• Journal of Embryo Transfer
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• v.21 no.2
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• pp.95-100
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• 2006

Thirty heads of proven bulls were used to identify the effects of mounting conditions (dummy cow vs. teaser bull) on semen characteristics in Hanwoo. Semen was collected from bulls daily two times with 1 h interval every $3{\sim}6$ days for 6 months. Bulls mounted dummy cow (BDC) had higher both the $1^{st}$ and the $2^{nd}$ sperm concentrations than in bulls mounted teaser bull (BTB), resulting in more total sperm number (p<0.05). The total sperm number in the $1^{st}$ collection was the highest in BDC with collection interval of 5 days. Total sperm number in the $1^{st}\;and\;2^{nd}$ collections tended to be more in the BDC of $4{\sim}5$ years old and BTB of $6{\sim}7$ years old. These results indicate that semen collection using dummy cow has a better effect than teaser bull on semen characteristics.

• Journal of Veterinary Clinics
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• v.26 no.4
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• pp.376-378
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• 2009

A surgery of penile translocation was performed on a seven-month-old male calf born in August 26, 2007. With a penis deviated, as to prevent proper coitus on a dairy farm, the calf would be introduced to the group of cows and heifers before sniffing around to detect which one is in heat and to indicate to a veterinarian the right time for artificial insemination or embryo transfer. This study showed how to make a teaser bull in his young age.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.8
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• pp.1113-1116
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• 2009

The objective of this study was to compare the follicular population during spontaneous and $PGF_2{\alpha}$ induced oestrous cycles in Nili-Ravi buffaloes. In Exp.1, (n = 13 oestrous cycles) follicular population was monitored using ultrasonography on alternate days. Buffaloes were monitored for ovarian follicles from day 0 (first oestrus) until next oestrus. These animals were observed for oestrus twice daily using a teaser bull. Of 12 oestrous cycles, 9 (75%) had two waves of follicular activity and only 3 (25%) had three waves during the oestrous cycle. The mean number of small, medium and large follicles among various days of the oestrous cycle between two and three waves of follicular development were not significantly different (p>0.05). In Exp. 2, follicular population 3 days before oestrus was compared in buffaloes undergoing spontaneous (n = 12 oestrous cycles) and $PGF_2{\alpha}$ induced (n = 6) luteolysis. The mean number of small and large follicles increased (p<0.05) and the number of medium follicles decreased (p<0.05) during the 3 days before oestrus in buffaloes undergoing induced luteolysis as compared to those with spontaneous luteolysis. These results showed that the mean number of small, medium and large follicles among various days of the oestrous cycle were similar between the two and three waves of follicular development, and three days before oestrous the number of small, medium and large follicles altered due to induced luteolysis on day 9, compared to those with spontaneous luteolysis.