Dermal Application of PGF2a for Estrus Synchronization in Goats: Preliminary Feasibility

Abstract Text:

The administration of vaccines and other veterinary products can result in abscesses and scar tissue within the carcass of the animal. The use of PGF_2a for estrus synchronization purposes only increases the likelihood of these occurrences. The objective of this study was to test the efficacy of PGF_2a dissolved in DMSO, a needle-less, transdermal delivery, compared with intramuscular injections of PGF_2a. In this study a total of 16 small cross-bred Spanish breed-type goats were used. The injection group received two 15 mg injections (im) of PGF_2a while the transdermal group received two 15 mg administrations dissolved in 2 ml of DMSO (placed between shoulder blades) both 10 days apart. All does were paint marked and exposed to a mature buck for four days. Approximately 35 days from buck removal all does were evaluated for pregnancy via ultrasonography. Statistical comparisons were performed in SAS using a chi-square analysis. There were no significant differences between the mean±SD BCS (1 to 5 scale) for does receiving the injection protocol (1.7±0.7) and does receiving the transdermal protocol (2.0±0.8). Also there were no significant differences in the number of transdermal does displaying estrus (within 4 days) (5/7, 71%) compared with injection does (4/9, 44%). The pregnancy rate was higher (P>0.05) for transdermal does (4/7, 57%) compared with injection does (2/9, 22%), however there was no significant different (P>0.05) in the number of pregnant does from those showing estrus in the transdermal (3/5, 60%) and injection group (2/4, 50%). There was no difference (P<0.05) in the time from last PGF_2a to onset of estrus among transdermal (58±13 h) and injection does (42±12 h). A total of 9 out of 16 does (56%) displayed estrus within a 4 day time period where only 19% would be expected randomly. These results suggest that administration of PGF_2avia DMSO (transdermal) should produce similar results as im injection for purposes of estrus synchronization. This procedure may result in a method of estrus synchronization without increasing carcass damage to goats.

Keywords:

goats, PGF_2a, DMSO, estrus synchronization

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