Judul: Kajian Prolonged Oestrus pada Sapi Simmental Crossbreed yang diberikan Human Chorionic Ghonadotropin (hCG) secara Intravena
Abstrak: Prolonged oestrus is a reproductive disorder in cows that have a normal estrous cycle but have a longed estrus duration of more than 36 hours, although ovulation is still followed afterwards. The result of prolonged oestrus is a discrepancy between the implementation of artificial insemination during the estrus period and the time of ovulation, which results in fertilization failure and a decrease in reproductive efficiency, which is characterized by the occurrence of repeat breeding (RB), high service per conception (S/C), and long calving intervals (CI). The case of prolonged oestrus in cattle is caused by an increase in preovulatory progesterone (P₄) concentrations, which results in inhibition of the preovulatory luteinizing hormone (LH) surge, which causes the duration of the estrous period to be long. The high concentration of progesterone provides negative feedback to the hypothalamus and hypophysis, which results in a low concentration of LH, which causes a preovulatory LH surge that inhibits ovulation. One way that can be used to increase the concentration of the LH hormone is by injecting the hormone hCG (human chorionic gonadotropin). The hCG hormone has the same power as LH by increasing preovulatory LH concentrations in cows with problems with pregnancy and increasing the success rate of pregnancy. Therefore, this study was conducted to analyze the effectiveness of hCG hormone administration in simmental crossbreed cattle experiencing prolonged oestrus by identifying estrous features, time of ovulation, ovarian dynamics, and analysis of P4 and LH hormone concentrations, as well as successful fertilization after artificial insemination. Four simmental crossbreed cows that experienced prolonged oestrus in Ogan Komering Ulu Timur Regency, South Sumatra, were used as research animals. Observations were made during the initial estrous period of the study (control cows) and in the next estrous period after being given hCG (treated cows). Parameters observed in control and treated cows were estrus intensity, estrus cycle, and duration of estrus, ovarian dynamics and dominant follicle diameter (FD). The treated cows were given an injection of hCG of 1500 IU/cow through the jugular vein (IV) ± 12 hours after signs of estrus were observed or shortly after the implementation of artificial insemination (AI). Examination of the success of fertilization followed by pregnancy using the rectal palpation method was carried out on the 90th day after IB. P4 and LH hormone testing was carried out by the ELISA method using a commercial kit from DRG International Inc., Germany. The collected data is presented using the mean ± SD calculation, while the qualitative data is presented descriptively. The statistical analysis of the data used a paired sample t-test with MS Office Excel 2016 and IBM SPSS Statistics 25 software. The results of the study in control cattle showed that the peak of estrus occurred 3.3±0.1 days after estrus, with a duration of 78 ± 12 hours of estrus and 54±12 hours of ovulation. Meanwhile, for cows treated with hCG, the peak of estrus occurred on day 2.0±0, with a duration of 36 ± 0 hours of estrus and 24 ± 0 hours of ovulation. An overview of the dynamics of the ovaries shows that
Keyword: hCG hormone, Prolonged oestrus, Simmental crossbreed