• Food Science of Animal Resources
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• v.24 no.2
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• pp.202-208
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• 2004

This review is summarized the importance of feed withdrawal treatment before slaughter based on the related recent research literature. Practical feed withdrawal program is required to prevent from carcass contamination when broilers are slaughtered. The feed withdrawal is more important in countries where regulate the microbial contamination. The feed withdrawal treatment for broiler has also advantage to reduce the carcass contamination from intestinal tract at slaughtering plant. Most researches were conducted to focus on proving the feed withdrawal effect on the efficiency of slaughtering and processing, proper duration and safety of broiler carcass. However, it is pointed out that the feed withdrawal programs are different depending on the production capability, feeding and slaughtering methods, inspection regulation of each country.

• Nuclear Engineering and Technology
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• v.55 no.4
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• pp.1225-1232
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• 2023

The ¹⁸⁰W is the lightest isotope of Tungsten with small abundance ratio. It is slightly radioactive (α decay), with an extremely long half-life. Its separation is possible by non-conventional single withdrawal cascades. The ¹⁸⁰W is used in radioisotopes production and study of metals through gamma-ray spectroscopy. In this paper, single withdrawal cascade model is developed to evaluate multicomponent separation in non-conventional transient cascades, and available experimental results are used for validation. Numerical studies for separation of ¹⁸⁰W in a transient single withdrawal cascade are performed. Parameters affecting the separation and equilibrium time of cascade such as number of stages, cascade arrangements, feed location and flow rate for a fixed number of gas centrifuges (GC) are investigated. The Salp Swarm Algorithm (SSA) as a bio-inspired optimization algorithm is applied as a novel method to minimize the feed consumption to obtain desired concentration in the collection tank. Examining different cascade arrangements, it is observed in arrangements with more stages, the separation is further efficient. Based on the obtained results, with increasing feed flow rate, for fixed product concentration, the cascade equilibrium time decreases. Also, it is shown while the feed location is the farthest stage from the collection tank, the separation and cascade equilibrium time are well-organized. Finally, using SSA optimal parameters of the cascade is calculated, and optimal arrangement to produce 5 gr of ¹⁸⁰W with 90% concentration in the tank, is proposed.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.1
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• pp.106-111
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• 2007

The current study was conducted to determine the optimum length of feed withdrawal for pre-harvest broilers. A total of three hundred broilers were sampled from an industrial population, and 30 chicks for each weight group (e.g., 1.5 and 2.5 kg) were randomly assigned to feed withdrawal treatments for 0, 3, 6, 9 and 12 h. Weight loss, yield, muscle pH, objective meat color and weights of gastro intestinal contents, crop, gizzard, provenriculus, small intestine, caecum, and rectum were determined. Live weight loss was significantly (p<0.05) increased as length of feed withdrawal extended. A significant (p<0.05) carcass yield for both 1.5 and 2.5 kg groups coincided after 9 and 6 h feed withdrawal, respectively. Net weights of intestinal contents for crop and gizzard were significantly (p<0.05) reduced by 6 h, and the reduction for proventriculus and small intestine occurred from 3 h. A noticeable effect of feed withdrawal on pH for breast muscle at 3 h postmortem occurred only when chicks were fasted for 3 h of which pH (6.05) was significantly (p<0.05) higher than that for other groups including the control (5.74). There was a linear tendency of higher lightness (Hunter L* value) numerically for chicks fasted for longer periods. The highest coefficient of determinations of regression models to estimate weight loss as a function of fasting period and body weights were achieved, when the models included both linear and quadratic terms for fasting period, and linear term for both 1.5 ($R^2=0.76$) and 2.5 kg ($R^2=0.78$) body weight groups. Given the practical aspect, approximately 1.5 kg of body weight is dominant, weight loss could be predicted by the following function; live weight $loss=26.6-0.28{\times}(fasting period)^2+12.34{\times}pasting\;period-0.012{\times}body\;weight$, $R^2=0.76$. Current data implied that the optimum fasting time for pre-slaughter chicks varied depending on slaughter weight; 6 and 9-h fasting were recommendable for 2.5 and 1.5 kg chicks, with little effect on objective meat color.

• Animal Bioscience
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• v.34 no.6
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• pp.1070-1077
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• 2021

Objective: An experiment was conducted to determine the appropriate fasting time prior to slaughter for broilers in floor-feed and scatter-feed mode. Methods: On 21 d since hatching, 120 Arbor Acres broilers were divided into floor-feed and scatter-feed groups, chicks from each group were further assigned to feed withdrawal treatments for 0, 4, 6, 8, and 10 h. Some resultant indicators such as carcass contamination, body weight loss, meat quality of 54-day-old broilers were measured. Results: It appears that longer feed withdrawal increased weight loss, lightness, drop loss of meat but reduced pH. A significant higher weight loss and lightness for both floor-feed and scatter-feed chicks coincided after 6 to 10 h feed withdrawal (p<0.05). pH for breast muscle at 45 min postmortem reduced when chicks of scatter-feed were fasted 6 and 10 h, while the reduction of floor-feed group occurred only in 10 h (p<0.05). A noticeable effect of feed withdrawal on drop loss occurred after 10 h fasting in scatter-feed of which drop loss were significantly higher than that for other groups including control (p<0.05). The change of contamination propensity revealed that 6 to 10 h fasting significantly reduced the likelihood of carcass contamination under both floor-feed and scatter-feed (p<0.05). Net weights of intestinal contents for gizzard were significantly reduced after feed deprived for 10 h in floor-feed and 6 and 10 h in scatter-feed (p<0.05). The decrease for whole intestine occurred after floor-feed broilers have been without feed for more than 4 h, scatter-feed broilers for more than 8 h (p<0.05). Conclusion: On the premise that poultry product properties and welfare were not significantly damaged, proper fasting time could reduce carcass contamination. Current data implied that 6 h fasting was recommendable for both floor and scatter feed pre-slaughter broilers.

• Korean Journal of Poultry Science
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• v.48 no.4
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• pp.287-295
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• 2021

In this study, we aimed to evaluate the impact of different feed withdrawal periods (2, 3, 4, 5, and 6 h) on Salmonella contamination in the crop, intestinal weight, and blood parameters of broilers before harvesting. A total of 100 broilers (initial live weight 1.906±0.06 kg) were randomly assigned to the same five treatment groups and broilers had access to water but no feed before catching. Feed withdrawal times were 2, 3, 4, 5, and 6 h prior to slaughter. Measurements included live weight, pre-slaughter weight, carcass weight, weight of gastrointestinal tract. In addition, Salmonella and Campylobacter contamination in the crop, serum biochemical profiles, counts of leukocytes, erythrocytes, and platelets, and meat quality were assessed. The results demonstrate that carcass weight, blood corticosterone, meat pH, meat color, and water holding capacity did not differ based on the feed withdrawal time. Carcass yield increased as the withdrawal time increased, but the weights of the crop, proventriculus, jejunum, ileum, and rectum were significantly reduced by 6 h (P<0.05). Salmonella counts were the lowest in the crops subjected to 6 h of feed withdrawal (P<0.05). Shear force was highest in chicken breast meat after 6 h of feed withdrawal (P<0.05). However, when the feed was withdrawn after 6 h, the shear force increased, but it did not affect the sensory characteristics in consumers, and the Salmonella count also decreased and had a reduction effect on contamination during slaughter. These findings can serve as reference data for setting the feed withdrawal time.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.10
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• pp.1445-1450
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• 2005

This experiment was conducted to evaluate the effect of feed withdrawal (F) and heat acclimatization (A) on malebroiler and -layer chickens responses to acute heat stress (AHS) at four weeks of age. Totals of ninety male chicks of broiler or layer type were randomly allocated into 30 pens of grower batteries with raised wire floors. Chicks were subjected to F and A three times a week through the first three weeks of age. At each time, feed withdrawal and heat acclimatization (T = $35^{\circ}C$) lasted for six and four hours, respectively. Feed consumption (FC), body weight (BW), and feed conversion ratio (FCR) were recorded weekly for broiler type chickens only. At four weeks of age, all groups of chickens were exposed to AHS (T = $39{\pm}1^{\circ}C$) for three hours. Before and after AHS challenge, body temperature (Tb), heterophil (H), and lymphocyte (L) counts were recorded, and H/L ratio was calculated. Antibody (Ab) response to sheep red blood cells (SRBC) was assessed from all treatments without being exposed to AHS. Group F of broiler-type chickens weighed less (p<0.05) compared to control group. Also, both A and F groups of broiler-type chickens consumed less (p<0.05) feed when compared to control group. Acute heat stress elevated Tb of all treatment groups, however the increase was more profound (p<0.001) in broiler chicks. Broiler chicks of both A and F groups showed a tendency to have higher (p = 0.08) Tb when compared to control group. Acute heat stress elevated (p<0.001) H/L ratio in both types of chickens. Broiler chicks maintained higher (p<0.001) H/L ratio. Both F and A groups reduced (p<0.01) the level of elevation in H/L ratio compared to control groups of both types of chickens. Neither A nor F group affected the Ab production in response to SRBC. However, there was a tendency towards higher Ab responses in F group when compared to other groups in both types of chickens. Results of the present study demonstrate that previous history of feed withdrawal or episodes of heat exposures improved chicks'physiological withstanding of AHS and a tendency to improved humoral immune response.

• Korean Journal of Poultry Science
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• v.29 no.1
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• pp.37-43
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• 2002

This experiment was conducted to study the effect of early-life feed restriction with diet dilution on compensatory growth, feed efficiency and abdominal fat pad deposition in broilers. In this study, the chicks were randomly assigned to five treatments. Twenty chicks were assigned to each floor pen, and each dietary treatment was replicated with three pens. Birds In control group (C) were full-fed a starter diet throughout the experimental period, and all birds in four dietary treatments (T1-T4) were fed as starter diet diluted with 50% rice hulls. Birds in T1 were fed with a diluted starter diet ad libitum from 7- to 74-d. In T2,the feeding program was 1-d withdrawal alternating with 3-d feed and in T3 1-d withdrawal alternating with 2-d feed. The feeding Program in T4 was alternate days withdrawal and feeding. The feeding with the diluted starter diet (T1) did not significantly affect to growth rate as compared to the birds of C. When periods of 24 h feed withdrawal were Imposed in conjunction with the diluted diets, birds were under weight at 49 d. As the diluted diet treatment was combined with feed withdrawal (T2-T4), there were further less growth. During the 22 to 49 d Period,T1 birds had greater weight gain compared to other treatments (P<0.05) . Birds consumed less feed from 7- to 49-d when the rice hull dilution was used, and this effect was increased by imposition of feed withdrawal (P<0.07) . If rice hull was excluded from the calculation of feed intake (assumed indigestible) then Intake of the starter diet was markedly less for restricted vs. control birds. After 22 d and from 7 to 49 d, restricted birds had superior feed conversion (P<0.05) compared to control birds. Abdominal fat pad deposition and mortality were not influenced by early feed restriction by diluted diet (P<0.05) .

• Journal of Sericultural and Entomological Science
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• v.53 no.2
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• pp.78-81
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• 2015

This study aimed to determine a feed withdrawal duration time of Gryllus bimaculatus (Gb), for removal of intestinal feces. Finally, this species of cricket has been temporarily approved for use as a human food source in Korea. To commercialize Gb as an edible insect, we attempted to prevent the proliferation of micro-organisms and improve taste of Gb by removing intestinal feces of live crickets. Our study showed that weak crickets were damaged in 2 days after feed withdrawal in farm. The microscope findings also revealed that feces of strong crickets' intestine almost disappeared at 1 day after feed withdrawal and instead, some of arms and legs of weak crickets were observed in the former's intestine. The results suggest that 1 day is deemed to be an adequate time for feed withdrawal, when it usually takes 1 day to deliver live crickets from the farm to a destination.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.2
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• pp.233-243
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• 1999

Food safety or sanitation are terms broadly applicable to procedures designed to ensure that food quality is high and free of factors which may adversely affect human health. These factors include zoonotic diseases and acute and chronic effects of ingesting natural and human-made xenobiotics. Use of drugs in animal production for the treatment and control of animal diseases, to promote growth rate, and to improve feed conversion efficiency has expanded year by year, thus increasing the possibilities for occurrences in animal products of residues harmful to humans. Governmental agencies have made efforts to control or prevent residue problems. The Korean Food and Drug Administration (KFDA) is charged with the responsibility of establishing tolerances for veterinary drugs, pesticides, and mycotoxins and other non-pharmaceutical substances. The Department of Veterinary Service is responsible for establishing guidelines regarding withdrawal times of drugs, approval of drugs, their uses, and sanitation enforcement of livestock products. The authors describe the toxicological basis for the establishment of tolerance levels for xenobiotics and the pharmacokinetic basis for establishing withdrawal time for veterinary drugs. The regulatory tolerance levels of chemicals in pork and swine feed, Korean regulations on the use of feed additives, rapid residue test methods, the National Residue Program, and the Food Animal Residue Avoidance Databank are discussed. Rapid EIA methods that are under development for the screening of live animals are described These methods predict tissue residues from an examination of blood samples taken from pigs before they are slaughtered.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.3
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• pp.412-417
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• 2006

This study evaluated the effectiveness of different arsenical sources on inducing fatty liver, on changes in lipid metabolism and on liver function in mule ducks. Sixty twelve-week-old mule ducks were selected and randomly divided into five treatments, including the control group and four different arsenical sources; Roxarsone (300 mg/kg), arsanilic acid, $As_2O_5$ or $As_2O_3$, containing 85.2 mg/kg arsenic were included in the basal diet. The ducks were fed the medicated basal diet for 3 weeks followed by a one-week drug withdrawal. The results showed Roxarsone treatment decreased body weight, feed intake, liver weight and abdominal fat weight (p<0.05), while it increased the relative liver weight (p<0.05) during medication period ($3^{rd}$ week). The $As_2O_5$ treatment decreased abdominal fat weight and relative abdominal fat weight when compared to the control (p<0.05). Only Roxarsone among the treatment groups increased feed intake, liver weight and relative liver weight, while the $As_2O_3$ group showed the lightest liver weight and relative liver weight among treatment groups during the withdrawal period ($4^{th}$ week). The Roxarsone group decreased (p<0.05) NADP-malic dehydrogenase (MDH) and acetyl-CoA carboxylase (ACC) activities and increased (p<0.05) cholesterol concentration during the medication period, and elevated the MDH and ACC activities during the withdrawal period. All four arsenical treatment groups showed lymphocytic infiltration in liver tissue, while the Roxarsone and $As_2O_3$ treatments showed an increase in aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) activities (p<0.05). During the withdrawal period, arsenical treatments resulted in liver vacuoles. However, the arsenicals differed in effectiveness and mechanisms of inducing fat vacuoles.