• Journal of Animal Science and Technology
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• 제65권1호
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• pp.197-208
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• 2023

The objective of this study was to investigate the effects of a traditional dry period (60 d) versus a no dry period (0 d) on the milk production, physiological response, and metabolic status of dairy cows exposed to heat stress during the transition period. Holstein dairy cows (n = 15) with similar expected calving dates were randomly assigned to two different dry period lengths: (1) no dry period (n = 7) and (2) a traditional dry period of 60 days (n = 8). All cows were studied from 8 weeks before expected calving to 10 weeks after calving and experienced heat stress during the transition period. The results showed that cows with no dry period decreased their milk yield in subsequent lactation, but compensated for the loss of milk yield accounted for by additional milk yield before calving. The energy balance at postpartum was improved in cows with no dry period compared to cows with a traditional dry period. There were no significant differences in the physiological response and blood metabolites at postpartum between the dry period lengths of dairy cows exposed to heat stress during the transition period. Taken together, our results showed that omitting the dry period improved the milk production and metabolic status of dairy cows exposed to heat stress during the transition period.

• Asian-Australasian Journal of Animal Sciences
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• 제25권4호
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• pp.486-495
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• 2012

Twenty four periparturient cows were used to determine the effects of DCAD on acid-base balance, plasma and urine mineral concentrations, health status, and subsequent lactation performance. Each group of 12 cows received either a diet containing -100 DCAD or +100 DCAD for 21 d prepartum. Both anionic and cationic groups were divided into two groups, one received a +200 DCAD and the other +400 DCAD diet for 60 d postpartum. Prepartum reduction of DCAD decreased DMI, urinary and blood pH, urinary concentrations of Na or K and increased plasma and urinary Ca, Mg, Cl and S. Also cows fed -100 DCAD diet consumed the most dry matter in the first 60 d after calving. Postpartum +400 DCAD increased milk fat and total solid percentages, urinary and blood pH and urinary Na and K concentrations, but urinary Ca, P, Cl and S contents decreased. Greater DMI, FCM yields were observed in cows fed a diet of +400 DCAD than +200 DCAD. No case of milk fever occurred for any diets but feeding with a negative DCAD diet reduced placenta expulsion time. In conclusion, feeding negative DCAD in late gestation period and high DCAD in early lactation improves performance and productivity of dairy cows.

• Asian-Australasian Journal of Animal Sciences
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• 제18권7호
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• pp.949-956
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• 2005

The weekly ultrasound scanner (US) observations of reproductive organs in a commercial dairy herd with the popular stanchion style management were conducted for over 26 months. Based on reproductive records, the following were evaluated: 1) the effect of postpartum period commencement of US monitoring on herd reproductive efficacy, and 2) the effectiveness of a US monitoring-based diagnosis and subsequent treatments of reproductive disorders on postpartum reproductive efficiency. The reproductive parameters of cows, which were subjected to US monitoring between Days 30-40 (Day 0 = day of parturition), Days 41-50, Days 51-60, and above Day 61, were compared. The reproductive parameters of cows diagnosed as having reproductive disorders (RD) with US monitoring before or after the first artificial insemination (AI) were also compared. It was found that the day of commencement of US monitoring in cows diagnosed with and without RD significantly affected the period towards the first AI and the open period. In particular, cystic follicles and anoestrus detected either before or after the first AI significantly affected herd reproductive efficiency. The implementation of US monitoring improved reproductive efficiency by reducing the open period and increasing the number of milking cows in the herd. The results of this field trial indicate that the postpartum reproductive management of dairy cows with the use of the US monitoring system is one strategy to improve reproductive efficiency, especially in a high-yielding dairy herd reared stanchion management style.

• 대한수의학회지
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• 제44권2호
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• pp.293-301
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• 2004

We investigated the effect of reproductive herd health program (RHHP) on the reproductive performance in high yielding dairy herds. Data collected from 205 lactations at Boeun County, Chungbuk from April 2001 to Dec. 2003 included postpartum reproductive and metabolic diseases, body condition score (BCS), reproductive performance and milking records. First we compared the reproductive performance of cows without RHHP (pre-RHHP group) and cows with RHHP (RHHP group). Intervals from calving to first service (99.6 vs. 81.8 days) and to conception (160.3 vs. 131.8 days) were shorter in the RHHP group than in the pre-RHHP group. Secondly, we determined the effect of milk yield (305 days) on the occurrence of postpartum diseases, BCS changes, and reproductive performance in cows under RHHP. The occurrence of metritis and metabolic diseases were greater in the over-10,000 kg group than in the under-10,000 kg group. The over-10,000 kg group lost more body condition than the under-10,000 kg group from calving to month 3 postpartum. Nevertheless, reproductive performance did not differ between the two groups. These results indicate that reproductive performance can be improved by the application of RHHP in high yielding dairy herds and that reproductive performance in the cows under RHHP are not affected by high milk yielding.

• 한국임상수의학회지
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• 제32권5호
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• pp.426-432
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• 2015

본 연구는 임상형 혹은 준임상형 자궁내막염에 이환된 젖소와 자궁내막염이 발생되지 않은 젖소 사이에 분만 전 후 기간 동안 혈액 대사물질의 농도를 비교하였다. 분만 전 4주, 분만 후, 분만 1, 2, 4, 6주 후 혈액을 채취하였으며, 혈청 분리 후 calcium, magnesium, non-esterified fatty acids (NEFAs), total cholesterol, albumin, urea nitrogen, ${\beta}$-hydroxybutyrate (BHBA), aspartate aminotransferase (AST), ${\gamma}$-glutamyltransferase, glucose 및 phosphorus 농도를 측정하였다. 분만 후 4주에, 임상형 혹은 준임상형 자궁내막염 발생 유무에 따라 대조군(n = 104), 임상형 자궁내막염군(n = 66) 및 준임상형 자궁내막염군(n = 37)으로 구분하였다. Calcium과 magnesium 농도는 실험 전 기간에 걸쳐 임상형 자궁내막염군이 대조군과 준임상형 자궁내막염군에 비해 낮았으나(p < 0.05 to 0.0001), NEFAs 농도는 실험전 기간에 걸쳐 임상형 자궁내막염군이 대조군에 비해 높았다(p < 0.01). Total cholesterol 농도는 분만 전 및 분만 후 기간 중 임상형 자궁내막염군이 대조군과 준임상형 자궁내막염군에 비해 낮았다(p < 0.05 to 0.001). Albumin 농도는 분만 후 기간 동안 임상형 자궁내막염군이 대조군과 준임상형 자궁내막염군에 비해 낮았다(p < 0.05 to 0.001). Urea nitrogen 농도는 분만 후 4주 및 6주에 임상형 자궁내막염군이 대조군과 준임상형 자궁내막염군에 비해 낮았다(p < 0.01). 분만 후 1주에, BHBA 농도는 임상형 자궁내막염군이 대조군에 비해 높았으나(p < 0.01), AST 농도는 임상형 자궁내막염군과 준임상형 자궁내막염군이 대조군에 비해 높았다(p < 0.05). 결론적으로, 분만 후 혈청 calcium, magnesium, total cholesterol, albumin 및 urea nitrogen 농도의 감소와 NEFAs, BHBA 및 AST 농도의 증가가 임상형 자궁내막염의 발생과 관련되었으며, 이것은 전환기 중의 균형 잡힌 영양의 중요성을 제시한다.

• 한국수정란이식학회지
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• 제20권3호
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• pp.279-287
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• 2005

본 연구는 젖소에 있어서 분만후 난소 활동의 재개 및 분만후 40일째 BCS가 $PGE_2a+PGE_2a+CIDR$ (PPC) program 적용에 미치는 영향을 구명하기 위하여 2002년부터 2003년까지 2년간에 걸쳐 축산연구소 및 천안 소재 전문 경영체 젖소농 장에서 사육중인 홀스타인 착유우를 대상으로 분만 후 난소 활동의 재개를 조사하기 위한 착유우21두 및 분만후 40일째 BCS가 PPC program 적용에 미치는 영향을 구명하기 위한 착유우 40두를 공시하여 수행한 결과 다음과 같은 성적을 얻었다. 1 분만후 처음으로 유즙중의 progesterone농도가 1.0ng/mL 이상을 나타내는 비율은 10${\~}$30일이 $42.9\%$, 31${\~}$50일이 $19.1\%$였고 분만 후 50일까지 1.0ng/mL 이상을 나타내지 않은 경우가 $38.1\%$였다. 2. 분만후 40일째부터 PPC program을 투입한 결과 1차 및 2차 $PGF_2a$ 처리에 대한 발정반응은 각각 $47.5\%$ 및 $52.4\%$였고, $PGF_2a+PGF_2a$ (PP) program투입에 의해 40두중 30두($75\%$)가 발정 반응을 나타내었다. PP program 투입에 의해 발정 반응을 나타내지 않은 10두에 대한 CIDR 처리의 발정 반응은 $50\%$를 나타내었다. 분만후 40일째에 PPC program 을 적용한 결과 40두중 35두가 발정 반응 ($87.5\%$)을 나타내었다. 3. 1차 및 2차 $PGF_2a$ 처리에 따른 발정 반응은 BCS 2.50 이하의 경우 13두중 8두($61.5\%$), BCS 2.75${\~}$3.50의 경우 27두중 22두($81.5\%$)로 2.75${\~}$3.50의 경우가 2.50 이하의 경우에 비하여 높은 발정반응을 나타내었다. 4. 2차 $PGF_2a$ 처리후 발정 반응을 나타내지 않은 개체에 대하여 CIDR을 처리한 결과, BCS 2.50이하의 경우 5두중 2두에서 발정 반응($40.0\%$)을 나타내었고 BCS 2.75${\~}$3.50의 경우 5 두중 4두에서 발정 반응($80\%$)을 나타내었다. 5. 분만후 40일째부터 PPC program을 적용하여 발정 반응을 검토한 결과 BCS 2.50 이하의 경우 13두중 10두가 발정 반응($76.9\%$)을 나타내었고 BCS 2.75${\~}$3.5의 경우 27두중 26두가 발정 반응($96.3\%$)을 나타내어 2.75${\~}$3.5의 경우가 2.50 이하의 경우에 비하여 높은 발정반응을 나타내었다.

• Animal Bioscience
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• 제35권11호
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• pp.1675-1688
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• 2022

Objective: Pregnant Nelore heifers (n = 417) were used to evaluate the effects of supplementation with monensin-molasses multinutrient block (B) during pre and/or postpartum on reproductive and progeny performance. Methods: Heifers were allocated in four treatments: i) CC: heifers received control supplement (C) in loose meal form (0.06% of body weight [BW] offered daily before and after parturition; n = 108); ii) CB: received C before parturition and B (0.07% of BW offered weekly after parturition; n = 117); iii) BC: received B before and C after parturition (n = 103) and iv) BB: received B before and after parturition (n = 89). During pre and postpartum periods, concentration of metabolites/hormones and cow/calf performance was evaluated over time. Cows were synchronized twice for fixed timed artificial insemination (FTAI) using an estradiol/progesterone-based protocol. Data was analyzed by orthogonal contrasts (C). Results: B increased pregnancy at first FTAI (p = 0.04) and overall pregnancy rate (C1: CC vs BB+BC+CB; p = 0.05). Supplemented cows had greater body condition score (BCS) only at parturition (D0; p = 0.04) and at D40 (p = 0.02). B increased BW (p = 0.03), glucose concentrations (p = 0.01) and subcutaneous fat thickness (p = 0.03) only at D40. Concentrations of insulin were higher in supplemented cows (p = 0.008). Calves born by cows supplemented before and after parturition (C2: BB vs BC+CB) were heavier at 80 (p<0.001), 120 (p<0.001), 170 (p = 0.002) and 210 (p = 0.02) days old. Conclusion: Regardless of period of treatment, block supplementation increased pregnancy at first FTAI and overall pregnancy rate. Additionality, block supplementation during both pre and postpartum periods improved progeny weight until weaning. Block supplementation can be a tool to optimize fertility and calf performance in Nelore primiparous cows.

• Asian-Australasian Journal of Animal Sciences
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• 제1권1호
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• pp.47-53
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• 1988

Daily milk yield estimates were obtained on 74 lactations of 35 Japanese Black cows on weeks 1 to 9, 11, 13, 17, 21 and 26 postpartum using the weigh-suckle-weigh method. The data obtained were analyzed by least-squares procedures according to the models including the following effects; dam, lactation number, season of calving, week of experiment and partial regressions on the lactation number. The overall mean and standard error for daily milk yield was $4.55{\pm}0.04\;kg$. The milk yield declined essentially linearly throughout the experimental period. The main effects of lactation number, season of calving and week of experiment were highly significant. Differences in daily milk yield among cows were significant, and the repeatability was estimated as $0.60{\pm}0.06$. The overall means(kg) and repeat-abilities of cumulative milk yield for 1, 4, 9, 13, 17, 21 and 26 weeks postpartum were 41, 0.08; 166, 0.40; 361, 0.61; 503, 0.66; 632, 0.67; 749, 0.65 and 884, 0.58; respectively. The means of calf weight at birth and 26 weeks weight for different lactations ranged from 25.5 to 33.6 kg and 145.6 to 185.4 kg, respectively. Calf daily gains between experiment weeks were low in earlier stages of lactation.

• 한국가축번식학회지
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• 제7권2호
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• pp.72-85
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• 1983

This presentation firstly is discussed the characteristics of estrus, the time of first postpartum estrus, and the relative accurate of various estrus detection aids and secondly discussed the abnormalities of estrus and ovarian function and its control by treatment of exogenous hormones in cattle and pig. Longer estrus cycles as well as the shorter than 18 day cycles showed the lowered conception rates as compared to the normal cycles of 18 to 25 days. Other characteristics of est겨s such as duration of estrus, intensity of estrus and time of estrus are reviewed to affect fertility. The first postpartum ovulation and estrus in cows usually occurs about 20 to 30 days and 40 to 50 days after parturition, respectively. Irregularities in estrus cycle length have been conducted during early postpartum period. In sows, weaning is followed by ovulation and estrus although there is some individual variation. The most common method of estrus detection is direct visual observation on standing estrus behavior, but various aids of estrus detection have been empolyed with varying degree of effectiveness. The results from heat detector devices are about as accurate as twice-daily observation(about 90%). The abnormal estrus can be classified into three types; irregular or continuous estrus, silent estrus and anestrus. Cystic ovarian disease, follicular cysts and luteal cysts, is a serious cause of reproductive failure in cattle and pig. The follicular cysts are much more common than luteal cysts and the incidence of ovarian cysts in dairy cattle is higher than beef cattle and pig. The occurrences of ovarian cysts have been closely associated with levels of milk production, stages of postpartum period, nutritional levels and seasons. The luteal cysts and persistent corpora lutea are responsive to the luteolytic effects of the recently synthetic analogues of PGF2$\alpha$ in cows and sows and recently GnRH or LH-RH has been successfully used as a treatment for cows and sows with ovarian follicular cysts.

• Asian-Australasian Journal of Animal Sciences
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• 제16권11호
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• pp.1614-1618
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• 2003

Twenty crossbred (HF${\times}$Tharparkar) dry pregnant cows were divided into four equal groups. They were supplemented with 1,000 I.U. $\alpha$-tocopheryl acetate from 0 (group I), 15 (group II), 30 (group III) and 60 (group IV) days before parturition to 1month of lactation. All the cows were kept under similar feeding and management conditions. Blood plasma samples collected on specific days were analyzed for $\alpha$-tocopherol, retinol, total antioxidant activity (FRAP), immunoglobulin and calcium. Plasma $\alpha$-tocopherol concentration at 30 days prepartum averaged 3.5, 4.1, 4.4 and $3.9{\mu}g/ml$ and decreased by 50.0, 41.4, 34.1 and 33.3 percent on the day of parturition in the four respective groups. After calving, plasma vitamin E started to recover earlier in groups II, III and IV as compared to group I. Mean plasma $\alpha$-tocopherol concentration at 21 days postpartum was significantly higher in groups II, III and IV (2.9, 3.5 and $3.1{\mu}g/ml$) compared to group I ($1.9{\mu}g/ml$) cows. Plasma retinol concentration also showed a substantial decrease in all the groups on the day of calving but recovered to its normal value at 3 weeks postpartum. Plasma total antioxidant activity averaged 901, 895, 859 and $875{\mu}mol/l$ in the four respective groups on 30 days prepartum and decreased on the day of calving in all the groups, but the decrease was less in groups III and IV. Plasma immunoglobulin concentration was higher in group IV, followed by groups III, II and I, respectively, showing better immune status of vitamin E supplemented cows due to less oxidative stress. Supplementation of vitamin E resulted in higher plasma calcium concentration. The data showed that vitamin E supplementation should be started at least 30 days prepartum to reduce oxidative stress in periparturient cows.