Despite the gradual increase in livestock feed demands, the supply faces enormous challenges due to extreme climatic conditions. As the presence of these climatic condition has the potential to affect the yield of sorghum-sudangrass hybrid (SSH), understanding the yield variation in relation to the climatic conditions provides the ability to come up with proper mitigation strategies. This study was designed to detect the effect of climatic factors on the long-term dry matter yield (DMY) trend of SSH using time series analysis in the Republic of Korea. The collected data consisted of DMY, seeding-harvesting dates, the location where the cultivation took place, cultivars, and climatic factors related to cultivation of SSH. Based on the assumption of normality, the final data set (n = 420) was generated after outliers had been removed using Box-plot analysis. To evaluate the seasonality of DMY, an augmented Dickey Fuller (ADF) test and a correlogram of Autocorrelation Function (ACF) were used. Prior to detecting the effect of climatic factors on the DMY trend, the Autoregressive Integrated Moving Average (ARIMA) model was fitted to non-seasonal DMY series, and ARIMA (2, 1, 1) was found to be the optimal model to describe the long-term DMY trend of SSH. ARIMA with climatic factors (ARIMAX) detected significance (p < 0.05) of Seeding-Harvesting Precipitation Amount (SHPA) and Seeding-Harvesting Accumulated Temperature (SHAMT) on DMY trend. This does not mean that the average temperature and duration of exposure to sunshine do not affect the growth and development of SSH. The result underlines the impact of the precipitation model as a major factor for the seasonality of long-term DMY of SSH in the Republic of Korea.

The sustainable supply of whole crop maize (WCM, Zea mays L.), as the domestic high‐quality forage source, is causing great concern among the related parties in the Republic of Korea. Many new cultivars were introduced or developed in recent decades. This study was conducted to construct the WCM weather‐crop yield prediction model considering cultivar maturity as well as to evaluate the effects of local climatic factors on yield. Data on the nationwide adaptability tests of WCM cultivars and the meteorological data were collected and merged into a dataset (n = 386, 22 years) after data cleansing. Three climatic variables, including the accumulation values of growing degree days, precipitation, and sunshine hours from seeding to harvesting, were generated. Then, the dataset was split into two sub datasets considering cultivar maturity. Subsequently, the models, including the three climatic variables and the cultivated location, were constructed for both sub datasets. The finesses and accuracy of the models were confirmed by residual diagnostics and 3‐fold cross‐validation. The accumulated temperature, sunshine time, and precipitation were found to significantly affect the WCM yield variance, while the precipitation factor caused stresses to the yield, which indicates water management is important for WCM cultivation.

This study investigated the effect of pasture grazing on growth performance and blood characteristics in nine-month-old Hanwoo (native Korean cattle) steers. Thirty one steers were randomly assigned to three groups: (CON) Italian ryegrass and concentrate (1.6% BW) until 14 month of age, (G1) pasture grazing 101 days without concentrate, (G2) pasture grazing 101 days and concentrate (1.6% BW). Initial BW of CON, G1 and G2 were 255 kg, 238 kg and 254kg respectively. Average daily gains were higher in CON (1.02 kg) and G2 (0.92 kg) than G1 (0.62 kg) (p &gt;0.05). Final weight and total weight gain were higher in the feeding concentrate (1.6% BW) groups (Con and G2) compared to the G1. Blood characteristics, such as such as total cholesterol (T-CHO), triglycerides (TG) and non-esterified fatty acid (NEFA) were investigated to test the effects on health and energy metabolism. T-CHO, an index of fat metabolism and liver function, was lower in Con (119.75 md/dL) and G2 (107.13md/dL) than G1 (87.79 mg/dL). TG was higher in Con (21.63 IU/L) than G1(15.14 IU/L) (P&lt; 0.08). NEFA was higher in G2 (384 uEq/L) than other groups (Con 138 uEq/L and G1 225 uEq/L). These results show that concentrates supplementation during grazing period is needed to increase BW of Hanwoo steer in the growing state.