Background and objective: The repeat breeding becomes the major reproduction problem in tropic area especially in Indonesia. It relates to blood metabolic and hormonal level. This research was conducted to investigate the level of blood metabolic and estradiol between the repeat breeder Friesian Holstein Cross Breed Cows (FHCB) and the fertile FHCB cows.
Materials and methods: Twenty FHCB cows in luteal phase on 2nd to 3rd lactation were used in this research. Group I consist of 10 repeat breeder FHCB cows and group II consist of 10 fertile FHCB cows. Blood samples were collected through jugular vein prior to feeding. The level of total protein, phosphorus, glucose, cholesterol and estradiol in serum were calculated. The data were analyzed by using the independent samples t-test for comparing the blood metabolic and estradiol between the repeat breeder FHCB cows and the fertile FHCB cows.
Results: The results showed that repeat breeder FHCB cows were found to have lower level of all of the parameters of blood metabolic and estradiol descriptively, however, only the serum cholesterol and serum phosphorus had the significant difference (p<0.05) between the repeat breeder FHCB cows and the fertile FHCB cows.
Conclusion: It could be concluded that level of serum cholesterol and serum phosphorus played a role in repeat breeding.
Keywords: Estradiol; Friesian Holstein cross breed; fertile cows; repeat breeder cows; serum cholesterol; serum glucose; serum phosphorus; serum protein.