• Journal of Animal Science and Technology
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• v.65 no.2
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• pp.324-335
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• 2023

Korea, located in East Asia in the northern hemisphere, is experiencing severe climate changes. Specifically, the heat stress caused by global warming is negatively affecting the dairy sector, including milk production and reproductive performance, as the major dairy cattle Holstein-Friesian is particularly susceptible to heat stress. Here, we collected artificial insemination and pregnancy data of the Holstein and the Jersey cows from a dairy farm from 2014 to 2021 and analyzed the association between the conception rate and the temperature-humidity index, calculated using the data from the closest official weather station. As the temperature-humidity index threshold increased, the conception rate gradually decreased. However, this decrease was steeper in the Holstein breed than in the Jersey one at a temperature-humidity index threshold of 75. To evaluate the effects of heat stress on the oocyte quality, we examined the nuclear and cytoplasmic maturation of Holstein (n = 158, obtained from six animals) and Jersey oocytes (n = 123, obtained from six animals), obtained by ovum pick-up. There were no differences in the nuclear maturation between the different conditions (heat stress: 40.5℃, non- heat stress: 37.5℃) or breeds, although the Holstein oocytes seemed to have a lower metaphase II development (p = 0.0521) after in vitro maturation under heat stress conditions. However, we found that the Holstein metaphase II oocytes exposed to heat stress presented more reactive oxygen species and a peripheral distribution of the mitochondria, compared to those of the Jersey cattle. Here, we show that weather information from local meteorological stations can be used to calculate the temperature-humidity index threshold at which heat stress influences the conception rate, and that the Jersey cows are more tolerant to heat stress in terms of their conception rate at a temperature-humidity index over 75. The lower fertility of the Holstein cows is likely attributed to impaired cytoplasmic maturation induced by heat stress. Thus, the Jersey cows can be a good breed for the sustainability of dairy farms for addressing climate changes in South Korea, as they are more resistant to hyperthermia.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.3
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• pp.219-221
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• 1995

Data on productive and reporductive performance of native cows maintained at Savar Dairy Farm, Central Cattle Breeding Station (CCBS), Savar, Dhaka, were collected from the periods of 1980-1988. The mean calving to first breeding during the second parity was longer (p < 0.01) than the fourth and fifth parities (152 vs 105 and 96 days respectively). There was no difference on the parameters like first breeding to conception, service period, gestation length, number of services per conception and total milk yield over the parities. The mean calving interval during the second parity was longer (p < 0.05) than the fourth and fifth parities. The mean lactation length during the first parity was longer (p < 0.01) than those of second, third, fourth and fifth lactations (317 vs 237, 266, 250 and 247 days respectively). The mean per day milk yield during the first lactation was lower (p < 0.01) than those of second, third, fourth and fifth lactations (1.88 vs 2.55, 2.75, 2.54 and 2.57 kg respectively). The mean dry period was longer in first lactation (p < 0.05) compared to third and fifth lactations (209 vs 141 and 129 days respectively).

• Journal of Biosystems Engineering
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• v.34 no.4
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• pp.228-233
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• 2009

In order to cut the round bale easily, a roughage cut-feeder for the round bale was developed in this study. This study consists of two parts. One is development of a cutting mechanism and a performance test reported in the previous paper. This is the second part of the study. For the study, recent trend of traditional cutting system was analyzed. Also, cost of the prototype cut-feeder was analyzed and determine the break-even point of farm size was determined by comparing with traditional method using a traditional cutter. A prototype cut-feeder was investigated with the fact that working performance, fiber length and shape of roughage and feeding quality was good. Operating cost of the prototype cut-feeder decreased rapidly with an increase of farm size. Break-even point in terms of farm size was 36 heads for beef and 28 heads for dairy. Also, costs estimated were 118,000 won/head year and 148,000 won/head year, respectively.

• Journal of Animal Science and Technology
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• v.59 no.2
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• pp.3.1-3.7
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• 2017

Background: The modelling of lactation curve provides guidelines in formulating farm managerial practices in dairy cows. The aim of the present study was to determine the suitable non-linear model which most accurately fitted to lactation curves of five lactations in 134 Gir crossbred cows reared in Research-CumDevelopment Project (RCDP) on Cattle farm, MPKV (Maharashtra). Four models viz. gamma-type function, quadratic model, mixed log function and Wilmink model were fitted to each lactation separately and then compared on the basis of goodness of fit measures viz. adjusted $R^2$, root mean square error (RMSE), Akaike's Informaion Criteria (AIC) and Bayesian Information Criteria (BIC). Results: In general, highest milk yield was observed in fourth lactation whereas it was lowest in first lactation. Among the models investigated, mixed log function and gamma-type function provided best fit of the lactation curve of first and remaining lactations, respectively. Quadratic model gave least fit to lactation curve in almost all lactations. Peak yield was observed as highest and lowest in fourth and first lactation, respectively. Further, first lactation showed highest persistency but relatively higher time to achieve peak yield than other lactations. Conclusion: Lactation curve modelling using gamma-type function may be helpful to setting the management strategies at farm level, however, modelling must be optimized regularly before implementing them to enhance productivity in Gir crossbred cows.

• Journal of Veterinary Science
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• v.19 no.6
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• pp.771-781
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• 2018

Staphylococcus aureus is one of the major pathogens causing bovine mastitis and foodborne diseases associated with dairy products. To determine the genetic relationships between human and bovine or bovine isolates of S. aureus, various molecular methods have been used. Previously we developed an rpoB sequence typing (RSTing) method for molecular differentiation of S. aureus isolates and identification of RpoB-related antibiotic resistance. In this study, we performed spa typing and RSTing with 84 isolates from mastitic cows (22 farms, 72 cows, and 84 udders) and developed a molecular prophage typing (mPPTing) method for molecular epidemiological analysis of bovine mastitis. To compare the results, human isolates from patients (n = 14) and GenBank (n = 166) were used for real and in silico RSTing and mPPTing, respectively. Based on the results, RST10-2 and RST4-1 were the most common rpoB sequence types (RSTs) in cows and humans, respectively, and most isolates from cows and humans clearly differed. Antibiotic resistance-related RSTs were not detected in the cow isolates. A single dominant prophage type and gradual evolution through prophage acquisition were apparent in most of the tested farms. Thus, RSTing and mPPTing are informative, simple, and economic methods for molecular epidemiological analysis of S. aureus infections.

• Journal of Animal Environmental Science
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• v.18 no.1
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• pp.19-24
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• 2012

The first objective of this study is to estimate emission coefficient of organic carbon regarding its inflow and discharge for dairy farm through reviewing domestic and foreign literature published or reported previously. Its second objective is to provide fundamental data to establish carbon cycle system related to livestock production. Based on literature review, emission coefficients by inflow of organic carbon into dairy farm were 5.9 ton C/head/year for feedstuff ingestion by milk cow, 2.3 ton C/head/year for recycling manure compost of milk cow to grassland, 318 g C/$m^2$/year for contents in grassland, 145 g C/$m^2$/year for contents in fodder crop, and 17 g C/$m^2$/year for $CO_2$ uptake by fodder crop, respectively. on the other hand, emission coefficients by discharge of organic carbon from dairy farm were 2,9 ton C/head/year for emission of $CO_2$ and $CH_4$ by respiration and burp of milk cow, 0.4 ton C/head/year for emission of $CO_2$ and $CH_4$ by decomposition of organic carbon in manure of milk cow, 440 g C/$m^2$/year for emission of $CO_2$ from grassland, and 0 for elution of organic carbon in grassland into underground water, respectively.

• Journal of Environmental Impact Assessment
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• v.13 no.1
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• pp.33-40
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• 2004

At Recent the number of livestock is rapidly increased and the scale of farm has changed to large operations in Korea. So the odors from livestock feeding operations have increased and become major environmental problem. The odor emission are dependent on the types of manure management system and the meteorological factors. This report presents the results of a questionnaire on the odor characteristics from livestock facilities for the beef, dairy, swine and poultry. It is founded that the impact by odors from the facilities for swine and poultry is higher than cow and dairy, and the odor intensity at morning is higher than other times.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.7
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• pp.1019-1025
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• 2004

The experiment was conducted to investigate the feasibility of using vegetable oil and non-fat dry milk (powdered milk) with skim milk for the preparation of dahi. In this experiment, six different types of dahi were prepared from whole milk, skim milk and admixture of non-fat dry milk with different levels of vegetable oil. The prepared dahi samples were subjected to physical, chemical and microbiological analysis to evaluate their quality. It was observed that the addition of non-fat dry milk and vegetable oil with skim milk improve the physical qualities (smell and taste, body and consistency, color and texture) of prepared dahi samples. Addition of non-fat dry milk and vegetable oil also improve the total solids, fat and protein content of dahi samples. It is concluded that the addition of vegetable oil at a rate of 4 to 6% together with 5% non-fat dry milk gave the best result.

• Journal of Veterinary Clinics
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• v.3 no.1
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• pp.235-241
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• 1986

The 587 Holstein cows which calved from January 1983 to December 1984 at an integrated dairy farm in Chung-Nam Province were investigated on incidence of retained fetal membrane. The results obtained were as follows ; 1. The incidence of retained fetal membrane was 15.2% (89 heads) among 587 heads which investigated. 2. The cows which calved in summer showed significantly higher incidence of retained fetal membrane than those which calved in winter(P<0.01), spring and autumn (P<0.05). 3. There was no difference in incidence of retained fetal membrane by calving number.

• Korean Journal of Veterinary Research
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• v.16 no.2
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• pp.115-119
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• 1976

The survey was carried out to investigate the average number of days from parturition to conception to 349 calving cases out of Holstein cows in total 154 heads observed. The results were as follows: 1. The average number of days from parturition to conception was $97.41{\pm}8.22$ and it's similar during the period from primipara to 4th calving order, and irregular during on and after 5th. 2. The average number of days from parturition to conception in calving month was observed all through the year: the prolongation among on April and July, and the brief duration among on January and March. 3. In the cases under 50 and 150 days after delivery, the distribution showed 53.56% and 83.91%, respectively, and it's about 20% between 70 and 90 days after delivery.