‘Luckyone 2ho’ is a new orchardgrass (Dactylis glomerata L.) cultivar developed by the National Institue of Animal Science (NIAS) in 2017. To develope the new variety of orchardgrass, 5 superior clones were selected and polycrossed for seed production. The agronomic growth characteristics and forage productivity of ‘Luckyone 2ho’ were examined at Cheonan from 2012 to 2014, and regional trials were conducted in Cheonan, Pheonchang, Jinju and Jeju from 2015 to 2017, respectively. ‘Luckyone 2ho’ showed medium type growth habit in fall, and medium in length of flag leaf and very long upper internode. Plant height of ‘Luckyone 2ho’ was 3 cm less than that of standard cultivar, ‘Potomac’ and heading date was 1 days later than 5th May compared to standard cultivar, ‘Potomac’. Characteristics such as waterlogging and disease resistance of ‘Luckyone 2ho’ were stronger or better than those of standard cultivar, ‘Potomac’, Especially, dry matter yield of ‘Luckyone 2ho’(15,980 kg/ha) increased 9 % compared to that of standard cultivar, ‘Potomac’(14,702 kg/ha). Nutritive values were appeared to be similar in both varieties except in Vitro dry matter digestibility(IVDMD) and crude protein and total digestible nutrients (TDN).

This study was conducted to evaluate feed value of imported hays and examine current situation of species and hay grade. To evaluate the quality of the imported hay, 133 pieces including 9 species of roughage types were collected at the national hay importers, the TMR companies and livestock farms from 2016 to 2018. The quality grades of imported hay were 3~4 and most imported hay were considered to had low. The ADF, Ash, TDN and DDM in feed composition of alfalfa by quality grades presented significant differences(p<0.05). The quality grade on alfalfa was not similar to the actual quality grades calculated through feed composition. The feed composition of grasses by quality degrees presented significant differences in all contents except DM and CP (p<0.05). As the distributed grasses of the unmarked quality grade was low quality and accounted for 49%, it is urgent to present quality standards based on feed composition. As these results, the grades of imported hays were lower than the marked quality grades. Therefore, the imported roughage’s(hay) price that considered to only quality grades on the marked imported roughages(hay) package can cause a loss to the livestock farms as economic damage. An institutional arrangement should be established to review the quality grades of imported hay.

This experiment was carried out to study the effects of different environmental conditions and cultivation techniques on productivity of forage corn in central and southern area of Korea on 2017 and 2018. Average dry matter yield of forage corn at 34 cultivation regions was 13,510kg/ha. Forage productivity of forage corn cultivated at actual production sites have positive correlation with cultivation techniques(p<0.01) but not correlated with cultivation environments. Forage productivity of forage corn have positive correlation with seeding techniques(p<0.01) but not correlated with fertilization techniques. These results suggest that practices of cultivation techniques are more important than cultivation environments for increasing the forage productivity of forage corn. Therefore, yield prediction techniques of forage corn in Korea have to be considered the practices of cultivation techniques along with soil and climate conditions.

In the summer season, natural ventilation is commonly used to reduce the inside air temperature of greenhouse when it rises above the optimal level. The greenhouse shape, vent design, and position play a critical role in the effectiveness of natural ventilation. In this study, computational fluid dynamics (CFD) was employed to investigate the effect of different roof vent designs along with side vents on the buoyancy-driven natural ventilation. The boussinesq hypothesis was used to simulate the buoyancy effect to the whole computational domain. RNG K-epsilon turbulence model was utilized, and a discrete originates (DO) radiation model was used with solar ray tracing to simulate the effect of solar radiation. The CFD model was validated using the experimentally obtained greenhouse internal temperature, and the experimental and computed results agreed well. Furthermore, this model was adopted to compare the internal greenhouse air temperature and ventilation rate for seven different roof vent designs. The results revealed that the inside-to-outside air temperature differences of the greenhouse varied from 3.2 to 9.6oC depending on the different studied roof vent types. Moreover, the ventilation rate was within the range from 0.33 to 0.49 min-1. Our findings show that the conical type roof ventilation has minimum inside-to-outside air temperature difference of 3.2oC and a maximum ventilation rate of 0.49 min-1.

This study was carried out to explore the accuracy of near infrared spectroscopy(NIRS) for the prediction of moisture content and chemical parameters on winter annual forage crops. A population of 2454 winter annual forages representing a wide range in chemical parameters was used in this study. Samples of forage were scanned at 1nm intervals over the wavelength range 680-2500nm and the optical data was recorded as log 1/Reflectance(log 1/R), which scanned in intact fresh condition. The spectral data were regressed against a range of chemical parameters using partial least squares(PLS) multivariate analysis in conjunction with spectral math treatments to reduced the effect of extraneous noise. The optimum calibrations were selected based on the highest coefficients of determination in cross validation(R2) and the lowest standard error of cross-validation(SECV). The results of this study showed that NIRS calibration model to predict the moisture contents and chemical parameters had very high degree of accuracy except for barely. The R2 and SECV for integrated winter annual forages calibration were 0.99(SECV 1.59%) for moisture, 0.89(SECV 1.15%) for acid detergent fiber, 0.86(SECV 1.43%) for neutral detergent fiber, 0.93(SECV 0.61%) for crude protein, 0.90(SECV 0.45%) for crude ash, and 0.82(SECV 3.76%) for relative feed value on a dry matter(%), respectively. Results of this experiment showed the possibility of NIRS method to predict the moisture and chemical composition of winter annual forage for routine analysis method to evaluate the feed value.