• Reproductive and Developmental Biology
• /
• v.41 no.2
• /
• pp.25-31
• /
• 2017

Effective estrus detection and artificial insemination (AI) are necessary for profitable management of dairy herd. In current study, 45 crossbred lactating cows have been selected with the complaint of unobserved oestrus for more than sixty days postpartum. All cows had functional corpus luteum as examined by transrectal ultrasonography. Cows were treated with $PGF_2{\alpha}$ analogue and AI was performed with observed oestrus and then single dose of GnRH was administered. Similar synchronization protocol has been repeated after 14 days in cows that did not repose to first treatment. Remaining cows received additional $PGF_2{\alpha}$ after 14 days of second treatment and timed AI was performed following GnRH administration. Among 45 cows, 28.89% showed estrus after first treatment and 78.79% responded to second hormonal intervention. A higher conception rate (88.89% vs 26.66 and 72.72%) was observed in cows after triple administration of $PGF_2{\alpha}$ and timed AI. We noticed a significant differences in body condition score (BCS, 1~5 scale), postpartum period, and daily milk production between cows that either responded of non-responded following first and second hormonal treatment. In addition, there was a significant positive correlation between daily milk production and BCS, age and postpartum days, milk production and estrus/BCS, and milk production/BCS/estrus and conception rate. Depending upon the findings we conclude that hormonal intervention with $PGF_2{\alpha}$ and GnRH enhances postpartum ovarian cyclicity and help decreasing the days open of dairy herd. Therefore, this finding might provide an excellent guideline for target breeding system for profitable dairy herd management.

• Journal of Animal Science and Technology
• /
• v.65 no.4
• /
• pp.748-758
• /
• 2023

This study was conducted to investigate the change in activity and mounting behavior in Hanwoo (Korean Native Cattle) during the peri-estrus period and its application to estrus detection. A total of 20 Hanwoo cows were fitted with a neck-collar accelerometer device, which measured the location and acceleration of cow movements and recorded the number of instances of mounting behavior by the altitude data. The data were analyzed in three periods (24-, 6-, and 2-h periods). Blood samples were collected for 5 days after the prostaglandin F2α (PGF2α) injection, and the concentrations of estradiol, progesterone, follicle-stimulating hormone, and luteinizing hormone were determined by enzyme-linked immunosorbent assays. Activity and mounting behavior recorded over 2-h periods significantly increased as estrus approached and were more efficient at detecting estrus than over 24- and 6-h periods (p < 0.05). Endocrine patterns did not differ with the variation of individual cows during the peri-estrus period (p > 0.05). Activity was selected as the best predictor through stepwise discriminant analysis. However, activity alone is not enough to detect estrus. We suggest that a combination of activity and mounting behavior may improve estrus detection efficiency in Hanwoo. Further research is necessary to validate the findings on a larger sample size.

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.8
• /
• pp.1093-1101
• /
• 2003

Reproductive data, such as numbers of days to the first estrus and A.I. service postpartum, number of days to conception, number of A.I. services required for conception, interval between the first estrus and first A.I. service and the average interval of A.I. service in Thai native-Friesian crossbred and pure Friesian dairy cows, were compiled in the National Dairy Training and Applied Research Institute in Chiang Mai, Thailand. The data were analyzed statistically and the effect of milk production on these reproductive traits was investigated. The reproductive efficiency of purebred cows was obviously inferior when compared with crossbred animals, in spite of special care being given to the purebred only in order to alleviate the effect of a tropical climate and provide better feeding. However, the regression analysis between reproductive and lactational parameters revealed a definite antagonistic effect of lactation on reproduction, especially in the purebred cows, which had a larger amount of milk production and longer lactation period. If these effects of lactation were eliminated, there would be no evident difference in reproductive efficiency between purebred and crossbred cows in the conditions of this study. Among the reproductive parameters examined, the number of days to the first estrus and interval between the first estrus and first A.I. service were less affected by breed difference and the magnitude of lactation than other reasons.

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.4
• /
• pp.470-474
• /
• 2005

The efficiency of a short-term treatment with an intravaginal device containing progesterone (CIDR) combined with pregnant mares' serum gonadotrophin (PMSG) and prostaglandin analogue ($PGF_{2\alpha}$) was evaluated for the induction of estrus, initiation of cyclic activity, and fertility in postpartum suckled yak cows. Seventy-five postpartum suckled yak cows were assigned to three treatments: (1) insertion of a CIDR intravaginal progesterone (1.9 g) (day 0), an administration of $PGF_{2\alpha}$ (0.2 mg i.m.) on day 6 and PMSG (1,000 IU i.m.) at the time of CIDR withdrawal on day 7 (CPP group, n=28); (2) an administration of $PGF_{2\alpha}$ (0.2 mg i.m.) on day 6 and PMSG (1,000 IU i.m.) on day 7 (PP group, n=21); (3) untreated animals served as the control (CG group, n=26). Seven yak bulls were placed in pastures with the cows for natural mating. Estrus rate in the CPP group (28/28) was higher (p<0.01) than in the PP group (6/21) and in the CG group (0/26) within 96 h after the end of treatment. The first service conception rate in the CPP group (21/28) was higher (p<0.01) compared with in the PP group (2/9) as judged by serum $P_4$ concentration $\geq$2.35 ng/ml on day 21 after breeding. It is concluded that a short-term progesterone treatment combined with PMSG and prostaglandin increased the proportion of yak cows that exhibited behavioral estrus with more synchronized estrus response and satisfactory conception rate in postpartum suckled yak cows.

• Journal of Embryo Transfer
• /
• v.31 no.2
• /
• pp.137-143
• /
• 2016

This study was conducted to evaluate a visual surveillance system. The advancement of recording technology and network service make it easy to record and transfer the videos. Moreover, progressed recognition technology help to make a distinction each other. Cows show distinguishing behaviors during their estrus period. The mounting is one of the behaviors. The result was different depending on the breed of the cows and the size of the farm. In the case of Korean native cattle, the estrus detection rate was 71.15%, however, dairy cows, the estrus detection rate was 39.38%. At the farms having below 6 modules, the estrus detection rate was 87.41%. On the other hand, at the farms having over 6 modules, the estrus detection rate was 77.78%. With the proper progress, the visual surveillance system can be used to detect heat detection.

• Journal of Embryo Transfer
• /
• v.18 no.2
• /
• pp.115-124
• /
• 2003

The objective of this study was to compare the effect of four different estrus induction methods in anestrus cows on the estrus induction and pregnancy following artificial insemination (AI). Sixty-five cows (3∼4 years old) were selected and divided into four different estrus induction treatment groups. Group 1, 12 cows were treated by Ovsynch program combined with GnRH and PGF$_2$a. Group 2, 12 cows were treated by "Tow plus Two" program with GnRH and PGF$_2$a. Group 3, 20 cows were treated by "Tow plus Two" program following intravaginal progesterone implantation (CIDR). Twenty one cows in Group 4 were treated by "Tow plus Two" program following follicular rupture and intravaginal progesterone implantation. Cows were then observed estrus induction and inseminated artificially at 12 h and 24 h after standing estrus. The rates of estrus induction in Group 4 (18/21, 86%) was significantly (P<0.05) higher than those in groups 1, 2 and 3 (8/12, 67%; 9/12, 75%; 14/20, 70%). In the mean time of onset of estrus after final administration of GnRH in different hormone-treated cows, the cows in Group 3 (24.2$\pm$2.2) and Group 4 (23.4$\pm$2.0) were significantly (P<0.05) shorter than that in Group 1 (28.5$\pm$4.6) and Group 2 (26.4$\pm$3.3). The rates of pregnancy diagnosed on Day 28 were significantly different between treatment groups. Significantly (P<0.05) higher rate of pregnancy was observed in Group 4 (17/20, 85.0%) than those in Groups 1, 2 and 3 (7/11, 63.6%; 8/12, 66.7%; 15/20, 75.0%, respectetively). The rate of abortion diagnosed on 49 days of gestation was significantly (P<0/05) lower in Group 4 (1/17, 5.9%) than those in Groups 1, 2 and 3 (2/7, 28.7%; 2/8, 25% and 3/15, 20%, respectively). In conclusion, combined treatments with GnRH and PGF$_2$a following follicular rupture and progesterone implant in anestrus cows was considered to be most effective in estrus induction and maintenance of pregnancy. Further studies are needed to verify the functional mechanisms of residual follicles in anestrus ovaries on retarding the response of hormonal treatments.sponse of hormonal treatments.

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.9
• /
• pp.1268-1273
• /
• 2003

Sixty postpartum lactating Friesian cows in 3 treatments at a commercial dairy farm were used to study the effect of using progesterone supplementation with GnRH and PGF2$\alpha$ synchronization with and without timed AI on fertility during summer. Cows in treatment1($Tr_1$) and treatment2 ($Tr_1$) were fitted with progesterone releasing intravaginal device (PRID) device and injected with 10 g GnRH agonist on $51{\pm}3$ d postpartum (pp). Seven days later, PRID was removed and cows received 25 mg PGF2$\alpha$. Two days later, $Tr_1$ cows received another injection of 10 g GnRH and timed AI 16-20 h later. Control cows received only 25 mg PGF2$\alpha$ $58{\pm}3d\;pp$. $Tr_2$ and control cows were AI at detected estrus. Serum progesterone for all cows was determined on days of injection, AI and 21, 23 and 28 d postinsemination. Pregnancy rates from first AI based on serum P4 concentrations on d 21, 23 and 28 postinsemination (50, 40 and 35%) and that based on rectal palpation 40-45 d postinsemination (30, 15 and 15% for $Tr_1$, $Tr_2$ and control cows, respectively) did not differ among the three groups. Whereas, pregnancy rate at 120 d pp for $Tr_1$ (65%) was higher (p<0.05) than that in $Tr_2$ (30%) or control (30%). The overall pregnancy rate was not significantly different (90, 90 and 75% for $Tr_1$, $Tr_2$ and control, respectively). Days open for cows in $Tr_1$ ($100.3{\pm}9$) was less (p<0.03) than that in $Tr_2$ ($130.9{\pm}9$) or control ($135.1{\pm}10$). Results indicate that using PRID device with Ovsynch program had significantly increased pregnancy rate and decreased days open compared to AI at detected estrus after synchronization with GnRH, PRID and PGF2$\alpha$ or synchronization with one injection of PGF2$\alpha$.

• Asian-Australasian Journal of Animal Sciences
• /
• v.30 no.3
• /
• pp.347-354
• /
• 2017

Objective: The effects of the pre- and postpartum supplementation of cows with Se on their plasma P4 concentrations after calving were investigated. Methods: Thirty-four Holstein cows were used to investigate the effects of dietary selenium supplementation on the postpartum recovery of the luteal function in cows. Selenium-rich yeast (containing 300 ppm selenium) was mixed with total mixed ration fed to 17 pregnant cows from 30 days before they were due to calve (10 g yeast daily) to 100 days after calving (20 g yeast daily). The control cows (n = 17) were fed the same amount of ordinary yeast. The cows' plasma progesterone concentrations were determined every two days using an enzyme immunoassay after calving. Results: Feed intake (total digestive nutrient, crude protein), milk production, body weight and the biochemical properties of blood plasma did not differ between the two groups; however, the plasma selenium concentrations of the supplemented animals were significantly greater than those of the controls at and after calving. The postpartum plasma progesterone concentrations of the selenium-yeast-supplemented group increased earlier than those of the control group. Moreover, during the estrus cycle after the 3rd ovulation or ovulation with estrus between 60 to 80 days after calving, the selenium-supplemented cows exhibited greater progesterone concentrations than the control cows. Conclusion: Selenium supplementation promotes the postpartum progesterone production of cows.

• Korean Journal of Veterinary Research
• /
• v.34 no.4
• /
• pp.881-890
• /
• 1994

Skim milk progesterone($P_4$) profiles in 74 dairy cows were determind to monitor postpartum ovarian activity by radioimmunoassay. Milk samples were collected from each cow every 5 days from 10 to 90 days postpartum. Signs of estrus were observed twice daily, and status of the ovaries and uterus were examined every 10 days by rectal palpation. Results are summarized as follows: 1. Cows were categorized into five types by the change of skim milk $P_4$ profiles; Type I(normal) : Cyclic changes of skim milk $P_4$ profiles appeared within 20 days postpartum(12 cows, 16.2%), Type II(cycle delayed) : Cyclic changes of skim milk $P_4$ profiles appeared from 21 to 60 days postpartum(39 cows, 52.7%), Type III(cycle ceased with low $P_4$) : Onset of the estrous cycle within 20 days postpartum but ceased later with low levels of $P_4$ (7cows, 9.5%), Type IV(cycle ceased with high $P_4$) : Onset of the estrous cycle within 20 days postpartum but ceased later with high levels(>3.0 ng/ml) of skim milk $P_4$ (4 cows, 5.4%), Type V(acyclicity) : Skim milk $P_4$ concentration remained low(<1.0 ng/ml) until 80 days postpartum(12 cows, 16.2%). 2. Out of the 17 cows classified as the Type III and Type V by skim milk $P_4$ profiles, 13 cows had inactive ovaries and remaining 6 cows had single or multiple follicular cysts in their ovaries by rectal palpation. All 4 cows of Type IV had a persistent corpus luteum in their ovaries. 3. Approximately eighty percent of the cows had begun ovarian activity by 60 days postpartum and 90.6% by 90 days by skim milk $P_4$ profiles, but only 39.2% by 60 days and 71.7% by 90 days had shown visible estrus signs. The mean days from parturition to the first, second and third ovulations determined by skim milk $P_4$ profiles was $28.0{\pm}11.0$, $46.4{\pm}13.3$ and $66.4{\pm}11.5$ days and the visible estrus signs were 9.3%, 38.1%, and 48.6%, respectively. The mean days from parturition to the first visible estrus was $57.2{\pm}15.9$ days. These results indicated that milk $P_4$ profile of each Types by radioimmunoassay can be utilized for monitoring postpartum ovarian and would be useful for the early detection of ovarian dysfunction in dairy cow.

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.2
• /
• pp.185-188
• /
• 2003

Data on the use of breeding records of dairy cattle farm of Fenghuang-shan in Chengdu areas during a period of six years is systematically analyzed. The results show that Holstein heifers have their 1st estrus at an average age of $513.6{\pm}46.7$ d which is not related to the calving season. Estrus mostly occurs in the months with mild ambient temperature (March, April, May, November and December). There is a very poor rate of estrus detection; only 30.0% successive estrus is observed within 24 d, 29.3% within 25-48 d, 40.6% over 48 d. The average number of insemination per conception is 1.50 for heifers and 1.74 for cows, but conception rate (CR) is lower in the relatively warm months (July, August and September) ranged from 48.1% to 51.9% compared with 58.1% to 68.5% in other months. High temperature is the most important factor affecting fertilization in warm months, but neither did CR decline immediately with the increased air temperature in June, nor did it increase immediately with the declined air temperature in September. Post partum anestrous period is $119.5{\pm}60.5$ d. The average interval from calving to conception is $159.4{\pm}85.6$ d with only 19.8% of the cows conceived within 85 d of calving. Cows with high milk yield have longer acyclic periods and lower conception rates. Improvement of efficient managements must be a precedent condition in Chengdu areas.