serum gonadotrophin at the time of sponge
removal.

Group 3. Nilevar (800 mg.) sponges inserted BB
removed 21.8.67.

Group 4. " it 3 inserted 10.7.67.,
removed 31.7.67.

All heifers in oestrus between August 21lst and 3lst
inclusive were inseminated. Sponges which were expelled were
replaced by new ones, usually within 24 hours.

¥ 'Cronolone', G.D. Searle & Co. Ltd.

75 'Nilevar' z " n n n

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