• Journal of Embryo Transfer
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• v.28 no.3
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• pp.177-184
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• 2013

The objective of this study was to analyze the accuracy of estrus detection of heat detector and analysis of estrus behavior (mounting and mounted), and the evaluation of conditions required for improving reproductive efficiency in Holstein dairy cows fitted with a estrous detector. The heat detection system consists of estrous detector based on wireless sensor and an electric bulletin board displayed estrus behavior data. When cow mounting other cows, the accuracy of estrus behavior displayed an electric bulletin board were 87.5% (mounting other cows only), 100% (mounting other cows but not standing), 80.0% (mounting other cows with standing for 1~4 seconds), 90.0% (mounting other cows but not standing for 1~4 seconds), 80% (mounting other cows with standing for more than 5 seconds) and 90.0% (mounting other cows but not standing for more than 5 seconds). When cow mounted other cows, the accuracy of estrus behavior displayed an electric bulletin board were 100% (mounted other cows but not standing), 100% (mounted other cows with standing for 1~4 seconds), 100% (mounted other cows but not standing for 1~4 seconds) and 100% (mounted other cows with standing for more than 5 seconds). Circadian distribution of first observed in estrus were 59.1% (am 8~pm 6) and 40.9% (pm 6~am 8). Distribution for the number of estrus behavior were 40.9% (less than 3 times), 36.4% (4~6 times) and 22.7% (more than 4 times). The conception rates relative to interval from first estrus behavior to insemination for estrus periods were 23.1% (less than 11 hours) and 55.6% (12~20 hours).

• Development and Reproduction
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• v.19 no.4
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• pp.227-234
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• 2015

The objective of this study was to investigate the expression of bovine luteum expressed sequence tags (ESTs), vascular endothelial growth factor (VEGF), and tumor necrosis factor receptor 1 (TNFR1) and the presence of functional ESTs in the bovine corpus luteum (CL) during different stages of the estrus cycle. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed a difference in the expression of ESTs during the CL stage. Concentration of ESTs in the CL tissue increased significantly from the mid-luteal stage and decreased thereafter. RT-PCR analysis showed higher levels of the EST genes in the CL of the mid-luteal stage than in other stages, and the same level of expression of VEGF. Immunohistochemistry analysis of the tissue from CL formation to regression showed low cytosol and aggregation of the nucleus. And activity caspase 3 (apoptosis detector) was most strongly detected in the CL1 stage of bovine. During the estrous cycle, the cytosol was magnified and differentiation of the nucleus was clearly manifested. The ESTs affected the CL, and the relationship between VEGF and TNFR1 played a pivotal role for CL development and activation, dependent on the stage of CL. These results suggest local production of ESTs, the presence of functional ESTs in the bovine CL, and that ESTs play a role in regulating the function of cell death in bovine CL.

• Development and Reproduction
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• v.6 no.2
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• pp.105-110
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• 2002

Numerous hormones are involved in the regulation of reproduction. Among them, estrogen and progesterone are the most important ovarian steroid hormones regulating female fertility. On the other hand, diverse stressors impede female receptivity and fertility. Since norepinephrine(NE) and epinephrine(E) are released from the adrenal during stress, it might play a role in stress-induced disruptions of fEmale reproductive parameters. The present study was performed to analyze the changes in adrenal catecholaminergic activities in cycling rats. The tissue content and secretion level of catecholamines were determined by high performance liquid chromatography coupled with electrochemical detector(HPLC-ECD). Adrenomedullary content of norepinephrine(NE) was increased on proestrus stage (59.47 $\pm$ 6.86 ug/gland), peaked on diestrus I stage(65.22 $\pm$ 5.99 ug/gland), and was nadir on diestrus II stage(41.63 $\pm$ 1.33 ug/gland). The highest E content was observed on proestrus stage(361.86 $\pm$ 15.58 ug/gland) while the lowest level was on diestrus II stage(285.58 $\pm$ 12.25 ug/gland). In addition to these observations, a significant reduction of the NE : E ratio was observed (1 : 4.81 on diestrus I vs 1 : 6.13～7.02 on other stages). In vitro secretion of adrenal NE and E was increased on proestrus stage, peaked on estrus stage, and decreased on diestrus II stage. Interestingly, the NE : E ratio in conditioned media was significantly increased on estrus stage (1 : 3.32 vs 1 : 2.34～2.65 on other stages. The biosynthesis of NE and E is mediated by tyrosine hydroxylase(TH) and phenylethanolamine-N-methyltransferase(PNMT) which acts conversion of tyrosine into DOPA and NE into E, respectively. These finding demonstrated that sex steroids, during setrous cycle, seem to be able to modify the adrenal catecholamines biosynthesis and secretion with stage-specific manner by modulation of the enzyme activities.