• Reproductive and Developmental Biology
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• v.36 no.1
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• pp.87-93
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• 2012

The purpose of this experiment is to compare the pregnancy rate (PR) according to the state of the ovaries and uterus, according to the number of embryos transferred from cows and heifers and to investigate the method of artificial twin induction with Hanwoo $in$ $vitro$ fertilized (IVF) embryos by embryo transfer (ET). Looking at the PR according to the condition of the ovaries and uterus, the result was not influenced by the condition of the ovaries, but was significantly influenced by the state of the uterus. The PR according to the number of embryos transferred from cows was 36.8%, 53.0%, 50.5% for 1, 2, and 3 embryos respectively, and although there was a higher frequency of twin calves with 3 embryos than with 2, the calving rate was the highest with 2 embryos. In case of heifers, the transfer of 1 embryo showed the best pregnancy and calving rate, and although the PR was similar with 2 embryos (67.7 versus 66.4), in case of 2 embryos transferred there was high frequency of embryonic loss( 6.1%) occurred when a cow was diagnosed at 28 and 53 d after ET, total loss (21.3%; sum of fetal death, abortion and stillbirth after pregnant diagnosis at 60 day).

• Reproductive and Developmental Biology
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• v.36 no.2
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• pp.95-101
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• 2012

The purpose of this experiment was to compare the pregnancy rate (PR) according to the state of the ovaries and uterus, according to the number of embryos transferred from cows and heifers and to investigate the method of artificial twin induction with Hanwoo in vitro fertilized (IVF) embryos by embryo transfer (ET). Looking at the PR according to the condition of the ovaries and uterus, the result was not influenced by the condition of the ovaries, but was significantly influenced by the state of the uterus. The PR according to the number of embryos transferred from cows was 36.8%, 53.0%, 50.5% for 1, 2, and 3 embryos, respectively and although there was a higher frequency of twin calves with 3 embryos than 2, the calving rate was the highest with 2 embryos. In case of heifers, the transfer of 1 embryo showed the best pregnancy and calving rate, and although the PR was similar with 2 embryos (67.7 versus 66.4), in case of 2 embryos transferred there was high frequency of embryonic loss (6.1%) occurred when a cow was diagnosed at 28 and 53 d after ET, total loss (21.3%); sum of fetal death, abortion and stillbirth after pregnant diagnosis at 60 day.

• Journal of Embryo Transfer
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• v.29 no.1
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• pp.7-12
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• 2014

This work was conducted to study the improvement of reproduction rate from the breeding data collected from four farms from January 2007 to October 2010. The average numbers of service per conception were 1) A farm $1.7{\pm}0.1$ times, 2) B farm $1.5{\pm}0.1$ times, 3) C farm $1.5{\pm}0.1$ times, 4) D farm $1.4{\pm}0.1$ times. The average days from calving to conception was $77.4{\pm}4.8$ days in A farm, $150.8{\pm}11.2$ days in B farm, $90.4{\pm}4.5$ days in C farm, and $71.4{\pm}2.5$ days in D farm. Number of artificial insemination (AI) service per conception was higher at the 30 days before first AI ($2.1{\pm}0.2$ times) than at the 31 days after first AI, and the days from calving to conception were shorter at the 90 days before first AI than at the 91 days after first AI. After timed AI (TAI) treatment, the pregnancy rate was 60.3% for the 58 cows with reproductive disorder. In order to improvement of reproduction rates, the farms has to improve the accuracy of estrus detection, pregnancy diagnosis, check-up for reproductive health, and control of day for first AI periods after calving. The result suggests that farmers need the careful management and reproductive examination of farm animals to improve of reproductive efficiency.

• Journal of Veterinary Clinics
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• v.28 no.4
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• pp.339-343
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• 2011

This study determined the effects of twin birth on subsequent postpartum disorders, culling and reproductive performance, and its risk factors in dairy cows. Detailed data related to reproduction, health, and calving events, including dates of artificial insemination (AI) and calving, hormonal treatment prior to conception, cow parity, twin birth, retained placenta, metabolic disorders, and endometritis were collected from 1,717 individual calvings on 9 dairy farms. The incidence rate of twin birth was 3.4%. Gestation length was shorter in cows with twin birth ($270.6{\pm}2.0$ days) than cows giving birth to singletons ($279.5{\pm}0.2$ days, P < 0.01). The incidence of retained placenta (47.5 vs. 16.0%), metabolic disorders (18.6 vs. 3.8%) endometritis (62.7 vs. 28.2%), and culling rate (32.2 vs. 16.5%) was greater in cows with twin birth than in cows giving birth to singletons, respectively (P < 0.01). The hazard of pregnancy (adjusted hazard ratio, AHR) by 210 days in milk analyzed using Cox proportional hazards model was affected by calving season, in that the rate of pregnancy for cows calved during spring was less than for cows calved during winter (AHR = 0.80; P = 0.01); this was also true for endometritis (AHR = 0.46, P < 0.01). AHR was not affected by twin birth. Logistic analysis demonstrated that increasing the cow parity (P < 0.01) and hormonal treatment prior to conception (adjusted odds ratio, AOR = 1.84, P < 0.05) increased the risk of twin birth. These results demonstrate that twin births are responsible for severe economic losses through the increased occurrence of postpartum disorders and culling; thus, appropriate management for the deleterious impact of twin birth, and/or reducing the risk factors by herd control regarding cow parity and the use of reproductive hormones prior to conception might be necessary.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.9
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• pp.1267-1272
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• 2002

The present research was undertaken to monitor the effects of restricted and ad. libitum feeding during last trimester of pregnancy on the performance of crossbred dairy cows and their calves. For this purpose two groups of crossbred cows having eight animals in each group were put into two plane of nutrition during their last three months of pregnancy. Dietary energy level in one group was calculated as per Ministry of Agriculture, Fisheries and Food, (MAFF, UK) and the cows on other group received ad. libitum feeding (concentrate level similar to MAFF, recommendation+ad. libitum roughage). After calving, the cows of both groups were given same diet (ad. libitum) to study the effect of feeding during pregnancy on subsequent lactation performance of the cows. It was observed that during pre-calving period cows on ad. libitum feeding gained significantly (p<0.05) more body weight than that of cows on restricted feeding ($38.50{\pm}6.04$ vs $21.37{\pm}8.04kg/cow$). There was no significant differences between the birth weight of calves of restricted ($21.31{\pm}2.18kg$) and ad. libitum ($20.31{\pm}3.27kg$) groups. Dietary energy intake of ad. libitum group ($50.22{\pm}4.24$ MJ ME/d/cow) was significantly higher (p<0.01) than that of restricted group ($39.76{\pm}1.03$ MJ ME/d/cow). During lactation period cows that were on restricted feeding produced little more milk (3.06 lit/cow/day), than that of the cows on ad. libitum feeding (2.84 lit/cow/day). Although growth rate of the calves of restricted group upto one month ($0.23{\pm}0.09kg/calf/d$) was significantly (p<0.01) higher than that of ad. libitum group ($0.17{\pm}0.08kg/calf/d$) but after four months the growth rate of the calves of two groups become nearly similar ($0.35{\pm}0.02$ vs $0.37{\pm}0.03kg/calf/d$) and difference between them was non-significant. During lactation period cows of restricted group gained little weight but cows of ad. libitum group lost significantly (p<0.05) more weight. Per day metabolizable energy intake in both group during lactation period was nearly similar (67.54 vs 69.58 MJ ME). It is concluded that ad. libitum feeding during last trimester of pregnancy is neither economic for getting maximum milk yield nor for calf growth rate and MAFF, recommended level of dietary energy during that period could be applied on our pregnant crossbred dairy cows.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.2
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• pp.229-232
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• 1997

Effects of short-term treatment with somidobove (recombinantly produced bovine somatotropin, BST) on estrous cyclicity and fertility were studied in dairy buffaloes. Twenty buffaloes of Nili-Ravi breed calving during the same season were assigned to either control (n=8) or treated group (n=12). The buffaloes of treated group received single infection (prolonged release) of 320 mg of somidobove on day-60 postpartum. The mean values for interval to first postpartum estrus, first service conception rate, services per conception, service period and calving interval for the treated group were 96.4 days, 66.7%, 1.70, 164 days and 473 days, respectively. The corresponding values for the control group were 92.5 days, 62.5%, 1.87, 135 days and 439 days. Means of all variables did not differ between control and treated group (p > 0.05). Three buffaloes of the control and four buffaloes of the treated group did not conceive at first service. Out of these, two buffaloes of control and one buffalo of treated group exhibited normal estrous cycles. It is concluded from these data that short term BST-treatment has no adverse effect on reproductive functions of dairy buffaloes.

• Korean Journal of Veterinary Research
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• v.59 no.4
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• pp.181-185
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• 2019

The traditional calculation of gestation length (GL) in Holstein cows relies solely on the insemination day and has a high error rate for actual calving dates. The present study was conducted to develop a more accurate method of estimating GL. Among 3,578 Holstein cows, the number of fetuses had a significant (p < 0.05) effect, with GLs of 282.4 ± 2.5 days for singletons and 276.0 ± 1.6 days for twins. Within the singleton group, the GLs were 284.6 ± 1.9 days for males and 280.3 ± 1.5 days for females, a significant difference (p < 0.05). However, within the twin group, there was no difference in GLs among twin males, twin females, or twins of both sexes. Gestation was significantly shorter for singleton males born from June to August but significantly longer for twin males born in the May to June period (p < 0.05). Neither parity nor housing type was associated with any significant difference in GL. In order to predict the calving dates of Holstein cows accurately and improve their management, calculations should consider the number and sex of fetuses as well as the insemination season.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.3
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• pp.331-334
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• 2003

The assessment of reproductive potentials of female gayal under semi-intensive management was conducted with 18 animals in Bandarban hilly area of Bangladesh. Age at first estrous (days), age at first conception (days), length of estrous cycle (days), number of service per conception (natural), gestation period (days), age at first calving (days), and calving interval (natural service) (days) of gayal were $598.2{\pm}168.44$, $723{\pm}169.94$, $21.86{\pm}2.93$, 1.41, $296.05{\pm}3.87$, $1014.42{\pm}260.32$ and $465{\pm}80.48$ respectively. Daily milk yield and lactation length of gayal were $304.98{\pm}30.46ml/day$ and $116.67{\pm}8.08days$. Gayal male calves had higher birth weight (19.67 kg) than female calves (15.58 kg) in first lactation. Birth weight increases in second and third lactation than first lactation in both male and female calves. Highest conception rate observed in winter season and 70.60% successful conception occur when service was given within 21-30 h of estrous. Maximum number of female gayal use to come in estrous in winter and calved in monsoon and autumn. Cervicitis and irregular heat were the most reproductive problems followed by metritis, case of abortion, anestrous and repeat breeding. From this study it was observed that the reproductive performance of gayal is very close with the domestic cattle. It may use as beef cattle for the hilly regions of Bangladesh.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.4
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• pp.580-585
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• 2016

The objective of this study was to determine cow characteristics and farm management factors during the dry period associated with early postparturient intramammary infection (IMI) and subsequent clinical mastitis (CM). Data were collected three times: before drying off (P1), during the dry period (P2), and 5 to 14 days after calving (P3), using questionnaires and farm investigation. Milk samples were aseptically collected for bacterial identification at P1 and P3. Factors associated with IMI and CM were analyzed using multiple logistic regression models. The final model showed that IMI in early postpartum was significantly associated with full insertion of dry cow antibiotic, dry cows in barns with a combination of tie and free stalls, body condition score (BCS) in dry period and after calving, and milk yield before drying off. For IMI cows, factors significantly associated with clinical expression of mastitis were having daily barn cleaning, teat disinfected with alcohol before administration of dry cow therapy, BCS before drying off, milk yield before drying off, and days in milk at drying off. In conclusion, both cow and farm management factors are associated with the IMI rate and subsequent expression of clinical signs of mastitis in early postpartum cows.

• Korean Journal of Veterinary Research
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• v.27 no.1
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• pp.137-140
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• 1987

Information on certain reproductive traits were obtained from field material. The data for this study were taken from 1,111 breeding records of 273 cows and 193 heifers at Koheung, Chonnam, during the period 1979 to 1984. The cattle were bred by artificial insemination; only one or two cattle were reared by one farmer. The heifers were first bred at 551.75 days after they were born; they were pregnant at 569.06 days after birth. The average estrous cycle length was 21 days; the average number of inseminations per conception was 1.56. The non-return rate for first inseminations for cows and heifers was 62.5% and 59.6%, respectively. The gestation length was 285.79 days. Of 1,111 viable calved born 582 were male, giving a sex ratio of 100:110. The average length between calving and first insemination was 88.9 days; average calving interval was 397.69 days.