• Asian-Australasian Journal of Animal Sciences
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• v.31 no.4
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• pp.537-547
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• 2018

Objective: This study was performed to understand transcriptional changes in the genes involved in gluconeogenesis and glycolysis pathways following castration of bulls. Methods: Twenty Korean bulls were weaned at average 3 months of age, and castrated at 6 months. Liver tissues were collected from bulls (n = 10) and steers (n = 10) of Korean cattle, and hepatic gene expression levels were measured using quantitative real-time polymerase chain reaction. We examined hepatic transcription levels of genes encoding enzymes for irreversible reactions in both gluconeogenesis and glycolysis as well as genes encoding enzymes for the utilization of several glucogenic substrates. Correlations between hepatic gene expression and carcass characteristics were performed to understand their associations. Results: Castration increased the mRNA (3.6 fold; p<0.01) and protein levels (1.4 fold; p<0.05) of pyruvate carboxylase and mitochondrial phosphoenolpyruvate carboxykinase genes (1.7 fold; p<0.05). Hepatic mRNA levels of genes encoding the glycolysis enzymes were not changed by castration. Castration increased mRNA levels of both lactate dehydrogenase A (1.5 fold; p<0.05) and lactate dehydrogenase B (2.2 fold; p<0.01) genes for lactate utilization. Castration increased mRNA levels of glycerol kinase (2.7 fold; p<0.05) and glycerol-3-phosphate dehydrogenase 1 (1.5 fold; p<0.05) genes for glycerol utilization. Castration also increased mRNA levels of propionyl-CoA carboxylase beta (mitochondrial) (3.5 fold; p<0.01) and acyl-CoA synthetase short chain family member 3 (1.3 fold; p = 0.06) genes for propionate incorporation. Conclusion: Castration increases transcription levels of critical genes coding for enzymes involved in irreversible gluconeogenesis reactions from pyruvate to glucose and enzymes responsible for incorporation of glucogenic substrates including lactate, glycerol, and propionate. Hepatic gluconeogenic gene expression levels were associated with intramuscular fat deposition.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.7
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• pp.1017-1035
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• 2018

The European Union (EU) is the world's third largest producer of beef. This contributes to the economy, rural development, social life, culture and gastronomy of Europe. The diversity of breeds, animal types (cows, bulls, steers, heifers) and farming systems (intensive, extensive on permanent or temporary pastures, mixed, breeders, feeders, etc) is a strength, and a weakness as the industry is often fragmented and poorly connected. There are also societal concerns regarding animal welfare and environmental issues, despite some positive environmental impacts of farming systems. The EU is amongst the most efficient for beef production as demonstrated by a relative low production of greenhouse gases. Due to regional differences in terms of climate, pasture availability, livestock practices and farms characteristics, productivity and incomes of beef producers vary widely across regions, being among the lowest of the agricultural systems. The beef industry is facing unprecedented challenges related to animal welfare, environmental impact, origin, authenticity, nutritional benefits and eating quality of beef. These may affect the whole industry, especially its farmers. It is therefore essential to bring the beef industry together to spread best practice and better exploit research to maintain and develop an economically viable and sustainable beef industry. Meeting consumers' expectations may be achieved by a better prediction of beef palatability using a modelling approach, such as in Australia. There is a need for accurate information and dissemination on the benefits and issues of beef for human health and for environmental impact. A better objective description of goods and services derived from livestock farming is also required. Putting into practice "agroecology" and organic farming principles are other potential avenues for the future. Different future scenarios can be written depending on the major driving forces, notably meat consumption, climate change, environmental policies and future organization of the supply chain.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.2
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• pp.151-156
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• 2013

Hanwoo (Also known as Korean native cattle; Bos taurus coreanae) have been used for transportation and farming for a long time in South Korea. It has been about 30 yrs since Hanwoo improvement began in earnest as beef cattle for meat yield. The purpose of this study was to determine the trend of improvement as well as to estimate genetic parameters of the traits being used for seedstock selection based on the data collected from the past. Hanwoo proven bulls in South Korea are currently selected through performance and progeny tests. National Hanwoo genetic evaluations are implemented with yearling weight (YW), carcass weight (CW), eye muscle area (EMA), backfat thickness (BF) and marbling score (MS). Yearling weights and MS are used for selecting young bulls, and EMA, BF, and MS are used for selecting proven bulls. One individual per testing room was used for performance tests, and five individuals per room for progeny tests. Individuals tested were not allowed to graze pasture, but there was enough space for them to move around in the testing room. Feeds including roughages and minerals were fed ad libitum, and concentrates were provided at the rate of about 1.8% of individual weight. Overall means of the traits were $352.8{\pm}38.56$ kg, $335.09{\pm}44.61$ kg, $77.85{\pm}8.838\;cm^2$, $8.6{\pm}3.7$ mm and $3.293{\pm}1.648$ for YW, CW, EMA, BF and MS. Heritabilities estimated in this study were 0.30, 0.30, 0.42, 0.50 and 0.63 in YW, CW, EMA, BF and MS, respectively, which are similar to results from previous research. Yearling weight was 315.54 kg in 1998, and had increased to 355.06 kg in 2011, resulting in about 40 kg of improvement over 13 yrs. YW and CW have improved remarkably over the past 15 yrs. Breeding values between 1996 and 2000 decreased or did not change much, but have moved in a desirable direction since 2001. These improvements correspond with the substantial increase in use of animal models since the late 1990s in Korea. Hanwoo testing programs have practically contributed to the improvement in aspects of quality and quantity. In sum, the current selection system is good enough to accommodate circumstances where fewer sires are used on many more cows. Although progeny tests take longer and cost more, they seem to be appropriate under the circumstances of the domestic market with its higher requirement for better meat quality. Consequently, accumulative data collection, genetic evaluation model development, revision of selection indices, as well as cooperation among farms, associations, National Agricultural Cooperative Federation, universities, research institutes, and government agencies must be applied to the Hanwoo selection program. All these efforts will assist the domestic market to secure a competitive position against imported beef under Free Trade Agreement trade system and will provide farmers with higher profits as well as the public with a higher quality of beef.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.5
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• pp.716-722
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• 2013

The aim of the present study was to determine the influence of age of animal, hot carcass weight, pH, conformation and fat class on basic beef quality attributes (tenderness, sarcomere length, basic chemical composition, marbling and colour) in a group of purebred animals. The object of the study was beef of Limousin bulls (25 to 27 months, hot carcass weight - $432{\pm}31$ kg, "U" conformation class, "2"-"3" fat class). Analysed cuts were Infraspinatus muscle from the blade and Longissimus dorsi muscle from the cube roll and the striploin. Tenderness was analysed with universal testing machine, colour - chromometer analysis, sarcomere length - microscopic method, basic chemical composition - near-infrared spectroscopy and marbling - computer image analysis. No differences in tenderness and sarcomere length were observed within the age groups of Limousin bulls (age of 25, 26, 27 months) (p>0.05). Moisture (p = 0.0123) and fat (p = 0.0250) content were significantly different for meat of animals slaughtered at the age of 25 and 27 months. No influence of pH value on tenderness was observed, but at the same time, influence on sarcomere length (p = 0.039) and $b^*$ component of colour (0.045) was found. For "U" conformation class, in subclasses, as well as for fat classes "2"-"3", there were no differences in tenderness, sarcomere length and colour components. Higher fat content was observed in the higher fat class, rather than in lower, however this feature was not associated with marbling.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.7
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• pp.951-960
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• 2018

Hanwoo cattle are an important food source in Korea and their supply can have a major impact on meat availability for Korean consumers. The Hanwoo population was 1.8 million head in 2005 and gradually increased to 2.6 million in 2015. Per capita beef consumption has also increased, to 11.6 kg per year in 2015, and is expected to continue to increase. Because intramuscular fat percentage is a critical contributor to meat quality, Hanwoo cattle are fed a high-energy corn-based diet for long fattening periods. Long fed diet causes significant alterations in fat percentage in the loin muscle and other areas of the carcass. However, these long feeding periods increase feeding costs and beef prices. Recently, there has been increased Korean consumer demand for lean beef which has less fat, but is tender and priced more reasonably. These consumer demands on the Korean beef industry are driving differing beef production systems and also changes to the beef grading methodology. Korean government has made a significant investment to select bulls with favorable production traits using progeny testing. Progeny tested bull semen has been disseminated to all Hanwoo farmers. A beef traceability system has been employed for all cattle breeds in Korea since 2009. Hanwoo cattle are ear-marked with a 12-digit identification number from birth to slaughter. This number allows traceability of the management history of individual cattle, and also provides information to consumers. Traceability including management information such as herd, farm, year of birth, and carcass data can determine estimated breeding values of Hanwoo. For a sustainable Hanwoo industry, research scientists in Korea have attempted to develop feeds for efficient fattening periods and precision feeding systems based on genetic information for Hanwoo cattle. These initiatives aim to Korean consumer demands for beef and provide more precision management in beef production in Korea.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.2
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• pp.255-260
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• 1994

Calving records of 107 heifers from two breed groups were used to identify the major factors contributing to calving difficulty (dystocia) and compare the influence of pelvic diameters, weight and height of heifers measured after breeding and before calving on dystocia. The horizontal and vertical pelvic diameters, hip height and weight of heifers were measured two months after breeding and again two months before calving. Snell transformed calving difficulty scores (0 = normal to 100 = surgical intervention) were used in analyzing the data by analysis of covariance. Body condition score of the heifer, sire birth weight of the calf, birth weight of the calf, and ratio of calf birth weight to pelvic area all had significant effects on dystocia. Calf birth weight, ratio of calf birth weight to pelvic area, and heifer's condition score were especially important. However, sex of calf did not have a significant influence on dystocia. Generally, the variables measured before calving accounted for a higher proportion of variation in dystocia than those measured after breeding. Thus, based on the relative importance of the major factors affecting dystocia, it is suggested that selection of bulls with low birth weight for breeding on normal size heifers with optimum body condition score, and well developed pelvic opening, would be effective in reducing the incidence and severity of dystocia in beef heifers.

• Journal of Animal Science and Technology
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• v.52 no.2
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• pp.83-90
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• 2010

Hanwoo proven bulls have been selected since 1987 and consequently contributed to farmers for the improvement of beef cattle in Korea. The demand for the quality beef production as well as higher production efficiency was erupted after early 2000 as relatively cheap imported beef released. Therefore the pressure on the reformation of selection index for Hanwoo proven bulls have been piled up to furnish with Hanwoo's competitive. A total of 734 progeny test data were analyzed to select traits and their weights in the selection index to meet the beef market requirement. Regression analysis with stepwise selection method was used to select proper trait and its weight for selection index. A series of computer simulation was carried out to compare the currently using selection index with the alternate two selection indices proposed in this study. New selection index using standardized breeding values of Loin eye Muscle Area (LMA), Backfat Thickness (BFT) and Marbling Score (MS) with weight ratio 1:-1:6 was proposed. Results showed higher performance in improving MS and BFT gain by 22% and 31% still holding 86%~89% of genetic gain achieved by current index in Carcass Weight (CW) and LMA when new selection index was fitted. Because, new index has little consideration for production cost, further research should be performed to build selection index including cost and income simultaneously.

• Food Science of Animal Resources
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• v.30 no.2
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• pp.321-327
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• 2010

The effect of cattle sex (cow, bull, and steer) on carcass traits of quality grade factors, physicochemical, and sensory traits of Longissimus Dorsi in Hanwoo was evaluated. Carcass traits of 42,113 heads were collected nation-wide and 257 heads were slaughtered to analyze beef quality. Sex affected significantly marbling score, meat color, fat color, texture, maturity, and quality grade of Hanwoo (p<0.05). Hanwoo steer carcasses had the highest marbling score (5.02), maturity (2.17), and texture (1.31) than those of cows and heifers. Crude fat of steers was higher than that of other cows and bulls. Steers showed the highest $L^*$(39.01), Warner-Bratzler shear force (4.03 kg), and water holding capacity (57.08%), however, there was no significant differences between those of cows and bulls. Ultimate$pH_{24}$ was shown difference among sex (5.58-5.69), however, the values remained within normal range. In sensory evaluation analyses, sex affected significantly tenderness, juiciness, and flavor (p<0.05). Also, the over all acceptability of steer beef was significantly higher than that of cow and bull beef. These results could be used as fundamental data set for further research activities to elevate Hanwoo beef qualities (p<0.05).

• Food Science of Animal Resources
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• v.30 no.6
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• pp.905-909
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• 2010

Two sets of data on carcass traits and beef cut parameters were used to investigate the relationships between carcass and beef cut measurements, which can be used to make predictions of retail cut percentages. One set had a total of 1,141 measurements of Hanwoo cattle of three different sex origins, which were slaughtered in an abattoir located at the National Institute of Animal Science, RDA, Korea from 1996 to 2008. To develop prediction models for retail cut percentage with higher accuracies than the current model, another set consisting of a total of 13,389 records of carcass and beef cut traits were collected from 30 abattoirs and butcheries in Korea from 2008 to 2009. Bulls yielded heavier and leaner carcasses than steers. High correlation coefficients were estimated between amount of body fat and percent retail cut (-0.82) as well as between back fat thickness (BF) and percent retail cut (-0.62). The amount of retail cut, however, was highly correlated with body weight before slaughter (BW, 0.95) or with cold carcass weight (CWT, 0.94). Relationships between percent retail cut and measurable beef yield traits, BF, loin eye area (LEA) or CWT varied by sex class, which must be considered for development of a prediction model with high accuracy. Models of data for all breeds and sexes fit the effects of breed, sex, and interaction of abattoir by butchers, whereas models of data for each breed and sex fit the effect of interaction of abattoir by butcher only. Due to possible future changes in back fat control, we performed a log transformation of BF. Our new models fit better than the currently used model.

• Korean Journal of Veterinary Service
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• v.28 no.1
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• pp.31-38
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• 2005

To examine the prevalence and type of lesions in urinary bladder of Korean cattle, a random sampling survey was performed at a Jeonju abattoir in September 2000 and January 2001. Collected urinary bladder were examined grossly and histopathologically and the patterns of disease were investigated with season and sex. Of 735 cattle(99 bulls and 246 cows in September and 141 bulls, 3 steers, and 246 cows in January) surveyed, $26.3\%$ cattle with evident lesions were found. The most common gross finding was urolithiasis of urinary bladder($23.8\%$). Other lesions included hemorrhage($5.9\%$), congestion($4.1\%$), hematuria($2.7\%$), pyuria($0.7\%$), hyperplasia($0.5\%$). Urinary calculi collected in this study contained 80 to $90\%$ of calcium oxalate and 10 to $20\%$ of struvite, with or without $20\%$ of cystine and $10\%$ of uric acid. This study on urolithiasis and pathology of urinary bladder of slaughtered Korean cattle revealed subclinical aspects and management problem in Korean beef product.