• Reproductive and Developmental Biology
• /
• v.36 no.1
• /
• pp.27-32
• /
• 2012

This study was carried out to investigate artificial insemination (AI) failure status and frozen semen characteristics in Korean proven bulls' number (KPN) semen used for AI of Hanwoo cows in Gangwon East region (Gangneung, Donghae, Taebaek, Samcheok, Sokcho, Yangyang, Goseong). Among semen used for AI, AI failure rate showed lowest at KPN506 (27.6%), whereas highest at KPN593 (77.2%). Correlations of AI failure in between Korean proven bulls semen and cows was 0.2941, which means that AI failure rate of Korean proven bulls semen may have respectable effect on reproduction of Hanwoo cow. In addition, present study was conducted to investigate spermatozoal viability rate, ruptured acrosome rate and active mitochondria in frozen Korean proven bulls semen with flow cytometry. The semen of KPN593 showed significantly ($p$<0.05) higher viability rate in KPN593 (30.49%) than that in KPN637 (37.34%). Furthermore, percentage of ruptured acrosome was lower in KPN637 as 21.37% than in KPN637 (21.37%), but it was not statistically significant. In conclusion, these results indicate that choice of Korean proven bulls semen may correlate positively with conception rate in Hanwoo cow. Therefore, KPN with high AI failure rate might be avoid to increase conception rate and characteristics of frozen semen might be evaluated before its use for AI.

• Journal of agriculture & life science
• /
• v.51 no.2
• /
• pp.117-126
• /
• 2017

Hanwoo young bulls are selected based on performance test using the weight at 12 months and pedigree index comprising marbling score. Pedigree index was not based on the progeny tested data but the breeding value of the proven bulls; resulting a lower accuracy. The progeny testing of the young bulls was categorized into testing at farm and at the test station. The farm tested data was difficult to compare with those from test station data. Farm tested bulls had different slaughter ages than those for test station bulls. Therefore, this study had considered a different age at slaughter for respective records on ultrasound traits. Records on body weight at 12 months, ultrasound measures at 12 and 24 months(uIMF, uEMA, uBFT, and uRFT), and carcass traits(CWT, EMA, BFT, and MS) were collected from steers and bulls of Hanwoo national improvement scheme between 2008 and 2013. Fixed effects of batch, test date, test station, personnel for measurement, personnel for judging, and a linear covariate of weight at measurement were fitted in the animal models for ultrasound traits. The ranges of heritability estimates of the ultrasound traits at 12 and 24 months were 0.21-0.43 and 0.32-0.47, respectively. Ultrasound traits at 12 and 24 months between similar carcass traits was genetically correlated at 0.52-0.75 and 0.86-0.89, respectively.

• Journal of Animal Science and Technology
• /
• v.48 no.6
• /
• pp.759-766
• /
• 2006

This study was conducted to investigate the genetic correlations among the traits used to select young bulls and proven bulls in Hanwoo Performance and Progeny Test Program in Korea. For the estimation of heritabilities and correlations among the growth traits of bulls and carcass traits of progeny steers, 2,532 records of performance tested bull calves and 1,819 records of progeny tested steers were collected from Livestock Improvement Main Center (LIMC), National Agricultural Cooperative Federation (NACF). Fixed effects of mixed model for each traits were selected by using stepwise regression analysis and prior values of variance components were estimated by MTDFREML. The prior values of variance components were estimated with pairwise 2 traits model followed by single trait analysis. The estimated heritability of backfat thickness(BF), dressing percentage(DP), loin-eye muscle area(LMA), marbling score(MS) and weight at 12 months(WT12) was 0.51, 0.32, 0.27, 0.33, 0.50 and 0.26, respectively. Genetic correlation of WT12 of bull calves with backfat thickness, carcass weight and loin-eye muscle area of steers was positive correlation as 0.05, 0.35 and 0.21, respectively. However genetic correlation of WT12 with DP and MS showed negative correlation as 󰠏0.09 and 󰠏0.27, respectively and these negative genetic correlations implies that bulls that may be superior in carcass traits can be lost at the first step of selection and current selection method should be modified to solve this problem.

• Journal of Embryo Transfer
• /
• v.21 no.4
• /
• pp.287-297
• /
• 2006

Concentration of hormones and blood components at the last fatting stage was changed before slaughter in Hanwoo steers and bulls. Two months before slaughter and shipment, concentration of cortisol and creatinine was increased, but that of calcium was decreased. Concentration of insulin growth factor-1 (IGF-1) was decreased after shipment, and inorganic phosphorus (IP) was decreased at slaughter. It is unclear that changes of concentration in between 2 months before slaughter and shipment were either caused by aging or stresses (abstinence, environmental change, blood drawing, and shipment). Changes of blood concentration between shipment and slaughter may be accounted for overall responses from abstinence, shipment, and unfamiliar environment. A positive correlation between 2 months before slaughter and before shipment was detected for IGF-1, total protein (TP), albumin, creatinine, high density lipoprotein cholesterol (HDLC), and globulin in steers, and creatinine and globulin in bulls. A positive correlation between 2 month before slaughter and slaughter was detected for IGF-1, blood urea nitrogen (BUN), IP and HDLC in steers, and creatinine in bulls. A positive correlation between before shipment and slaughter was detected for testosterone, IGF-1, creatinine, triglyceride, HDLC and globulin in steers, and TP, creatinine, HDLC and globulin in bulls.

• Journal of Animal Science and Technology
• /
• v.44 no.4
• /
• pp.383-390
• /
• 2002

The data were consisted of 1,262 records for carcass traits observed at Hanwoo steers from 1998 to 2001 at Namwon and Deakwanryung branch of National Livestock Research Institute, Rural Development Administration. Pedigrees of young bulls were traced back to search for magnifying inbreeding. Genetic parameters for carcass traits with Gibbs sampling in a threshold animal model were compared to estimates with REML algorithm in linear model. As the results, most of bulls were not inbred and sire pedigree group was non-inbred population. However, most of the bulls fell in some relationship with each other. Heritability estimates as fully posterior means by Gibbs samplers in threshold model were higher than those by REML in linear model. Furthermore, these estimates in threshold model using GS showed higher estimates than estimates using tested young bulls in previous study and same model. Heritability estimate by GS for marbling score was 0.74 and genetic correlation estimate between marbling score and body weight at slaughter was –0.44. Further study for correlation of breeding values between REML algorithm in linear model and Gibbs sampling algorithm in threshold model was needed.

• Journal of Embryo Transfer
• /
• v.21 no.2
• /
• pp.95-100
• /
• 2006

Thirty heads of proven bulls were used to identify the effects of mounting conditions (dummy cow vs. teaser bull) on semen characteristics in Hanwoo. Semen was collected from bulls daily two times with 1 h interval every $3{\sim}6$ days for 6 months. Bulls mounted dummy cow (BDC) had higher both the $1^{st}$ and the $2^{nd}$ sperm concentrations than in bulls mounted teaser bull (BTB), resulting in more total sperm number (p<0.05). The total sperm number in the $1^{st}$ collection was the highest in BDC with collection interval of 5 days. Total sperm number in the $1^{st}\;and\;2^{nd}$ collections tended to be more in the BDC of $4{\sim}5$ years old and BTB of $6{\sim}7$ years old. These results indicate that semen collection using dummy cow has a better effect than teaser bull on semen characteristics.

• Journal of Embryo Transfer
• /
• v.29 no.4
• /
• pp.321-325
• /
• 2014

The present study was performed on farm animals to test the effectiveness of progesterone-releasing intravaginal device (Cue-Mate$^{(R)}$ 1.56 g) and injection of prostaglandin $F_{2{\alpha}}$ ($PGF_{2{\alpha}}$) for synchronization estrus in Hanwoo cattle. The cattle were at random stage of the estrus cycle. The cows were artificially inseminated at day 7 after Cue-Mate withdrawal, using commercial semen from Korean native bulls. There was a season effect on the estrus synchronization rate. It was higher in spring (94.3%) followed by winter (93.3%), autumn (90.4%) and summer (67.2%). In summary, The results of this study revealed that season has influences on estrus behavior of cattle with no significant effect on pregnancy rate. In summary, we suggest summer reproductive management to alleviate the effects of heat stress. It should be based on intensive cooling combined with hormonal treatment. Given that different subgroups of cows benefit differently from the treatments, selective hormonal administration should be considered.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.7
• /
• pp.1059-1066
• /
• 2008

This study was carried out to investigate the effects of dietary sulfur (S) and vitamin E (Vit E) supplementation on the quality of beef from longissimus muscle of Hanwoo bulls. Eleven, 29 months-aged Hanwoo bulls were randomly divided into three feed supplementation groups (S (n = 4), Vit E (n = 4) and S+Vit E (n = 3)). S was given as much as 12 g/head/d and Vit E was given as much as 1,200 IU/head/d; both supplements were given for 3 months prior to slaughter. At 24 h post-slaughter, the carcasses were weighed and evaluated by official grader for carcass traits. At 48 h post-slaughter, the M. longissimus from each carcass was collected and stored at $4{\pm}0.2^{\circ}C$ for 10 days. There were no significant differences in yield and quality grades of carcass and proximate composition, physical properties and aroma pattern of meat among all groups. At 5 days of storage, the TBARS value of meat from cattle with S+Vit E supplementation was significantly lower (p<0.05) than other groups; and at 10 days of storage, the TBARS value of meat from cattle with Vit E and S+Vit E supplementations was significantly lower (p<0.05) than from cattle with S supplementation. At 5 days of storage, MetMb concentration of meat from cattle with S+Vit E supplementation was significantly lower (p<0.05) than from cattle with Vit E supplementation; and at 10 days of storage, MetMb concentration of meat from cattle with S+Vit E supplementation was significantly lower (p<0.05) than from other groups. At 10 days of storage, the redness value of meat from cattle with S supplementation was significantly higher (p<0.05) than from cattle with Vit E supplementation and the hue-angle value of meat from cattle with S and S+Vit E supplementations was significantly lower (p<0.05) than from cattle with Vit E supplementation. Dietary Vit E supplementation had a better effect on lipid stability whereas dietary S supplementation had a better effect on OxyMb stability. The dietary combination of S and Vit E created the highest protection for beef from myoglobin oxidation and thus improved the color stability of meat.

• Journal of Animal Science and Technology
• /
• v.45 no.4
• /
• pp.517-522
• /
• 2003

Scrotal measurements and semen production records of 19,742 during 7 years from 63 Hanwoo breeding bulls(6${\sim}$7 years of age) were used to determined the relationship between scrotal circumference(SC) and semen production including concentration and total number of sperm. The average of SC is 41.2$\pm$4.54cm; extreme ranges between a low of 34cm to a high of 48cm. Quantity of semen, concentration and total number of sperm are 5.47$\pm$0.89ml/ejaculation, 16.16${\pm}2.78{\times}10^8$/ml and 88.47${\pm}15.24{\times}10^8$/ejaculation, respectively. SC is positively correlated with semen production(0.14 with quantity of semen and 0.15 with total number of sperm). Reproduction data from 16 breeding bulls produced 1,289 offspring from spring 1993 to spring 2000 to examined relationship between SC and reproduction. Rate of fertility and delivery are 0.80$\pm$0.13 and 0.78$\pm$0.15, respectively. Also, SC is positively correlated with delivery rate(r=0.26) and favorably related to fertility rate(r=0.39). These results, that is, - SC correlates positively with semen production and with reproduction -, suggested that SC should be considered when selecting breeding bull.

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