Feeding a calcium-enriched fatty acid could ameliorate the growth performance of broilers under the chronic heat stress

( Yu Bin Kim ),( Shan Randima Nawarathne ),( Hyun Min Cho ),( Jun Seon Hong ),( Jung Min Heo ),( Jiseon Son ) 한국축산학회 2022 한국축산학회지 Vol.64 No.1

The current study was conducted to evaluate the effect of calcium-enriched fatty acid supplementation on the growth performance, blood metabolites, intestinal morphology, carcass traits, and nutrient digestibility of broilers subjected to chronic heat stress. A total of 210 one-day-old broiler chicks (40.12 ± 0.25 g) were randomly allocated to one of five dietary treatments, to obtain six replicates per treatment. Broilers were subjected to chronic heat stress from day 21 to day 35, post-hatching, at 34℃ for 9 h per day. The body weight (BW) and feed intake of the experimental broilers were recorded weekly, and the average daily gain (ADG) and feed conversion ratio (FCR) were calculated accordingly. Rectal temperature was measured to compare the basal body temperatures between individuals, and blood samples were collected on days 21 and 35 to evaluate basal body temperature, serum total cholesterol, and the triglyceride content of the broilers. On days 21 and 35, one broiler from each cage (n=6) was euthanized to measure carcass trait parameters, nutrient digestibility in digesta, and intestinal morphology. On days 14, 28, and 35, the broilers fed 2.0% calcium-enriched fatty acids had higher BW (p < 0.05) than those fed the other diets. However, no differences (p > 0.05) were found in the average daily feed intake (ADFI) between dietary treatments over the 35 experimental days. On the other hand, on day 21, post-hatching, the broilers fed the 2.0% calcium-enriched fatty acid diet had improved (p < 0.05) dietary feed efficiencies compared to the other treatments. On day 28, the broilers fed the 5.0% of calcium-enriched fatty acid diet also had higher (p < 0.05) dietary feed efficiencies than those fed with the other dietary treatments. No effects (p > 0.05) on carcass weight, nutrient digestibility, intestinal morphology, or blood parameters were found between broilers fed with dietary treatments. This study demonstrated that the inclusion of an additive, containing 2.0% calcium-enriched fatty acid, to broiler diet could ameliorate the negative growth performance of broilers; and no interaction (p > 0.05) was observed between the calcium-enriched fatty acid and nutrient digestibility, digestive anatomy, blood metabolism, and carcass traits of broilers subjected to chronic heat stress conditions for 35 days post-hatching.

Effects of transport time and feeding type on weight loss, meat quality and behavior of broilers

Fu Yajie,Yin Jingwen,Zhao Ning,Xue Ge,Zhang Runxiang,Li Jianhong,Bao Jun 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.7

Objective: The purpose of this study is to determine the optimal time of transportation of floor-feed and scatter-feed broilers. Methods: Eighty healthy Arbor Acres (AA) broilers (21-day-old, 624.4 g, male, standard error = 6.65) were selected and randomly divided into two experimental groups (floor-feed and scatter-feed), then fed for three weeks. The experiment comprised a 2×4 factorial design with 2 feed patterns (floor-feed and scatter-feed) and 4 transport periods (2, 3, 4, and 5 h), and 4 replicates of 5 broilers (54-day-old, 2243 g, standard error = 46.65) was used to compare weight loss, meat quality and behavior index of different groups. Results: It appeared that drip loss, meat color and resting behavior of experimental broilers changed as length of transportation (p<0.05), however, weight loss and pH were not significantly transformed (p>0.05). Compared with floor-feed group, broilers in scatter-feed group had lower pH at 24 hours (3 h) and different behavioral indicators (p<0.05). Especially indicators after 3 h transportation, there were obvious differences between the two feeding modes in the behavior reaction of stress events before slaughter with different transport duration (p<0.05). The fluctuation of data on resting behavior with scatter-feed was significantly higher than that of floor-feed broilers. There was no interaction between transport time and different feeding methods for index tested of our experiment (p>0.05). Conclusion: Comprehensive analysis showed that the maximum transport duration of floor-feed and scatter-feed broilers should not exceed 3 h, and scatter-feed broilers were more likely prone to fear. Objective: The purpose of this study is to determine the optimal time of transportation of floor-feed and scatter-feed broilers.Methods: Eighty healthy Arbor Acres (AA) broilers (21-day-old, 624.4 g, male, standard error = 6.65) were selected and randomly divided into two experimental groups (floor-feed and scatter-feed), then fed for three weeks. The experiment comprised a 2×4 factorial design with 2 feed patterns (floor-feed and scatter-feed) and 4 transport periods (2, 3, 4, and 5 h), and 4 replicates of 5 broilers (54-day-old, 2243 g, standard error = 46.65) was used to compare weight loss, meat quality and behavior index of different groups.Results: It appeared that drip loss, meat color and resting behavior of experimental broilers changed as length of transportation (p<0.05), however, weight loss and pH were not significantly transformed (p>0.05). Compared with floor-feed group, broilers in scatter-feed group had lower pH at 24 hours (3 h) and different behavioral indicators (p<0.05). Especially indicators after 3 h transportation, there were obvious differences between the two feeding modes in the behavior reaction of stress events before slaughter with different transport duration (p<0.05). The fluctuation of data on resting behavior with scatter-feed was significantly higher than that of floor-feed broilers. There was no interaction between transport time and different feeding methods for index tested of our experiment (p>0.05).Conclusion: Comprehensive analysis showed that the maximum transport duration of floor-feed and scatter-feed broilers should not exceed 3 h, and scatter-feed broilers were more likely prone to fear.

The effect of protease on growth performance, nutrient digestibility, and expression of growth-related genes and amino acid transporters in broilers

박재홍,이상인,In Ho Kim 한국축산학회 2020 한국축산학회지 Vol.62 No.5

During the course of this trial, our team assessed the influence of protease upon the growth performance, the nutrient digestibility, and the expression of growth-related genes and amino acid transporters within the liver, muscle, and small intestines of broilers. During the first step, our team allocated 600 broilers into four dietary treatments for a period of 35 days in order to measure the growth performance and nutrient digestibility of the broilers selected. The separate treatments contained 10 replicates (15 birds per replicate). The treatments were composed of: 1) CON, basal diet; 2) T1, basal diet + 0.03% protease; 3) T2, basal diet + 0.06% protease; and 4) T3, basal diet + 0.09% protease. Next, the broiler chick sample tissue was harvested from the CON and T3 groups in order to conduct gene expression analysis following the feeding trials the broilers underwent. Our team discovered that the broilers fed protease diets possessed increased body weight and an average daily gain, but conversely, had lower feed conversion ratios when their dietary protease levels increased from 0% to 0.09% (p < 0.05). Additionally, significant linear improvements were identified among the nutrient digestibility of dry matter, crude protein, energy, and amino acids within broilers supplied with protease diets when contrasted and compared with broilers supplied with the basal diet (p < 0.05). In addition, the gene expression of the genes IGF1, IGF2, GH, and LEP in the liver, and the genes MYOD1 and MYOG in the breast muscles, was significantly increased after broilers were fed with a protease diet as compared to broilers that subsisted on a basal diet (p < 0.05). Protease supplementation also raised the expression levels within these amino acid transporters: SCL6A19, SLC7A1, SLC7A7, SLC7A2, SLC7A6, SLC7A9, and SLC15A1, located in the small intestine, when compared to the basal diet (p < 0.05). Our results suggest that protease supplementation in their diet improved the growth performance of broilers via an increase in the expression growth-related genes within broiler liver and muscle tissue. In addition, protease supplementation enhanced broiler digestibility via the upregulation of amino acid transporter expression within the small intestine.

다양한 지방원의 급여가 육계의 생산성, 도체특성, 분내 미생물 조성 및 혈액특성에 미치는 영향

조진호,곽용철,이장형,노환국,김인호,Cho, J.H.,Kwak, Y.C.,Lee, J.H.,Nho, W.G.,Kim, I.H 국립한국농수산대학교 교육개발센터 2014 현장농업연구지 = Journal of practical agricultural resear Vol.16 No.1

This experiment was conducted to investigate the effects of different fat source feeding on growth performance, visceral organ weight, meat color, excreta microflora and blood profiles in broilers. A total of 768 1-d-old ROSS 308 broilers (mixed gender) with an initial average body weight of 39.68 ± 0.14 g were randomly allotted to 4 treatments with 12 replicate pens per treatment and 16 broilers per pen for 32 days. Dietary treatments were: 1) SBO, basal diet + 5% soybean oil, 2) PF, basal diet + 5% poultry fat, 3) TAL, basal diet + 5% tallow, and 4) LARD, basal diet + 5% lard. During d 1 to 14, broilers fed TAL diet had a higher (P<0.05) body weight gain (BWG) than broilers fed with PF and LARD diets, moreover, broilers fed TAL diet had a higher (P<0.05) feed intake than broilers fed SBO, PF and LARD diets. Overall (d 0-32), BWG in SBO and TAL treatments was greater (P<0.05) than that in LARD treatment. The meat color a^* (redness) of broilers fed with LARD diet was increased (P<0.05) compared with broilers fed with PF and TAL diets. No difference was observed in visceral organ weight of liver, spleen, bursa of Fabricius, breast muscle, abdominal fat, gizzard and excreta concentrations of Lactobacillus and Escherichia coli. The blood LDL cholesterol concentration in TAL treatment was higher (P<0.05) than that in LARD treatment. In conclusion, broilers supplementation with tallow could improve not only the body weight gain and feed intake but also blood LDL cholesterol concentration. Moreover, broiler fed lard could increase a^* (radness) of meat color, while the soybean oil supplementation improve body weight gain in broilers.

Patch-YOLO: Counting Small-Sized Broilers in Large-Scale Cage-Free Broiler Houses

( Do-hwan Kim ),( Ömer Faruk İnce ),( Jiwoong Lee ),( Kyeong-hwan Lee ) 한국농업기계학회 2023 한국농업기계학회 학술발표논문집 Vol.28 No.2

In large broiler houses, using PTZ cameras for automatic broiler counting is challenging. Though zooming with PTZ cameras and using detection algorithms like YOLO can help recognize small broilers, it demands more shots and is inefficient for counting actively moving broilers. This study introduces the Patch-YOLO algorithm, designed for the efficient detection of small-sized broilers from images captured at maximum Field of View (FOV), without utilizing the zoom function. It operates by segmenting the input image into multiple patches and independently applying YOLO to each segment, guaranteeing precise detection of smaller broilers. The proposed approach was evaluated using images captured by CCTV installed on a commercial broiler farm, and the results showed that the approach can detect broilers with the mean average precision(mAP) of 97% when IOU threshold was set to 0.6. The proposed approach contributes to a comprehensive and improved detection of broilers even in expansive and large-scale settings.

고온 스트레스 하에 타우린 첨가가 육계 간의 Heat Shock Protein 70 및 In Vitro의 단백질 합성에 미치는 영향

조은소리(Eun So Ri Cho),박강희(Garng Hee Park),심관섭(Kwan Seob Shim) 한국가금학회 2016 韓國家禽學會誌 Vol.43 No.4

본 연구는 고온 스트레스 하에 타우린 첨가가 육계의 간에서 heat shock protein 70(hsp 70) 및 cell free system 상태에서 단백질 합성에 미치는 영향을 조사하였다. 공시동물은 1일령 육계 120수를 2주간 사육 후, 대조(CO, 24℃)와 고온스트레스 처리(34℃)에서 타우린을 공급하지 않은 처리구(HO)와 타우린 0.1%를 공급한 처리구(HT)로 나누어 3처리 4반복, 반복 당 10수씩 배치하였다. 고온 스트레스는 3, 6, 9, 12일간 진행하였다. 최종 체중과 간 무게는 HO와 HT가 CO보다 유의적으로 낮았다(P<0.05). 그러나 타우린을 첨가한 HT은 HO보다 유의적으로 높았다(P<0.05). 육계 간에서 hsp70 발현은 HO가 CO와 HT보다 유의적으로 높았으나(P<0.05), CO와 HT는 유의적인 차이가 없었다. In vitro 실험에서 고온 및 타우린은 21일령 육계 간의 총 단백질 합성률에 영향을 미치지 않았다. 따라서 타우린 섭취가 in vivo 육계의 성장에서 고온 스트레스를 완화시키지만, 생체 내의 단백질합성에 직접적인 영향을 미치지 않는 것을 보이며, 이러한 결과는 타우린이 다양한 생리학적 기전을 통해 단백질 turnover 대사에 간접적으로 영향을 미칠 수 있다는 것으로 사료된다. This study was conducted to investigate the effect of taurine supplementation on heat shock protein 70 and in vitro protein turnover in broiler chicks under chronic heat stress. Chicks were allocated into 3 groups of 10 birds per group; the control group was maintained at a temperature of 24℃ without taurine (CO group), the heat-stressed group maintained at a temperature of 34℃ without taurine (HO group), and heat-stressed group maintained at a temperature of 34℃ with taurine (HT group). The final body and liver weights of broilers in the HO and HT groups were significantly lower than those of broilers in the CO group (P<0.05). However, these parameters of the broilers in the HT group were significantly higher than those of broilers in the HO group (P<0.05). The heat shock protein 70 (hsp70) concentration in the liver of broilers in the HO group was significantly higher than that of broilers in the CO and HT groups, but the hsp70 concentration in the liver of broilers in the HT group was not different from that of broilers in the CO group. Liver homogenates of 21 day-old broilers were incubated at temperatures of 37°C and 45℃ to prove the effect of high temperature and taurine on total protein syntheses. Neither high temperature nor taurine supplementation affected protein syntheses in liver homogenates of the broilers. However, the more the temperature increased, the more the degradation rates of cytoplasmic protein in liver homogenates increased; however, taurine supplementation had no effects on the protein syntheses in the liver of the broiler. It is possible that taurine indirectly affected protein turnover via various physiological mechanisms.

Effects of yeast hydrolysate supplementation on intestinal morphology, barrier, and anti-inflammatory functions of broilers

Wang Ting,Cheng Kang,Li QiMing,Wang Tian 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.6

Objective: This study was conducted to evaluate the effects of dietary yeast hydrolysate (YH) supplementation on intestinal morphology, barrier, and anti-inflammatory functions of broilers. Methods: A total of 320 one day old male broilers were randomly allocated into four groups with eight replicates of ten broilers each. The broilers were supplemented with a basal diet (the control group) or basal diets adding 50, 100, 150 mg/kg YH, respectively. This trial lasted for 42 days. The orthogonal polynomial contrasts were used to determine the linear and quadratic effects of increasing levels of YH. Results: In our previous research, supplementing YH improved growth performance by enhancing body weight gain but decreased feed-to-gain ratio. In this study, compared with the control group, dietary YH addition linearly and quadratically decreased serum diamine oxidase activity (p<0.05). Additionally, supplementing YH linearly and/or quadratically decreased jejunal crypt depth (CD), tumor necrosis factor-alpha (TNF-α) concentration as well as mucin 2, interleukin-6 (IL-6), IL-1β, TNF-α, nuclear factor kappa B, and myeloid differentiation factor 88 gene expression levels (p<0.05). Whereas the jejunal villus height (VH), VH/CD, IL-10 concentration as well as zonula occludens-1 and IL-10 gene expression levels were linearly and/or quadratically increased by YH supplementation (p<0.05). Conclusion: Dietary YH supplementation improved intestinal morphology, barrier and anti-inflammatory functions while decreased intestinal permeability of broilers, which might be related with altering pertinent genes expression. This study provides evidence of YH as a promising feed additive for broilers. Objective: This study was conducted to evaluate the effects of dietary yeast hydrolysate (YH) supplementation on intestinal morphology, barrier, and anti-inflammatory functions of broilers.Methods: A total of 320 one day old male broilers were randomly allocated into four groups with eight replicates of ten broilers each. The broilers were supplemented with a basal diet (the control group) or basal diets adding 50, 100, 150 mg/kg YH, respectively. This trial lasted for 42 days. The orthogonal polynomial contrasts were used to determine the linear and quadratic effects of increasing levels of YH.Results: In our previous research, supplementing YH improved growth performance by enhancing body weight gain but decreased feed-to-gain ratio. In this study, compared with the control group, dietary YH addition linearly and quadratically decreased serum diamine oxidase activity (p<0.05). Additionally, supplementing YH linearly and/or quadratically decreased jejunal crypt depth (CD), tumor necrosis factor-alpha (TNF-α) concentration as well as mucin 2, interleukin-6 (IL-6), IL-1β, TNF-α, nuclear factor kappa B, and myeloid differentiation factor 88 gene expression levels (p<0.05). Whereas the jejunal villus height (VH), VH/CD, IL-10 concentration as well as zonula occludens-1 and IL-10 gene expression levels were linearly and/or quadratically increased by YH supplementation (p<0.05).Conclusion: Dietary YH supplementation improved intestinal morphology, barrier and anti-inflammatory functions while decreased intestinal permeability of broilers, which might be related with altering pertinent genes expression. This study provides evidence of YH as a promising feed additive for broilers.

Silymarin seed extract supplementation enhances the growth performance, meat quality, and nutrients digestibility, and reduces gas emission in broilers

Shanmugam Suresh kumar,박재홍,Cho Sungbo,김인호 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.8

Objective: A feeding trial was carried out to determine the effect of dietary inclusion of silymarin seed extract on growth performance, nutrient digestibility, excreta microbiota, excreta gas emission, blood profiles, and meat quality in broilers. Methods: A total of 1,088 one-day-old Ross 308 broiler chicks (mixed-sex) with an initial body weight of 42.34±0.82 g, were randomly allocated into 1 of 4 dietary treatments with 17 replicates of 16 chicks per cage and fed a basal diet supplemented with 0%, 0.02%, 0.04%, and 0.06% of silymarin. Results: The inclusion of silymarin supplementation linearly increased the body weight of broilers during days 7 to 21 and 1 to 35 days. On day 35, broilers fed a diet containing graded levels of silymarin supplementation linearly increased the nutrient digestibility of dry matter, gross energy, and nitrogen and cecal Lactobacillus counts (p = 0.038). While silymarin supplement linearly reduced the methyl mercaptans (p = 0.039) and acetic acid (p = 0.007) emission in broilers. No significant effects were observed on the blood profile. Relative weights of organs such as breast muscle, bursa of fabricius were increased (linear effect, p<0.05), water holding capacity was enhanced by increasing the silymarin level from 0% to 0.06%. A linear reduction (p>0.05) in drip loss from meat samples during days 1, 3, 5, and 7 by the addition of graded level of silymarin to the diet. Conclusion: An increasing level of silymarin supplementation to the diet of broiler would be beneficial to enhance growth performance, nutrient digestibility, excreta microflora, blood profile, and meat quality traits. Objective: A feeding trial was carried out to determine the effect of dietary inclusion of silymarin seed extract on growth performance, nutrient digestibility, excreta microbiota, excreta gas emission, blood profiles, and meat quality in broilers.Methods: A total of 1,088 one-day-old Ross 308 broiler chicks (mixed-sex) with an initial body weight of 42.34±0.82 g, were randomly allocated into 1 of 4 dietary treatments with 17 replicates of 16 chicks per cage and fed a basal diet supplemented with 0%, 0.02%, 0.04%, and 0.06% of silymarin.Results: The inclusion of silymarin supplementation linearly increased the body weight of broilers during days 7 to 21 and 1 to 35 days. On day 35, broilers fed a diet containing graded levels of silymarin supplementation linearly increased the nutrient digestibility of dry matter, gross energy, and nitrogen and cecal <i>Lactobacillus</i> counts (p = 0.038). While silymarin supplement linearly reduced the methyl mercaptans (p = 0.039) and acetic acid (p = 0.007) emission in broilers. No significant effects were observed on the blood profile. Relative weights of organs such as breast muscle, bursa of fabricius were increased (linear effect, p<0.05), water holding capacity was enhanced by increasing the silymarin level from 0% to 0.06%. A linear reduction (p>0.05) in drip loss from meat samples during days 1, 3, 5, and 7 by the addition of graded level of silymarin to the diet.Conclusion: An increasing level of silymarin supplementation to the diet of broiler would be beneficial to enhance growth performance, nutrient digestibility, excreta microflora, blood profile, and meat quality traits.

최근 3년간 (2005-2007년) 전북지역 육계의 주요 바이러스성 질병 발생추이 분석

박종범 ( Jong Beom Park ),차세연 ( Se Yeoun Cha ),박영명 ( Young Myoung Park ),조단단 ( Dan Dan Zhao ),송희종 ( Hee Jong Song ),장형관 ( Hyung Kwan Jang ) 한국가축위생학회 2008 韓國家畜衛生學會誌 Vol.31 No.1

Recently, the major viral diseases, Newcastle disease(ND), infectious bronchitis(IB), low pathogenic avian influenza(LPAI), avian pneumovirus infection(APV), Marek`s disease(MD) and infectious bursal disease(IBD), have led to huge economic losses in chicken industry of Korea. To evaluate prevalence of the major viral disease infections in broiler breeder and broiler farms, epidemiological survey has been conducted in Jeonbuk province from 2005 to 2007 by serological ELISA test for APV, PCR for MD, and RT-PCR for ND, IB, LPAI and IBD, respectively. A total of 424 cases was submitted to our labo-ratory for diagnosis of the major viral disease from broiler breeder and broiler farms in the above period. The diagnosed results were analysed for the detection rate of infections on basis of years, seasons and ages, respectively. This study was showed that the detec-tion rates of ND and APV were considerably high for every years regardless of seasons and ages in both broiler breeder and commercial broiler. In comparison with detection rates of ND and APV, IB and LPAI were lower but detected around 10% for every years. Especially, detection rate of IB was significantly high in commercial broiler than in broiler breeder. Therefore, to minimize economic losses for broiler breeder and broiler farms, it will need for effective countermeasures to decrease detection rate of the viral respira-tory diseases. Although the detection rates of MD and IBD were gradually decreased from 2005 to 2007 in both broiler breeder and commercial broiler, it will continually make an effort about disease control for increasing productivity in chicken industry.

Influence of pre-slaughter fasting time on weight loss, meat quality and carcass contamination in broilers

Xue Ge,Cheng Silu,Yin Jingwen,Zhang Runxiang,Su Yingying,Li Xiang,Li Jianhong,Bao Jun 아세아·태평양축산학회 2021 Animal Bioscience Vol.34 No.6

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. 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.