This study was conducted at the National Institute of Animal Science (NIAS) from 2010 to 2017 to develop a late-maturing variety with high productivity for cultivation in the southern region of South Korea. The new variety of Italian ryegrass, ‘IR901’, was a late-maturing variety, and its heading date was 22 May, 17 days later than that of the control variety ‘Kowinearly’. ‘IR901’ had a flag leaf width of 11.2 mm, flag leaf length of 31.8 cm, and plant length of 103 cm on its heading date. The combined average dry matter yield of ‘IR901’ in all three adaptability evaluation regions (Cheonan, Pyeongchang and Haenam) was 7,747 kg/ha, which was similar to that of the ‘Kowinearly’ variety (7,734 kg/ ha). However, the average dry matter yield over three years in Cheonan and Pyeongchang was 82% and 96%, respectively, compared to that of the control, which was most likely because of the poor cold tolerance of ‘IR901’. By contrast, in Haenam, in the southern region, the average dry matter yield of ‘IR901’ was 19% higher than that of the ‘Kowinearly’ variety. The proportions of crude protein (CP), total digestible nutrients (TDN), acid detergent fiber (ADF), and neutral detergent fiber (NDF) in ‘IR901’ were 8.6%, 59.7%, 36.9%, and 54.8%, respectively; the proportions were 0.2% lower, the same, the same, and 2.5% lower than those in the ‘Kowinearly’ variety. The determined in vitro dry matter digestibility (IVDMD) of ‘IR901’ was 72.2% higher than that of ‘Kowinearly’ (67.2). In general, of the two varieties, the forage quality of ‘IR901’ was marginally superior to that of ‘Kowinearly’.

This study was conducted at the National Institute of Animal Science from 2010 to 2017. As a variety that is sufficiently productive in the southern regions to replace imported varieties and sufficiently cold-resistant to be cultivated in the central-northern regions, "IR605" was developed and submitted to the Korea Seed & Variety Service in an application for protection. The novel Italian ryegrass variety "IR605" is a diploid with green leaves, a semi-erect growth habit before wintering, and an erect growth habit in the spring. "IR605" was a medium maturing variety with a heading date of around May 15th. "IR605" had a flag leaf width of 9.9 mm, flag leaf length of 26.7 cm, and plant length on the heading date of 100 cm, which was approximately 5 cm longer than "Kowinearly." The stem thickness and ear length of "IR605" are 0.08 mm thicker and 0.5 cm longer than those of "Kowinearly", respectively. The cold-resistance of "IR605" was weaker than that of "Kowinearly", but strong enough to be cultivated in Pyeongchang, Gangwon province. The dry matter yield of "IR605" (9,308 kg/hectare) was 20% higher than that of "Kowinearly", which was further pronounced in the southern region of Haenam, where there was a 52% increased (p < 0.05). The in vitro dry matter digestibility of "IR605" was 68.4% at which was slightly higher than that of "Kowinearly", The total digestible nutrients was 58.5%, which was slightly lower than "Kowinearly". Overall, the feed quality characteristics of "IR605" were similar to those of "Kowinearly".

The present study was conducted to investigate the effects of feed types (powder vs. pellet) from potato by-product containing glycoalkaloid on rumen fermentation with different rumen pH (low vs. high) using in vitro technique. Rumen fluid was collected from two cannulated Hanwoo heifers before morning feeding (high rumen pH at 6.71) and 3 h after feeding (low rumen pH at 6.20). A 0.5 gram of powder or pellet from potato by-product was incubated in the rumen buffer for 48 h at 39℃. Four replications for each treatment were used along with two blanks. Pellet had higher (p<0.05) the immediately degradable fraction, the fractional degradation rate, and the lag phase than those of powder. However, feed type had no effects on the potentially degradable fraction and the total degradable fraction. In fermentation characteristics, powder had higher (p<0.05) concentrations of ammonia-N, total volatile fatty acid (VFA), and acetate than those of pellet. In addition, a high rumen pH had higher (p<0.05) concentrations of ammonia-N and acetate, but lower (p<0.05) total VFA concentration than those of a low rumen pH. The interaction effects between feed type and rumen pH were found on the total degradable fraction and concentrations of ammonia-N, total VFA, and acetate. The present study concluded that generally feed type had no effects on rumen degradation kinetics, but potato by-product in the powder form is recommended due to produce higher fermentation characteristics than in the pellet form.

In this study, we examined number, motility and plasma membrane integrity of spermatozoa from six regions of epididymis in bull. Six testicles with epididymides were castrated from six bulls (mean±standard error, age of days = 441.3±9.6, body weight (kg) = 367±8.4, scrotal circumference (cm) = 30.7±0.4) at Hanwoo Research Institute, NIAS and transported to laboratory within 1 hour. Testicular weight, length, width and circumference were recorded. Epididymis in each bull was randomly used for recovery of spermatozoa. Epididymis was divided into six regions: efferent duct (ED), caput, corpus, proximal cauda (Pcauda), distal cauda (Dcauda) and vas deferens (VD). In experiment 1, we examined sperm number of each region of epididymis. Each region of epididymis contained different number of spermatozoa: ED (37.8±15.7 × 106cells/ml, 8.2%), caput (93.6±18.8 × 106cells/ml, 20.2%), corpus (33.0±8.5 × 106cells/ml, 7.1%), Pcauda (104.2±23.5 × 106cells/ml, 22.5%), Dcauda (180.5±32.5 × 106cells/ml, 39.0%) and VD (14.0±5.0 × 106cells/ml, 3.0%). In experiment 2, sperm motility of each epididymal region was examined by computer assisted sperm analysis (SCA, MicroOptic) system. Sperm motility was divided into 4 groups (fast progressive, slow progressive, non-progressive and immotile) based on WHO guideline. Percentages of fast progressive of Pcauda and Dcauda (11.0±2.3 and 15.4±3.6%) were significantly higher than that of ED, Caput, Corpus and VD which is 0.1±0.1, 1.5±0.6, 1.9±0.7 and 0.3±0.2%, respectively (p<0.05). In experiment 3, percentage of intact plasma membrane spermatozoa of each regions were examined by hypoosmotic swelling test. Percentages of intact plasma spermatozoa were not significantly different among six regions of epididymis: ED, caput, corpus, Pcauda, Dcauda and VD which is 68.0±8.6, 74.0±5.3, 68.5±6.2, 70.8±5.5, 71.0±5.8 and 64.6±10.8%, respectively. In conclusion, in the present study, we found out distribution, motility and plasma membrane integrity of spermatozoa from six regions of epididymis in Hanwoo bull. These results will be contributed to basic research about spermatozoa transportation and characters in epididymis of bull.

In this study, we examined total number, motility and plasma membrane integrity of epididymal spermatozoa from cauda epididymis of bull after preservation at 4ºC. Totally, 23 testicles were castrated from 23 bulls (mean±standard error, age of days = 426.0±7.3, body weight (kg) = 379.7±8.4, scrotal circumference (cm) = 31.0±0.4) at Hanwoo Research Institute, NIAS, and transported to laboratory and preserved on 1, 4 and 6 days at 4 ºC. As control, epididymal spermatozoa recovery from 7 testicles was conducted after transportation to laboratory immediately. In experiment 1, we compared total number of spermatozoa among groups. Total number of spermatozoa from epididymis was not significantly on different preservation day of 0, 1, 4 and 6 which is 1778.0±304.7, 1824.8±343.9, 1228.4±91.7, 1201.8±178.6×106 cells/ml, respectively). In experiment 2, we examined spermatozoa motility and motility parameters (VCL (μm/s), VSL (μm/s), VAP (μm/s), LIN (%)) by computer assisted sperm analysis (SCA, MicroOptic) system. Percentage of motile on 0 and 1 day (88.9±5.2 and 85.8±6.1) was significantly higher than that on 4 and 6 days (32.6±6.5 and 34.3±8.25). Percentage of VCL (μm/s) on 0 and 1 day (93.5±7.6 and 83.0±14.9) was significantly higher than that on 4 and 6 days (36.6±5.1 and 39.5±5.5) (p<0.05). Percentage of VSL (μm/s) on 0 day (28.0±2.1) was significantly higher than that on 1, 4 and 6 days (20.2±3.0, 9.0±2.0 and 8.5±1.6, p<0.05). Percentage of VAP (μm/s) on 0 and 1 days (49.4±3.8 and 41.3±6.6) was significantly higher than that on 4 and 6 days (18.2±3.0 and 19.3±2.8, p<0.05). Percentage of LIN (%) on 0 day (30.7±2.6) was significantly higher than that on 4 and 6 days (23.4±2.7 and 21.1±1.0, p<0.05). Motility of spermatozoa was divided into 4 groups (fast progresive, slow progressive, non-progressive and immotile) based on WHO guideline. Percentage of fast progressive on day at 0 was significantly higher than that on 1, 4 and 6 days (0, 1, 4 and 6 days vs. 19.8±1.9, 10.2±1.1, 2.6±1.0 and 2.3±1.2%, respectively). In conclusion, cauda epididymal spermatozoa should be recovered within one day after preservation at 4 ºC to recover high quality of epididymal spermatozoa in Hanwoo bull

This study aimed to investigate the effect of using corn flakes, produced by pressurized steam chamber, on nutrient disappearance rate and energy value in three Hanwoo and three Holstein cows, implanted with a ruminal fistula. Corn flakes were categorized in 2 groups based on the chamber type: control (corn flakes produced using a steam chamber) and treatment (corn flakes produced using a pressurized steam chamber). Dry matter (DM) disappearance rate was 5.17% higher in treatment than in control (p<0.01). Starch disappearance rate was also higher in the treatment than in the control (p<0.01). Nitrogen free extract (NFE) and non-fiber carbohydrate (NFC) disappearance rates were 6.08 and 5.71% higher in treatment compared to control, respectively (p<0.01). In comparison by breed and incubation time, DM, starch, NFE, and NFC disappearance rates were higher in treatment than in control. The mean total digestible nutrients (TDN) was higher in treatment than in control (p<0.05). In comparison between Hanwoo and Holstein, TDN of corn flakes was slightly but not significantly higher in Holstein than in Hanwoo. Thus, these results indicate that the use of the pressurized steam chamber is recommended to increase the nutrient (starch, NFE, NFC etc.) disappearance rate and TDN.

We observed the external genitalia and uterus of a 24-month-old freemartin Hanwoo. The vulva was smaller than observed in a normal female Hanwoo, while the clitoris was larger in the freemartin. The angle between the external genitalia and the perineum also varied. Upon internal genital examination, the uterus of the freemartin was a thin tube approximately 18 cm in size and had not differentiated into a normal uterus and uterine horns.

Bropirimine, a class of antineoplastic agents, is known as one of the potent immunomodulators and is currently under clinical development for the treatment of cancer. However, the effect of bropirimine on the cow remains unknown as a therapeutics agent. In this experiment, the effect of bropirimine in the peripheral blood mononuclear cells (PBMCs) stimulated by lipopolysaccharide (LPS) or concanavalin-A (Con-A) was examined. Jugular venous blood was collected from Korean Hanwoo calves and PBMCs were isolated. It was used to study the effect of bropirimine upon stimulation with LPS or Con-A for 72 hours. The expression pro-inflammatory cytokines like Tumor Necrosis Factor α (TNF-α) and Interferon γ (IFN-γ) were confirmed. Bropirimine significantly inhibited LPS- or Con-A-induced TNF-α and Con-A-induced IFN-γ in dose-dependent manner. Furthermore, Bropirimine inhibited TNF-α and Con-A mRNA expression at the transcription level. These results clearly indicated that bropirimine inhibited LPS or Con-A stimulated up-regulation of proinflammatory cytokines in a dose-dependent manner without conspicuous cytotoxicity. The bropirimine has potential to protect cow from LPS or Con-A induced endotoxin shock, possibly through inhibition of the production of proinflammatory cytokines. It suggesting that bropirimine may be a novel therapeutic agent for the prevention of inflammatory diseases. This result revealed specific features of the immune responses depending on the bropirimine compound and would help to knowledge of bovine immunity.

The present study was conducted to investigate the effect of different heights from liquid nitrogen (LN2) vapor on sperm motility and morphology after frozen-thawing. Two ejaculates were collected from 2 fertile Hanwoo bulls (A and B) by using artificial vagina at Hanwoo Research Institute. After collection, ejaculates were transferred to laboratory immediately and diluted with semen extender (Optixcell, France). Sperm dilutions were extended to a final concentration of 40 x 106 sperm/ml, and cooled at 4°C for 4 h and loaded to 0.5 ml straws. The straws were divided into 2 groups. Straws were placed in 3 or 9 cm of LN2 vapor for 14 min and then plunged into LN2 tank and cryopreserved until evaluation. Sperm motility and motility parameters (total motility, VSL with 25μm≥, VCL, VSL, VAP, LIN, STR, WOB, ALH and BCF) were evaluated by sperm class analysis (SCA, IVOS, Spain) after frozen-thawed. In bull A, 3cm group showed higher percentages of total motility, VSL with 25μm and VAP compared those with 9cm group (98.0 vs. 93.4%, 62.4 vs. 54.0% and 98.6 vs. 93.2%, 3 vs. 9 cm, irrespectively; p<0.001). In bull B, frozen-thawed sperm of 3cm group showed higher percentages of VSL with 25μm, VCL, VSL, VAP and BCF compared with those of 9cm group (43.5 vs. 26.0%, 123.8 vs. 111.6 μm, 62.9 vs. 57.3 μm and 81.5 vs. 72.5 μm; 3 vs. 9 cm, irrespectively; p<0.001). The viability and acrosomal integrity of spermatozoa were evaluated by Trypanblue/Giemsa staining method divided into 4 groups; live and intact acrosome (LIA), live and damaged acrosome (LDA), dead intact acrosome integrity (DIA), dead damaged acrosome (DDA). In bull A, frozen-thawed sperm of 3 and 9cm groups showed no significant difference in LIA, LDA, DIA and DDA. In bull B, 3 cm group showed higher LIA and lower DIA compared with those of 9 cm group (73.2 vs. 23.7% and 23.7 vs. 32.2%, 3 vs. 9 cm, irrespectively; p<0.001). We suspected that 3 cm vapor on LN2 vapor might be affected positively spermatozoa viability and acrosomal integrity compared with 9 cm group. In conclusion, semen freezing procedure in the present study will improve sperm quality after frozen thawing.

This experiment was carried out to investigate the effect of harvesting time of Italian ryegrass (Lolium multiflorum Lam; IRG) in spring on dry matter (DM) yield. IRG cultivars ‘Kowinearly’ and ‘Greenfarm’ were seeded at 50 kg/ha and grown on rice paddy fields. There was no difference in growth characteristics between both varieties before winter. However, cold tolerance of Kowinearly was higher than that of Greenfarm, as demonstrated by post-wintering growth characteristics. The heading date of both varieties was affected by the spring weather. The IRG was harvested three times at 5-day intervals beginning from 9 May. The DM yield of Greenfarm was 6,306; 7,335; and 8,109 kg/ha, and that of Kowinearly was 7,498; 9,196; and 10,449 kg/ha at the three consecutive harvests. The delay of the harvesting time for 5 and 10 days increased the DM yield of Greenfarm by 16% and 29% and that of Kowinearly by 23% and 39%, respectively, compared to the yield at first harvest (p < 0.05). Therefore, IRG harvest later than early to mid-May is expected to increase productivity. The feed values of Greenfarm were: 12.2% of crude protein (CP), 34.5% of acid detergent fiber (ADF), 57.7% of neutral detergent fiber (NDF), 61.6% of total digestible nutrients (TDN), and 72.3% of in vitro DM digestibility (IVDMD). For Kowinearly, these values were 16.4% of CP, 30.4% of ADF, 52.7% of NDF, 64.9% of TDN and 79.0% of IVDMD.

The present study investigated the effects of different seeding rates on growth characteristics and seed productivity of the “Kowinearly” cultivar of Italian ryegrass (Lolium multiflorum Lam.) in paddy fields. Sowing Kowinearly in paddy fields under growing rice at the rates of 20, 30, 40, and 50 kg/ha resulted in seed yields of 1.57, 1.92, 2.06, and 2.09 ton/ha, respectively. Seed yield of Kowinearly was the highest at a seeding rate of 50 kg/ha (p<0.05), at which the cultivar was able to survive in winter and the weed ratio was low. Under these conditions, most growth characteristics such as winter survival (85%), weed ratio (10%), stems per square meter (1,006) were superior than those sown at other seeding rates (p<0.05). In addition, it has been reported that the economic efficiency of the 50 kg/ha seeding rate was higher than that of the other seeding rates.

The recovery of epididymal sperm in animals is considered as one of the important tools to preserve high value or endangered species. However, there are no appropriate castrating indicators such as months of age in bull, sperm morphology, and motility, particularly in young Korean native bull (Hanwoo). Therefore, this study aimed to investigate sperm number, morphology, and motility of sperm in the epididymis tail of young Hanwoo bulls at 8 and 15 months of age. After castration, epididymal tails were collected and minced with blades to recover sperm. In experiments 1 and 2, sperm number, morphology, and motility were examined. Total number of sperm and percentage of normal sperm from bulls at 8 months of age was lower than that of bulls at 15 months of age after collection (P<0.05). Percentage of abnormal head, tail, proximal cytoplasmic droplet, dead and damaged acrosome of sperm from bulls at 8 months of age were higher than those of bulls at 15 months of age (P<0.05). In experiment 3, sperm motility from bulls at 8 and 15 months of age were examined before freezing and after thawing. Frozen-thawed sperm at 8 months of age showed low total motility and motile sperm with ≥ 25 μm/sec compared to those at 15 months of age and commercially-used sperm (P<0.05). In conclusion, sperm derived from the epididymal tail of bulls at 8 months of age showed high abnormal morphology and poor motility, which are not adequate for AI and IVF. On the other hand, sperm derived from the epididymal tail of bulls at 15 months of age showed high normal morphology and motility.

The present study was performed on farm animals to test the effectiveness of progesterone-releasing intravaginal device (Cue-Mate® 1.56 g) and injection of prostaglandin F2α (PGF2α) for synchronization estrus in Hanwoo cattle. The cattle were at random stage of the estrus cycle. The cows were artificially inseminated at day 7 after Cue-Mate withdrawal, using commercial semen from Korean native bulls. There was a season effect on the estrus synchronization rate. It was higher in spring (94.3%) followed by winter (93.3%), autumn (90.4%) and summer (67.2%). In summary, The results of this study revealed that season has influences on estrus behavior of cattle with no significant effect on pregnancy rate. In summary, we suggest summer reproductive management to alleviate the effects of heat stress. It should be based on intensive cooling combined with hormonal treatment. Given that different subgroups of cows benefit differently from the treatments, selective hormonal administration should be considered.