• Journal of Animal Science and Technology
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• v.46 no.1
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• pp.97-106
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• 2004

The study was conducted to investigate the effects of practical variations in feed restriction, pre-slaughter handing and chilling regime on pork quality during ageing. A total of twenty male landraces were allocated into three treatments(i.e., pre-slaughter feeding, stress and chilling regime) in a factorial arrangement. pH, temperature, free calcium ions, WB-shear force, sarcomere length, cooking loss, drip loss and objective color were determined during rigor development and/or 1, 3, 7 d postmortem. Pre-slaughter chasing stress for approximately 15 min had no effects on pH/temperature profile and objective meat quality. There was an interaction(P < 0.05) between the fasting treatment and chi1ling regime for muscle temperature at pH 6.2. Sarcomere length indicated that the current experiment conditions did not induce muscle shortening, with 1.7 to 1.8 ${\mu}m$, in spite of a significant effect of the fasting treatment (P<0.01). Pigs fed until the morning of slaughter showed a low WB-shear force(P < 0.05) until 3 d at I "C. The treatment also resulted in a higher Hunter L* and a*(P < 0.05) at 24 h and 7 d. Fasted pigs showed a significantly(P < 0.05) reduced cooking loss. The current results indicated that feeding upon the morning of slaughter became detrimental on meat color and the negative effect on cooking loss were linearly elevated with increased ageing time. On the other hand, WB-shear force did not distinguishable after 3 d. Collectively, it appeared that feed restriction from a day before slaughter could produce more a desirable meat quality at the time of consuming. However, the limited effect of animal handling and chilling rate on meat quality is not necessarily to extend to that these do not affect pork quality, as that largely depends on experimental design.

• Korean Journal of Poultry Science
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• v.36 no.4
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• pp.351-356
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• 2009

This work was carried out to investigate the effects of CDDGS (corn distillers dried grains with solubles) colors and phytase levels on the amino acid digestibility of broilers for 7 days. One hundred eight Ross broilers were used in 9 treatment groups with a $3\;{\times}\;3$ factorial design as three colors of DDGSs (DDGS1, DDGS2, and DDGS3) in combination with phytase (0, 500, and 1,000 FTU/kg). The $L^*$ values of DDGS1, DDGS2, and DDGS3 were 55.2, 39.8, and 28.3; the $a^*$ values, 8.8, 7.5, and 6.1; and the $b^*$ values, 41.3, 27.1, and 15.4, respectively. The ileal digestibility of amino acids was decreased as DDGS color was dark, and increased as additive phytase level was increased in the diet. Average digestibilities of essential amino acids were 67.6~80.0%, and those of nonessential amino acids 67.4~77.3. Amino acid digestibility was low in the dark DDGS with no phytase in the diet.

• Korean Journal of Food Science and Technology
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• v.30 no.2
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• pp.348-355
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• 1998

The developments of various processed foods and the high quality dried fruits, in particular, are urgently needed for the enhancement of fruit consumption and their competitive values. Therefore, in this study, three variables by three level factorial design and response surface methodology were used to determine optimum conditions for osmotic dehydration of kiwifruit. The relationships of moisture losses, solid gains, weight reductions, sugar contents, titratable acidities and vitamin C contents depending on changes with temperature, sugar concentration and immersion time were investigated. The moisture loss, solid gain, weight reduction and reduction of moisture content after osmotic dehydration were increased as temperature, sugar concentration and immersion time increased. The effect of concentration was more significant than those of temperature and time on mass transfer. Sugar content was increased by increasing sugar concentration, temperature, immersion time during osmotic dehydration. Titratable acidity and vitamin C content were increased by decreasing temperature, immersion time and increasing concentration during osmotic dehydration. The regression models showed a significant lack of fit (P>0.05) and were highly significant with satisfying values of $R^2$. At the given conditions such as $66{\sim}69%$ moisture content, above $24^{\circ}Brix$ sugar content and more than 23 mg% vitamin C, the optimum condition for osmotic dehydration was $37^{\circ}C,\;55^{\circ}Brix$ and 1.5 hour.

• Korean Journal of Poultry Science
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• v.15 no.3
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• pp.229-246
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• 1988

These studies were conducted to investigate the effects of dietary protein and metabolizable energy(ME) levels on layer performance during summer period. Total 480 ISA Brown egg-type layers ageing 49 weeks housed 2 birds per cage with 4 replictes of 20 birds were employed in this study. Mean environmental temperature over experimental period ranged from 22.3$^{\circ}$to 29.5$^{\circ}C$. The treatments consisted of dietary ME levels of 2500, 2700, 2900kcal/kg of diet containing 15% and 17% protein, respectively, to provide $3{\times}2$factorial design. As metabolizable energy level increased form 2500 to 2900 kcal/kg of diet, daily feed and protein intake, egg production. egg weight, egg mass decreased, but the reverse was true for the daily energy intake, energy requirement and feed costs per kg egg. Feed conversion(kg feed/kg egg) and viability were not affected by the dietary energy levels. However, there were no significant difference in egg production, protein requirement per kg egg, and egg weight between those hens fed 2500 kcal ME/kg diets and those fed 2700 kcal ME/kg diets, and no difference was found in egg weight between those fed 2700 kcal ME/kg and those fed 2900 kcal ME/kg, either. In addition, no specific trend was observed in protein requirement per egg by the different level of metabolizable energy in diets. On the other hand, as dietary protein level increased from 15 to 17%, daily protein in-take, egg production, egg weight, egg mass, and protein requirement and feed costs per kg egg increased, but feed and energy requirement per kg egg decreased, and no significant difference in the daily feed and energy intake and viability were observed among dietary protein levels. It was concluded that metabolizable energy level of 2500 kcal/kg of diet and 17% dietary protein level were considered to be adequate to support the optimum productivity of layers during summer period.

• Korean Journal of Poultry Science
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• v.18 no.3
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• pp.167-181
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• 1991

In order to study the effects of dietary yeast (Saccharomyces cerevisiae) products on the performance of broiler chickens, tow feeding trial using Arbor Acres strain were conducted. In experiment 1, 200 hatched male broiler chickens were divided into groups of 10 birds each and four groups were given each of the five dietary treatments : control, 0.25% yeast culture supplemented (YC-0.25%), 2.5% yeast culture supplemented(YC-2.5%), 0.05% live yeast supplemented(LY-0.05%) and 0.1% live yeast supplemented(LY-0.1%) . In experiment 2, 240 hatched broiler chickens(120 birds in each sex) were assigned to 2$\times$3(sex$\times$feed) factorial design Dietary treatments were control, 0.1% live yeast supplementation in finisher diet(LY-Finisher) , and 0.1% live yeast supplementation in whole period (LY-Whole). Results of experiment 1 showed that weight gain, feed intake and mortality were not significantly different among treatments. However, weight .gain of YC-0.25% and LY-0.1% tended to be greater than other treatments after 3wks of age Feed efficiency of LY-0.05% was poorer than those of control, YC-0.25% and LY-0.1% . Although nutrients availabilities were not significantly different among treatments, availiabilities of Ca and P were greater in yeast products supplemented groups than in control group. The number of Lactobacillus spp., Streptococcus spp . and yeast in small intestine tended to be greater in supplemented groups while that of Coliforms bacteria tended to be greafter in control group. In experiment 2, there were significant effects of factors (feed and sex) and interaction on growth rate. LY-Whole groups showed best weight gain in male while LY-Finisher groups did best in female broiler chickens. Feed intake and mortality were significantly higher in male broiler chickens. Feed$\times$sex interaction had a significant effect on feed efficiency. LY-Whole groups showed best feed efficiency in male while LY-Finisher did best in female broiler chickens. Availabilities of dry matter, Ca and P were higher in male than in female broiler chickens. Availabilities of Ca and P were higher in live yeast supplemented groups than in control groups. Live yeast supplemented groups tended to have greater number of Lactobacillus spp . and yeast in the small intestine and Stre))tococcu spp. in the small intestine and cecum, and lesser number of Coliforms bacteria in the small intestine The pH of small intestinal contents tended to be higher in live yeast supplemented groups.

• Journal of Animal Science and Technology
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• v.50 no.5
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• pp.695-704
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• 2008

This study was conducted to investigate effects of dietary crude protein(CP) level and supplementation of conjugated linoleic acid(CLA) on growth performances and meat quality parameters in finishing pigs. The experiment was designed using protein levels(11.3%, 16.0%) and CLA levels(0%, 2.5%) according to 2×2 factorial design. A total of forty-eight pigs [(Landrace×Yorkshire)×Duroc] with an average initial weight of 79±1kg were allotted to one of four dietary treatments. Each treatment had four replications of three pigs per replicate. Final body weight(P<0.05) and average daily gain(P<0.01) were lower in 11.3% CP treatments than in 16.0% CP treatments, while feed/gain was high(P<0.01) in 11.3% CP treatments compared with 16.0% CP treatments. Carcass weight was lighter in 11.3% CP treatments(P<0.001) and CLA 2.5% treatments(P<0.01) than in 16.0% CP and CLA 0% treatments, respectively. A significant interaction between CP and CLA on carcass weight was observed(P<0.01), where supplementation of 2.5% CLA to finishing diets decreased carcass weight in 16.0% CP treatments, while no difference was found in 11.3% CP treatments. Backfat thickness was thinner in 11.3% CP treatments and CLA 2.5% treatments than in 16.0% CP and CLA 0% treatments, respectively(P<0.05). A significant interaction between CP and CLA on backfat thickness was observed(P<0.001), where supplementation of 2.5% CLA to finishing diets decreased backfat thickness in 16.0% CP treatments, while no difference was found in 11.3% CP treatments. Marbling score and intramuscular fat contents were higher in 11.3% CP treatments than in 16.0% CP treatments(P<0.01). In conclusion, feeding of protein-deficient diets in finishing pigs could produce favorable pork with high marbling score and thinner backfat. On the other hand, supplementation of CLA was considered to decrease backfat thickness when diets with optimal level of crude protein were fed to finishing pigs.

• Journal of Animal Science and Technology
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• v.50 no.5
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• pp.687-694
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• 2008

This study was conducted to investigate effects of dietary supplementation of lysine and leucine on growth performance and meat quality parameters in finishing pigs. The experiment was designed using lysine levels(0.45%, 0.75%) and leucine levels(1.0%, 2.0%, 3.0%) according to 2×3 factorial design. A total of thirty-six pigs[(Landrace×Yorkshire)×Duroc] with an average initial weight of 75.5±2kg were allotted to one of the six dietary treatments. Each treatment had three replications of two pigs per replicate. No difference was found in average daily gain(P>0.05), while feed intake and feed/gain were higher in 0.45% of lysine treatments than in 0.75% of lysine treatments(P<0.05). Retail lean meat percentage was lower in 0.45% of lysine treatments than in 0.75% of lysine treatments(P<0.05), but there were no differences in other carcass characteristics(P>0.05). Marbling score was significantly increased(P<0.05) in 0.45% of lysine treatments compared to 0.75% of lysine treatments, while other meat quality parameters were not affected by lysine levels(P>0.05). Supplemental dietary leucine had no effect on growth performance, carcass characteristics, and meat quality parameters(P>0.05) except that Hunter b* value were increased with added levels of leucine(P<0.05). In conclusion, feeding of lysine-deficient diets in finishing pigs improved marbling scores of pork. Feeding diets high in leucine, however, did not increase intramuscular fat or marbling scores.

• Korean Journal of Poultry Science
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• v.40 no.4
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• pp.351-359
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• 2013

This study was undertaken to assess dietary crude protein (CP) and amino acid (AA) concentrations for growth performance and carcass characteristics in Korean native ducks. In a $2{\times}3$ factorial arrangement, 1-d-old Korean native male ducks were allotted to 6 dietary treatments in a completely randomized design. Experimental diets contained 23 or 21% CP with 1.31/1.09, 1.21/1.00, 1.11/0.91 and 1.11/0.91, 1.02/0.83, 0.92/0.75 AA (Lysine/Total sulfur amino acid, Lysine/TSAA), respectively, from 0 to 3 wk of age. From 4 to 8 wk of age, experimental diets had 19 or 17% of diet; each contained 1.00/0.79, 0.94/0.75, 0.88/0.71 and 0.88/0.71, 0.82/0.67, 0.76/0.63 AA (Lysine/TSAA), respectively. Each dietary treatment has 6 replicates and feed and water were provided ad libitum. Body weight (BW), feed intake and uniformity were measured at 3 wk and 8 wk and carcass characteristics were evaluated at 8 wk of age. As CP increased from 21 to 23%, the BW and BW gain significantly increased (P<0.05) during 0 to 3 wk of age. From 4 to 8 wk of age, BW, feed intake, BW gain, feed conversion rations (FCR) and uniformity were not different (P>0.05) between treatments. Carcass yield and relative weights of liver, spleen, right breast and leg per 100 of BW were not different (P>0.05) between treatments. The meat color, shear force value, cooking loss and pH were not affected by dietary treatments (P<0.05). Korean native ducks require relatively low levels of dietary CP and AA for late growth and carcass yield due to low daily weight gain. This suggests the possible differences in CP and AA needs between Korean native ducks and commercial breeds from foreign breeding companies, especially late growth stage.

• Journal of Food Hygiene and Safety
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• v.31 no.6
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• pp.451-457
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• 2016

The purpose of this study was to determine the antimicrobial effects of $ClO_2$ gas on pathogenic E. coli and Salmonella spp. colonizing on the fruit surface of strawberries for export. Factorial design was employed to treat strawberries inoculated with pathogenic E. coli or Salmonella spp. with a combination of $ClO_2$ gas concentrations (10, 20, 30, 40, and 50 ppmv), RH (50, 70, and 90%), and treatment time (0, 5, 10, 20, and 30 min). Interaction between the factors was observed to note that the reduced levels of microbial population were the highest when RH is set at 90% with gas concentration- and treatment time-dependent manner. With RH and gas concentration fixed at 90% and 50 ppmv, the populations of E. coli and Salmonella spp. decreased by 2.07 and 2.28 log CFU/g when treated for 20 min whereas population reduction by 0.5 and 0.7 log CFU/g were observed when treated for 5 min, respectively. The results help establish most effective conditions for $ClO_2$ gas treatment to enhance microbial safety of strawberries for export.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.10
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• pp.1407-1413
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• 2005

An experiment was conducted in order to assess the effect of level of RDP:UDP ratio and level of feeding concentrate on milk yield, milk composition and nutrient utilization in lactating crossbred cattle. Twenty four medium producing (-10 kg/d, 45 to 135 days postpartum) lactating crossbred cows were divided into four groups of six animals each in a 2${\times}$2 factorial completely randomized design. The cows in group 1 were fed concentrate mixture I containing 59:41 RDP:UDP ratio (low UDP) at normal plane (LUDP+NP), in group 2 were fed low UDP ration at 115% of NRC (1989) requirements (LUDP+HP), whereas cows in group 3 were fed concentrate mixture II containing 52:48 RDP:UDP ratio (high UDP) at normal plane (HUDP+NP) and in group 4 were fed high UDP ration at 115% of NRC (1989) requirements (HUDP+HP). Green jowar was fed ad libitum as the sole roughage to all the animals. The experimental feeding trial lasted for 105 days. The total dry matter intake (DMI), DMI/100 kg body weight, DMI/kg $W^{0.75}$, digestibilities of DM, OM, CP, CF, EE and NFE and intakes of TDN and DCP did not differ significantly among the different groups and also due to both UDP level and plane of nutrition and also due to their interaction. The total dry matter intake varied from 145 g in group 1 (LUDP +NP) to 152.57 g/kg $W^{0.75}$ in group 2 (LUDP+HP) diet. However, increase in milk yield with increased UDP level and also with increased plane of nutrition was observed consistently throughout the experimental period. The average milk yield was 7.66, 8.15, 8.64 and 9.35 kg in groups 1, 2, 3 and 4, respectively and there was no significant difference in milk yield among different groups of cows. The overall daily average milk yields in cows fed with low and high UDP diets were 7.91 and 8.99 kg, respectively and at normal and higher plane of feeding the milk yields were 8.15 and 8.75 kg/day, respectively. Thus, there was 13.65% increase in milk yield due to high UDP level and 7.36% due to higher plane of feeding. The daily 4% FCM yields were 9.20 kg for low UDP diet and 10.28 kg for high UDP diet, whereas it was 9.11 kg at normal plane of feeding and 10.37 kg at higher plane of feeding. Fat yields for the corresponding treatment groups were 0.37, 0.43, 0.41 and 0.48 kg, respectively. The 4% FCM yield and also fat yield did not differ significantly among different dietary treatments and also due to UDP level and plane of nutrition, however, 4% FCM yield was increased by 11.74% with high UDP level and 13.83% with higher plane of feeding. The values for total solids, fat, lactose, solids-not-fat and gross energy contents in milk differed significantly (p<0.05) among the different groups and were significantly (p<0.05) higher in milk of cows fed LUDP+HP diet followed by HUDP+HP diet. Total solids (14.65 and 13.83%), lactose (5.44 and 4.92%), solids-not-fat (9.44 and 8.83%) and gross energy (887 and 838 kcal/kg) of milk decreased significantly (p<0.05) with increased UDP level while total solids (13.84 and 14.64), fat (4.84 and 5.36%) and gross energy (832 and 894 kcal/kg) increased significantly (p<0.05) with increase in plane of feeding. Gross and net energetic efficiencies and also gross and net efficiencies of nitrogen utilization for milk production were not significantly different among different groups and also were not affected significantly due to either UDP levels or plane of feeding. Results of the present study suggest that, increasing UDP level from 41% to 48% of CP in concentrate mixture and also increasing plane of feeding from normal (100%) to 115% of NRC requirements maintain a consistently higher milk production.