Dinamika ovarium pada kuda hasil persilangan pejantan thoroughbred dengan induk lokal Indonesia

Abstract

The development of horse breeding industry in Indonesia was commenced through horse racing events held all over the country. It were accelerated by the development of Thoroughbred-Indonesian local Crossbred horses. There are many broodmares injured during their racing time and retired from the racetracks. They may still has a reproductive vigor to continue on producing offsprings. Very little information has been reported on the monitoring the reproductive capacity of the mares. The objective of this study was to explore ultrasonography imaging of the ovarian dynamics, correlated with the estrus behavior of the Thoroughbred- Indonesian local crossbred mares. Three Thoroughbred-Indonesian local crossbred mares with 6.25-12.5% of local genetics aged 12-20 years old were used in this study. Estrus and ovulation synchronized by 10 mg PGF2α i.m. at luteal phase and 1500 IU hCG i.m. injection when the dominant follicle reach ≥30 mm in diameter. Ultrasonography examination was done every morning at approximately at the same time. Estrus behavior was observed by using teaser stallions following a standard method. Results of the experiment indicated that onset of the estrus was reached 1.33 ± 0.58 days after the hCG injection, with the average duration of 4.00 ± 1.00 days. The ovulations were done at 5.33 ± 1.15 days after PGF2α treatment and 66.67 ± 10.07 hours after hCG treatment. Maximum follicle diameter was identified to reach 4.50 ± 0.52 cm at one day before ovulation. The mares performed 25.4 ± 3.38 days length of estrous cycle with 2-3 follicular waves. It had been identified that the estrus duration was 6.8 ± 1.92 days in mares with the age of 12-20 years. The average of maximum diameter of the largest follicle before ovulation was 4.2 ± 1.24 cm. In conclusion, to improve the efficiency of breeding, several information are needed i.e. the optimal time of ovulation, relevan parameters related to follicular development.

Perkembangan ternak kuda di Indonesia dalam beberapa tahun terakhir ini cukup pesat seiring dengan berkembangnya olahraga pacuan kuda. Persilangan kuda betina lokal Indonesia dengan pejantan Thoroughbred telah menghasilkan kuda generasi ke-3 (G3), generasi ke-4 (G4), dan Kuda Pacu Indonesia (KPI) yang memiliki 6.25-25 persen materi genetik kuda lokal. KPI berasal dari perkawinan kuda G3 dengan G3, G3 dengan G4, maupun G4 dengan G4. Sistem peternakan kuda di Indonesia masih mengacu pada sistem manajemen tradisional. Salah satu subsistem dalam hal penentuan waktu perkawinan kuda dengan mengacu pada tingkah laku estrus. Hal ini menyebabkan hasil yang didapatkan belum optimal. Pemanfaatan teknik ultrasonografi pada kuda sudah mulai dilakukan oleh beberapa praktisi peternakan kuda. Diharapkan dengan teknik ini yang dikombinasikan dengan pengamatan tingkah laku estrus dapat memberikan acuan yang lebih baik dalam penentuan waktu perkawinan pada kuda, sehingga diharapkan dapat membantu peningkatan angka kebuntingan pada kuda. Penelitian dilakukan terhadap tiga ekor kuda hasil persilangan antara pejantan Thoroughbred dengan induk lokal, dengan kandungan genetik lokal antara 6.25% sampai dengan 25% dengan kisaran umur 12-20 tahun yang dipelihara secara intensif di Unit Rehabilitasi Reproduksi Bagian Kebidanan dan Kemajiran Departemen Klinik, Reproduksi, dan Patologi, Fakultas Kedokteran Hewan, Institut Pertanian Bogor. Kuda-kuda tersebut diberi pakan berupa rumput segar dan konsentrat dengan kadar protein 12 %.