• Asian-Australasian Journal of Animal Sciences
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• v.18 no.8
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• pp.1075-1079
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• 2005

The main objective of this study is to examine genetic changes in growth rate and carcass composition traits in group housed, ad libitum fed pigs, from lines of Large White divergently selected over four years for high and low post-weaning daily gain on a fixed but restricted ration. Genetic parameters for production and carcass traits were also estimated by using average information-restricted maximum likelihood applied to a multivariate individual animal model. All analyses were carried out on 1,728 records of group housed ad libitum fed pigs, and include a full pedigree of 5,324 animals. Estimates of heritability (standard errors in parentheses) were 0.11 (0.04) for lifetime daily liveweight gain (LDG), 0.13 (0.04) for daily carcass weight gain (CDG) and 0.28 (0.06) for carcass backfat (CFT). Genetic correlations between LDG and CDG were highly positive and between LDG and CFT negative, suggesting that selection for lifetime daily gain under commercial conditions of group housing with ad libitum feeding would result in favourable improvement in carcass traits. CFT showed negative genetic correlations with CDG. Correlated genetic responses evaluated as estimated breeding values (EBVs) were obtained from a multivariate animal model-best linear unbiased prediction analysis. After four years of divergent selection for 6 week post-weaning growth rate on restricted feeding, pigs performance tested on ad libitum feeding in groups exhibited changes in EBVs of 6.77 and -9.93 (g/d) for LDG, 4.25 and -7.08 (g/d) for CDG, and -1.42 and 1.55 (mm) for CFT, in the high and low lines, respectively. It is concluded that selection for growth rate on restricted feeding would significantly improve genetic performance and carcass composition of their descendants when group housed and ad libitum fed as is a common commercial practice.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.4
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• pp.543-548
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• 2002

Fresh elephant grass was replaced by urea treated rice straw (UTRS) to evaluate the effects on milk production of crossed lactating cows. A total of 16 crossbred F1 cows (Holstein Friesian ${\times}$ Vietnamese Local Yellow), with a body weight of about 400 kg and lactation number from three to five, were used in the experiment. The experimental cows were blocked according to the milk yield of the previous eight weeks and divided into 4 homogenous groups. The experiment was conducted with a Latin Square design with 4 treatments and 4 periods. Each period was 4 weeks, with 2 weeks of feed adaptation and 2 weeks for data collection. The ratio of concentrate to roughage in the ration was 50:50. All cows were given constant amounts of elephant grass dry matter (DM), with ratios of 100% grass without UTRS (control treatment 100G), and 75% grass (75G), 50% grass (50G) and 25% grass (25G) with ad libitum UTRS. Daily total DM intake on 100G, 75G, 50G and 25G was 12.04, 12.31, 12.32 and 11.85 kg, and the daily ME intake was 121.6, 121.5, 119.4 and 114.3 MJ, respectively. The daily CP intake was similar for all treatments (1.85-1.91 kg). There was a difference (p<0.05) in daily milk yield between the 25G and the 100G and 75G (11.7 vs. 12.6 and 12.5 kg, respectively). Milk protein concentration was similar for all treatments, while a tendency to increased milk fat concentration following the increase of UTRS ratio was observed. The cows gained 4-5 kg body weight per month and showed first oestrus 3-4 months after calving. The overall feed conversion for milk production was not affected by ratio of UTRS in the ration. It is concluded that replacement of green grass by UTRS with a ratio of 50:50 for crossbred lactating cows is as good as feeding 100% green grass in terms of milk yield, body weight gain and feed conversion. UTRS can preferably replace green grass in daily rations for crossbred dairy cows in winter to cope with the shortage of green grass, with the ratio 1:1.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.4
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• pp.260-265
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• 2018

Limited researches are available to demonstrate the effect of TMR (Total Mixed Ration) and SF (Separate feeding) system on ruminal methane production. Two experiments were performed at two different levels of daily feed intake (1.8 and 2.4% of BW) to investigate methane production by using a triplicated $2{\times}2$ Latin square design. Each experiment was conducted using six Holstein steers. Animals were provided either TMR or SF containing 73% concentrate and 27% forage, with the same ration of same ingredients. No differences in daily methane productions (MP) and per dry matter intake (DMI) were observed in both experiments. Relationship for daily methane production on DMI was $MP(g/d)=11.5({\pm}1.3){\times}DMI(kg/d)+14.2$, $R_2=0.73$, p<0.001.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.3
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• pp.213-217
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• 1995

Leucaena leucocephala (lam. de Wit) is a multipurpose leguminous tree/shrub, promoted extensively for reforestation and rural development programmes, as well as in ruminant production. After a year of establishment in the plots, the overall leaves and twigs yield was on average 0.92 kg/plant, containing an average 23.34, 10.61, 5.32 and 10.13 percent CP, CF, and ash, respectively. The proximate and mineral compositions are affected by factors such as stage of maturity, type of cultivar, seasons, cutting intervals, different plant parts. Though leucaena contains toxic mimosine and tannins, these are not always deleterious for ruminants and rumen microbes can often degrade toxic factors into a nontoxic utilizable product Mimosine content is generally higher in the seed than other plant parts. Leucaena supplementation in ruminant ration showed higher digestibility co-efficient of proximate component, which may results in higher productivity. Considering its productivity, composition and nutritive value. L. Leucocephala could be more widely used as a protein source for ruminants in tropical and sub-tropical countries.

• Journal of Environmental Health Sciences
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• v.27 no.4
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• pp.79-83
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• 2001

The sludge wastes fermentation process reactors were operated to produce the VFAs(volatile fatty acids) as supplemental carbon sources and to determine the optimum operating conditions. The experiment was carried out by varied mixture ration of 400:0 350:30 300:100 200:200 and operating temperature 2$0^{\circ}C$ 3$0^{\circ}C$ and 4$0^{\circ}C$ The results were as follows: Higher VFAs production rate observed at higher mixed ratio of primary sludge. When the mixed ratio of primary sludge and return sludge were 400:0 350:50 300:100 200:200 respectively. VFAs production are were 829.6mg/l 944.2 mg/l 597.9mg/ml an d441.6 mg/l , respectively. the yield of VFAs increased with temperature, but decreased with initial TSS concentration Because fermented sludge has relatively low nitrogen and phosphorus and relatively high VFAs it can be used as a substitute for external carbon in biological nutrient removal process.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.593-596
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• 2000

Chiral epoxides are useful chiral synthons in organic synthesis and various biological methods have been investigated for the production of chiral epoxides. In this work, enantioselective resolution of racemic styrene oxide was investigated using an isolated Aspergillus niger sp. for the production of optically pure (S) -styrene oxide. The enantioselectivity and initial hydrolysis rates of racemic substrate were highly dependent on the pH, temperature, and the volume ratio of cosolvent. The experimental sets of pH, temperature, and the volume ratio of cosolvent were designed using central composite experimental design, and the reaction conditions were optimized using response surface analysis. The optimal conditions of pH, temperature, and the volume ration of cosolvent were determined to be 7.78, $28.32^{\circ}C$, and 2.4 %(v/v), respectively, and optically pure (S)-styrene oxide (> 99% ee) could be obtained with the 35 % yield by microbial enantioselective hydrolysis reaction.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.2
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• pp.213-215
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• 1994

Poultry feeding systems are likely to change for increased efficiency of production. An experiment was conducted to compare the response of broilers to choice feeding of corn with a standard broiler ration. The treatments consisted of providing broiler feed as the only feed (SINGLE FEED) and access to corn as a choice to a complete broiler feed (CHOICE FEEDING). Weights and feed consumption were obtained at weekly intervals. Samples at the conclusion of the experiment were taken to determine the weight of abdominal fat. Results showed that there was no significant difference in term of liveweight between the two feeding regimes. However, birds given a choice of the broiler feed and corn had better feed efficiency which is reflected by the lower total feed intake. Corn intake was 23.1% of total feed intake in the choice fed birds. In term of carcass colour, birds fed corn as a choice was observed to have a deeper yellow skin colour than the birds fed with broiler feed only.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1996.03b
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• pp.130-137
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• 1996

Several cold extrusion processes to produce an axisymmetric steel piston-pin are investigated for comparing each other. Two methods among four conventinal ones are selected to be simulated using the rigid-plastic finite element method. One of the both methods using a mechanical press has one stage process and the other utilizing a cold header applies a multi-stage process to produce a final product. Because the main process is a backward extrusion, the design criteria such as the backward extrusion ration and punch diameter to depth rationare ocnsidered. FEM analysis is performed mainly for strain distributin and load-stroke relationshis. Based on the results of preliminary simulatin, both process sequences are proved to have proper charicteristics suitable for each production method in terms of maximum load. Those simulation results will be a good design criteria in the future work to advance the manufacturing process.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.3
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• pp.307-312
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• 2000

Fasting heat production (FHP) of growing buffalo calves (Bubalus bubalis) in the body weight range of 76 to 236 kg was determined using open circuit respiration chamber. The details of the chambers, calibration of gas analysers and operation of the systems are described. Animals were fasted for 96 hrs during which only water was provided. FHP was determined during next 24 hrs. The mean oxygen consumed, carbon dioxide and methane produced and urinary N excretion per 24 h was $17.03{\ell}$, $11.70{\ell}$, and $0.12{\ell}$ and 0.35 g respectively. The mean respiratory quotient ranged from 0.68 to 0.71, which indicated that post absorptive stage is reached after 96 hrs in growing buffalo calves previously fed ammoniated straw-based ration. Mean FHP of calves was $331.4kJ/kg\;W^{0.75}$. FHP of calves with range of mean body weights of 167 to 235 kg, although nonsignificant but, was almost 12% higher than of calves having mean body weight of 101 kg. Suitable exponent to body weight to describe FHP of buffalo calves was 0.87.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.2
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• pp.253-258
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• 1993

The study on the nutritive value and the potential use of two kinds (local vs. import) of sesame meal (SSM) in layer diets as substitute for soybean meal (SBM) at 25, 50, and 75% was carried out. Three hundred and thirty six layers were kept individually on a battery cage and fed isonitrogenous diets, 16% crude protein (CP), for 252 days. The local and the imported SSM contained on air dry basis 35.7 and 36.3% CP, 24.7 and 9.1% ether extract (EE), respectively. Their amino acid contents are all lower than those reported by NRC (1984). The local material contained remarkably lower lysine (0.44 vs. 0.94), methionine + cystine (1.06 vs. 1.75) and threonine (0.52 vs. 1.22) than the imported meal. Imported SSM could be substituted for SBM as high as 50% in layer ration without statistically adverse effect on egg production, feed intake, body weight gain, average egg weight and egg size, while local SSM was inferior to the control in all aspects. However, when production performance of the groups fed either kind of SSM was compared, no significant difference was found at the two lower substitution levels.