Table 1 Mean ± SE pre-treatment concentrations of LH, androstenedione, testosterone, and total estrogens in Group I (14–16 months), Group II (9–12 months), and Group III (6–8 months) Holstein × Tharparkar bull calves

2.90 ± 0.84^a

2.35 ± 0.67^a

2.46 ± 0.35^a

2.10 ± 0.17^a

0.79 ± 0.06^b

0.05 ± 0.01^c

0.97 ± 0.08^a

0.32 ± 0.06^b

0.19 ± 0.03^b

43.1 ± 23.6^a

47.3 ± 26.0^a

20.93 ± 5.48^a