Bae-Hun Lee

Coat and hair color: hair cortisol and serotonin levels in lactating Holstein cows under heat stress conditions

The deleterious effects of heat stress on animal health are being increasingly recognized. This study aimed to determine hair cortisol (HC) and serotonin levels in lactating Holstein cows under heat stress conditions with different coat and hair-cut color. Forty-five multiparous lactating Holstein cows (days in milk = 130 ± 47, body weight = 753 ± 85 kg) were divided to two main groups of over 80% black coat color (BC) and over 85% white coat color (WC) visually observed based on registry certificates and subdividing to black hair sample (BH) and white hair samples (WH) in 2 × 2 factorial arrangements. Hair samples were taken from the forehead of the individuals. Higher HC levels were observed in BC than WC cows (P < 0.05). No differences were found in HC levels between BH and WH groups (P > 0.05). Serotonin levels showed no difference between BC and WC (P > 0.05). Interaction between coat color and hair color was not significant (P > 0.05). The cortisol levels in hair are not affected by pigmentation. However, pigmentation within the coat alters cortisol levels. In conclusion, white coat color retains less cortisol than the black coat. Therefore, white coats are preferable for dairy cows under heat stress conditions.

Effects of forage level and chromium-methionine chelate supplementation on performance, carcass characteristics and blood metabolites in Korean native (Hanwoo) steers

A feeding trial was carried out to determine the effects of chromium methionine (Cr-Met) chelate and forage level over two years, 1st fattening and 2nd fattening period on growth parameters, carcass characteristics and blood metabolites of 46 Korean native (Hanwoo, Bos Taurus, BW = 183 ± 44 kg) steers. Treatments were: 1) Steers in the low forage (LF) group were fed diets that consisted of 60% concentrate and 40% forage; 2) Steers in the high forage (HF) group were fed diets that consisted of 40% concentrate and 60% forage. Following the 1st fattening period, steers (BW = 480 ± 37.6 kg) were randomly assigned to four treatment groups: LF (40 F plus no Cr-Met supplementation in the 2nd fattening period), LFCM (40LF plus added 400 ppb of Cr-Met during the 2nd fattening period), HF (60 F plus no added Cr-Met during the 2nd fattening period) and HFCM (60 F plus added 400 ppb of Cr-Met in the 2nd fattening period). Dry matter intake of the treatment diets did not differ during the raising and 1th fattening period (P > 0.05). The ADG in the raising period showed no difference between the 40 F and 60 F groups (P > 0.05). Carcass characteristics including rib-eye area and meat yield index were higher in HF than the other treatment groups (P < 0.05). The HF group tended to show a higher (P = 0.08) marbling score than the LF group whereas the HFCM group showed a higher marbling score than the LFCM group (P < 0.05). HDL was higher and LDL lower in groups fed with Cr-Met than in other groups whereas glucose showed the lowest value in HF group (P < 0.05). Triglyceride (TG), Cholesterol, PUN and total protein (TP) were the same among all treatment groups (P > 0.05). The Insulin concentration in the blood was significantly higher for the HFCM group than for the LF, LFCM and HF groups (P < 0.05). It is concluded that supplementation of chromium-methionine chelate could improve meat quality in beef steers.

Effects of Feeding Levels of Starter on Weaning Age, Performance, Nutrient Digestibility and Health Parameters in Holstein Dairy Calves

To evaluate the effects of feeding four different levels of starter in male Holstein dairy calves, a completely randomized study was conducted, using 28 calves with initial body weight of 40.5±2.4 kg. The animals were fed iso-nitrogenous starter and were weaned when they consumed 350, 500, 650 and 800 g/d of starter for 3 d consecutively. Starter and water were available ad-libitum throughout the experiment. Body weight at pre-weaning (less than 5 wk) and post-weaning (8 wk) was lower in calves that received 350 g/d of starter than in the other treatments (p<0.05). Feed conversion ratio (FCR) was the highest among all treatments in pre-weaning period (p<0.05). Dry matter intake (DMI) at weaning and total DMI was higher in that calves received 800 g/d of starter compared with other treatments (p<0.05). Calves fed 350 and 500 g/d of starter were weaned earlier (p<0.05) and showed lower milk consumption (kg, DM) compared with other treatments whereas no significant difference was observed between calves fed 350 and 500 g/d of starter (p>0.05). Dry matter, organic matter and crude protein digestibilities were lower in calves that received 350 g/d of starter compared with other treatments (p<0.05). No differences were observed in acid detergent and neutral detergent fiber digestibility among all treatments (p>0.05).Treatments had no significant effect on time of starting rumination, respiratory score, and days of drug administration for pneumonia. There were no meaningful differences in feces, fecal odor scores, body temperature, and days of drug administration for diarrhea among all treatments (p>0.05). Total dry matter intake at the end of experiment showed no significant difference among calves fed 600 and 800 g/d of starter, but calves fed 350 and 500 g/d of starter showed more dry matter (DM) intake than calves in the 600 and 800 g/d groups (p<0.05).

Effects of Chromium Methionine Supplementation on Blood Metabolites and Fatty Acid Profile of Beef during Late Fattening Period in Holstein Steers

The objective of this study was to determine the effects of chromium methionine (Cr-Met) chelate supplementation on blood metabolites and fatty acid profile of beef from Holstein steers during late fattening period. Fifteen Holstein steers were allotted randomly into two groups including the control (non Cr-Met feeding, NCM, ave. body weight [BW] = 483±25.7 kg) and the treatment (Cr-Met feeding for 4 months, 4CM, ave. BW = 486±27.5 kg) group. The feeding amount of Cr-Met to animals was limited to 400 ppb/cow/d and was supplemented to total mixed ration. No difference in blood albumin, alkaline phosphatase, urea-nitrogen, calcium, creatine, glucose, total protein, triglyceride, and cholesterol were observed between the treatment groups (p>0.05). The level of high density lipoprotein was higher in the 4CM group than the NCM group, whereas low density lipoprotein was lower in the 4CM group (p<0.05). The fatty acid composition (caprate, laurate, myristate, pentadecanoate, palmitate, palmitoleate, margarate, cis-11 heptadodecanoate, stearate, oleate, trans-vaccenate, linoleate, cis-11 eicosenoate, docosa hexaenoic acid, and docosa pentaenoic acid) of the beef showed no difference between the two groups (p>0.05). The arachidonic acid level tended to be higher in the 4CM than the NCM group (p = 0.07). Cr-Met had no influence (p>0.05) on the ratio of saturated, unsaturated, unsaturated/saturated, monounsaturated/saturated and polyunsaturated/saturated fatty acids whereas the ratio of polyunsaturated fatty acids (PUFA) in the 4CM group was comparatively higher than the NCM group (p<0.05). This study concluded that feeding Cr-Met supplementation in 400 ppb/d to Holstein steers for 4 months during late fattening period can improve some blood metabolites and beef quality by increasing PUFA and gamma-linoleate compositions of beef.

Effects of water addition to total mixed ration on water intake, nutrient digestibility, wool cortisol and blood indices in Corriedale ewes

Objective The objective of this study was to determine the effect of adding water to total mixed ration (TMR) on fresh water intake, nutrient digestibility, wool cortisol, and blood indices in Corriedale ewes under hot and humid conditions. Methods Nine non-pregnant Corriedale ewes (ave. body weight = 41±3.5 kg) were individually fed diets based on maintenance requirements in metabolic crates. Ewes were assigned to three treatment groups according to a triplicate 3×3 Latin Square design for 3 periods of 21 days duration each (9 ewes per treatment, 27 replications). Treatments were TMR (crude protein [CP] = 16.1, total digestible nutrients = 69.1%) moisture levels for 40%, 50%, and 60%. Results No differences were found in body weight gain among all treatment groups (p>0.05). Nitrogen balance including digestible N, retained N, and urinary and fecal N showed no change among the treatment groups (p>0.05). Fresh water intake was the lower in 50% TMR moisture group than in the other groups (p<0.05). Other than ether extract which was higher in 60% TMR moisture group (p<0.05) the differences among nutrient digestibilities including CP, organic matter, dry matter, neutral detergent fiber, acid detergent fiber, and non-fiber carbohydrate were not significant (p>0.05). No significant difference was observed for serum protein, blood urea nitrogen, glucose, and triglyceride among the treatment groups (p>0.05). Wool and blood cortisol were not different among the treatment groups (p>0.05). Blood hematology including red blood cell, white blood cells, hemoglobin, hematocrit, basophils, and eosinophils were not different among the treatment groups (p>0.05). Conclusion It is concluded that TMR moisture at 40%, 50%, and 60% had no effects on N balance parameters, and nutrient digestibilities except for the ether extract under hot and humid conditions. Additionally there were no effects on stress conditions include wool cortisol, as well as blood cortisol levels of ewes.

Microbial nitrogen production, nitrogen balance and excretion of urinary purine derivatives in Corriedale ewes under water deprivation

Abstract The objective of this study was to determine microbial N production, and urinary excretion of PDs in Corriedale ewes under water deprivation. Nine Corriedale ewes (average BW=45±4.5 kg) were individually fed diets based on maintenance requirements in metabolic crates. Ewes were assigned to three treatment groups according to a 3×3 Latin square design for 3 periods of 21 days duration. The treatments were free access to water (FAW ), 2h water deprivation (2hWD), and 3h water deprivation (3hWD) following feeding. Daily water intake decreased linearly as water deprivation time following feeding increased. Feed intake and fecal excretion were not different among the treatment groups. Urine weight and volume were higher in FAW than water deprived groups. Nitrogen balance including urinary N, retained N, urinary N/intake N, and retained N/intake N were lower in FAW group than other treatment groups, whereas no differences were observed in intake N, fecal N, digestible N, and fecal N/intake N among the treatment groups. Allantoin concentration tended to be higher in FAW group than 2hWD and 3hWD groups while no differences were observed in uric acid, xanthine+hypoxanthine and creatinine concentrations. Microbial N production per DOMR was higher in 2hWD and 3hWD groups than FAW group whereas no differences were observed between 2hWD and 3hWD groups. Index of PDC decreased linearly with water deprivation. It is concluded that water deprivation following feeding, especially 2 h water deprivation in ewes improved microbial N production.

Fatty acid profile of meat, diurnal changes in volatile fatty acids, rumen fluid parameters, and growth performance in Korean native (Hanwoo) steers fed high- and low-forage diets supplemented with chromium-methionine

The objective of this study was to determine the effects of forage level in diets supplemented with chromium-methionine (Cr-Met) on rumen fluid parameters, meat fatty acid composition, and performance of Korean beef (Hanwoo) steers. Twenty-three Hanwoo steers were used in this experiment. A completely randomized design and repeated measurements were used to analyze the data set. Beef steers were fed diets containing high (10 head; average body weight (BW) = 525.1±27.5; forage:concentrate (F:C) = 60:40) (60F) and low (13 head; average BW = 531.8±32.4; F:C = 40:60 ratio) (40F) forage diets supplemented with Cr-Met for 60 d. Dry matter intake, BW, and feed efficiency were not different between the two treatment groups. Fatty acid composition of meat including myristate, stearate, and gamma linoleate was not different between the two groups; however, palmitate, palimtoleate, and linoleate were higher in 60F group than 40F group. Ammonia-N showed a higher trend in 40F group, whereas pH demonstrated higher values in 60F group. Ruminal acetate was higher in 60F group than 40F group and maintained a high trend throughout the sampling time, whereas no differences were found in ruminal propionate, butyrate, and valerate between two groups. A high-forage diet (60%) improves meat quality and has no adverse effects on performance of Hanwoo steers.

Accuracy evaluation of the crop-weather yield predictive models of Italian ryegrass and forage rye using cross-validation

The objective of this study was to evaluate the accuracy of the yield predictive models of Italian ryegrass (IRG, Lolium multiflorum Lam.) and forage rye (FR, Secale cereale L.) reported in previous studies through K-fold cross-validation method. In previous studies, statistical models were constructed for dry matter yield prediction of IRG and FR using general linear model based on climatic data by locations in the Republic of Korea. The yield predictive model for IRG cultivated in the southern region of the Korean Peninsula and Jeju Island were DMY = 78.178AGD–254.622MTJ + 64.156SGD–76.954PAT150 + 4.711SAP + 1028.295 + Location and DMY =–8.044AAT + 18.640SDS–7.542SAT + 9.610SAP + 17282.191, respectively. The yield predictive model for FR was as follows: DMY = 20.999AGD + 163.705LTJ + 113.716SGD + 64.379PAT100–4964.728 + Location. However, accuracy evaluation was not performed in the previous research. In this study, the reported models and the data set used for model construction were investigated. Subsequently, K-fold cross-validation was performed to assess the accuracy of the models. The results showed that the yield predictive models fit to the data sets well, while the accuracy of these models was in the common level since the data sources might keep major variances in cultivars, climatic conditions, and cultivated locations. Therefore, models with better fitness and accuracy might be constructed based on a data set with smaller variance. Hence, the standardization of the crop cultivation experiments is very necessary to decrease the variance in the historical data used for future crop yield modeling.

Detecting the Climate Factors related to Dry Matter Yield of Whole Crop Maize

The purpose of this research is to identify the significance of climate factors related to the significance of change of dry matter yield (DMY) of whole crop maize (WCM) by year through the exploratory data analysis. The data (124 varieties; n=993 in 7 provinces) was prepared after deletion and modification of the insufficient and repetitive data from the results (124 varieties; n=1027 in 7 provinces) of import adaptation experiment done by National Agricultural Cooperation Federation. WCM was classified into early-maturity (25 varieties, n=200), mid-maturity (40 varieties, n=409), late-maturity (27 varieties, n=234) and others (32 varieties, n=150) based on relative maturity and days to silking. For determining climate factors, 6 weather variables were generated using weather data. For detecting DMY and climate factors, SPSS21.0 was used for operating descriptive statistics and Shapiro-Wilk test. Mean DMY by year was classified into upper and lower groups, and a statistically significant difference in DMY was found between two groups (p 0.05). These results indicate that the SHAGDD, SHP and SHH are related to DMY of WCM, but the comparison of R 2 among three variables (SHAGDD, SHP and SHH) couldn’t be obtained which is needed to be done by regression analysis as well as the prediction model of DMY in the future study.

Effects of Cultivars and Seeding Dates on Chemical Composition and Energy Content of Switchgrass (Panicumvirgatum L.) in Republic of Korea

The objective of this study was to determine the best performing switchgrass (Panicumvirgatum L.) cultivar with three different seeding dates as a bioenergy source in Republic of Korea. Split-plot in time with three replications was performed and three switchgrass cultivars, Carthage (CT), Cave-in-Rock (CIR), and Forestburg (FB) were used in this experiment from 2009 to 2012. Plots were seeded on April 23, May 4, and May 13, 2009 and were harvested once in November each year. No fertilizer was applied to the field for the first year; however, in second and third years (June 2010 and May 2011, respectively), N, P2O5 and K2O fertilizers were applied in 67,45 and 90 kg h a -1 , respectively. Soil pH (5.9) and climate condition including temperature (10.4~17.5℃) and precipitation (89.4~109.8 mm month -1 ) were suitable for switchgrass cultivation. Total dry matter yields were higher in CT and CIR compared to FB and were 16.9, 15.9, and 4.5 ton ha -1 , for CT, CIR, and FB, respectively (p 0.05) were found. Seeding dates did not affect DM yield (ton ha -1 ), chemical composition and energy content significantly (p>0.05). Significant difference was observed for heights among CT, CIR, and FB (177.59, 169.98, and 94.89 cm, respectively, p = 0.0002). In conclusion, based on soil characteristics and climate condition in Korea compared to other countries, switchgrass can be cultivated successfully. Considering dry matter yield and energy content of these three cultivars of switchgrass CT and CIR adapted better to climate in Middle Eastern of Republic of Korea than Forestburg for bioenergy purpose.