• Journal of Animal Reproduction and Biotechnology
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• v.34 no.3
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• pp.173-182
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• 2019

This study was performed to evaluate the effect of heat stress on the status of physiological responses, blood parameter, serum T3 and cortisol, and heat shock proteins (HSP 27, 70, and 90) of Hanwoo cattle. Six Hanwoo steers (242.8 ± 7.2 kg of BW) were housed in the climate-controlled respiration chambers. The experiment consisted of 7 days (control; 0 day) at thermoneutral (air temperature (Ta) of 15℃ and relative humidity (RH) of 60%; temperature-humidity index (THI) = 64), and by 3 and 6 days (treatment groups) at heat stress (Ta of 35℃ and RH of 60%; THI = 87). Body temperature of each parts (frank, rump, perineum and foot) and rectal temperature elevated in heat stress groups (3 days and 6 days) than the control group (0 day). Respiration rates increased in 3 days and 6 days (88.5 ± 0.96 bpm and 86.3 ± 0.63 bpm, respectively) from 0 days (39.5 ± 0.65 bpm). Feed intake significantly decreased in heat stress groups (3 days and 6 days, 3.7 ± 0.14 kg and 4.0 ± 0.15 kg, respectively) than the control group (0 day, 5.0 ± 0.00 kg). In addition, final BW significantly decreased in heat stress groups (3 days and 6 days, 211.8 ± 4.75 kg and 215.5 ± 3.50 kg, respectively) than the control group (0 day, 240.0 ± 25.00 kg). However, heat stress has no significant effect on blood parameter, serum T3 and cortisol. Nevertheless, heat stress increased HSPs mRNA expression in liver tissue, and serum concentration of HSPs. Despite Hanwoo cattle may have high adaptive ability to heat stress, our results suggested that heat stress directly effect on body temperature and respiration rate as well as serum and tissue HSPs. Therefore, we are recommended that HSPs could be the most appropriate indicators of Hanwoo cattle response to heat stress.

• Journal of Animal Science and Technology
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• v.46 no.3
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• pp.387-396
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• 2004

This experiment was carried out to investigate the effects of dietary vitamin C and E on carcass characteristics of Hanwoo steers. Thirty seven Hanwoo steers were randomly assigned to one of four treatments. The four treatments were control(vitamin E 20 IU/kg feed), vitamin C(vitamin C 0.1%/kg feed and vitamin E 20 IU/kg feed), vitamin E(vitamin E 220 IU/kg feed) and vitamin C plus E(vitamin C 0.1%/kg feed and vitamin E 220 IU/kg feed). Hanwoo steers were fed experimental diets for 3 months of the last finishing period. Animals fed the diet containing vitamin C plus E had higher(P<0.05) yield grade than those fed the other diets but quality grade was not different between animals fed the control diet and vitamin-supplemented diets. Proximate analysis in longissimus dorsi was not different between animals fed the control diet and vitamin-supplemented diets. Vitamin C concentration in longissimus dorsi was higher (P<0.05) in the animals fed the vitamin C diet and the vitamin C plus E diet than in those fed the control diet and the vitamin E diet. Vitamin E concentration in longissimus dorsi was higher(P<0.05) in the animals fed the diet supplemented with vitamin E and the diet supplemented with vitamin C plus E than in those fed the control diet and the vitamin C diet. Animals fed the diet supplemented with vitamin C was higher(P<0.05) in myristic acid, palmitic acid, palmitoleic acid and oleic acid in the longissimus dorsi than those fed the other diets, but linoleic acid in longissimus dorsi was higher(P<0.05) in the animals fed the vitamin E diet than those fed the other diets. However, saturated fatty acid and unsaturated fatty acid were not different between animals fed the control diet and vitamin-supplemented diets.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.2
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• pp.155-160
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• 2000

In order to understand the effects of sex or age on cellular characteristics of adipocytes from Hanwoo and sheep, samples were obtained from omental, subcutaneous, intermuscular and intramuscular adipose tissue depots of bulls, steers, heifers and cows in Hanwoo, and perirenal, omental and subcutaneous adipose tissues of fetal lambs, suckling lambs and wethers in sheep. In case of Hanwoo, mean diameter, surface area and volume of adipocytes from each depot were obtained by multisizer II (Coulter Co., UK). Osmium-fixed adipocytes were sized and counted using $560{\mu}m$ aperture. For samples obtained from sheep, cellularity was measured by using microscope and MCV program of Texas Instrument. Bulls had less subcutaneous and kidney fat than steers even though their slaughter and carcass weight were heavier. The amounts of fat from cows were greater in subcutaneous, kidney and internal organs than heifers. Steers had larger adipocytes in subcutaneous, intermuscular and intramuscular adipose tissues than bulls, although the differences were significant only for the subcutaneous adipose tissue depots. Adipocytes appeared to be largest in omental and smallest in intramuscular adipose tissue, although there were no significant differences among tissues. In a comparison of heifers and cows, significant site effects (p<0.05) were shown in adipocyte diameter, surface area and volume, and adipocyte appeared to be largest in omental tissue. Statistical difference (p<0.05) was only shown in cell volume of intramuscular tissue which was higher in cow than heifer. Intramuscular adipose tissue tended to have relatively greater numbers of cells per gram tissue and reflect lesser maturity of intramuscular adipose tissue relative to other adipose tissues. In sheep, regardless of adipose tissue depots, wethers had the greater adipocyte diameters than those at any other growth stage of sheep. Within adipose depots, the ranking of cell size was the greatest in the omental tissue of wether and the lowest in the renal and subcutaneous adipose tissue depots of fetal lamb. The cell size of adipocyte became larger with age, especially from fetal to suckling lamb due to a rapid hypertrophy of both perirenal and subcutaneous adipocytes during the suckling period.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.9
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• pp.1215-1221
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• 2016

The prediction of carcass composition in Hanwoo steers is very important for value-based marketing, and the improvement of prediction accuracy and precision can be achieved through the analyses of independent variables using a prediction equation with a sufficient dataset. The present study was conducted to develop a prediction equation for Hanwoo carcass composition for which data was collected from 7,907 Hanwoo steers raised at a private farm in Gangwon Province, South Korea, and slaughtered in the period between January 2009 and September 2014. Carcass traits such as carcass weight (CWT), back fat thickness (BFT), eye-muscle area (EMA), and marbling score (MAR) were used as independent variables for the development of a prediction equation for carcass composition, such as retail cut weight and percentage (RC, and %RC, respectively), trimmed fat weight and percentage (FAT, and %FAT, respectively), and separated bone weight and percentage (BONE, and %BONE), and its feasibility for practical use was evaluated using the estimated retail yield percentage (ELP) currently used in Korea. The equations were functions of all the variables, and the significance was estimated via stepwise regression analyses. Further, the model equations were verified by means of the residual standard deviation and the coefficient of determination ($R^2$) between the predicted and observed values. As the results of stepwise analyses, CWT was the most important single variable in the equation for RC and FAT, and BFT was the most important variable for the equation of %RC and %FAT. The precision and accuracy of three variable equation consisting CWT, BFT, and EMA were very similar to those of four variable equation that included all for independent variables (CWT, BFT, EMA, and MAR) in RC and FAT, while the three variable equations provided a more accurate prediction for %RC. Consequently, the three-variable equation might be more appropriate for practical use than the four-variable equation based on its easy and cost-effective measurement. However, a relatively high average difference for the ELP in absolute value implies a revision of the official equation may be required, although the current official equation for predicting RC with three variables is still valid.

• Journal of Animal Science and Technology
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• v.48 no.2
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• pp.227-236
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• 2006

Twenty four Hanwoo steers(average body weight=550.4±42.8kg) were used in the experiment to determine the effects of supplementing coated vitamin C+E with cottonseed on meat quality, meat color and carcass grade in Hanwoo steers fed brewers grain and cracked corn-based fermented feedstuff. Steers were randomly assigned to feeding groups of fermented feedstuff without any supplements(T1) and fermented feedstuff supplemented with coated vitamin C+E and cottonseed(T2). Ether extract content of longissimus dorsi was higher in T2 than in T1(p<0.05). Yellowness and hue-angle among surface colors of longissimus dorsi was lower(p<0.05) in T2 than in T1 but lightness was higher(p<0.05) in T2 than in T1. Ratio of yield grade ‘A’ was higher from T2 group than from T1 group. Marbling score was higher in T2 than in T1(p<0.05). Present results indicate that supplementation of coated vitamin C+E and cottonseed to brewers grain and cracked corn-based fermented feedstuff has positive effects on ether extract content, color, marbling score of longissimus dorsi in Hanwoo steers.

• Food Science of Animal Resources
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• v.28 no.5
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• pp.604-609
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• 2008

Analyses were conducted to estimate carcass component of yield grade factors by sex and live weight class and to develop the prediction equation of retail product weight by sex in Korean native cattle (Hanwoo). Data from 42,113 Hanwoo carcasses were used to estimate the traits of yield grade factor and an additional 1,066 carcasses were used to develop the prediction equation of retail meat weight. The average of fasting weight of cow, bull and steer were 529 kg, 596 kg, and 634 kg respectively. Carcass weight (CW), backfat thickness (BFT), loineye area (REA), Index score of wholesale meat and yield grade were significantly (p<0.01) affected by sex and live weight. The lean meat percentage, fat percentage and bone percentage based on the weight of cold carcasses were significantly different (p<0.05) between sex groups. The equation of predicting the retail meat product from this study could be expressed as a multiple regression $Y=-4.18+0.63{\times}CW\;(kg)-0.17{\times}BFT\;(cm)+0.16{\times}REA\;(cm^2)$, $R^2=0.93$. Among the independent factors, the BFT was the highest contributor to the prediction equation. Using the equation from this study should allow for rapid, precise and cost-effective assessment of the retail product in Hanwoo beef carcasses.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.4
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• pp.290-297
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• 2013

This study was carried out to investigate the effects of a by-product feed-based silage (BF silage) feeding on behavior patterns of growing Hanwoo steers. A total of 10 Hanwoo steers (11 months old, 302kg of body weight) were assigned to 2 dietary treatments: the control (concentrate mix + free access to rice straw), and the treatment (concentrate mix + free access to BF silage). The behavior patterns were observed for 48 hours. The intakes of dry matter (DM) and neutral detergent fiber (NDF) of the treatment group were higher than those of the control group. Eating time, ruminating time and resting time were not different between the control and treatment. But, the intake time per kg DM was higher for the control than treatment. The number of bolus, total chewing frequency, number of ruminating per bolus and number of bolus per minute were not different between the control and treatment. But the chewing frequency per bolus was higher in the treatment than control (p<0.05), and feed value index was lower in treatment than control (p<0.05). Frequencies of drinking and defecating were not different between the two groups, but the frequency of urinating was higher for the treatment (p<0.05) than control. Eating rate, ruminating efficiency and chewing efficiency were much higher in the treatment group than control (p<0.05). These results indicate that the replacement of conventional rice straws with the BF silage (physically effective NDF, about 25%) did not affect the ruminating behaviors of Hanwoo steers significantly.

• Journal of Animal Science and Technology
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• v.54 no.1
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• pp.15-22
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• 2012

This study was conducted to investigate the effects of grain sources on the ruminal methane production in Hanwoo steers. Six Hanwoo steers (BW = 614.4 ${\pm}$ 8.3 kg) were fed, on a DM basis (TDN 6.91 kg), 10% rice straw and 90% barley or corn based concentrate, respectively, according to Korean Feeding Standards (Hanwoo). Each period lasted 18 days including a 14-day adaptation and a 4-day measuring period. The steers were in the ventilated hood-type respiration chamber system (one cattle per chamber) during each measuring period to measure heat and methane production for 1 day. Nutrient intake and digestibility were not affected by steer fed grain sources. Methane concentration was not affected by steer fed either barley or corn-based concentrate, respectively (0.022% vs. 0.025%). Methane production was greater by steers fed corn than those fed barley (119.3 g/day vs. 139.4 g/day). This result indicated that methane emission factor by maintenance energy requirement for the late fattening Hanwoo fed corn was higher than the steers fed barley (43.6 kg/head/year) vs. corn (50.9 kg/head/year). Methane conversion rate (Ym) was 0.04 Ym and 0.05 Ym for barley and corn, respectively.

• Journal of Animal Science and Technology
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• v.54 no.1
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• pp.51-58
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• 2012

The purposes of the study were to examine the changes in carcass traits and surface meat color, and cortisol concentration by different altitudes and shipping distances for steer and cow. The experimental animals were shipped from Kangwondo, Kyunggido, Choongchungdo, and Kyungsangdo to Wonju LPC. The animals were examined for yield traits, quality traits, carcass grade, lightness, redness, yellowness, croma value, and cortisol concentration by different altitudes and shipping distances. The results showed that the carcass traits of steer like back fat thickness were not different by shipping distances of 100 km, 150 km, and 200 km. However, the fat thickness was higher in steers shipped from 250 km than 100 km, 150 km, and 200 km distance. Ribeye area was reduced significantly in 200 km and 250 km than 50 km. Yield index and yield grade were significantly low in 250 km than 50-200 km. However, meat color, fat color, texture, mature, and quality grade had no differences between shipping distances. Marbling score was not different in 50-200 km. However, the marbling score in 250 km was significantly lower than that of 50 km. In case of surface meat color by shipping distance, redness, yellowness, chroma value, and hue-angle were not different in shipping distance of 250 km. The lightness had similar result in 50-200 km. However, in case of 250 km the lightness was significantly low. The REA of cow carcass by shipping distance had no differences by shipping distance. The BET had similar results in 50-150 km. However, it had significantly thick in 200 km. The yield index and yield grade had no differences in 50-150 km. However, yield index and grade were significantly low in 200 km. The carcass trait of cow had no differences in all items by shipping distance. Although the carcass traits and the BET for steer by altitude had no differences between 100, 200, 300 and 500 m, but those were significantly thick in 400 m. And the yield index and the yield grade at altitude 400 m were lower than that of other altitudes. The quality traits and the quality grade had no differences between 100, 200, 300, 400, and 500 m altitudes. The yield traits, quality traits, yield grade, and quality grade had no significant differences by altitudes. In case of yield index of cow for 300 m was low than the cases of 100 m and 200 m. The surface meat color for steer and cow had no differences by altitudes. However, the lightness of cow had positive result in 100 m than 200 m and 300 m. In case of steer and cow the cortisol concentration by shipping distance was high as the shipping distances were longer. However, the cortisol concentrations of steer and cow by altitudes were decreased as the altitudes were increased. From the above results carcass traits and carcass grade were decreased and the cortisol concentration was increased as the altitudes were decreased for steer and cow.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.12
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• pp.1729-1735
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• 2015

This study was conducted to evaluate the effect of medicinal plant by-products (MPB) supplementation to a total mixed ration (TMR) on growth, carcass characteristics and economic efficacy in the late fattening period of Hanwoo steers. Twenty seven steers (body weight [BW], $573{\pm}57kg$) were assigned to 3 treatment groups so that each treatment based on BW contained 9 animals. All groups received ad libitum TMR throughout the feeding trial until slaughter (from 24 to 30 months of age) and treatments were as follows: control, 1,000 g/kg TMR; treatment 1 (T1), 970 g/kg TMR and 30 g/kg MPB; treatment 2 (T2), 950 g/kg TMR and 50 g/kg MPB. Initial and final BW were not different among treatments. Resultant data were analyzed using general linear models of SAS. Average daily gain and feed efficiency were higher (p<0.05) for T1 than control, but there was no difference between control and T2. Plasma albumin showed low-, intermediate- and high-level (p<0.05) for control, T1 and T2, whereas non-esterified fatty acid was high-, intermediate- and high-level (p<0.05) for control, T1 and T2, respectively. Carcass weight, carcass rate, backfat thickness and rib eye muscle area were not affected by MPB supplementation, whereas quality and yield grades were highest (p<0.05) for T1 and T2, respectively. Daily feed costs were decreased by 0.5% and 0.8% and carcass prices were increased by 18.1% and 7.6% for T1 and T2 compared to control, resulting from substituting TMR with 30 and 50 g/kg MPB, respectively. In conclusion, the substituting TMR by 30 g/kg MPB may be a potential feed supplement approach to improve economic efficacy in the late fattening period of Hanwoo steers.