• Asian-Australasian Journal of Animal Sciences
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• 제23권7호
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• pp.907-915
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• 2010

Three hundred and seventy-three steers (approximately 7 mo of age and $247{\pm}19.4\;kg$) were utilized to determine the effects of trace mineral (TM) source and growth implants on trace mineral status. Steers were blocked by ranch, post-weaning treatment within ranch, stratified by initial body weight, and randomly assigned to one of 36 pens (9-12 head/pen). Treatment consisted of: I) control (no supplemental Cu, Zn, Mn, and Co), ii) inorganic trace minerals, and iii) organic trace minerals. Six pens of steers per treatment received a growth implant at the beginning of the experiment and were re-implanted during the finishing phase. The remaining steers received no growth implants. Steers were fed a corn silage-based growing diet for 56 d then were gradually switched to a high concentrate finishing diet. Treatments during the finishing phase consisted of: i) control (no supplemental Zn); ii) inorganic Zn (30 mg of Zn/kg DM from $ZnSO_4$); and iii) organic Zn (iso-amounts of organic Zn). By the end of the growing and finishing phases, implanted steers had greater (p<0.01) plasma Cu concentrations than non-implanted steers. During the growing phase, liver Cu concentrations (p<0.01) and plasma Zn concentrations (p<0.02) were greater in steers supplemented with TM compared to control steers. Steers supplemented with inorganic minerals had greater liver Cu concentrations than steers supplemented with organic minerals at the beginning (p<0.01) and end (p = 0.02) of the growing phase. During both the growing (p = 0.02) and finishing phases (p = 0.05), nonimplanted control steers had greater plasma Cu concentrations than non-implanted steers supplemented with TM, whereas, implanted control steers had similar plasma Cu concentrations than implanted steers supplemented with TM. Non-implanted steers that received inorganic TM had lower plasma Cu concentrations (p = 0.03) during the growing phase and ceruloplasmin activity (p<0.04) during the finishing phase than non-implanted steers that received organic TM, whereas, implanted steers supplemented with either organic or inorganic TM had similar plasma Cu concentrations.

• 농업과학연구
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• 제48권4호
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• pp.975-985
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• 2021

The sufficient amount of protein supply is crucial for improving the growth performance of growing beef cattle. In addition, due to the improvement in the genetic potential of the carcass weight of Hanwoo steers, dietary protein requirements may be increased during the rapid growth period. Accordingly, the dietary crude protein (CP) level in growing Hanwoo steers has been increasing in the field. However, little scientific evidence is available in relation to this. Therefore, this study was conducted to test whether a higher dietary CP level than convention would improve the growth performance and body metabolism in growing Hanwoo steers. Fifty growing Hanwoo steers were randomly divided into two groups and fed either a commercial diet (CON) or a higher CP (HCP) concentrate mix, provided with a similar level of dietary energy. Tall fescue hay was provided ad libitum. The dietary CP level did not affect growth performance and blood metabolite. Nitrogen intake, predicted nitrogen excretion, and retained nitrogen were higher in the HCP group than in the CON group (p < 0.01). Although there was no difference in the nitrogen utilization efficiency, the growth efficiency per retained nitrogen decreased in the HCP group (p = 0.02). A higher dietary CP level may increase nitrogen retention in growing Hanwoo steers without improving growth performance, which leads to reduced growth efficiency per retained nitrogen. Furthermore, considering the high price of feed protein and increased nitrogen excretion to the environment, a further increase in the protein level may not be sustainable.

• Asian-Australasian Journal of Animal Sciences
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• 제19권10호
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• pp.1450-1454
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• 2006

Three hundred and seventy-five steers (approximately 7 mo of age and $239.0{\pm}10.4kg$) were utilized to determine the effects of trace mineral (TM) supplementation and source on performance during the on-farm backgrounding and feedlot receiving phases of beef cattle production. At their respective ranches, steers were stratified by body weight into six groups. Groups were then assigned to one of six pens and pens were randomly assigned to treatments. Treatments consisted of: 1) control (no supplemental Cu, Zn, Mn, and Co), 2) inorganic trace mineral ($CuSO_4$, $ZnSO_4$, $MnSO_4$, and $CoCO_3$), and 3) organic trace mineral (iso-amounts of organic Cu, Zn, Mn, and Co). Mineral treatments were fed in alfalfa pellets formulated to supply 360 mg of Zn, 200 mg of Mn, 125 mg of Cu, and 12.5 mg of Co per head per day from either organic or inorganic trace mineral sources. Control steers received alfalfa pellets with no additional Cu, Zn, Mn, or Co. Steers were allowed free access to harvested alfalfa-grass hay throughout the 30-d on-farm backgrounding phase. On day 30 post-weaning, steers were weighed and transported to the feedlot. Steers were blocked by treatment within ranch, stratified by initial body weight, and randomly assigned to one of 36 pens (9-12 head per pen; 12 pens per treatment). Steers remained on the same on-farm backgrounding trace mineral treatments, however, trace mineral treatments were included in the total mixed growing ration. Steers were fed a corn silage-based growing diet throughout the 28 d feedlot receiving period. There was no effect of TM supplementation on performance of steers during the on-farm backgrounding phase. By the end of the 28-d feedlot receiving phase, ADG was similar between control and trace mineral supplemented steers. Steers supplemented with organic TM had greater (p<0.05) ADG than steers supplemented with inorganic TM by the end of the 28-d feedlot receiving phase. Morbidity and mortality rates were similar across treatments.

• Asian-Australasian Journal of Animal Sciences
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• 제1권3호
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• pp.163-166
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• 1988

Water turnover and consumption of steers fed either fresh cut grass or hay and water turnover of steers grazed in summer or in fall were determined using 18 Holstein steers weighing 226 to 382 kg. Steers consumed 7.0 or 7.5 kg of dry-matter from hay or fresh cut grass. Animals fed hay drank significantly more water than those given fresh cut grass (P<0.01). Total water consumption, however, was greater in steers fed fresh cut grass than those given hay (P<0.05). Water turnover was about the same as total water consumption with a tendency for slightly higher values in water turnover irrespective of feeding regimes. Steers grazed in summer had greater water turnover than those grazed in fall. Water turnover was about the same in steers fed fresh cut grass and grazed in summer but decreased in steers on the dry ration or grazing in a cool season of the year.

• Asian-Australasian Journal of Animal Sciences
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• 제16권8호
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• pp.1131-1136
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• 2003

Forty-eight individually fed Angus steers (body weight $220kg{\pm}9.1$) were utilized to investigate the effects of copper (Cu) source and concentration on lipid metabolism and carcass quality. Steers were stratified by body weight and initial liver Cu concentration and randomly assigned to one of five groups. Groups were then randomly assigned to treatments. Treatments consisted of: 1) control (no supplemental Cu); 2) 10 mg Cu/kg DM from $CuSO_4$; 3) 10 mg Cu/kg DM from a Cu amino acid complex (Availa Cu) 4) 20 mg Cu/kg DM from $CuSO_4$; and 5) 20 mg Cu/kg DM from Availa Cu. Steers were fed a corn-alfalfa-based growing diet for 56 d. Steers were then switched to a high concentrate finishing diet for 145 d. On day 74 of the finishing phase subcutaneous adipose tissue biopsies were obtained from three steers/treatment to determine basal and stimulated lipolytic rates in vitro. Steers were then slaughtered after receiving the finishing diet for 145 d. Control steers tended (p<0.12) to have lower ceruloplasmin (Cp) activity than Cu supplemented steers. Steers receiving 20 mg Cu/kg DM from Availa Cu had higher (p<0.03) Cp activity than steers receiving 20 mg Cu/kg DM from $CuSO_4$. Plasma non-esterified fatty acids were similar across treatments. Steers receiving 10 mg Cu/kg DM from Availa Cu had higher (p<0.02) total plasma cholesterol concentrations relative to steers receiving 10 mg Cu/kg DM from $CuSO_4$. Steers receiving 20 mg Cu/kg DM from Availa Cu had lower (p<0.03) plasma triglyceride concentrations than steers supplemented with 20 mg Cu/kg DM from $CuSO_4$. Fatty acid profile of longissimus muscle was similar across treatments. Backfat depth tended (p<0.18) to be lower in Cu supplemented steers relative to controls. Steers supplemented with 20 mg Cu/kg DM from Availa Cu had heavier (p<0.03) hot carcass weights and a greater (p<0.02) dressing percentage than steers supplemented with 20 mg Cu/kg DM from $CuSO_4$. Furthermore, in vitro basal (p<0.06) and epinephrine stimulated (p<0.04) lipolytic rates of subcutaneous adipose tissue were higher in Cu supplemented steers relative to controls. The results of this study suggest that Cu supplementation has minimal effects on blood and lean tissue lipid profile. However, it appears that Cu may play a role in lipid metabolism in subcutaneous adipose tissue.

• Asian-Australasian Journal of Animal Sciences
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• 제2권4호
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• pp.599-605
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• 1989

A comparison of the ARC metabolizable energy system and the NRC net energy system was made with special reference to growing steers. Two simulation models, one based on the ARC and other on the NRC system, were constructed to examine differences between the energy systems. The average daily live-weight gains predicted from both models for growing steers were compared under various conditions in which equal feeding levels and metabolizabilities were assumed. The two simulation models yielded similar results with very high energy intake with high quality feed. Difference between the two systems became larger as feeding conditions deviated from the above. The ARC system generally predicted higher daily live-weight gains than the NRC system. This appeared to be due to the higher efficiency of utilization of metabolizable energy ($k_m$ and $k_f$) and basal metabolism (F), and lower energy value of growth (EVG) in the ARC system.

• Asian-Australasian Journal of Animal Sciences
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• 제23권11호
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• pp.1469-1475
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• 2010

A study was conducted to investigate the effects of methods of feeding a total mixed ration (TMR) on behavior patterns of growing Hanwoo steers. A total of 15 growing steers (13 months old) were assigned to the control (fed roughage and concentrate mix separately), TMR1 (fed restricted TMR), and TMR2 (fed TMR ad libitum) groups. Individual behaviors of steers were observed for 48 hours. Compared with the control, feeding restricted TMR (TMR1) resulted in short eating time, long ruminating time, short chewing time, high frequencies of defecation, urination, and drinking of water, great numbers of boluses and chews, long ruminating time per bolus, low feed value index, high eating and chewing efficiencies (p<0.05). Compared with feeding restricted TMR (TMR1), feeding TMR ad libitum (TMR2) resulted in 1.2 kg more daily feed DM intake, long eating and chewing times, short resting time, great frequencies of defecation, urination and drinking of water, more numbers of boluses and chews, long ruminating time per bolus, low feed value index, low eating and high ruminating efficiencies (p<0.05) and similar chewing efficiency (p>0.05). Considering all these results, the wet TMR feeding system induced generally more desirable eating and ruminating behaviors of growing Hanwoo steers, but made the barn floor wetter due to more defecation and urination.

• Animal Bioscience
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• 제34권1호
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• pp.85-92
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• 2021

Objective: The objectives of this study were to determine the in situ degradation parameters and appropriate feeding level of pineapple cannery by-products (PCB) based on the growth performance and blood parameters of growing Hanwoo (Bos taurus coreanae) steers fed various levels of PCB. Methods: Two ruminally cannulated Holstein cows were used for in situ disappearance rate measurements. Nylon bags (5×10 cm, 45 ㎛ pore size) filled with 5 g of PCB in triplicate were inserted into the ventral sac of the two cannulated Holsteins cows and incubated for 0, 2, 4, 8, 16, 24, and 48 h. A total of 16 castrated growing Hanwoo steers (12.5±0.5 months old, 302.9±25.7 kg of initial body weight [BW]) were used for the experiment. Animals were stratified by initial BW and then randomly assigned to one of four experimental diets (0%, 1.5%, 3.0%, or 6.0% of PCB, on the dry matter [DM] basis) fed for 91-d, including 30-d of adaptation. Results: Soluble fraction a of DM and crude protein (CP) was 61.9% and 86.0%, fraction b of DM and CP was 32.7% and 11.2%, and indigestible fraction c of DM and CP was 5.4% and 2.8%. The 6.0% PCB feeding group showed lower productivity compared to animals in the other treatments. Increasing the dietary level of PCB did not alter DM intake, but it was numerically lowest in the 6.0% feeding group. The gain to feed ratio was linearly decreased by increasing of PCB. The quadratic broken-line test estimated that 2.5% (DM basis) was the maximum feeding level of PCB in growing Hanwoo steers (y = 0.103 - 0.001×[1.245-x]2, R2 = 0.18). Conclusion: Diets containing up to 2.5% PCB can be fed to growing Hanwoo steers without adverse effects on growth performance.

• 농업생명과학연구
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• 제50권5호
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• pp.163-172
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• 2016

우리는 심각한 열스트레스 및 서로 다른 사료 에너지 급여가 사료 소화율 변화에 미치는 영향과 심각한 열스트레스 조건에서 유지를 위한 에너지 요구량을 설정하기 위해 한우 육성기 거세우 4두(평균체중 200±11.7kg)를 이용하였다. 사료 처리는 서로 다른 에너지 공급을 위해 4 시험구(TDN 기준, 쾌적한 상태 하에서 한국사양표준 한우 육성우 에너지 요구량의 100%(대조구), 심각한 열스트레스 하에서 에너지 100%(E100), 115%(E115), 130%(E130)로 나누어 4×4 라틴 방각법으로 수행하였다. 온도 및 습도에 노출한 열스트레스 조건을 위해 대조구는 쾌적한 온습도지수(THI)=71.5, 나머지 3개 처리구는 THI=81.4로 심각한 스트레스 수준으로 설정하였다. 심각한 열스트레스는 진정 건물소화율을 유의적으로(p<0.05) 감소시켰으며(대조구 81.5 vs E100 79.1, E115 77.0 및 E130 76.0%), 사료에너지 공급 수준의 증가는 건물소화율의 감소를 가져오는 것으로 나타났다. 심각한 열스트레스 및 서로 다른 사료 에너지 급여 수준은 혈중 생리대사물질 함량 및 체온 변화에 유의적인 영향을 미치진 않았다(p>0.05). 본 연구를 통해 심각한 열스트레스 하에서 육성기 한우거세우의 유지를 위한 에너지 요구량은 Y=0.235X+115.03과 같은 산정식으로 계산될 수 있으며, 이러한 결과는 육성기 한우거세우에게 열스트레스 하에서 체중변화없는 유지 에너지 요구량을 만족시키기 위해서는 현재 한국사양표준 대비, 사료에너지 15.03%를 더 공급해야 할 것으로 판단된다.

• Animal Bioscience
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• 제35권10호
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• pp.1545-1555
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• 2022

Objective: Our study aimed to investigate the effects of a 2% increase in dietary total digestible nutrients (TDN) value during the growing (7 to 12 mo of age) and fattening (13 to 30 mo of age) period of Hanwoo steers. Methods: Two hundred and twenty Hanwoo steers were assigned to one of two treatments: i) a control group (basal TDN, BTDN, n = 111 steers, growing = 70.5%, early fattening = 71.0%, late fattening = 74.0%) or high TDN (HTDN, n = 109 steers, growing = 72.6%, early = 73.1%, late = 76.2%). Growth performance, carcass traits, blood parameters, and gene expression of longissimus dorsi (LD) (7, 18, and 30 mo) were quantified. Results: Steers on the BTDN diets had increased (p≤0.02) DMI throughout the feeding trial compared to HTDN, but gain did not differ appreciably. A greater proportion of cattle in HTDN received Korean quality grade 1 (82%) or greater compared to BTDN (77%), while HTDN had a greater yield grade (29%) than BTDN (20%). Redness (a^*) of LD muscle was improved (p = 0.021) in steers fed HTDN. Feeding the HTDN diet did not alter blood parameters. Steers fed HTDN diet increased (p = 0.015) the proportion of stearic acid and tended to alter linoleic acid. Overall, saturated, unsaturated, monounsaturated, and polyunsaturated fatty acids of LD muscle were not impacted by the HTDN treatment. A treatment by age interaction was noted for mRNA expression of myosin heavy chain (MHC) IIA, IIX, and stearoyl CoA desaturase (SCD) (p≤0.026). No treatment effect was detected on gene expression from LD muscle biopsies at 7, 18, and 30 mo of age; however, an age effect was detected for all variables measured (p≤0.001). Conclusion: Our results indicated that feeding HTDN diet could improve overall quality grade while minimum effects were noted in gene expression, blood parameters, and growing performance. Cattle performance prediction in the feedlot is a critical decision-making tool for optimal planning of cattle fattening and these data provide both benchmark physiological parameters and growth performance measures for Hanwoo cattle feeding enterprises.