Dermal Application of PGF2a for Estrus Synchronization in Goats: Preliminary Feasibility
The administration of vaccines and other veterinary products can result in abscesses and scar tissue within the carcass of the animal. The use of PGF2a for estrus synchronization purposes only increases the likelihood of these occurrences. The objective of this study was to test the efficacy of PGF2a dissolved in DMSO, a needle-less, transdermal delivery, compared with intramuscular injections of PGF2a. 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 PGF2a 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 PGF2a 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 PGF2avia 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.
goats, PGF2a, DMSO, estrus synchronization
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