• Asian-Australasian Journal of Animal Sciences
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• 제9권4호
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• pp.363-370
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• 1996

The effect of breeding length of sire on genetic progress was examined in the Holstein dairy cattle population in Japan. Genetic progress was extimated by gene flow method. Breeding length of sires directly influences the replacement rates of sires and the selection intensity of sires because there are a fixed number of progeny tested young bulls per year. As breeding length of sires increased, rate of gene flow decreased and average proportions of genes deriving from selected animals had lower asymptotic values. When breeding length was short, average proportions of genes required a longer period to converge to asymptotic values. Changes of Rcow-sire's(sire to breed recorded cows) and Ncow-sire's(sire to breed non recorded cows) breeding length influenced not only transmission of their genes but also that of genes derived from all other selected animals. Irrespective of whether the discount rate was assumed to be 0 or 6%, longer term (${\geq}$ 20 years) expected total genetic improvement was maximized by a sire breeding length of five years. For shorter term assessment(10 years), genetic improvement was maximized by a sire breeding length of three years. There was a linear increase in the contribution of the sire to bulls pathway to the total genetic improvement, with increase in the term of assessment.

• Asian-Australasian Journal of Animal Sciences
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• 제12권6호
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• pp.850-853
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• 1999

Angus postweaning daily gain (PWDG) was analyzed to investigate effects of the heterogeneous variance and the genotypes by sex interaction on prediction of EBVs with data sets of various environmental levels. A whole data (16,239 records) was divided into six data sets according to averages of the best linear unbiased estimator (BLUE) of herd environment. The results comparing prediction models showed that single-trait model is adequate for most of the data sets except for the data set of poor environment for both of the bulls and the heifers where the heterogeneity of variance and the genotypes by sex interaction exists. In the prediction with the data set of the low environment level, the bull's EBVs by single-trait models had high product moment correlations with male EBVs of the bulls by the multitrait model. Whereas the heifer's EBVs had moderate correlations with female EBVs by the multitrait model. This moderate correlation seems to be resulted by the heterogeneity of variance and low heritability of the heifer's PWDG. The prediction models with heterogeneity of variance had little effect on the prediction of EBVs for the data sets with moderate to high genetic correlations.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2017년도 춘계공동학술대회
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• pp.23-23
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• 2017

Recent favor on high quality food and concern on food safety have demonstrated the superiority of Hanwoo (Korean native cattle). In general, the price of cow is higher than those of steer and bull, causing cheating issues in the market. Hence, this study is to discriminate genders of Hanwoo with identification of factors which highly influence gender discrimination based on the big-size deboning data. Totally, there were 31 variables in the deboning data, and we divided into them two categories: data obtained before and after deboning. Discriminant function analysis was then applied into the data to determined the accuracy of gender discrimination in Hanwoo. The result showed that Hanwoo could be classified by gender with 99.2% of accuracy when using all 31 variables. In detail, it was possible to identify 93 of 94 bulls (98.9%), 96 of 96 cows (100%) and 74 of 75 steers (98.7%). The most significant variables was chuck, sirloin, armbone shin, plates, retail and cuts percentage, sequentially. With variables obtainable before deboning, accuracies of classification were 91.5% for bulls, 92.7% for cows, and 89.3% for steers. The most significant variables was water, cold carcass weight and back-fat thickness. The discrimination accuracy was higher with data obtainable after deboning: bulls (98.9%), cows (99.0%) and steers (98.7%). In this case, chuck, sirloin and armbone shin were the factors determined the classification ability. This study showed that Hanwoo can be classified based on deboning data with appropriate statistics, further suggesting weight of cut of beef might be the standard for gender classification.

• 한국가축번식학회지
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• 제20권2호
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• pp.197-205
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• 1996

This study was conducted to examine the effect of sustained release recombinant bovine somatotropin(SR-rBST) with different dosage(0, 0.03mg/kg body weight/14 day, 0.06mg/kg body weight/14 day, 0.09mg/kg body weight/14 day) on the economical traits of the semen characteristics and sexual behaviors and blood chemical values with sixteen Holstein dairy young bulls in Dairy Cattle Improvement Center of National Livestock Co-operatives Federation. Sensual testings of collected semens of Holstein young bulls were not different among treatments (p>0.05). Ejaculated semen volumes of control, SR-rBST 0.03mg, 0.06mg and 0.09mg groups were 5.6ml, 5.6ml, 6.0ml and 6.7m, respectively, but the result of SR-rBST 0.09mg group significantly increased semen volume(P<0.05). In sperm concentration, SR-rBST 0.06mg and 0.09mg groups significantly increased the total number of sperms than the other groups(P<0.05). In otherwise, SR-rBST treatments did not affect on pH, osmotic pressure, anti forzen rate, abnormality and motility of collected semen during whole experimental period. Reaction time(RT), sexual aggressiveness(SA) and tactile stimulation(TS) were not different among treatments. The libido scores(LS) of control, 0.03mg, 0.06mg and 0.09mg groups were 68.0, 80.5, 73.9 and 80.8, respectively, and LS were significantly improved by SR-rBST administration(P<0.05). The effect of SR-rBST on scrotal circumference measurement that is important factor to determine the ability of semen production, was not different among treatments. These studies indicates that SR-rBST treatments favourably affect on semen quality and sexual libido in Holstein young bull.

• 한국가축번식학회지
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• 제10권1호
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• pp.91-99
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• 1986

This experiment was undertaken to examine the effects of HIS treatment on the motility and acrosome reaction of frozen bovine spermatozoa and to test their abilities to interact with zona-free hamster eggs in vitro. Also, in vitro results were compared with those of bull's fertility in AI. The frozen semen from four Holstein bulls were exposed to HIS-DM for 5 minutes after thawing and then preincubated for 60 minutes in DM prior to insemination. The hamster eggs were mounted, fixed and stained 6 hours after exposure to boving spermatozoa and examined under a phase-contrast microscope. 1. The sperm motility expressed as a mobility index dro, pp.d significantly from 60-75 to 12-24 after exposure to HIS-DM, but increased in 32 to 41 at insemination. Bull C showed a low motility index than those of the orher bulls. The percentage of acrosome reaction by staining procedure were increased by HIS-DM treatment but did not change during 7 hours incubation period in DM. 2. The overall percentage of hamster eggs interacting with bull spermatozoa was 56.3%, 58.3%, 66.6% and 70.0%, respectively. Although there was no significant difference among bulls in the penetration rate of spermatozoa into hamster eggs, high proportions of eggs interacted with spermatozoa from Bull C and D than those from Bull A and B. 3. The conception rates (60-90 day RP) resulting from AI were 62.5%, 67.5% and 70.9% for Bull A, B and C, respectively. These results were in good agreement with the invitro results that the proportions of bull sperm-egg interction were greater for Bull C than for Bull A and B.

• 농업과학연구
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• 제44권3호
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• pp.375-383
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• 2017

This study was conducted to investigate the effects of sex, environmental factors, and feeding system on the carcass traits of Hanwoo (Korean Native Cattle). Data were collected from 7,866 heads slaughtered in Chungnam province during one-year period. Using the collected carcass traits data which greatly influence a Hanwoo's carcass grade, the effects of sex class, slaughter season, and feeding system were estimated. Backfat thickness of steers was significantly higher than that of bulls (p < 0.05). Marbling score was also the highest in steers when compared with cows and bulls (p < 0.05). Live weight and carcass weight were significantly higher in winter than in summer (p < 0.05). However, backfat thickness was significantly lower in summer than in other seasons (p < 0.05). Marbling score was higher in spring and fall than in summer and winter (p < 0.05). In terms of feeding systems, TMR (Total mixed ration) and TMF (Total mixed fermentation feed) fed groups showed the highest carcass grade (p < 0.05). However, the group fed TMR and formula feed at the final fattening period showed the lowest performance (p < 0.05) and it is assumed that some stress was associated to the feed change. The results reconfirm that castration may be recommended in order to improve meat quality and marbling scores in bulls. There was no consistent trend of seasonal effects of slaughter on carcass traits although some traits were significantly affected. Regarding the feeding system, either TMR or TMF can be supplied to achieve high feed efficiency and good carcass characteristics in Hanwoo.

• Journal of Animal Science and Technology
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• 제45권4호
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• pp.517-522
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• 2003

한우의 고환둘레와 정액 생산 및 번식과의 관계를 구명하기 위하여, 농협중앙회 가축개량사업소 보유 종모우 63두의 고환둘레와, 이들의 19,742번의 정액 생산기록(정액량, 농도/ml 및 총정자수) 및 이중 16두가 생산한 1,289두의 자손기록을 이용하였다. 정액량, 정액 농도와 총 정자수 모두 정액채취년도, 정액채취월, 정액 채취 순서에 따라 영향을 받았다(P<0.001). 고환 둘레의 평균은 41.2$\pm$4.54cm 이었고, 1회 평균 사정량은 5.47$\pm$0.89ml 이었으며, 정액 농도는 16.2$\pm$2.78(${\times}10^8$/ml), 사정당 총정자수는88.47$\pm$15.24(${\times}10^8$)이었다. 고환둘레와 정액량 및 총 정자수 간에는 0.14 및 0.15의 정의 상관을 나타내었으며, 임신율과는 0.39, 출산율과는 0.26의 상관을 나타내었다.

• Asian-Australasian Journal of Animal Sciences
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• 제26권12호
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• pp.1717-1725
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• 2013

The objectives of this study were to compare visual observation and an electronic grazing time method and to evaluate the effects of nutritional plans on intake, grazing behavior and horizontal and vertical locomotion of young bulls in a tropical pasture. Thirty-nine Nellore young bulls with an average body weight of $345{\pm}9.3$ kg kept in pasture were used. The experimental treatments consisted of: restricted: animals kept in a plot with a low mass of forage receiving mineral mixture only; control: animals receiving mineral mixture only; HPHC: a high protein and high carbohydrate supplement; HPLC: a high protein and low carbohydrate supplement; LPHC: a low protein and high carbohydrate supplement; LPLC: a low protein and low carbohydrate supplement. GPS collars equipped with activity sensors were used. Information about head position, latitude, longitude and altitude were recorded. Daytime grazing behavioral patterns monitored by a continuous focal animal recording method was compared to behavior estimated by the activity sensor. Feed intake was estimated by a marker method. The Restricted group presented lower (p<0.05) intake of dry matter and TDN. However, difference in dry matter intake was not found (p>0.05) between non-supplemented and supplemented animals. Difference was not found (p>0.05) in daytime grazing time obtained by visual observation or the activity sensor method. The restricted group showed longer (p<0.05) grazing time (9.58 h/d) than other groups, but difference was not found (p>0.05) in the grazing time between Control (8.35 h/d) and supplemented animals (8.03 h/d). The Restricted group presented lower (p<0.05) horizontal locomotion distance (2,168 m/d) in comparison to other groups (2,580.6 m/d). It can be concluded that the use of activity sensor methods can be recommended due to their being similar to visual observation and able to record 24-h/d. While supplements with high carbohydrates reduce pasture intake, they do not change grazing behavior. Moderate supplementation (until 50% of protein requirement and 30% of energy requirement) of beef cattle on tropical pasture has no effect on daily locomotion.

• 한국축산시설환경학회지
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• 제5권3호
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• pp.157-170
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• 1999

This study was conducted to investigate the effects of Scoria, Quartz porphyry and Oak charcoal powder feeding by 1% level of concentrate on the fattening cross bred bulls(5/8 Korean Native Cattle, 2/8 Charolais, 1/8 Brahman germ plasma) Feeding trial was conducted with 4 treatment groups which were T1(Full feeding of concentrate and roughage for 12 months), T2(T1 and Scoria addition), T3(T1 and Quartz porphyry addition) and T4(Oak charcoal addition) for 360 days, consisting of 32 heads whose initially weights were about 299.7kg. The results obtained are summarized as follows; 1. During the over-all period, average daily gains by T3, T4, T2 and T1 were 1.024, 0.987, 0.977kg and 0.964, respectively, without a significant difference by treatments. 2. Concentrate intakes per body weight and TDN intakes required per unit of kilogram gain were lower in addition agent groups than in control, and in all the treatments feed efficiency was higher at early stage for 360 fattening day than at end stage. 3. Carcass weight, dressing percent, back-fat thickness and loin eye muscle area by treatments were 330.9 to 348.4kg(average 340.3kg), 55.2~56.2(average 55.8%), 0.41~0.55(average 0.46cm)and 76.0~80.9$\textrm{cm}^2$(average 77.6$\textrm{cm}^2$), respectively, and were improved in addition agent groups than in control. 4. Meat quality grade is higher in addition agent groups than in control, and heads of 1st grade by treatments was 3, 2, 1 and none in T4, T2, T3 and T1, respectively. 5. Incidence heads of diseases by treatment were not apparently different, but diseases of digestive system was decreased in addition agent groups than in control. 6. The nitrate nitrogen content of fattening bull dung which collected in rectum were 0.082~0.089% (average 0.084%), and the content in addition agent groups was smaller than in controll. 7. Income was higher in order of T4, T3, T2, and T1 and incomes of treatment groups were grater than that of control group by 21.4 to 33.5 percent. According to the above results it may be concluded that fattening bulls may be required to feed no more than 1% of Scoria, Quartz porphyry and Oak charcoal powder based on the concentrate feeding level during the fattening period(12 to 24 month of age) to produce high quality meat and increase income.

• Asian-Australasian Journal of Animal Sciences
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• 제27권4호
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• pp.488-494
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• 2014

Twenty-eight Brangus cattle were used to determine the effect of copper and selenium supplementation on performance, feed efficiency, composition of fatty acids in Longissimus dorsi (LD) muscle, and cholesterol concentration in serum and in LD muscle and enzymes activities, reduced glutathione (GSH) and oxidized glutathione (GSSG). The treatments were: i) Control, without copper (Cu) and selenium (Se) supplementation; ii) Se, 2 mg Se/kg of dry matter such as sodium selenite; iii) Cu, 40 mg Cu/kg of dry matter such as copper sulfate; iv) Se/Cu, 2 mg Se/kg of dry matter such as sodium selenite and 40 mg Cu/kg of dry matter such as copper sulfate. LD muscle fatty acid composition was not influenced by the treatments (p>0.05). The serum concentration of cholesterol was not influenced by the treatments (p>0.05), however, the concentration of cholesterol in LD was lower in cattle supplemented with copper and selenium (p<0.05). Oxidized glutathione and reduced glutathione increased (p<0.05) with Cu, Se and Se/Cu supplementation. The supplementation of copper (40 mg/kg DM) and selenium (2 mg/kg DM) altered the metabolism of lipids in confined Brangus cattle, through a decrease in cholesterol deposition in the LD, possibly by changing the ratio between reduced glutathione/oxidized glutathione. Copper and selenium supplementation improved animal performance and feed efficiency (p<0.05) when compared to the control group, providing advantages in the production system, while also benefiting consumers by reducing cholesterol concentration in the meat.