• Journal of Embryo Transfer
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• v.31 no.3
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• pp.273-279
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• 2016

The Korean native cattle, Hanwoo, is the most popular breed of beef cattle in Korea. However, the reproductive performance data are limited although reproduction is one of the most economically and biologically important in beef production. Therefore, this study was undertaken to investigate reproductive performance parameters including calving interval, parity for life time production. Data collected from 206,827 calvings were analyzed. There were no significant differences in calving interval and gestation days as parity increased from 2nd and 13rd parity cow, from spring to winter. However, we found a dramatic increase in calving interval after year 2000. About 1 month were increased per year ( y = 30.578x + 344.45 $R^2=0.9157$). Interestingly, we observed that parities for life time can be affected by birth weight. Calves with 23 kg at birth showed highest parities, $3.4{\pm}2.0$ times. In summary, this study provides valuable data on reproductive performance of Hanwoo and the data presented here can be used as a standard target for optimising and enhancing reproductive performance.

• The Korea Swine Journal
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• v.20 no.5 s.225
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• pp.155-158
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• 1998

• 종축개량
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• v.12 no.10 s.80
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• pp.43-47
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• 2007

• Journal of agriculture & life science
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• v.50 no.5
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• pp.183-188
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• 2016

This experiment was conducted to investigate the effects of artificial insemination(AI) frequency on reproductive performance of sows. A total of 48 F1 sows(Yorkshire×Landrace) were allocated to 1 of 4 treatments using completely randomized design(CRD). Four experimental treatments were AI frequency from one to four times(AI1, AI2, AI3, AI4) respectively. Estrus detection was done at approximately 09:00 and 21:00 daily by applying back pressure to females with the presence of a mature boar and the weaning to estrus interval(WEI) of all sows were 5~6 day. Sows detected in estrus were mated at 12 hour after and mating interval was 12 hour by treatments. This experiment demonstrated that the lowest farrowing rate was observed AI3 treatment. Frequency of AI did not influence on reproductive performance when WEI was 5-6 day. No significant differences were observed on litter size, born alive and litter birth weight. Consequently, decreased AI frequency did not have any detrimental effect on reproductive performance when estrus detection was adequate. Decreased AI frequency could reduce cost of production of pigs when sows showed normal reproductive performance.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.91-91
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• 2003

소의 생산성 향상을 위해서는 번식효율의 증진과 개체의 유전능력을 충분히 발휘할 수 있도록 적절한 사양관리를 실시하여야 한다. 특히 번식관리는 발정관찰로부터 출발하며 발정관찰의 원활한 수행이 없이는 좋은 번식성적을 기대할 수 없다. 그러나 발정관찰은 많은 시간과 노동력이 요구되며 이로 인하여 발정관찰방법과 보조기구가 개발되어 시판되고 있다. 본 연구는 발정관찰의 편리성과 정확성을 개선하고자 (주)한경게놈텍에서 개발한 무인발정관리시스템(HMS)을 활용하여 발정발현양상을 분석하였다. 실험에 공시된 시험축은 안성인근 지역에서 사육되는 35두의 홀스타인 경산우를 선발하였으며, 발정주기에 관계없이 무작위로 선발하여 미근부에 감지센서를 부착하고 감지시간을 0.1초 이상으로 설정하여 매직닥터를 설치하였다. 발정감지횟수와 감지시간의 분석은 승가허용 감지시간이 0.5초 이상인 것만을 승가허용으로 간주하고 분석하였다.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2006.10a
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• pp.104-105
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• 2006

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.78-78
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• 2002

Meat type 의 돼지 개량으로 체조직내 지방함량의 감소에 의하여 종빈돈의 번식성적 저하 및 경제수명이 단축됨에 따라 후보종빈돈의 등지방 두께가 첫발정 및 첫수정 시기에 미치는 영향을 조사하여 후보종빈돈의 번식관리 기술개발에 기초자료로 활용코자 하였다. 공시축은 충남 천안시 소재 중소규모의 양돈장에서 사육하고 있는 후보종빈돈 47두에 대하여 첫 발정일령 및 첫수정일령의 조사와 등지방 두께를 측정하였다. 첫발정일령은 등지방 두께가 13 -16㎜일 때 생후 182.1±17.3일, 17-20㎜일 때 생후 173.0±18.4일, 21-22㎜일 때 생후 162.2±17.8 일로 등지방 두께가 앓을 수록 첫발정시기가 늦어졌다. 첫수정일령은 등지방 두께가 13-16㎜일 때 생후 211.8±14.8 일, 17-20㎜일 때 생후 203.0±24.3일, 21-23㎜ 일 때 생후 195.4±13.2일로 등지방 두께가 밟을 수록 첫수정 시기가 늦어졌다. (중략)

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.277-284
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• 2020

This study was undertaken to determine the effects of dietary supplementation with herbal extracts of Portulaca oleracea L. (POL), on the reproductive performance, blood profiles, immune response, and fecal microbial population in multiparous sows. On the basis of initial body weight, a total of 20 multiparous sows (Landrace×Yorkshire; 229.2±1.15 kg) were randomly allotted to 2 treatment groups, each including 10 replicates. The dietary treatments were administered during the lactation period, and included a corn-soybean meal-based diet (control group) and diet supplemented with 0.05% POL. Throughout the experimental period, no significant differences were observed between the two diet groups for body weight, backfat thickness, and reproductive performance. Blood profile analysis revealed significantly decreased lymphocyte concentrations and IL-1β levels (p<0.05), and increased serum IgG levels (p=0.051), of sows consuming the POL supplemented diet. Furthermore, coliform counts tended to decrease in sows consuming diet supplemented with POL (p=0.063). Taken together, our results indicate that POL supplemented diets exert beneficial effects on blood profiles, immune response, and fecal microflora of multiparous sows, without any negative effect on the reproductive performance.

• Korean Journal of Ornithology
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• v.25 no.2
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• pp.69-76
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• 2018

Sexual dimorphism in birds refers to male-female differences in body size, plumage, color and/or behavior. In general, many seabirds, including the family of Laridae, are monomorphic in plumage-color, which makes the determination of sex difficult in the field because both parents also tend to share a great portion of parental care. The development of an inexpensive sexing tool facilitates understanding the degree of sex-specific parental care in the evolution of the life history. Here, we developed a non-invasive method for the determination of sex using the bill-head morphometric of known captive pairs and applied this tool to wild pairs to document factors underlying male-female parental care during the incubation period of Saunders's gulls (Saundersilarus saundersi). Males exhibited relatively larger bill-head ratios than their mates within naturally formed pairs in captivity, resulting in the determination of sex in12 wild pairs at the nest during the incubation period. Males and females equally shared the incubation role during the daytime, attending the nest at a high rate of 95%. However, the male's proportion of nest attentiveness greatly increased with time towards sunset, presumably reflecting the male duty for nighttime incubation. The present study provides a non-invasive method for the determination of sex in a monomorphic seagull species and highlights how male-female incubation behavior is associated with time of the day, rather than other ecological conditions.

• Korean Journal of Animal Reproduction
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• v.24 no.1
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• pp.19-33
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• 2000

Eighty dairy farms (38 farms responded) in Palmerston North area of New Zealand were questioned by mail questionnaire on: 1) general characteristics, 2) milk yield and feed supplementary, 3) reproductive efficiencies (12 questions) and 4) reproductive disorders (12 questions) from February to July, 1998. Among those 4 items, the reproductive efficiencies (3) and disorders (4), various diseases and culling rates were surveyed and analyzed for Korean dairy farmers (especially in Cheju island) and compared with New Zealand. The results are as follows: 1. Fifteen farms in 38 dairy farms relied entirely on artificial insemination, the rest of 23 dairy farms (60.5%) raised 5∼6 bulls to increase conception rate. The dairy farmers in Palmerston North used artificial insemination from Oct 4th to Dec 10th for 42.8 days, and then used bulls from that point to coming Jan 10th for 41.4 days. The submission rate within 3, 6 and 10 weeks following the initiation of AI season was 84.7, 93.9 and 97.9% respectively. 2. The average age of heifers at the first estrus, pregnancy and calving was 11.0, 18.0 and 24.7 months respectively, and an average 1.4 estrus cycles were required for conception. The intervals of estrus recurrence and the following conception after calving were 38 and 68 days respectively. 3. Among inseminated cows, calving, abortion and empty cow was 90.9, 1.6 and 7.4% respectively. Calving rate decreased according to increasing farm size, while the number of empty cows decreased. 4. Stillbirth, retained placenta and delivery abnormalities were 5.3, 3.7 and 5.5% respectively, not different depend on herd size. 5. The incidence of milk fever, grass tetany, and ketosis was 3.6, 3.0 and 1.0%, respectively. The delivery abnormality and mastitis treated with medicine were 3.1 and 6.7%, but decreased according to farm size. Lameness was 8.6% on average, but over 10% in farms which has more than 400 milking cows. 6. Among the culled cows (15.5% of the total), those culled due to an old age, lameness and other diseases were 2.9, 1.8 and 4.3% respectively and those culled due to low milk production, reproductive abnormality reduced with farm size. 7. Compared with the data collected in Korea, the reproductive efficiency was better, and lameness, metabolic problem and culling rate were higher in New Zealand