• Asian-Australasian Journal of Animal Sciences
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• v.20 no.9
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• pp.1402-1406
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• 2007

Thirty pregnant heifers (Jersey, Holstein Friesian and Hariana) were divided into three groups (10 animals/group) according to their stage of pregnancy viz. seven-month (181-210 days) pregnancy (SMP), eight-month (211-240 days) pregnancy (EMP) and nine-month (241-280 days) pregnancy (NMP) group. Time spent in various feeding activities (eating fodder, eating concentrate, standing rumination, sitting rumination and drinking) by each animal in the three pregnant groups was recorded in four different sessions (each session of 24 h per week). The time spent eating concentrate, eating fodder, standing rumination, sitting rumination and drinking was 61.4, 271.3, 84.6, 367.6 and 10.6 min/day, respectively in the SMP group; 52.7, 289.5, 103.3, 345.8 and 9.2 min/day, respectively in the EMP group and 65.0, 277.7, 138.1, 291.0 and 9.8 min/day, respectively in the NMP group. The animals in the EMP group spent significantly (p<0.01) more time on eating fodder and concentrate compared to the animals in SMP and NMP groups. The pregnant heifers preferred rumination in standing posture in comparison to sitting posture. The time spent on standing rumination was significantly higher in the NMP group whereas the time spent on sitting rumination was significantly lower in this group. Except for the sitting rumination activity, all the other activities were predominant in daytime compared to night time; the diurnal variation was significant (p<0.01) for all the activities.

• Journal of Veterinary Clinics
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• v.14 no.2
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• pp.301-307
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• 1997

These studies were performed to provide some basic informations for developing an automatic system in dairy farming cattle in order that the farmers may easily and automatically detect the maintenance of pregnancy and the fact of abortion of the pregnant cows and also to find out the diseased animals with fever. As a method of automatical detection of the maintenance of pregnancy or the fact of abortion, weighing the pregnant cows was conducted from one month-pregnancy to the term using a digital balance. From the first to the 3rd month of pregnancy the body weight of dairy cows was slowly increased (less than 2% per month), then, relatively high increase (3.4% -4.3% per month) from the fourth to the seventh month followed by decrease (3.3%) in the 8th month and very low increase (0.8-0.9%) from the 9th month to the term were shown, resulting in increase of 128.8 kg (25.05%) of body weight to be compared with the first weight. More than 107, increase of body weight to be compared with the first month-weight was denoted from the 61th month of pregnancy and more than 20% increase from the 7th or the 8th month of pregnancy as wells consequently it was presumed that detection of the maintenance of pregnancy is possible from the 4th or the 5th month of pregnancy. It was possible to diagnose a cow aborted at the 6th month by continual weighing the cow from the 1st month of pregnancy. The calved cows showed considerably higher decrease of body weight even in the third week after parturition (p<0.01)to be compared with the body weight near to the term (81.8-102.0 kg, 14-16% decrease). During the same period of 8months, the pregnant cows gained 127.4 kg (24.78% increase), whereas the non-pregnant cows gained 33.0 kg (0.71% increase) to be compared with the first weight showing considerably higher increase of body weight gain in the pregnant cows than the non-pregnant cows (p<0.01). The statistics of body temperatures of dairy cattle were collected from three clinics including the Teaching Hospital of Chonbuk University and the diseases were classified simply by the major symptoms manifested, denoting the highest temperature in respiratory disease ($39.8{\circ}C$) and the lowest in alimentary disease ($39.6{\circ} C$). These informations of body temperatures were expected to be of value for early and automatical detection of the diseased animals with fever when automatic machinery would be established. The results of periodic weighing the body weight of pregnant cows while milking were also expected to be of great use for the farmers to detect the maintenance of pregnancy and the fact of abortion when the automatic system is established in the near future.

• Journal of Embryo Transfer
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• v.9 no.1
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• pp.43-48
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• 1994

This study was carried out to produce monozygotic twin calves by transfer of bisected embryos. Four Korean native cattle donors were superovulated with FSH and flushed to collect embryos on day 6 or 7 of the estrus cycle. Morula and early blastocyst embryos showed 1 or 2 grade were bisected with microblade and each set of demi-embryos without zona pellucida were transferred nonsurgically to 10 recipients respectively. The results obtained were as follows; 1. Twenty four demi-embryos (92.3%) were separated from 13 original embryos and among them 20 demi-embryos (83.3%) had normal appearance without severe damage. 2. Four sets of fresh demi-embryos were transferred to 4 recipients and one recipient was twin pregnant 3. Six sets of frozen-thawed demi-embryos were transferred to 6 recipients. Two recipients were pregnant, one of them twin.

• Reproductive and Developmental Biology
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• v.32 no.4
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• pp.255-261
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• 2008

The early diagnosis of bovine pregnancy is an essential component of successful reproductive planning on farms, because lack of bovine pregnancy over the long term results in reproductive failure and low milk yield-the latter of which is a special concern on dairy farms. This study was designed to identify early pregnancy-specific whey proteins in bovine, by comparing milk samples collected from cattle during pregnancy (Days 30 and 50) and from non-pregnant cattle. In this study, differentially expressed proteins in five pregnant and five non-pregnant Holstein dairy cattle were investigated and compared, using proteomics analysis. The first dimension was applied to a pH $3.0{\sim}10.0$ strip, by loading a 2-mg milk protein sample. After the second-dimension separation was performed, the gels were stained with colloidal Coomassie brilliant blue. The stained gels were scanned and the images were analyzed, to detect variations in protein spots between non-pregnant and pregnant cattle milk protein spots, using ImageMaster, this was followed by analysis with MALDI TOF-MS. Analysis of the 2-DE gel image resulted in a total of approximately $500{\sim}600$ protein spots, of which 12 spots were differentially expressed, six spots were up-regulated, and four spots were down-regulated; two spots were identified as pregnancy-specific proteins. These proteins were identified as lactoferrin, NA-DH dehydrogenase subunit 2, albumin, serum albumin precursor and transferrin. Our results via 2-D PAGE analysis revealed composite profiles of several milk proteins related to early bovine pregnancy, implying the possible use of these milk proteins in the early detection of bovine pregnancy.

• Korean Journal of Veterinary Research
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• v.28 no.2
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• pp.261-270
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• 1988

This study was performed to investigate the effect of gestation on the histological and histochemical changes of the uterine cervix of the native Korean cattle. A total of 110 cows obtained from the Chonhuk abattoir were divided into six groups. The 1st group was of 9 non-pregnant cows and 101 singleton pregnant cows were grouped into 5 groups from pregnant I to pregnant V according to gestation periods by means of crown rump length measures. For light microscopy the tissues were fixed in 10% neutral formalin and processed routinely for paraffin sections The $6{\mu}m$ sections were taken and stained with H-E, Alcian blue pH 1.0, Alcian blue pH 2.5, Alcian blue pH 2.5/PAS, PAS reaction, toluidin blue, and trichrome. The results obtained were as follows: 1. The cervical lengths and widths were increased in relation to advancing gestation. 2. The cervical folds of the pregnant groups were increased and complicated with many branches, and the cervical muscosal epithelia were increased in according to advancing gestation. 3. As advancing gestation, the tunics muscularis of cervix was increased following moderate distribution of fibroblast and vascularity, meanwhile decreased mast cells were found. 4. The cervical mucosubstance was composed of mixed mucopolysaccharides; the acid mucus was increased from the early pregnant state but the neutral mucus was found after pregnant IV, and the mucus was stained deeply in each staining in the fold cavity in according to gestation state.

• Journal of Embryo Transfer
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• v.13 no.1
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• pp.77-86
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• 1998

A combined technology of transvaginal ovum pick-up(OPU) system with in vitro-oocyte manipulation technique can be used for improving reproductive efficiency in the cattle. The objective of this study was to establish a newly-conceived breeding program using OPU in the pregnant cows. The OPU trial was performed in pregnant cows every 10 days from 40 through 90 days of artificial insemination (Al), and number of follicles in ovary, number of retrieved oocytes and embryo development following in vitro-fertilization, were evaluated. Reduced number of follicles in the ovaries of pregnant cows was firstly detected from 70 days after A' and a significant (P<0.05) decrease in the follicle number (5.4 follicles /donor) was found at 90 days than at 40, 50, 60 and 80 days after Al (8.0~9.2). A similar pattern was also observed in the number of oocytes retrieved by OPU apparatus during experimental period. When retrieved oocytes were matured and inseminated in vitro with frozen bull semen, development of the oocytes to the blastocyst stage was not significantly affected by the retrieval time. Four embryos (morula or blastocyst stage) derived from oocytes retrieved from pregnant cows were nonsurgically transferred to four recipient cows on day 7 of estrus cycle. For the first time in Korea, three of four transferred embryos developed to live calves with normal physiological parameters. In conclusion, an effective breeding program employing pregnant cow can be developed by use of OPU trial and in vitro culture techniques of oocytes ; OPU system could be repeated in pregnant cows with no risk of abortion and viable offsprings were borne after transfer to the recipients.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.2
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• pp.176-179
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• 2003

Insulin-like growth factor-I (IGF-I) is a polypeptide that has the function of regulating the expression of steroid hormones through endocrine, paracrine, and autocrine actions in reproductive organs. Moreover, IGF-I is involved in ovulation, implantation, maintenance of pregnancy, and development of fetuses in animals. Therefore, this study was conducted to investigate the effects of serum IGF-I concentration on progesterone ($P_4$) concentration and pregnancy rates in Korean native cattle (Hanwoo). Blood was collected at estrus (Day 0) and Day 11. Artificial insemination was performed at Day 0. Serum IGF-I and $P_4$ concentrations were measured by radioimmunoassay (RIA). Overall, $P_4$ concentration was higher at Day 11 than Day 0, whereas the pattern of IGF-I concentration was reversed. When animals were divided into two groups depending on the pregnancy status, $P_4$ concentrations of the pregnant group was significantly higher than that of the non-pregnant group at Day 0 (p<0.05) and Day 11 (p<0.05). But, lower IGF-I concentrations were detected in the pregnant group at Day 0 (p<0.05) and Day 11 (p<0.05) compared to the non-pregnant group. In conclusion, these results indicated that serum IGF-I is inversely associated with $P_4$ concentration during early pregnancy in Hanwoo.

• Korean Journal of Veterinary Service
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• v.31 no.1
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• pp.137-147
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• 2008

Investigations for hematologic and biochemical values and the differential count of WBC for Korean indigenous cattle (KIC)is rarely performed. Therefore, when the index of complete blood counts (CBC) and biochemical analysis of KIC was requested, it had many difficulties to make the results for blood condition since the standard hematologic and biochemical values of KIC are lacking. In the present study, we have investigated the hematologic and biochemical values and the differential count of WBC for blood of total 252 KIC and 17 striped cattle (SC) as a control. As a result, the mean values of RBC and platelet of KIC were significantly decreased by age (P<0.05). The mean values of RBC, HCT, MCV and MCHC between KIC and SC of the same age (2 - 3 years) showed the statistical significance (P<0.05). Also, in the WBC of KIC, the mean values were decreased according to the age from $12.8{\times}10^3/{\mu}l$ under 1 year to $8.5{\times}10^3/{\mu}l$ over 5 years. In the differential count of WBC of KIC, it showed generally the rates of 45% lymphocyte and 35% segmented neutrophil. In the biochemical analysis, the mean values of BUN and globulin were significantly increased according to the age (P<0.05). Additionally, in comparative analysis between pregnant and non-pregnant group of KIC, the mean values of Hg and HCT in pregnant group were significantly decreased (P<0.05). In conclusion, data obtained from this study may be valuable as a standard for interpretation of the results in hematologic and biochemical analysis of KIC.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.1
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• pp.35-44
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• 2021

A pregnancy diagnosis is an important standard for control of livestock's reproduction in paricular dairy cattle. High reproductive performance in dairy animals is a essential condition to realize of high life-time production. Pregnancy diagnosis is crucial to shortening the calving interval by enabling the farmer to identify open animals so as to treat or re-breed them at the earliest opportunity. MicroRNAs are short RNA molecules which are critically involved in regulating gene expression during both health and disease. This study is sought to establish the feasible of circulating miRNAs as biomarkers of early pregnancy in cattle. We applied Illumina small-RNA sequencing to profile miRNAs in plasma samples collected from 12 non-pregnant cows ("open" cows: samples were collected before insemination (non-pregnant state) and after pregnancy check at the indicated time points) on weeks 0, 4, 8, 12 and 16. Using small RNA sequencing we identified a total of 115 miRNAs that were differentially expressed weeks 16 relative to non-pregnancy ("open" cows). Weeks 8, 12 and 16 of pregnancy commonly showed a distinct increase in circulating levels of miR-221 and miR-320a. Through genome-wide analyses we have successfully profiled plasma miRNA populations associated with pregnancy in cattle. Their application in the field of reproductive biology has opened up opportunities for research communities to look for pregnancy biomarker molecules in dairy cattle.

• Journal of Embryo Transfer
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• v.26 no.3
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• pp.209-214
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• 2011

Endometrium undergoing hormonal change plays important roles in preparation for implantation, fetal growth, and well-being. During pregnancy, cellular remodeling and hormonal changes in endometrium could change two-pore domain K$^+$ channel (K$_{2P}$) expression. This study was performed to identify whether K$_{2P}$ channel expression is changed in endometrium of pregnant Korean cattle, and whether the expression level is modulated by progesterone treatment. We investigated changes in the mRNA and protein expressions of K$_{2P}$ channel in pregnant endometrium using RT-PCR and Western blot analyses. The expression levels of all K$_{2P}$ channel mRNAs tested in this study, except that of TREK-1, were changed in the pregnant endometrium. mRNA levels of TASK-3 and TRAAK were significantly down-regulated, whereas those of TREK-2 and TRESK were up-regulated in the pregnant endometrium. In parallel with the RT-PCR results, Western blot analysis revealed up-regulations of TREK-2 (7.9-fold) and TRESK (2-fold) proteins levels in the pregnant endometrium. In addition, TREK-2 and TRESK protein levels were up-regulated in bovine endometrial cells by progesterone treatment (10 ${\mu}g$/ml). From these results, we suggest that the up-regulation of TREK-2 and TRESK by progesterone may contribute to the regulation of physiological changes during pregnancy.