Dietary effects of protected fat, glycerol, and soybean meal on performance, physiological parameters, carcass characteristics, and behavioral measurements of late-fattening Hanwoo steers under heat stress conditions.

Objective: This study aimed to determine the effects of increasing energy and protein levels in diets by including protected fat (PF), glycerol (GL), and soybean meal (SBM) on growth performance, physiological parameters, carcass characteristics, and behavioral measurements of late-fattening Hanwoo steers under heat stress conditions. Methods: Thirty-six steers (initial BW, 724.9 ± 58.3 kg; age, 25.5 ± 0.4 month) were assigned into Control (TDN 76%, CP 15%), PF (TDN 83.6%, CP 15%), PF+GL (TDN 83.6%, CP 15%) and PF+GL+SBM (TDN 83.6%, CP 16.5%) by randomized complete block design for a total of 16 weeks with division of 4 week periods. The average temperature-humidity index was 87.0 (1st period; Severe), 82.8 (2nd; Moderate), 71.4 (3rd; Comfort), and 68.1 (4th; Comfort). Results: The DMI showed no treatments differences during the whole experiment. However, DMI in 1st and 2nd period decreased by approximately 30% and 10% compared to 4th period, respectively. Higher ADG and FCR were noted for treatments compared to Control at both 1st and 2nd period (p<0.05). There were no treatment effects on rectal temperature (RT), cortisol, and behaviors during the entire experiment. However, both RT and cortisol in 0, 1st and 2nd period were higher than those of 3rd and 4th period (p<0.05). Carcass yield and grade remained unaffected by increasing TDN and CP levels. Behavioral changes in the hot season (1st period) included reduced lying (43%), increased standing (48%), decreased walking (62%), and decreased eating (38%) (p<0.05), with an increase in drinking by 54%. Rumination during standing was 53% higher, while rumination during lying was about 33% lower compared to the post-hot season (3rd period) (p<0.05). Conclusion: Dietary supplementation of protected fat in late-fattening Hanwoo steers under heat stress had a positive effect on preventing a reduction in performance.

Effects of heat stress on performance, physiological parameters, and blood profiles of early-fattening Hanwoo steers in climate chambers.

OBJECTIVE: This study was conducted to assess effects of heat stress on growth performance, physiological parameters, and blood profiles of Hanwoo steers during early-fattening period in climate chambers. METHODS: Four Hanwoo steers (body weight, 454.3±10.9 kg; age, 14±0.1 month) were allocated into four levels of temperature-humidity index (THI) in a 4×4 Latin square design for 21 days (pre-adaptation, 7 d; heat stress, 7 d; post-adaptation, 7 d) per period. Experimental treatments were assigned according to THI chart based on National Institute Animal Science (NIAS, 2022): Comfort (25.5°C to 26.5°C, 60%; THI 73 to 75), Mild (28°C to 29°C, 60%; THI 77 to 79), Moderate (29.5°C to 30.5°C, 80%; THI 82 to 84), and Severe (31°C to 32°C, 80%; THI 85 to 86) in separate climatic controlled chambers. RESULTS: The dry matter intake (DMI) of the formula feed was lower in Severe compared to Mild and Comfort (p<0.05). The DMI of rice straw was the lowest in Severe and lower in Moderate than Comfort and Mild (p<0.05). Both average daily gain and feed conversion ratio of Severe and Moderate were lower than those of Mild and Comfort (p<0.05). Water intake was the highest in Severe and lower in Moderate compared with Comfort and Mild (p<0.05). Heart rate and rectal temperature increased as THI level increased (p<0.05). Glucose was the lowest in Severe and lower in Moderate compared to Comfort (p<0.05). On the contrary, non-esterified fatty acid was the highest in Severe and lower in Moderate compared with Comfort (p<0.05). Blood urea nitrogen of Moderate and Severe were higher than those of Comfort and Mild (p<0.05). Cortisol increased as THI increased (p<0.05). CONCLUSION: This study demonstrated the negative effects of heat stress on the performance and physiological responses of Hanwoo steers during the early-fattening period. In addition, it is judged that the THI chart for Hanwoo steers of National Institute of Animal Science (2022) was properly calculated.

Heat Stress Effects on Physiological and Blood Parameters, and Behavior in Early Fattening Stage of Beef Steers.

This study was conducted to investigate the effect of heat stress (HS) on physiological, blood, and behavioral parameters, according to the temperature-humidity index (THI), in beef steers. Twelve Korean native beef steers (342.7 ± 13.81 days old, body weight (BW) of 333.0 ± 18.53 kg) were used in this experiment. Beef steers were randomly distributed into three homogenized groups (four beef steers each) for 14 days, namely, threshold (THI = 64-71), mild-moderate (THI = 72-79), and severe (THI = 80-87). Feed and water intake were recorded daily. Physiological parameters, including heart rate and rectal temperature, and behavioral patterns (standing and lying down) were measured weekly. Blood was sampled every week to analyze hormones, heat shock protein (HSP) levels, metabolites, and hematological parameters. All data were analyzed using repeated-measures analysis. Beef steers exposed to severe THI had significantly increased (p < 0.001) water intake, heart rate, and rectal temperature compared to the threshold and mild-moderate THI beef steers. Additionally, increased blood cortisol (p < 0.001), HSP70 (p < 0.001), blood urea nitrogen (BUN) (p = 0.014), and time spent standing (p < 0.001) were observed in beef steers after exposure to severe THI compared to beef steers in the threshold and mild-moderate THI groups. However, dry matter intake, blood glucose, and non-esterified fatty acids were not different among the THI groups. In conclusion, heart rate, rectal temperature, blood cortisol, HSP70, BUN, and time spent standing were closely associated with severe HS conditions in beef steers. These phenomena indicated that beef steers exposed to HS modulated their behavior and blood parameters, as well as their physiological response, to maintain homeostasis.

Prediction of total digestible nutrient and crude protein requirements according to daily weight gain, and behavioral measurements of Hanwoo heifers.

OBJECTIVE: This study was conducted to investigate the effects of energy and protein levels in the diet of Hanwoo heifers on growth response and animal behavior. METHODS: Forty heifers were randomly allocated into three experimental groups according to the target daily weight gain in 8 pens (T-0.2, 2 replications; T-0.4 and -0.6, 3 replications) based on similar body weight (BW) and age in months. The target average daily gain (ADG) was set at 0.2 (T-0.2), 0.4 (T-0.4), and 0.6 kg/d (T-0.6), and feed was based on National Institute of Animal Science (NIAS, 2017). In order to minimize hunger stress of T-0.2 and -0.4, the feeding ratio of rice straw was set to 55%, 50%, and 45% for T-0.2, -0.4 and T-0.6, respectively, so that the dry matter (DM) intake for all treatment groups was uniform but the energy and protein levels in the diet were adjusted differently. A total of 6 items (lying, standing, eating, rumination, walking and drinking) of animal behavior were analyzed. RESULTS: During the whole period of the experiment, the ADG of the T-0.2, -0.4 and -0.6 treatments were 0.48, 0.56, and 0.65 kg/d (p<0.05), respectively, showing higher gain than the predicted value, especially for the low target ADG group. Based on these results, regression equations for the total digestible nutrient (TDN) and crude protein (CP) requirements were derived. No behavioral differences were found according to the energy and protein levels in the diet because the DM intake was kept constant by adjusting the roughage and concentration ratio. However, eating time was longer (p<0.05) at T-0.2 than T-0.6 during the whole day. CONCLUSION: Through this study, it was possible to derive regression equations for predicting TDN and CP requirements according to the target ADG and BW.

Nutritional value and in situ degradability of oak wood roughage and its feeding effects on growth performance and behavior of Hanwoo steers during the early fattening period.

OBJECTIVE: This study was conducted to evaluate changes in nutritional value and in situ dry matter (DM) degradability of oak and pine wood before and after steam-digestion process (60 min/160°C/6 atm) and feeding effect of the oak roughage on performance and behavior of Hanwoo steers. METHODS: Chemical composition and tannin concentration were analyzed for oak and pine trees before and after the pretreatment. In situ DM and effective degradability of these samples were assessed using a nylon bag method. In vivo trial was performed to estimate animal performance and behavior, using steers fed total mixed ration (TMR) diets containing 0% (control), 25% (OR-25), and 50% (OR-50) of the oak roughage. Eighteen steers were allocated into nine pens (2 steers/pen, 3 pens/treatment) for 52 days according to body weight (BW) and age. RESULTS: By the steam-digestion treatment, the neutral detergent-insoluble fiber was decreased from 86.5% to 71.5% for oak and from 92.4% to 80.5% for pine, thereby increasing non-fiber carbohydrate. In situ DM degradability of treated oak reached 38% at 72 h, whereas that of untreated oak was only 11.9%. The 0 h degradability of the treated pine increased from 5.9% to 12.1%, but the degradability was unchanged thereafter. Animal performance including BW, average daily gain, DM intake, and feed conversion ratio was not different among control and oak treatments. No differences were detected in animal behavior such as lying, standing, rumination, drinking, and eating, except walking. Walking was higher in control than oak treatments with numerically higher eating and lower lying times, probably due to bulkier characteristics of rice straw in the diet. CONCLUSION: This study demonstrates that the oak roughage can be substituted for 50% of total forage or 100% of rice straw in TMR diets at early fattening stage of Hanwoo steers.

Characteristics of sawdust, wood shavings and their mixture from different pine species as bedding materials for Hanwoo cattle.

OBJECTIVE: This study was conducted to evaluate the physicochemical properties and changes in moisture concentrations of bedding materials under the conditions of rearing Korean Hanwoo cows. METHODS: Two experiments were conducted to investigate the physicochemical characteristics (Exp. I) and usefulness as beddings for rearing cattle (Exp. II) by the type of beddings such as sawdust (SD), wood shavings (WS) and sawdust+wood shavings (S+W; 1:1 in volume), and the species of pine trees from different countries of origins (China, Pinus armandii, AR; Vietnam, Pinus kesiya, KE; USA, Pinus rigida, RI). RESULTS: In Exp. I, SD-AR showed the largest proportion (78.3%) of fine particles (250 µm+ below 250 µm) and the highest bulk density (208 kg/m3) among treatments (p<0.05). The water absorption capacity at 24 h of both S+W-RI (713%) and -KE (701%) was the highest among treatments (p<0.05) and higher than those of SD or WS alone within each species of pine tree (p<0.05). Moisture evaporation rates (%) at 12 h were ranged from 52.3 to 60.8 for SD, 69.9 to 74.4 for WS, and 72.3 to 73.5 for S+W. Total amounts (mg/m2) of ammonia emissions were the lowest (p<0.05) in KE species among the pine species within each type of bedding material, having higher ability of ammonia absorption. In Exp II, KE species in both side A and B had lower moisture concentrations (%) than other species. Regardless of types of beddings except SD-AR, moisture concentrations of beddings within a pen were higher (p<0.01) at side A than B. CONCLUSION: The KE species has better physical characteristics than other beddings and more useful for rearing Hanwoo cattle than other beddings, probably caused by the differences in the method and degree of wood processing rather than the species.

Nutritional value and in situ degradability of fruit-vegetable byproducts and their feeding effects on performance of growing Hanwoo steers.

OBJECTIVE: This study was conducted to evaluate nutritional value and in situ degradability of fruit-vegetable byproducts and their feeding effects on performance of growing Hanwoo steers. METHODS: Nutritional value and in situ degradability of cabbage, Chinese cabbage and fruit-vegetable byproducts were assessed. In vivo feeding trial was also performed for 12 weeks. Thirty-six growing steers were randomly allocated into three groups according to body weight (BW) and age in 12 pens (4 replications/treatment) and assigned to one of the three dietary treatments: control (byproduct 0%), FV-B (fruit-vegetable byproduct 20%), and CA-B (cabbage peel 15% plus Chinese cabbage peel 15%, total byproduct 30%). RESULTS: The crude protein contents of cabbage, Chinese cabbage and fruit-vegetable byproducts were 18.69%, 20.20%, and 10.07%, respectively. Concentrations of neutral detergent fiber (NDF) were higher in cabbage (22.31%) and Chinese cabbage (28.83%) than fruit-vegetable (13.94%). Higher concentrations of non-fiber carbohydrate were observed for fruit-vegetable (66.72%) than cabbage (44.93%) and Chinese cabbage byproducts (24.69%). The effective degradability (ED) of both dry matter (DM) and NDF for fruit-vegetable byproduct (DM, 84.69%; NDF, 85.62%) was higher (p<0.05) than cabbage (DM, 68.47%; NDF, 55.97%) and Chinese cabbage byproducts (DM, 68.09%; NDF, 54.22%). The DM intake was not different among treatments because the amount of feed was kept constant according to the BW of growing steers to prevent overweight during the growing period. The average daily gain during the whole experimental period was not different among treatments (1.26, 1.25, and 1.34 kg/d for control, FV-B, and CA-B). The ED of both DM and NDF degradability of the total mixed ration (TMR) diets were very similar among treatments. Feed conversion ratio during the whole period showed no significant difference among treatments. CONCLUSION: This study demonstrates that fruit-vegetable and cabbage byproducts up to 20% and 30% (as fed basis), respectively can be included in TMR diets for growing beef cattle.

Growth performance and blood profiles of Hanwoo steers at fattening stage fed Korean rice wine residue.

The aim of this study was to investigate the effects of Korean rice wine residue (RWR) on the growth performance and blood profiles of Hanwoo steers in the fattening stage. In situ and in vivo experiments were conducted to analyze rumen fermentation characteristics and total tract digestibility, respectively. Three cannulated Hanwoo steers (mean body weight: 448 ± 30 kg) were used in both analyses. The growth performance of 27 experimental animals in the fattening stage (initial body weight: 353.58 ± 9.76 kg) was evaluated after 13 months of feeding. The animals were divided into three treatment groups (n = 9/group). The treatments comprised total mixed ration (TMR) only (CON), TMR + 10% RWR (10% RWR), and TMR + 15% RWR (15% RWR). The diets of equal proportions were fed daily at 08:00 and 18:00 h based on 2% of the body weight. The animals had free access to water and trace mineral salts throughout the experiment. Supplementation of 15% RWR significantly decreased (p < 0.05) the rumen fluid pH compared with the control treatment, but there was no significant difference in the total volatile fatty acid concentration. It also significantly increased (p < 0.05) dry matter digestibility compared with the other treatments. The total weight gain and average daily gain of the animals in the RWR-supplemented groups were significantly higher (p < 0.05) than those in the control group. Furthermore, the feed intake and feed efficiency of the RWR-supplemented groups were higher than those of the control group. Supplementation of RWR did not affect the alcohol, albumin, glucose, total cholesterol, triglyceride, and low-density lipoprotein concentrations, and aspartate aminotransferase and alanine transaminase activities in the blood; these parameters were within the normal range. The high-density lipoprotein and creatinine concentrations were significantly higher in the 15% RWR group, whereas the blood urea nitrogen concentration was significantly higher in the 10% RWR group than in the other groups. These results suggest that TMR with 15% RWR can serve as an alternate feed resource for ruminants.

Dietary effects of lutein-fortified chlorella on milk components of Holstein cows.

This study was conducted to investigate the dietary effect of conventional or lutein-fortified chlorella on milk production and lutein incorporation in milk. Fifteen Holstein cows in mid-lactation were used in a 3 × 3 Latin square design each with a 21-day period. Cows were top-dressed daily with 30 g of conventional or lutein-fortified chlorella for 3 weeks. Cows without chlorella served as the control. The feed intake and milk yield were not affected by dietary treatments. The concentrations of milk protein and solids non-fat in groups fed diets containing both conventional and lutein-fortified chlorella were significantly higher than those of the control group (P < 0.001). There was no significant difference in content of milk fat among groups. The levels of plasma glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, interferon-gamma and interleukin-2 were not influenced by the dietary treatments. Lutein content in milk was significantly increased in groups fed lutein-fortified chlorella as compared with those of conventional chlorella and control, respectively (P < 0.01). These results imply that conventional and lutein-fortified chlorella has positive effects on milk components and the use of lutein-fortified chlorella in a dairy diet is effective in the production of milk enriched with lutein.

Characteristics of Wet Distillers Grains on In vitro Ruminal Fermentation and Its Effects on Performance and Carcass Characteristics of Finishing Hanwoo Steers.

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±123 kg) 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.

Characteristics of Rice Hulls, Sawdust, Wood Shavings and Mixture of Sawdust and Wood Shavings, and Their Usefulness According to the Pen Location for Hanwoo Cattle.

In this study, two experiments were conducted to investigate the physicochemical characteristics (Exp. I) of bedding materials such as rice hulls (RH), sawdust (SD), wood shavings (WS) and sawdust+wood shavings (S+W; 1:1 in volume), and utilization of these beddings except RH (Exp. II) for rearing beef cattle. In Exp. I, the distribution of particle size (%) with 250 µm and below 250 µm was greater (p<0.05) in SD (30.4) than RH (4.4), WS (18.8) and S+W (20.1). Bulk density (kg/m(3)) of bedding materials was directly proportional to the percentage of 250 µm and below 250 µm particles, 178, 46, 112, and 88 for SD, WD, S+W and RH, respectively. Water absorption rate (%) after submersion in water for 24 h was higher (p<0.05) in WS (540.2) compared to SD (270.2), S+W (368.2). The S+W had an intermediate value of the absorption rate between SD and WS, but had an outstanding durability of water absorption capacity. Moisture evaporation rate (%) for 12 h was higher (p<0.05) in WS (75.4) than SD (70.5), S+W (72.2) and RH (57.8). Average ammonia emission (mg/m(2)/h) for 36 h was higher (p<0.05) in RH (3.15) than SD (1.70), WS (1.63), and S+W (1.73). In Exp. II, thirty six Hanwoo cows were allocated in 9 pens with one side on feed bunk side (Side A) and another side equipped with water supply (Side B) for 3 weeks with duplicated periods. Average moisture concentrations (%) of beddings were higher (p<0.05) in WS (side A, 65.7; side B, 57.9) than SD (side A, 62.5; side B, 52.2) and S+W (side A, 61.6; side B, 50.7). Regardless of types of beddings, moisture concentrations (%) of beddings within a pen were lower (p<0.05) at side B than A, implying longer period of utilization. These results suggest that using S+W would be a better choice than SD or WS alone, considering physicochemical characteristics and economics, and RH is not a suitable material as a bedding for beef cattle.

Characteristics of Sawdust and Cocopeat Beddings, and Their Usefulness According to the Fan and Pen Location for Rearing Hanwoo Cattle.

This study was designed to examine the characteristics of sawdust and cocopeat bedding materials, including physicochemical properties (Exp. I) and on-farm trial (Exp. II). In Exp. I, the proportion of particle size was in the order of sawdust> cocopeat India>cocopeat Vietnam (p<0.05), and cocopeat contained higher proportion of small particles (250 µm+below 250 µm) than sawdust, causing a dust production problem. Bulk density was cocopeat India>cocopeat Vietnam>sawdust (p<0.05), thus cocopeat treatments showed 4.4 times higher bedding cost than sawdust. The water absorption rates were 702.0% in cocopeat India, 678.3% in cocopeat Vietnam, and 444.0% in sawdust, showing cocopeat had approximately 1.5 times higher water absorption rate than sawdust. Moisture evaporation rates after 12 h of air blowing (2.00 m/s) were higher (p<0.05) in cocopeat Vietnam (80.4%) than sawdust (71.2%) and cocopeat India (72.8%). In vitro ammonia emissions were higher (p<0.05) in sawdust (2.71 mg/m(2)/h) than cocopeat India (1.59 mg/m(2)/h) and Vietnam (1.22 mg/m(2)/h), and total ammonia emissions were higher (p<0.05) in sawdust (37.02 mg/m(2)) than cocopeat India (22.51 mg/m(2)) and Vietnam (13.60 mg/m(2)). In Exp. II, an on-farm trial was conducted with 48 Hanwoo cattle in 16 pens using the same bedding materials as in Exp. I, with fan (blowing 2.00 m/s) and no fan treatments, and feed bunk side (FB) and water supply side (WS) within a pen (4.5 m, width×9.0 m, length). Beddings were replaced with fresh bedding materials when moisture concentrations were over 65%. No interactions among treatments were detected for moisture concentration and increment rates, and ammonia concentrations, but a significant effect was observed (p<0.01) for each of the treatments. Both concentrations and increment rate of moisture were higher (p<0.01) in the beddings without fan than with fan. Moisture concentrations and increment rate within a pen were also higher (p<0.01) in FB than WS. Thus, the whole no-fan-FB and sawdust-fan-FB were replaced with fresh bedding material between 4 to 5 experimental weeks. The ammonia concentrations and pH of beddings were not significantly different among treatments. Therefore, using cocopeat bedding with a blowing fan can extend twice the bedding utilization period, and WS within a pen showed twice the bedding-life compared to FB. Despite the outstanding characteristics of cocopeat compared with sawdust, using cocopeat as an alternative for sawdust bedding is not recommended for cattle management, considering it has 4.4 times higher bedding cost and a dust production problem.

Rumen fermentation and performance of Hanwoo steers fed total mixed ration with Korean rice wine residue.

BACKGROUND: This study was conducted to evaluate the effects of adding Korean rice wine residue (RWR) in total mixed ration (TMR) on in vitro ruminal fermentation and growth performance of growing Hanwoo steers. METHODS: For in vitro fermentation, the experimental treatments were Control (Con: 0 % RWR + TMR), Treatment 1 (T1: 10 % RWR + TMR), and Treatment 2 (T2: 15 % RWR + TMR). The rumen fluid was collected from three Hanwoo steers and mixed with buffer solution, after which buffered rumen fluid was transferred into serum bottles containing 2 g dry matter (DM) of TMR added with or without RWR. The samples were then incubated for 0 h, 12 h, 24 h, or 48 h at 39 °C and 100 rpm. For the in vivo experiment, 27 Hanwoo steers (6 months old) with an average weight of 196 ± 8.66 kg were subjected to a 24-week feeding trial. The animals were randomly selected and equally distributed into three groups. After which the body weight, feed intake and blood characteristics of each group were investigated. RESULTS: The pH of the treatments decreased significantly relative to the control during the 12 h of incubation. Total gas production and ammonia nitrogen (NH3-N) was not affected by RWR addition. The total volatile fatty acid (VFA) was lower after 24 h of incubation but at other incubation times, the concentration was not affected by treatments. Feed cost was 8 % and 15 % lower in T1 and T2 compared to control. Blood alcohol was not detected and a significant increase in total weight gain and average daily gain were observed in Hanwoo steers fed with RWR. CONCLUSION: Overall, the results of this study suggest that TMR amended with 15 % RWR can be used as an alternative feed resource for ruminants to reduce feed cost.

Characteristics of Wet and Dried Distillers Grains on In vitro Ruminal Fermentation and Effects of Dietary Wet Distillers Grains on Performance of Hanwoo Steers.

Two experiments were conducted to evaluate the nutrient composition, in vitro dry matter disappearance (IVDMD) and organic matter disappearance (IVOMD) of three kinds of distillers grains (DG); i) wet distillers grains (WDG, KRW 25/kg), ii) dried distillers grains (DDG, KRW 280/kg), iii) dried distillers grains with solubles (DDGS, KRW 270/kg) produced from tapioca 70% and rice 30%, and to evaluate dietary effects of WDG on the performance of Hanwoo steers. In Exp. 1, twelve-WDG, four-DDG and one-DDGS were collected from seven ethanol plants. Average crude protein, crude fiber, neutral detergent fiber, and acid detergent fiber of WDG, DDG, and DDGS were: 32.6%, 17.8%, 57.5%, and 30.2% for WDG, 36.7%, 13.9%, 51.4%, and 30.5% for DDG, and 31.0%, 11.9%, 40.3%, and 21.2% for DDGS (DM basis), respectively. The DDGS had a higher quantity of water-soluble fraction than WDG and DDG and showed the highest IVDMD (p<0.05) in comparison to others during the whole experimental time. The IVDMD at 0 to 12 h incubation were higher (p<0.05) in DDG than WDG, but did not show significant differences from 24 to 72 h. The same tendency was observed in IVOMD, showing that DG made from tapioca and rice (7:3) can be used as a feed ingredient for ruminants. Considering the price, WDG is a more useful feed ingredient than DDG and DDGS. In Exp. 2, 36 Hanwoo steers of 21 months (495.1±91 kg) were randomly assigned to one of three dietary treatments for 85 days; i) Control (total mixed ration, TMR), ii) WDG 10% (TMR containing 10% of WDG, as fed basis), and iii) WDG 20% (TMR containing 20% of WDG, as fed basis). With respect to body weight and average daily gain, there were no differences between control and WDG treatments during the whole experimental period. Dry matter intake of control (9.34 kg), WDG 10% (9.21 kg) and 20% (8.86 kg) and feed conversion ratio of control (13.0), WDG 10% (13.2) and 20% (12.1) did not show differences between control and WDG treatments. Thus, the use of WDG up to 20% in TMR did not show any negative effect on the performance of Hanwoo steers.

Effects of various anesthetic protocols on 18F-flurodeoxyglucose uptake into the brains and hearts of normal miniature pigs (Sus scrofa domestica).

This study used positron emission tomography-computed tomography (PET-CT) to evaluate the effects of 4 anesthetic protocols on 2-deoxy-2-[18F]-fluoro-D-glucose (18F-FDG) accumulation in the brains and hearts of miniature pigs (Sus scrofa domestica). The 18F-FDG standard uptake value was quantified by dividing the brain into 6 regions: cerebellum, brainstem, and frontal, parietal, temporal, and occipital lobes. Five (2 female and 3 male) clinically normal miniature pigs were premedicated with medetomidine (200 µg/kg IM) after which the following 4 anesthetic protocols were administered by using a crossover design: 1) propofol (4 mg/kg IV)-isoflurane inhalation; 2) propofol (4 mg/kg IV); 3) ketamine (5 mg/kg IV); 4) tiletamine-zolazepam (4.4 mg/kg IM). Compared with levels after other protocols, brain accumulation of 18F-FDG increased during propofol anesthesia but decreased with tiletamine-zolazepam. Relative to that due to other protocols, heart accumulation of 18F-FDG increased with propofol-isoflurane anesthesia but decreased with tiletamine-zolazepam. Comparing glucose accumulation in the brain and heart of miniature pigs by using PET-CT, we found that glucose accumulation varied according to the anesthetic protocol and between the 2 organs. These results can be used to evaluate how different anesthetic agents affect glucose metabolism in brain and heart of miniature pigs. Furthermore, these data should be considered when selecting an anesthetic agent for miniature pigs that will undergo PET-CT imaging with 18F-FDG.

Effects of catechins and wheat bran on the beef color in the late fattening period of hanwoo steers.

This study was conducted to evaluate the effects of dietary supplementation of catechins and wheat bran on growth performance, carcass characteristics and meat color using forty-eight Hanwoo steers. Each steer was randomly assigned to one of four treatments. Treatments were as follows: control, catechins, wheat bran, and catechins+wheat bran (CW). At the end of the feeding trial, blood samples were collected for analysis of hemoglobin and iron concentration, and then steers were slaughtered at a commercial abattoir. Catechins, wheat bran, and CW had no effect on growth performance and carcass characteristics. Percentage of myoglobin in M. longissimus dorsi was not affected by treatments. Percentage of oxymyoglobin was increased (p<0.05) by CW and maintained at the highest level (p<0.05) for CW during meat display time up to 24 h. Percentage of metmyoglobin was the lowest (p<0.05) for CW between 5 and 24 h during display time. Although blood iron concentration was not affected by treatments, total concentration of muscle iron was the lowest (p<0.05) for CW compared with that of other treatments. Therefore, the results of the present study suggest that CW may provide good protection against oxidation of myoglobin, and might be an effective dietary supplement for improving meat color in the late fattening period of Hanwoo steers.

Chromosome remodeling and differentiation of tetraploid embryos during preimplantation development.

Although it is known that the tetraploid embryo contributes only to the placenta, the question of why tetraploid embryos differentiate into placenta remains unclear. To study the effect of electrofusion on the development of mouse tetraploid oocytes, mouse two-cell embryos were fused and cultured in vitro in Chatot-Ziomek-Bavister medium. After electrofusion, two chromosome sets from the tetraploid blastomere were individually duplicated before nuclear fusion. At 8-10 hr after electrofusion, each chromosome set was condensing and the nuclear membrane was breaking down. Around 12-14 hr after electrofusion, the two chromosome sets had combined together and had reached the second mitotic metaphase, at this point with 8n sets of chromosomes. Interestingly, we discovered that expression of OCT4, an inner cell mass cells biomarker, is lost by the tetraploid expanded blastocysts, but that CDX2, a trophectoderm cells biomarker, is strongly expressed at this stage. This observation provides evidence clarifying why tetraploid embryos contribute only to trophectoderm.

Developmental arrest of scNT-derived fetuses by disruption of the developing endometrial gland as a result of impaired trophoblast migration and invasiveness.

Somatic cell nuclear transfer (scNT)-derived pig placenta tissues of gestational day 30 displayed avascularization and hypovascularization. Most of the cytotrophoblast-like cells of the developing scNT-derived placenta villi were improperly localized or exhibited impaired migration to their targeting loci. Id-2, Met, MMP-9, and MCM-7 were barely detectable in the cytotrophoblast cells of the scNT-derived placenta villi. Active MMP-2 and MMP-9 expression was significantly down-regulated in the scNT-embryo transferred recipient uteri. scNT clones exhibited a hypermethylated pattern within the pig MMP-9 promoter region and the significance of GC box in the regulation of MMP-9 promoter activity. Marked apoptosis was observed in the developing endometrial gland of scNT-embryo transferred recipient uteri. Collectively, our data strongly indicated that early gestational death of scNT clones is caused, at least in part, by disruption of the developing endometrial gland as a result of impaired trophoblast migration and invasiveness due to the down-regulation of active MMP-9 expression.

Essential role of paternal chromatin in the regulation of transcriptional activity during mouse preimplantation development.

Several lines of evidence indicate that the formation of a transcriptionally repressive state during the two-cell stage in the preimplantation mouse embryo is superimposed on the activation of the embryonic genome. However, it is difficult to determine the profile of newly synthesized (nascent) RNA during this phase because large amounts of maternal RNA accumulate in maturing oocytes to support early development. Using 5-bromouridine-5'-triphosphate labeling of RNA, we have verified that nascent RNA synthesis was repressed between the two-cell and four-cell transition in normally fertilized but not in parthenogenetic embryos. Moreover, this repression was contributed by sperm (male) chromatin, which we confirmed by studying androgenetic embryos. The source of factors responsible for repressing nascent RNA production was investigated using different stages of sperm development. Fertilization with immature round spermatids resulted in a lower level of transcriptional activity than with ICSI at the two-cell stage, and this was consistent with further repression at the four-cell stage in the ICSI group. Finally, study on DNA replication and chromatin remodeling was performed using labeled histones H3 and H4 to differentiate between male and female pronuclei. The combination of male and female chromatin appeared to decrease nascent RNA production in the fertilized embryo. This study indicates that paternal chromatin is important in the regulation of transcriptional activity during mouse preimplantation development and that this capacity is acquired during spermiogenesis.

Effect of trichostatin A on chromatin remodeling, histone modifications, DNA replication, and transcriptional activity in cloned mouse embryos.

Our group and others have found that the treatment of embryos with trichostatin A (TSA) after cloning by somatic cell nuclear transfer (SCNT) results in a significant improvement in efficiency. We believe that TSA treatment improves nuclear remodeling via histone modifications, which are important in the epigenetic regulation of gene silencing and expression. Some studies found that treatment of SCNT-generated embryos with TSA improved lysine acetylation of core histones in a manner similar to that seen in normally fertilized embryos. However, how histone methylation is modified in TSA-treated cloned embryos is not completely understood. In the present study, we found that TSA treatment caused an increase in chromosome decondensation and nuclear volume in SCNT-generated embryos similar to that in embryos produced by intracytoplasmic sperm injection. Histone acetylation increased in parallel with chromosome decondensation. This was associated with a more effective formation of DNA replication complexes in treated embryos. We also found a differential effect of TSA on the methylation of histone H3 at positions K4 and K9 in SCNT-generated embryos that could contribute to genomic reprogramming of the somatic cell nuclei. In addition, using 5-bromouridine 5'-triphosphate-labeled RNA, we showed that TSA enhanced the levels of newly synthesized RNA in 2-cell embryos. Interestingly, the amount of SCNT-generated embryos showing asymmetric expression of nascent RNA was reduced significantly in the TSA-treated group compared with the nontreated group at the 2-cell stage. We conclude that the incomplete and inaccurate genomic reprogramming of SCNT-generated embryos was improved by TSA treatment. This could enhance the reprogramming of somatic nuclei in terms of chromatin remodeling, histone modifications, DNA replication, and transcriptional activity.