• Asian-Australasian Journal of Animal Sciences
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• 제5권3호
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• pp.435-438
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• 1992

Data were collected on productive and reproductive performance of different $F_1$ crossbred cows (Deshi cows joined by A.I. to Sindhi, Sahiwal, Jersey or Holstein-Friesian Bull semen) reared by farmers in and around the Bangladesh Agricultural University campus at Mymensingh. The traits considered were birth weight, age at first heat, age at first calving, gestation length, post-partum heat period, milk yield, lactation length, dry period and calving interval. Data were analyzed statistically using a completely randomized design and Duncan's Multiple Range Test to compare and determine the significance of between individual group means. It was observed that the Holstein $\times$ Deshi had the highest birth weight (21.4 kg) followed by Sahiwal (17.6 kg), Jersey (16.7 kg) and Sindhi (16.1 kg). Shortest age at first heat (854 and 920 days) and age at first calving (1002 and 1201 days) were found for the Jersey $\times$ Deshi and Holstein $\times$ Deshi crosses respectively. The post-partum heat period were significantly different between breeds with Jersey and Holstein sired calves having the shortest intervals. There was no difference in the gestation length of the four crosses. Holstein $\times$ Deshi and Jersey $\times$ Deshi cows gave the highest milk yields due to longer lactation periods and higher daily milk production. Similarly, Holstein $\times$ Deshi and Jersey $\times$ Deshi crosses had significantly shorter dry periods and Jersey $\times$ Deshi had a shorter calving interval. From this study it may be concluded that exotic genotypes such as Holstein-Friesian and Jersey can perform very well under rural conditions in Bangladesh.

• Asian-Australasian Journal of Animal Sciences
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• 제17권2호
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• pp.159-163
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• 2004

Data pertaining to first lactation records of 316 Murrah buffaloes, progeny of 47 sires, maintained at NDRI Farm for a period of 18 years were analysed to construct selection indices and to examine their robustness by changing the relative economic values of different economic traits. A total of 120 selection indices were constructed for three sets of relative economic values ( 40 for each set) considering different combinations of seven first lactation traits viz. age at first calving (AFC), first lactation 305 day or less milk yield (FLMY), first lactation length (FLL), first calving interval (FCI), milk yield per day of first lactation length (MY/FLL), milk yield per day of first calving interval (MY/FCI) and milk yield per day age at second calving (MY/ASC). The three sets of relative economic values were based on economic values of different traits, 1% standard deviation of different traits and regression of different traits on FLMY. The 'optimum' indices for the first two sets had five traits each namely AFC, FLMY, FLL, FCI and MY/ASC giving improvement in aggregate genotype of Rupees 269.11 and Rs. 174.88, respectively. The accuracy of selection from both indices was 70.79 and 69.39%, respectively. The 'best' selection index from the third set of data again had five traits (AFC, FLMY, FLL, FCI and MY/FLL) giving genetic gain of Rs. 124.16 and accuracy of selection of 71.81%. The critcal levels or break-even points for FLMY for varying levels of AFC and FCI estimated from the "optimum index" suggested the need of enhancement of present production level of the herd or reduction of AFC or FCI. It was concluded that economic values of various first lactation traits were the most appropriate to construct selection indices as compared to other criteria of assigning relative economic weights in Murrah buffaloes.

• 한국동물생명공학회지
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• 제36권4호
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• pp.230-238
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• 2021

This study attempted to determine the characteristic features of postpartum dairy cows during their return to estrus. Moreover, it investigated the effects of abnormal ovarian cycles (AOC) on subsequent reproductive performance and the relationship between normal ovarian cycles (NOC) and the blood urea nitrogen (BUN) level postpartum. Incidentally, 56.3% of the Holstein cows and 66.7% of the Jersey cows had NOC, whereas the 43.7% and 33.3% of the Holstein and Jersey, respectively, had AOC. Within 100 days of calving, the cows with AOC had significantly lower rates of artificial insemination (AI) submission as well as pregnancy and a significantly longer interval to first AI, as compared to that in the cows with NOC. Additionally, the cows with NOC had a significantly higher first AI conception rate than that in the cows with AOC. In this study, of the 32 Holstein cows, 8 resumed their ovarian cycle within 20 days of calving, 10 resumed the cycle with 21-40 days of calving, 8 within 41-60 days of calving, while the remaining 6 did not resume their ovarian cycles until 60 days postpartum. Furthermore, the likelihood ratios of incidence of NOC are 0.93, 1.94, and 0.38, respectively, in the groups with BUN levels < 15, 15-19.9, and ≥ 20 mg/dl. In conclusion, AOC postpartum adversely affects reproductive performance such as AI submission rate, pregnancy rate, interval to first AI and first AI conception rate; moreover, an increase or decrease in the BUN levels beyond 15-19.9 mg/dL leads to the AOC postpartum.

• 한국임상수의학회지
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• 제25권4호
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• pp.280-285
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• 2008

한우에서 분만 전, 분만 시 및 분만 후의 body condition score(BCS)와 이후의 번식능력과의 상관관계를 조사하였다. 2년 6개월에 걸쳐 33두의 한우에서 얻은 73회의 분만 산차(평균 $2.0\pm0.9$)에 대한 BCS 평가를 위하여 분만 2개월 및 1개월 전, 분만 시, 그리고 분만 후 7개월까지 매 1개월 간격으로 수행하였다. 분만 전 현저한 BCS의 감소에 대해서도 조사하였다. 분만 후 임신까지의 간격과 분만 1개월 전, 분만 시 그리고 분만 1개월 및 2개월 후 BCS 사이의 상관관계에 대하여 Pearson correlation analysis를 이용하여 분석하였다. 분만 후 임신까지의 간격과 분만 전 BCS의 감소에 대한 상관관계도 또한 분석하였다. 분만 후 임신까지의 간격은 분만 1개월 전 BCS (r=0.389, P=0.0007) 및 분만 전 BCS의 감소(r=0.488, P<0.0001)와는 정의 상관관계를 나타내었으나, 분만 시(r=-0.070, P=0.56)그리고 분만 1개월(r=0.107, P=0.37) 및 2개월 후(r=0.102, P=0.39)의 BCS와는 유의적인 상관관계를 나타내지 않았다. 분만 전 BCS의 감소는 분만 1개월 전 BCS와 정의 상관관계를 나타내었다(r=0.587, P<0.0001). 본 연구의 결과는 한우에서 분만 1개월 전 BCS는 이후의 번식능력을 예측하는데 유용한 기준으로 활용될 수 있으며, 또한 분만 전 비만 및 과도한 BCS의 감소의 예방은 번식능력을 증진시킬 수 있음을 보여 준다.

• Asian-Australasian Journal of Animal Sciences
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• 제14권11호
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• pp.1516-1519
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• 2001

The data consisted of 369 lactation records for calvings over a sixteen-year period (1972-1987) and included only cows that had normal milk records. The data were analysed using a linear model containing the fixed effects of parity, year of calving and season of calving. The least squares means${\pm}$S.E. were $1,273{\pm}58.4kg$ for milk yield, and for post-partum body weight (kg) at 2, 3 and 4 months after calving were $343.40{\pm}3.96$, $346.10{\pm}4.10$ and $352.54{\pm}4.26$, respectively. With the exception of season of calving, the effects of parity and year of calving were significant (p<0.01) on the performance of the animals. Thus, the mean-milk yields 1162, 1351 and 1350, were similar for pre-, peak- and post rainy seasons, respectively. On the other hand, as parity increased from 1 to 3, milk yield also increased, but thereafter, there was a gradual decline in milk yield. Similarly, post-partum body weight also increased with parity. However, no consistent pattern for year effect was observed which probably was a reflection of the variation in climatic conditions, or forage quality and/or availability. The phenotypic correlations between milk yield and post-partum body weights were negative and small (ranging from -0.01 to -0.08). However, high milk production in cows was associated with longer calving interval. The implications from the phenotypic correlations are suggestive of one or two possibilities. Firstly, selection for increased body weight may actually result in decreased milk yield. Also, a substantial genetic antagonism may exist between milk yield and fertility in the crossbred cows. Therefore, it is important that selection to improve milk production should take into consideration the reproductive performance of the cows.

• Journal of Animal Science and Technology
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• 제44권2호
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• pp.191-200
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• 2002

본 연구는 1986년부터 1995년도 사이에 한우개량단지의 한우 암소에 대하여 조사된 번식성적에 근거하여 한우의 번식형질에 미치는 환경요인의 효과를 추정하기 위하여 실시하였으며, 분석된 결과를 요약하면 다음과 같다. 1) 평균능력에서 초종부일령은 466.11${\pm}$5.72일, 초임일령은 480.10${\pm}$6.15일, 초산일령은 742.79 ${\pm}$7.48일, 분만후 초종부일령은 64.97${\pm}$1.42일, 공태일수는 72.06${\pm}$1.73일, 번식간격은 355.93 ${\pm}$1.92일, 임신기간은 285.38${\pm}$0.42일 및 수태당 종부회수는 1.21${\pm}$0.02회였다. 2) 지역별 각 형질에 대한 범위는 초종부일령은 447.62${\pm}$5.94-490.72${\pm}$5.94일, 초임일령은 464.27${\pm}$6.38-505.20${\pm}$6.39일, 초산일령은 721.91 ${\pm}$ 7.85-772.75${\pm}$7.80일, 분만 후 초종부일령은 62.27${\pm}$1.55～68.97${\pm}$1.74일, 공태일수는 69.74${\pm}$ 1.97-74.36${\pm}$2.27일, 번식간격은 352.71${\pm}$2.18-359.64${\pm}$2.09일, 임신기간은 284.52${\pm}$0.42-286.04 ${\pm}$0.47일 및 수태당 종부회수는 1.11${\pm}$0.02-1.30 ${\pm}$0.02회였다. 3) 초종부일령은 혈통등록우가 가장 길었고 상위등록일수록 일령이 빨라지는 경향이 있 었다. 수태당 종부회수는 상위등록우로 갈수록 종부회수가 많게 추정되었다. 4) 분만후 초종부일수는 2산차에서 가장 길었으며 산차가 진행될수록 줄어드는 경향을 보였다. 수태당 종부회수는 산차가 진행될수록 적어지는 경향을 보였다. 5) 분만년도가 1987년부터 1995년까지 경과할수록 분만후 초종부일수, 공태일수 및 번식 간격이 길어지고 수태당 종부회수는 많아지는 경향이 있었다. 6) 분만후 초종부 일수, 공태일수 및 번식간격은 봄과 여름에 분만한 소들에서 가을과 겨울에 분만한 소들에 비하여 다소 짧게 추정되었다. 수태당 종부회수는 봄과 여름에 분만한 소들에 비하여 가을과 겨울에 분만한 소들에서 더 많은 경향이 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제13권6호
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• pp.837-841
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• 2000

The study was conducted at semi urban area in Bangladesh. It was based on a field survey by a prepared questionnaire. Various milking and reproduction performance were analyzed. The effects of grazing hour were found significant on age at weaning (AW) (p<0.001), age at first heat (AFH) (p<0.001), age at first conception (AF conception) (p<0.001), age at first calving (AF calving) (p<0.001), post partum heat period (PPHP) (p<0.001), calving interval (CI) (p<0.001), lactation length (LL) (p<0.001) and total lactational production (TLP) (p<0.001). The effects of concentrate feed were significant on AW (p<0.01), AFH (p<0.01), AF conception (p<0.001), AF calving (p<0.001), PPHP (p<0.001) CI (p<0.001), LL (p<0.001) and TLP (p<0.001). The effects of management level were significant on AW (p<0.001), PPHP (p<0.01), CI (p<0.001), daily milk yield (DMY) (p<0.05) and TLP (p<0.001). The overall mean values were $251.88{\pm}2.97$ days for AW, $37.29{\pm}0.33$ months for AFH, $38.43{\pm}0.34$ months for AF conception, $47.62{\pm}0.34$ months for AF calving, $1.30{\pm}0.02$ number of services per conception (NSPC), $191.57{\pm}3.92$ days for PPHP, $17.02{\pm}0.15$ months for CI, $2.49{\pm}0.06kg$ for DMY, $247.23{\pm}3.51$ days for LL and $590.40{\pm}15.00kg$ for TLP.

• 한국임상수의학회지
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• 제36권1호
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• pp.68-73
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• 2019

We determined the risk factors for displacement of the abomasum (DA), and the relationships between DA and postpartum disorders, milk yield, and reproductive performance in dairy cows. Initially, we identified the risk factors for DA using data regarding cow health and calving season from 2,208 lactations. Then, we compared the incidence of postpartum disorders, culling, death, and reproductive performance between cows with DA and their control herdmates (each n = 57). In addition, serum metabolites concentrations and milk yield were compared between cows with DA and controls (each n = 33). Ketosis (odds ratio [OR] = 9.27, p < 0.0001) and twin calves (p = 0.06) increased the risk of DA. Cows with a parity of three had a higher risk (OR = 5.23, p < 0.01) of DA than primiparous cows. Serum total cholesterol concentration was lower but non-esterified fatty acid, ${\beta}-hydroxybutyrate$, and alanine aminotransferase concentrations were higher after calving in cows with DA than in controls (p < 0.05). The removal rate from the herd by 2 months after calving was higher (p < 0.05) but milk yield 1 and 2 months after calving (p < 0.01) and the rate of first insemination by 150 days postpartum were lower (hazard ratio = 0.49, p < 0.05) in cows with DA than controls. In conclusion, higher parity, twin calves, and ketosis are risk factors for DA in dairy cows, which is associated with a higher removal rate from the herd, lower milk yield, a longer calving to first insemination interval, and unfavorable levels of metabolites related to energy and liver function.

• Asian-Australasian Journal of Animal Sciences
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• 제5권3호
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• pp.427-433
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• 1992

Reproduction and growth to weaning were compared for Brahman crossbred (BX) and a local strain of South-East Asian cattle, "Javanese Zebu" (JZ) and their reciprocal crosses at "Erap" in the humid equatorial lowlands of Papua New Guinea. Forty heifers of each breed were mated continuously, half to bulls of each breed, for five years. BX calved first at 35 months while JZ calved at 31 months. Subsequent calving intervals were very short, at 370 and 341 days. JZ cows weighed about two thirds of the BX cattle at each stage of reproduction. Birth weights and growth to weaning were : BX 35 kg and 0.68 kg/d ; BX male $\times$ JZ female 29.3 kg and 0.53 kg/d ; JZ male $\times$ BX female 30.8 kg and 0.61 kg/d ; JZ 25 kg and 0.50 kg/d. The combination of small cow size, short calving interval and rapid calf growth resulted in the BX male $\times$ JZ female being the most efficient producer, in kg of calf weaned per cow mated per year while the reciprocal cross was the least efficient ; both straight-breds were equal and intermediate. These data show that indigenous equatorial cattle may not be inferior under good grazing conditions. For all traits, breed interactions (heterosis) was small and non-significant.

• 한국임상수의학회지
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• 제33권6호
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• pp.351-355
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• 2016

This study was conducted to investigate reasons for culling of Chungcheong dairy herds and to investigate the relationships between cow parity, interval from calving to culling, or season and culling reasons. Lactation data from 826 cows on 9 dairy farms from 2013 to 2015, including reasons for culling, dates of birth, last calving, and culling, were analyzed. The overall culling rate was 29.8% (246/826), with mammary problems (23.2%) being the most prevalent reason for culling, followed by infertility (14.2%) and downer cow syndrome (11.0%). The culling rate varied among farms (18.8-43.1%, p < 0.05), but was greater in parity $4{\leq}(40.7%)$ than parities 1, 2, or 3 (17.9-23.6%), whereas the rate was less frequent during mid lactation (21.1%) than in early (36.2%) or late (42.7%) lactation. Moreover, the culling rate was greater during summer (35.8%) than other seasons (20.3-23.2%). Mammary problems, downer cow syndrome, and metabolic disorders were the more common reasons for culling during early lactation, whereas infertility was predominant during late lactation. Our data show that the culling rate in Chungcheong dairy herds was associated with cow parity, interval from calving to culling, and season, with the main reasons for the removal of cows from dairy herds being mammary problems, infertility, and downer cow syndrome.