• Asian-Australasian Journal of Animal Sciences
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• v.29 no.12
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• pp.1719-1724
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• 2016

The objective of this study was to determine the effects of physically effective neutral detergent fiber (peNDF) content in total mixed ration (TMR) on dry matter intake, digestibility, and chewing activity in fattening Hanwoo (Bos taurus coreanae) heifers. The experiment was designed as a replicated $3{\times}3$ Latin square using 12 heifers. Fattening heifers were offered one of three diets [high (T1), medium (T2), and low (T3) peNDF] obtained by different mixing times (3, 10, and 25 min) for the same TMR feed. The peNDF content of TMR was determined by multiplying the proportion of dry matter retained by a 1.18 mm-screen in a Penn State Particle Separator by the dietary NDF content. The $peNDF_{1.18}$ content was 30.36%, 29.20%, and 27.50% for the T1, T2, and T3 diets, respectively (p<0.05). Dry matter intake was not affected by peNDF content in TMR. Total weight gain in T1 group was significantly higher (p<0.05) than in T2 and T3 groups. However, weight gain did not differ between T2 and T3 groups. The feed conversion ratio decreased with an increase in the peNDF content (T1: 12.18, T2: 14.17, and T3: 14.01 g/g). An increase in the peNDF content of TMR was associated with a linear increase in the digestibility of dry matter, crude protein, crude fiber, neutral detergent fiber, and acid detergent fiber (p<0.05). Also, an increase in peNDF content of the TMR resulted in a linear increase in the number of chews in eating and ruminating (p<0.05), and consequently in the number of total chews (p<0.05). These results indicate that peNDF content affects digestibility and chewing activity. Consequently, the peNDF content of TMR should be considered for improving feed efficiency, digestibility, body weight gain, and performance in fattening heifers.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.2
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• pp.257-264
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• 2019

Objective: Dairy cattle nutrient requirement systems acknowledge amino acid (AAs) requirements in aggregate as metabolizable protein (MP) and assume fixed efficiencies of MP used for milk protein. Regulation of mammary protein synthesis may be associated with AA input and milk protein output. The aim of this study was to evaluate the effect of nanoemulsified methionine and cysteine on the in-vitro expression of milk protein (casein) in bovine mammary epithelial cells (MAC-T cells). Methods: Methionine and cysteine were nonionized using Lipoid S 75 by high-speed homogenizer. The nanoemulsified AA particle size and polydispersity index were determined by dynamic light scattering correlation spectroscopy using a high-performance particle sizer instrument. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to determine the cytotoxicity effect of AAs with and without nanoionization at various concentrations (100 to $500{\mu}g/mL$) in mammary epithelial cells. MAC-T cells were subjected to 100% of free AA and nanoemulsified AA concentration in Dulbecco's modified Eagle medium/nutrient mixture F-12 (DMEM/F12) for the analysis of milk protein (casein) expression by the quantitative reverse transcription polymerase chain reaction method. Results: The AA-treated cells showed that cell viability tended to decrease (80%) in proportion to the concentration before nanogenesis, but cell viability increased as much as 90% after nanogenesis. The analysis of the expression of genetic markers related to milk protein indicated that; ${\alpha}_{s2}$-casein increased 2-fold, ${\kappa}$-casein increased 5-fold, and the amount of unchanged ${\beta}$-casein expression was nearly doubled in the nanoemulsified methionine-treated group when compared with the free-nanoemulsified methionine-supplemented group. On the contrary, the non-emulsified cysteine-administered group showed higher expression of genetic markers related to milk protein ${\alpha}_{s2}$-casein, ${\kappa}$-casein, and ${\beta}$-casein, but all the genetic markers related to milk protein decreased significantly after nanoemulsification. Conclusion: Detailed knowledge of factors, such nanogenesis of methionine, associated with increasing cysteine and decreasing production of genetic markers related to milk protein (casein) will help guide future recommendations to producers for maximizing milk yield with a high level of milk protein casein.

• Journal of Animal Science and Technology
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• v.50 no.1
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• pp.33-44
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• 2008

The purpose of this study was to estimate the genetic parameters and trend of Landrace and Yorkshire pigs, which were raised on private farms from 1999 to 2005 and tested for their reproductive performance by the Korea Animal Improvement Association. Prior to analysis, records without pedigree or having value with larger than±3×standard deviation for the Total number of born were excluded. The effects of breed and environmental factors were estimated with least square method(Harvey, 1979), and estimation of breeding values and genetic parameters were performed on the data of 1’st litter only with GIBBSF90(Misztal, 2001) which was programmed according to Gibbs Sampling method based on Bayesian Inference by Gianola and Fernando(1986), Jensen(1994) and others. Gibbs sampling was performed 50,000 times for each parameter, and the first 5000 samples were regarded as those in burn-in period and thus, excluded for post hoc analysis. Total number of born and total number of accident were statistically significant(p<0.01) for the breed, farrowing year, farrowing season and parity effects, and the number born alive at birth was statistically significantp<(0.01) for the breed, farrowing year, farrowing season and parity effects. No particular trend was observed in the genetic and phenotypic improvement of the total number of born and number born alive at birth before 2001, when the piglet registration system started, but the tendencies of increasing for the total number of born and number born alive and decreasing for the total number of accident were observed since 2001. Somewhat higher heritability estimates of our study seems to be attributed to the situations that first parity records with poor farrowing performances were used in the analyses and it was impossible to obtain accurate reproductive performance due to the absence of criteria for record keeping at the level of individual farms.

• Korean Journal of Poultry Science
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• v.49 no.3
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• pp.139-144
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• 2022

This study was conducted to investigate the effect of three different photoperiods on growth performance, blood properties, and stress indicators in broiler chicks between 1-7 days after hatching. Two hundred and fifty-two 1-day-old male broiler chicks (57.0±0.12 g) were divided into three treatments, with 4 replicates per treatment and 22 birds per replicate subjected to three different photoperiods of 24L, 22L/2D and 18L/6D. A light-emitting diode bulb served as the light source, with an illuminance of 30 lx. As an experimental diet, a commercial feed based on a corn-soybean meal, with 22% CP and 3,150 kcal/kg ME diet, and water were fed ad libitum. Body weight gain, feed conversion ratio, and liver weight ratio showed a statistically significant difference between the 18L/6D and 24L treatments (P<0.05), but with no significant difference between the 22L/2D treatment and either the 24L or 18L/6D treatment. The breast meat ratio was 5.59% in the 18L/6D treatment group, which was lower than that of other treatment groups (P<0.05). The triglyceride levels were highest (P<0.05) in the 18L/6D treatment among treatments, but alanine aminotransferase levels were significantly higher (P<0.05) in the 22L/2D treatment than in the 24L treatment. Levels of cytokines, i.e., Interleukin-6 and Tumor Necrosis Factor-α did not show a significant difference among the treatments, but corticosterone content was significantly higher (P<0.05) in the 24L treatment than in the 18L/6D treatment. In conclusion, 22 hours of lighting is appropriate between 1~7 days after hatching, considering growth performance and the overall health of broiler chicks.

• Journal of Animal Science and Technology
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• v.54 no.2
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• pp.71-75
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• 2012

The present study data were obtained from 36,894 cows in Korea Animal Improvement Association from 2001 to 2009 which was subjected for ultrasound measurements (eye muscle area, back-fat thickness, marbling score) and descent. Repeated record models were carried out using 7,913 of 36,894 of total animal traits. The ultrasound measured traits and performance test data were used to study the chest girth, body condition score, eye muscle area, back-fat thickness and marbling score with genetic correlation and parameters for the ultrasound measured traits using REMLF90 program. Genetic correlation of eye muscle area with back-fat thickness, marbling score and back-fat thickness with marbling score were noticed in repeated records animal model as 0.69, 0.54, and 0.59, whereas in multiple trait animal model method were 0.07, 0.66, and 0.39, respectively. Repeated records of animal models were used as positive correlation of traits. Multiple trait animal models were used as negative correlation of eye muscle area with marbling score. The analysis on repeat records of animal models using ultrasound measurements about Korean cattle showed positive effects for each traits. In comparison differences between the repeat records of animal models and multiple trait animal models was found with higher traits of her, the heritability and repeatability was found higher in repeat records animal models. In light of these assessments, carcass traits by ultrasound measurements are expected to help and improve an accurate analysis of each trait and if the research analysis using repeat records of animal models continue when we estimate genetic ability of these traits.

• Journal of agriculture & life science
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• v.44 no.3
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• pp.41-52
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• 2010

This study was conducted to estimate genetic parameters for growth traits using multivariate animal models in Yorkshire breed. For the study, 16,202 records for growth traits collected between the year 1999 and 2005 from Yorkshire pigs in K GGP were used. The effects of environmental factors such as sex, birth year, birth season, parity and birth weight group affected growth traits significantly (p<0.01). Birth weight tended to be positively correlated with average daily gain (ADG) and lean percent. But it seemed to affect age at 90 kg, average adjusted backfat thickness (BF), and eye muscle ares (EMA) negatively. For average pig suckling weight (ASW) and total weight at suckling (TWS), the higher birth weight is the better performance. But, in case of total number of born and number of suckling, the result was shown vice versa. Approximately 10~30% lower heritability estimates were obtained for growth traits by using the model that includes descriptions of common litter effects (CL) than by using the model that ignores those (NCL) for more accurate estimation of heritability. The estimates of heritabilities were 0.468, and 0.328 for ADG, 0.474 and 0.326 for age at 90 kg, 0.452, and 0.396 for BF, 0.240 and 0.200 for EMA and, 0.458, and 0.380 for lean percent in NCL and CL, respectively. Therefore, in order to estimate optimal genetic parameters, it could be inferred that the statistical model which considers litter effects must be applied.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.4
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• pp.267-272
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• 2021

This experiment was conducted to the purpose of evaluating the effect of feeding on Korean Native Cattle to expand the production and utilization of whole crop rice (WCR). TMR (Total mixed ration) feed was prepared by using WCR produced in Pyeongtaek, Gyeonggi-do, and the growth capacity and meat quality characteristics of 16 Korean Native Cattle raised up to 29 months of age were investigated. The produced WCR silage for feed had a moisture content of 64.02% and a crude protein content of 7.54%, and was blended with about 45% during the growing season, and lowered to 35, 15 and 9%, respectively, in the fattening period (early, middle and late stages). The body weight of the WCR-TMR feeding group was significantly higher than that of the control in the middle and late fattening stage, and at the end (29 months of age), the control group was 631 kg/head, but the WCR-TMR feeding group was 647 kg/head, which was higher. The average daily gain was significantly higher in the WCR-TMR feeding group in the growing and early fattening period, and there was no difference in the mid- and late fattening period. In the whole period, 0.71 vs 0.75 kg/head/day, WCR-TMR feeding group was high. In terms of meat quantity, the back fat thickness of the control group (11.7 mm) was significantly thicker than that of the WCR-TMR fed group (9.3 mm) (P<0.05). There was no difference in Rib eye area, Carcass weight and Meat yield index (P>0.05). In terms of meat quality, the Marbling score was higher in the WCR-TMR feeding group (P<0.05), and there were no significant differences in Meat color, Fat color, Texture and Maturity. Considering the above results, TMR feeding mainly on whole crop rice silage for feed improved the productivity of livestock, but there was no significant difference in meat quality. Therefore, it is judged that it is necessary to produce and use the whole crop rice for feed in countries with poor forage conditions.