• Asian-Australasian Journal of Animal Sciences
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• 제18권3호
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• pp.358-363
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• 2005

Five crossbred beef cattle (Simmental${\times}$yellow cattle, Shantung Province) fitted with permanent cannulae in the rumen and T-type cannulae at the proximal duodenum and terminal ileum, were fed five different diets containing corn, cotton meal or soybean meal and ammoniated straw to determine the dry matter, crude protein and amino acid flows in duodenal and ileum digesta, and to calculate the regression equations between theoretical and experimental concentration of AA in duodenal digesta. The results showed that there was a strong correlation between experimental (g/d, y) and theoretical CP flows (g/d, x) at the proximal duodenum, the $R^2$-value regression equation of crude protein is very high (0.9636). The $R^2$-value regression equation of the limiting amino acid (such as Met or Lys) is high (0.7573 or 0.9252 respectively). This results indicated that we can formulate better diets fed to beef cattle according to the theoretical amino acid concentration. A mathematical model has been successfully constructed for predicting the supply of absorbed amino acids at the proximal duodenum in growing beef cattle.

• Asian-Australasian Journal of Animal Sciences
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• 제13권10호
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• pp.1467-1481
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• 2000

The Korean cattle industry is important to farming households, the national economy, and the security of foodstuffs in Korea. Since Korean cattle have had inferior ability to produce meat, the Korean cattle industry aimed to improve the meat production ability and to increase numbers to meet the demand from the growing beef cattle market in Korea. This paper reviews the history of the Korean cattle industry and surveys the efforts devoted to improve genetic abilities of the Korean cattle. Discussed are current situations of the Korean cattle industry, projects related to improvement of Korean cattle, Korean cattle's genetic characteristics of economic traits, and some issues to deal with.

• Animal Bioscience
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• 제34권9호
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• pp.1425-1438
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• 2021

Maintaining a high level of beef consumption requires paying attention not only to quantitative traits but also to the quality and dietary properties of meat. Growing consumer demands do not leave producers many options for how animals are selected for breeding and animal keeping. Meat and carcass fatness quality traits, which are influenced by multiple genes, are economically important in beef cattle breeding programs. The recent availability of genome sequencing methods and many previously identified molecular markers offer new opportunities for animal breeding, including the use of molecular information in selection programs. Many gene polymorphisms have thus far been analyzed and evaluated as potential candidates for molecular markers of meat quality traits. Knowledge of these markers can be further applied to breeding programs through marker-assisted selection. In this literature review, we discuss the most promising and well-described candidates and their associations with selected beef production traits.

• Journal of Animal Science and Technology
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• 제61권5호
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• pp.260-271
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• 2019

The objective of this study was to determine the effect of different stocker management programs on skeletal muscle development and growth characteristics, satellite cell (SC) activity in growing-finishing beef cattle as well as the effects of SC-conditioned media on preadipocyte gene expression and differentiation. Fall-weaned Angus steers (n = 76; $258{\pm}28kg$) were randomly assigned to 1 of 4 stocker production systems: 1) grazing dormant native range (NR) supplemented with a 40% CP cottonseed meal-based supplement ($1.02kg{\cdot}steer^{-1}{\cdot}d^{-1}$) followed by long-season summer grazing (CON, 0.46 kg/d); 2) grazing dormant NR supplemented with a ground corn and soybean meal-based supplement fed at 1% of BW followed by short-season summer grazing (CORN, 0.61 kg/d); 3) grazing winter wheat pasture (WP) at high stocking density (3.21 steers/ha) to achieve a moderate rate of gain (LGWP, 0.83 kg/d); and 4) grazing winter WP at low stocking density (0.99 steers/ha) to achieve a high rate of gain (HGWP, 1.29 kg/d). At the end of the stocker (intermediate harvest, IH) and finishing (final harvest, FH) phases, 4 steers / treatment were harvested and longissimus muscles (LM) sampled for cryohistological immunofluorescence analysis and SC culture assays. At IH, WP steers had greater LM fiber cross-sectional area than NR steers; however, at FH, the opposite was observed (p < 0.0001). At IH, CORN steers had the lowest Myf-5+:Pax7+ SC density (p = 0.020), while LGWP steers had the most Pax7+ SC (p = 0.043). At FH, CON steers had the highest LM capillary density (p = 0.003) and their cultured SC differentiated more readily than all other treatments (p = 0.017). At FH, Pax7 mRNA was more abundant in 14 d-old SC cultures from HGWP cattle (p = 0.03). Preadipocytes exposed to culture media from proliferating SC cultures from WP cattle isolated at FH had more $PPAR{\gamma}$ (p = 0.037) and less FABP4 (p = 0.030) mRNA expression compared with NR cattle. These data suggest that different stocker management strategies can impact skeletal muscle growth, SC function, and potentially impact marbling development in growing-finishing beef cattle.

• Asian-Australasian Journal of Animal Sciences
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• 제29권3호
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• pp.372-377
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• 2016

The objectives of the trial were to investigate the effects of supplementing vitamin E (VE) on nutrient digestion, nitrogen (N) retention and plasma parameters of beef cattle in feedlot. Four growing Simmental bulls, fed with a total mixed ration composed of corn silage and concentrate mixture as basal ration, were used as the experimental animals. Four levels of VE product, i.e. 0, 150, 300, 600 mg/head/d (equivalent to 0, 75, 150, 300 IU VE/head/d), were supplemented to the basal ration (VE content 38 IU/kg dry matter) in a $4{\times}4$ Latin square design as experimental treatments I, II, III and IV, respectively. Each experimental period lasted 15 days, of which the first 12 days were for pretreatment and the last 3 days for sampling. The results showed that supplementing VE did not affect the nutrient digestibility (p>0.05) whereas decreased the urinary N excretion (p<0.01), increased the N retention (p<0.05) and tended to increase the microbial N supply estimated based on the total urinary purine derivatives (p = 0.057). Supplementing VE increased the plasma concentrations of VE, glucose and triglycerol (TG) (p<0.05) and tended to increase the plasma concentration of total protein (p = 0.096) whereas did not affect the plasma antioxidant indices and other parameters (p>0.05). It was concluded that supplementing VE up to 300 IU/head/d did not affect the nutrient digestibility whereas supplementing VE at 150 or 300 IU/head/d increased the N retention and the plasma concentrations of VE and TG (p<0.05) of beef cattle.

• Asian-Australasian Journal of Animal Sciences
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• 제8권3호
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• pp.281-287
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• 1995

A study was conducted to investigate the effect of different inclusion levels of urea treated whole-crop wheat silage (UWCWS) in grass silage based rations on the performance of growing beef cattle. The winter wheat (variety, Riband) was harvested (in the summer of 1991) at a dry matter proportion of 520 g/kg and treated with feed grade urea at the rate of 37 kg/tonne crop dry matter and preserved in a heavy duty plastic bag using a silo press. The urea treated whole crop wheat silage (UWCWS) was mixed with grass silage to replace 0.00 (S100), 0.33 (S33) and 0.67 (S67) parts of the forage dry matter and fed ad libitum in a cross over design to 18 Simmental X Holstein Friesian growing beef animals. Two energy sources {one high in starch, rolled barley (RB) and one high in digestible fibre, sugar beet pulp (SBP)} were fed to supply sufficient energy for the efficient use of nitrogen by the rumen micro-organisms. The data on DMIF (dry matter intake of forage), TDMI (total dry matter intake), DLWG (daily live weight gain), FCR (feed conversion ratio) were recorded and faecal samples were collected to determine the digestibility coefficients. Results revealed that with the inclusion of UWCW in the animals' diets the DMI of the forage was significantly increased (p < 0.05). The highest DMIF was found in the treatment "S33" ($6.28{\pm}0.25kg$) where 67% of the silage dry matter was replaced with the UWCW and the lowest value for DMIF was observed in the control treatment ($5.03{\pm}0.23kg$). The DLWG did not differ significantly between the treatments. However, treatment "S100" showed a trend towards a superior DLWG. Feed conversion ratio in the control treatment differed significantly from "S67" and "S33". The addition of the UWCW in the animals' diet resulted in the lower FCR There was no effect of type of energy supplement on any aspect of performance either overall or in interaction with grass silage: UWCWS ratio. The regression and correlation coefficients for DMIF (r = 5.22 + 0.0184x*), DLWG (r = $1.04-0.00086x^{NS}$) and FCR (r = 4.78 = 0.022x*) on the inclusion of UWCW in the diet were calculated. The effect of the inclusion of UWCW on the overall digestibility coefficients was significant (p < 0.05). The addition of the UWCWS in the diet decreased the digestibility of the DM, OM, ADF and NFE but effect on the protein digestibility was non significant. The results of present study suggests that a DLWG slightly over 1 kg can be achieved with UWCW during the store period (period in which animal performance targets are low especially during winter) and the prediction of ME was overestimated as the high intake of DM did not reflect in improved animal performance.

• Asian-Australasian Journal of Animal Sciences
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• 제13권5호
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• pp.702-710
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• 2000

A large portion of total energy expenditure associated with ruminant livestock production goes towards maintenance. Approximately 55% of whole body energy use is consumed by visceral tissues (including internal organs) with the majority of this going to the liver and gastrointestinal tract. Muscle and adipose tissues consume about 27% of total body energy expenditure. Metabolic components within the viscera responsible for the majority of energy consumption include ion transport, protein turnover, substrate cycling, and urea synthesis (liver). Within muscle tissue of growing animals ion transport and protein turnover account for most of the energy expenditure. Protein synthesis consumes approximately 23% of whole body energy use and visceral tissues account for proportionally more of whole body protein synthesis than skeletal muscle. Research efforts focused on improving energetic efficiency of the tissues and metabolic mechanisms responsible for the majority of whole animal energy expenditure should provide information leading to more efficient production of an edible product.

• Asian-Australasian Journal of Animal Sciences
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• 제20권12호
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• pp.1909-1916
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• 2007

This study compared the growth performance and carcass evaluation of Jeju native cattle (JNC) and its crossbreds (CBK = 25 JNC:50 Charolais:25 Brahman and BCBK = 62.5 JNC:25 Charolais:12.5 Brahman). Eight male calves of each JNC, CBK and BCBK were weaned at 4 month of age and were fed for 24 months of age. All animals grazed a pasture between 5 to 10 months of age then they were fed growing ration at the rate of 1.5% of their BW along with ad libitum supply of Italian ryegrass hay between 11 to 16 months of age and thereafter switched to ad libitum feeding of finishing ration and hay between 17 to 24 months of age. Mean body weight (BW) and BW gain were higher in CBK compared with BCBK and JNC at 4, 10, 16 and 24 months of age. Average daily BW gain during 4 to 10 months of age was the highest for CBK followed by BCBK and JNC. However, daily BW gain was higher in BCBK than in CBK and JNC during 11 and 16 months of age. During fattening period (17 to 24 months) average daily BW gain was higher in JNC than in CBK and BCBK. Slaughter weight, hot and cold carcass weight were higher in CBK compared with JNC and BCBK. Weight of bones, boneless meat, ribs, excluded rib meat, retailed cut meat, tender loin, sir loin, strip loin, sticking, top round, bottom round, fore leg, shank, and thin-flank were higher in CBK than in BCBK and JNC. Fat weight in these carcass cuts and kidney fat was similar in JNC and its crossbreds. Logissimus dorsi and its ratio were higher in CBK compared with BCBK and JNC. Percent moisture, crude protein, and ash contents of beef were similar in JNC and its crossbreds. Percent beef fat was higher in JNC and BCBK than in CBK. Cooking loss and water holding capacity of beef was similar in JNC and its crossbreds. Sheer force was lower in BCBK compared with JNC and CBK. Juiciness, tenderness and flavor of beef were higher in BCBK compared with JNC and CBK. In conclusion, CBK has shown higher growth rate and produced heavier carcasses with good degree of fatness compared with JNC and BCBK. However, fattening for longer period could increase the maintenance cost in CBK and BCBK because of their higher BW which they attained during growing period.

• Asian-Australasian Journal of Animal Sciences
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• 제17권5호
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• pp.648-654
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• 2004

This study was carried out to assess whether feeding of alcohol-fermented feeds (AFF) affects the nutritional metabolism and growth characteristics of Korean native steers. Ten steers were randomly assigned to one of two treatment groups. The dietary treatments were AFF (50% commercial beef cattle feed+30% alcohol-fermented soybean curd dregs+20% rice straw) and control (80% commercial beef cattle feed+20% rice straw). The change of serum metabolites and growth characteristics were measured every two months during the whole twelve months experimental period and the relationships between serum metabolites and growth characteristics were simultaneously analyzed. Four hours after feeding AFF, serum alcohol concentration reached its peak with a significantly higher value than that after control feeding (11.9 and 4.9 mg/dl, respectively). Serum glucose and inorganic phosphorus (IP) concentrations (63.1 and 8.4 mg/dl, respectively) of steers fed AFF were higher than those (56.6 and 7.0 mg/dl) fed the control diet. In both treatments, the serum glucose concentration rapidly increased when body weight (BW) of the steer reached about 600kg, while IP concentrations were rapidly diminished at that BW. Lower concentrations of both blood urea nitrogen (BUN) and cholesterol were observed in steers fed AFF up to 450 kg of BW. The IP concentration was correlated with concentrations of BUN, cholesterol and glucose in AFF fed cattle but not in the cattle fed control diets. Average daily gain was higher in steers fed AFF than steers fed control, particularly during the growing stage of cattle. These findings indicated a capability of AFF to improve BW gain of Korean native steers by decreased protein degradation as well as increased fat synthesis.

• Journal of Animal Science and Technology
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• 제66권3호
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• pp.523-542
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• 2024

Hanwoo and Jeju Black cattle (Jeju Black) are native breeds of Korean cattle. Jeju Black cattle are recognized as natural monuments and are known to exhibit slower growth rates compared to Hanwoo. While several studies have analyzed the genetic characteristics of these cattle, there has been limited research on the differences in their microbiome. In this study, rumen fluid was obtained from three Hanwoo steers and three Jeju Black steers, and three different diets (total mixed rations [TMRs] for growing, early fattening, and late fattening periods) were used as substrates for in vitro fermentation. The in vitro incubation was conducted for 3 h and 24 h following a 2 × 3 factorial arrangement. After both incubation periods, fermentation characteristics were analyzed, and ruminal microbiome analysis was performed using 16S rRNA gene sequencing, employing both QIIME2 and PICRUSt2. The results revealed significant differences in the ruminal microbiota due to the inoculum effect. At the phylum level, Patescibacteria and Synergistota were found to be enriched in the Jeju Black inoculum-treated group. Additionally, using different inocula also affected the relative abundance of major taxa, including Ruminococcus, Pseudoramibacter, Ruminococcaceae CAG-352, and the [Eubacterium] ruminantium group. These microbial differences induced by the inoculum may have originated from varying levels of domestication between the two subspecies of donor animals, which mainly influenced the fermentation and microbiome features in the early incubation stages, although this was only partially offset afterward. Furthermore, predicted commission numbers of microbial enzymes, some of which are involved in the biosynthesis of secondary metabolites, fatty acids, and alpha amylase, differed based on the inoculum effect. However, these differences may account for only a small proportion of the overall metabolic pathway. Conversely, diets were found to affect protein biosynthesis and its related metabolism, which showed differential abundance in the growing diet and were potentially linked to the growth-promoting effects in beef cattle during the growing period. In conclusion, this study demonstrated that using different inocula significantly affected in vitro fermentation characteristics and microbiome features, mainly in the early stages of incubation, with some effects persisting up to 24 h of incubation.