• Asian-Australasian Journal of Animal Sciences
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• v.29 no.4
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• pp.530-538
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• 2016

Two experiments were conducted to determine the nutrient composition, in vitro ruminal ammonia concentrations and pH of wet distillers grains (WDG, produced from tapioca 70% and rice 30%) and to evaluate dietary effects of fermented total mixed ration (TMR) using WDG on the performance, blood metabolites and carcass characteristics of Hanwoo steers from mid fattening to slaughter. In Exp. I, average dry matter (DM), crude protein, ether extract, crude fiber, ash, neutral detergent fiber, acid detergent fiber, and nitrogen free extract of seven WDG samples from an ethanol plant with different sampling dates were 19.9%, 24.8%, 3.8%, 21.8%, 8.87%, 60.3%, 34.5%, and 40.7% (DM basis), respectively. For in vitro ammonia concentrations and pH, each sample was assigned to 7 incubation times (0, 4, 8, 12, 24, 48, and 72 h). Linear increase was observed between 12 and 48 h for ammonia concentrations, but final ammonia concentrations (72 h) were not significantly different among WDG samples and fermentation patterns of WDG samples showed similar tendency. In vitro pH varied among treatments from 0 to 24 h, but were not different statistically after 48 h. In Exp. II, 45 Hanwoo steers of 23 months ($641{\pm}123kg$) from mid fattening period to slaughter (248 days) were randomly divided into three groups of 15 pens each (five repetitions/each treatment) and assigned to one of three dietary treatments; i) Control (TMR), ii) WDG 15 (TMR containing 15% of WDG, as fed basis) and iii) WDG 28 (TMR containing 28% of WDG, as fed basis). The body weight (BW), ADG, and feed conversion ratio (FCR) of control and WDG 15 and 28 during 248 days were 760.8, 740.1, and 765.5 kg, and 0.50, 0.50, and 0.52 kg/d, and 18.6, 17.6, and 17.1, respectively. The dry matter intake (DMI) (kg/d) of control (9.11) was higher (p<0.05) than WDG treatments (WDG 15%, 8.57; 28%, 8.70). Nevertheless, DMI did not affect BW, ADG, and FCR of Hanwoo finishing steers. Blood metabolites were in normal ranges and were not different among treatments except the albumin concentration. In carcass characteristics, WDG 15 (30%) showed higher frequency of A-carcass yield grade than WDG 28 (15%) and control (7%), and WDG 28 (61%) showed higher frequency of $1^{{+}{+}}$ and $1^+$-carcass quality grade than WDG 15 (40%) and control (60%). In conclusion, using WDG up to 28% in TMR did not show any negative effect on the performance and blood metabolites, and improved carcass quality of Hanwoo steers. Therefore, WDG can be a useful feed ingredient for Hanwoo steers in mid-fattening period to slaughter.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.2
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• pp.209-213
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• 2005

This study was conducted to determine the optimum substitution level of dried leftover food (DLF) in formula feed for Hanwoo (Korean Native Cattle) steers. A total of forty growing steers were assigned to 5 treatments based on substitution level of DLF (at 0, 25, 50, 75 and 100% level of formula feed). The experiment was carried out with growing steers from 6 months of age to 24 months of age. Average daily gain (ADG) was not affected by DLF substitution level up to 75% of formula feed. However ADG decreased at 100% substitution level. Daily feed intakes were similar among treatments but the amount of feed per 1 kg gain increased with increasing substitution level of DLF. Dressing percentage was around 62% in all treatments without any significant differences. Proportion of quality beef higher than grade 1 was the greatest from animals fed 25% substitution level of DLF. Economic efficiency for Hanwoo steer operator was the highest with 50% substitution level of DLF.

• Food Science of Animal Resources
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• v.33 no.3
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• pp.305-316
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• 2013

The strategy for increasing the palatability of Hanwoo beef through fattening could lead to a decline in yield grade. The aim of this study was to examine the meat quality traits of Longissimus dorsi (LD) muscle from carcasses of Hanwoo steers at different yield grades. A total of 246 Hanwoo steers was divided into the following yield grades: A (n=77), B (n=76) and C (n=93). Meat quality traits, including proximate composition, cholesterol content, nucleotide content, dipeptide content, creatine and creatinine, free amino acid content, fatty acid composition, instrumental meat color, pH, water holding capacity, drip loss, cooking loss, and sensory qualities of the LD muscle from the 3 yield grades of Hanwoo carcasses were measured. The decline in yield grade from A to C resulted in an increase in crude fat and cholesterol content as well as a decrease in inosine 5'-monophosphate and aspartic acid in the LD muscle (p<0.05). In terms of fatty acid composition, the LD muscle from yield grade A had higher SFA and PUFA and lower MUFA content than that from yield grade C (p<0.05). However, the ratio of PUFA/SFA and n-6/n-3 did not differ among LD muscles from the 3 yield grades. There were no significant differences among other meat quality traits in relation to the yield grade. In conclusion, we suggest that the changes of substances related with health and flavor can be considered in order to obtain better quality Hanwoo beef.

• Journal of Animal Science and Technology
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• v.52 no.6
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• pp.505-511
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• 2010

Thirty six Hanwoo steers (average BW, $564.5\;{\pm}\;25.7\;kg$; average age, approximately 23 months) were used to evaluate the effects of a mixture of eugenol (14%), thymol (1%) and malate (85%) on growth performance, beef quality and liver function in Hanwoo finishing steers fed a high-concentrate diet. A feeding trial was conducted for 7 months in National Agricultural Cooperative Federation farm located in Anseong, Korea. Steers were assigned randomly to one of three treatments: control (without additive supplementation), treatment 1 (0.05% additive of concentrate), treatment 2 (0.1% additive of concentrate). The results of this study showed that initial and final BW averaged 564 and 755 kg, respectively, and BW gain was significantly higher (P<0.05) for steers fed the additive mixture than for those fed no mixture (0.78 and 0.79 vs. 0.69 kg/d, respectively). Serum aspartate aminotransferase in the T2 treatment was decreased during the 24 to 31 months of age. Although supplementation of additives resulted in no substantial effect on carcass characteristics, it had a potential effect to improve feed efficiency and AST concentration in Hanwoo finishing steers fed a high-concentrate diet. In conclusion, a mixture of eugenol, thymol and malate has shown promise in improving feed efficiency and liver function in the finishing phase of Hanwoo steers.

• Journal of Animal Science and Technology
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• v.54 no.6
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• pp.443-448
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• 2012

This study was conducted to investigate changes of blood metabolites and enzyme activities at different slaughter ages of Hanwoo cattle. Blood samples were taken from six hundred thirty two steers (24~33 months of age) and one hundred twenty eight bulls (17~24 months of age) by venipuncture from caudal vein immediately prior to slaughter. Glucose concentrations were linearly increased (P<0.001) with increases of the slaughter age in steers, and blood urea nitrogen (BUN) concentrations were linearly decreased (P<0.001) with increases of the slaughter age in steers. Likewise, glucose and albumin concentrations in bulls were linearly decreased (P=0.009 and P<0.001, respectively) with increases of the slaughter age. BUN, cholesterol, triglycerides, and total cholesterol concentrations were linearly increased (P<0.001, 0.018 and 0.002, respectively), and creatinine concentrations were quadratically increased (P=0.009) with increases of the slaughter age. Activity of gamma glutamyltransferase (${\gamma}$-GT) and aspartate aminotransferase (AST) was linearly increased (P<0.001) with increases of the slaughter age in both steers and bulls, whereas alanine aminotransferase (ALT) was not affected by increasing slaughter age. In addition, the concentrations of ${\gamma}$-GT and AST were higher (P<0.05) for bulls than those of steers at 24 months of age. Increased levels of ${\gamma}$-GT and AST indicate impaired liver function; it may be associated with increases of concentrate level which is a concomitant of the extended fattening periods in Hanwoo feeding. In conclusion, the results in the present study may be one of the useful information for diagnosis of the metabolic disorder in Hanwoo cattle.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.7
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• pp.1087-1095
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• 2020

Objective: The present study aimed to evaluate the effects of γ-aminobutyric acid (GABA)-producing bacteria (GPB) on in vitro rumen fermentation and on the growth performance and meat quality of Hanwoo steers. Methods: The effects of GPB (Lactobacillus brevis YM 3-30)-produced and commercially available GABA were investigated using in vitro rumen fermentation. Using soybean meal as a substrate, either GPB-produced or commercially available GABA were added to the in vitro rumen fermentation bottles, as follows: control, no additive; T1, 2 g/L GPB; T2, 5 g/L GPB; T3, 2 g/L autoclaved GPB; T4, 5 g/L autoclaved GPB; T5, 2 g/L GABA; and T6, 5 g/L GABA. In addition, 27 Hanwoo steers (602.06±10.13 kg) were subjected to a 129-day feeding trial, during which they were fed daily with a commercially available total mixed ration that was supplemented with different amounts of GPB-produced GABA (control, no additive; T1, 2 g/L GPB; T2, 5 g/L GPB). The degree of marbling was assessed using the nine-point beef marbling standard while endotoxin was analyzed using a Chromo-Limulus amebocyte lysate test. Results: In regard to in vitro rumen fermentation, the addition of GPB-produced GABA failed to significantly affect pH or total gas production but did increase the ammonia nitrogen (NH₃-N) concentration (p<0.05) and reduce total biogenic amines (p<0.05). Animals fed the GPB-produced GABA diet exhibited significantly lower levels of blood endotoxins than control animals and yielded comparable average daily gain, feed conversion ratio, and beef marbling scores. Conclusion: The addition of GPB improved in vitro fermentation by reducing biogenic amine production and by increasing both antioxidant activity and NH₃-N production. Moreover, it also reduced the blood endotoxin levels of Hanwoo steers.

• Journal of Animal Science and Technology
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• v.56 no.3
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• pp.9.1-9.8
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• 2014

This study was performed to investigate the effects of different forms of concentrate fed to Hanwoo steers on performance, carcass characteristics, and economic performance. Forty-two Hanwoo steers (average age of $5.1{\pm}0.8mo$. with body weight of $147.05{\pm}10.85kg$) were randomly allotted into FC (animals fed flakes for entire experimental period) and GC (animals fed grounded concentrate during growing and fattening phases followed by flaked concentrate during finishing phase) groups for 758 d after reaching an age of $30.0{\pm}0.82mo$. There was no difference in body weight (BW) or ADG between the treatments until fattening (15 ~ 22 mo.) phase. However, by finishing phase (23 ~ 30 mo.), the GC group (739.24 kg BW and 0.67 kg ADG) showed greater (P < 0.05) BW and ADG than the FC group (702.93 kg BW and 0.59 kg ADG). Steers in the GC group also showed greater (P < 0.05) BW and ADG than the FC group throughout the entire experimental period (5 ~ 30 mo.). There was no significant difference in carcass weight or backfat thickness between the treatments. M. Longissimus dorsi area of the GC group ($91.00cm^2$) was greater (P < 0.05) than that of the FC group ($83.59cm^2$). Marbling score and percentage of $1^{{+}{+}}$ meat quality grade were 14.0 and 48.0% higher in the GC group compared to the FC group. There was no significant difference in physicochemical characteristics, including moisture and crude protein levels, between the treatments. Gross income per head excluding operating expenses was 59.3% greater in the GC group (1,647,512 won) compared to the FC group (1,034,343 won).

• Journal of Animal Science and Technology
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• v.44 no.6
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• pp.747-756
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• 2002

This experiment was carried out to investigate the effects of proportion of concentrates and roughages on growth and carcass traits of Hanwoo steers. Concentrates and roughages were allotted three levels of 35 to 11%, 44 to 12% and 53 to 13%, respectively from the growing period to finishing period. Concentrate and roughage intake of Hanwoo steers were increased progressively until body weight reached 450kg and 300kg, respectively and reached 1.8 to 1.9% and 1.04 to 1.44% to body weight, respectively but thereafter were decreased gradually. Marbling score and beef grade were tended to be increased when steers were fed 44% roughage compared with the steers fed 35% or 53% at the growing period. Therefore, it can be concluded that feeding 44% of roughage is desirable rather than feeding 35% or 53% of roughage when steers are fattening.

• Journal of Animal Science and Technology
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• v.65 no.6
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• pp.1270-1289
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• 2023

This study evaluates how different feeding systems impact ruminal fermentation, methane production, and microbiota of Hanwoo steers native to Korea. In a replicated 2 × 2 crossover design over 29 days per period, eight Hanwoo steers (507.1 ± 67.4 kg) were fed twice daily using a separate feeding (SF) system comprising separate concentrate mix and forage or total mixed rations (TMR) in a 15:85 ratio. The TMR-feeding group exhibited a considerable neutral detergent fiber digestibility increase than the SF group. However, ruminal fermentation parameters and methane production did not differ between two feeding strategies. In addition, TMR-fed steers expressed elevated Prevotellaceae family, Christensenellaceae R-7 group, and an unidentified Veillonellaceae family genus abundance in their rumen, whereas SF-fed steers were rich in the Rikenellaceae RC9 gut group, Erysipelotrichaceae UCG-004, and Succinivibrio. Through linear regression modeling, positive correlations were observed between the Shannon Diversity Index and the SF group's dry matter intake and methane production. Although feeding systems do not affect methane production, they can alter ruminal microbes. These results may guide future feeding system investigations or ruminal microbiota manipulations as a methane-mitigation practice examining different feed ingredients.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.4
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• pp.375-382
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• 2009

This study examined the influence of forage source (grass hay and rice straw) and shipping time (24, 26, 28 and 30 months) on feed conversion ratio, growth performance and carcass characteristics of Hanwoo steers. Sixty four Hanwoo steers at 6 months age were fed either grass hay (n=32) or rice straw (n=32) for 24, 26, 28 and 30 months of age. Steers fed on mixed grass hay gained significantly higher body weight at 24, 26, 28 and 30 months compared with those fed on rice straw. Feed efficiency was slightly better in steers fed mixed grass hay compared to those fed rice straw. Back fat thickness and marbling score were increased with the age of steers (p<0.05). Carcass quality traits (meat color, fat color, texture and maturity) were not affected by forage source and shipping time. Shear force, cooking loss and water holding capacity of beef were reduced with advancing age of steers (p<0.05). Moisture content was lower and fat content was higher in beef produced from steers fed mixed grass hay than those fed rice straw (p<0.05). Beef juiciness was reduced with the advancing shipping time of steers. In conclusion, it would be beneficial to feed hay compared with rice straw during whole period of Hanwoo steer to produce high quality beef.