From 2020, Korean Animal and Plant Quarantine Agency has reset the withdrawal time (WT) for veterinary drugs typically used in livestock in preparation for the introduction of positive list system (PLS) program in 2024. This study was conducted to reset the MRL for tiamulin (TML) in broiler chickens as a part of PLS program introduction. Forty-eight healthy Ross broiler chickens were orally administered with TML at the concentration of 25 g/L (TML-1, n=24) and 50 g/L (TML-2, n=24) for 5 days through drinking water, respectively. After the drug treatment, tissue samples were collected from six broiler chickens at 1, 2, 3 and 5 days, respectively. According to the previously established analysis method, residual TML concentrations in poultry tissues were determined using LC-MS/MS. In TML-1, TML in all tissues was detected less than LOQ at 2 days after drug treatment. In TML-2, TML in liver and kidney was detected more than LOQ at 2 days after treatment. According to the European Medicines Agency’s guideline on determination of withdrawal periods, withdrawal periods of TML-1 and TML-2 in poultry tissues were established to 0 and 2 days, respectively. In conclusion, the estimated WT of TML in poultry tissues is shorter than the current WT recommendation of 5 days for TML in broiler chickens.

This study was conducted to reset the maximum residue limit (MRL) for didecyldimethylammonium chloride (DDAC) in broiler chickens. The disinfectant containing DDAC (10%, w/w) was diluted 160 times and evenly sprayed on the bodies of twenty-four broiler chickens at a rate of 15 mL per day per bird for 7 days. After the disinfectant treatment, tissue samples were collected from six broiler chickens at 0.25, 1, 3 and 5 days, respectively. Residual DDAC concentrations in poultry tissues were determined using LC-MS/MS. Correlation coefficient (0.99 >), the limits quantification (LOQ, 2.0~10.0 μg/kg), recoveries (86.9~118.6%), and coefficient of variations (<19.98%) were satisfied the validation criteria of Korean Ministry of Food and Drug Safety. In all tissues except for liver, DDAC was detected more than LOQ at 5 days after the disinfectant treatment. In liver tissues, DDAC was detected more than LOQ at 3 days after treatment. According to the European Medicines Agency’s guideline on determination of withdrawal periods, withdrawal period of DDAC in poultry tissues was established to 26 days. In conclusion, the developed analytical method is sensitive and reliable for detecting DDAC in poultry tissues. When DDAC disinfectant is sprayed on a poultry house in the presence of broiler chickens, it is necessary to keep the disinfectant from contacting the body of the livestock.

This study investigated ethopabate (EPB) residues in edible tissues of broiler chickens given in drinking water and established the withdrawal time (WT) of EPB in poultry tissues. Twenty-four healthy Ross broiler chickens were orally administered with EPB at the concentration of 3.8 mg/L for 14 days (EPB-1, n=24) and 15.2 mg/L for 7 days (EPB-2, n=24) through drinking water, respectively. After the drug treatment, tissue samples were collected from six broiler chickens at 0, 1, 3, and 5 days, respectively. EPB residue concentrations in poultry tissues were determined using LC-MS/MS. Correlation coefficient values ranged from 0.9980 to 0.9998, and the limits of detection and quantification (LOQ) were 0.03~0.09 and 0.1~0.3 μg/kg, respectively. Mean recoveries in muscle, liver, kidney and skin/fat tissues were 95.9~109.8, 108.7~115.3, 89.9~96.6 and 86.7~96.8%, respectively, and coefficient of variations were less than 17.11%. At the end of the drug-administration period (0 day), EPB was detected at levels under the LOQ in all tissues from both the EPB-1 and EPB-2 groups. According to the results of EPB residue in Ross broiler tissues, withdrawal periods of both EPB-1 and EPB-2 in poultry tissues were established to 0 day. In conclusion, the developed analytical method is suitable for the detection of EPB in poultry tissues, and the estimated WT of EPB in poultry tissues will contribute to ensuring the safety of Ross broiler chickens.

From 2020, Korean Animal and Plant Quarantine Agency has reset the withdrawal time (WT) for veterinary drugs typically used in livestock in preparation for the introduction of positive list system (PLS) program in 2024. This study was conducted to reset the MRL for amprolium (APL) in broiler chickens as a part of PLS program introduction. Forty-eight healthy Ross broiler chickens were orally administered with APL at the concentration of 60 mg/L (APL-1, n=24) for 14 days and 240 mg/L (APL-2, n=24) for 7 days through drinking water, respectively. After the drug treatment, tissue samples were collected from six broiler chickens at 0, 1, 3 and 5 days, respectively. Residual APL concentrations in poultry tissues were determined using LC-MS/MS. Correlation coefficient (0.99 >), the limits quantification (LOQ, 0.3~5.0 μg/kg), recoveries (81.5~112.4%), and coefficient of variations (<15.5%) were satisfied the validation criteria of Korean Ministry of Food and Drug Safety. In APL-1, APL in all tissues except for kidney was detected less than LOQ at 3 days after drug treatment. In APL-2, APL in liver and kidney was detected more than LOQ at 5 days after treatment. According to the European Medicines Agency’s guideline on determination of withdrawal periods, withdrawal periods of APL-1 and APL-2 in poultry tissues were established to 3 and 2 days, respectively. In conclusion, the developed analytical method is sensitive and reliable for detecting APL in poultry tissues. The estimated WT of APL in poultry tissues is longer than the current WT recommendation of 2 days for APL in broiler chickens.

This study was conducted to evaluate the effects of ImmunoSEB as an immune-booster additive on the performance of broiler chicks. A total of 1150 broiler chickens were randomly allotted to three treatments on the basis of body weight (10 pens per treatment with 40 broilers in each pen): the control (CON), CON + ImmunoSEB 0.025% in feed (SEB25), and CON + ImmunoSEB 0.050% in feed (SEB50). The experiment was conducted for d 42 in three phases (phase 1, d 0–14; phase 2, d 15–28; and phase 3, d 29–42). There were significant differences in the average daily gain (ADG) and feed intake. The ADG at d 14 in the SEB50 treatment was greater than that in the CON treatment. The overall ADG in the SEB50 treatment was greater than that in the CON treatment. During d 0–14, the feed intake of chickens in the SEB50 treatment increased compared to that in the CON treatment. The crude protein and lysine digestibility improved in the SEB25 and SEB50 treatments compared to those in the CON treatment at d 28. Superoxide dismutase concentration significantly increased in the SEB50 treatment compared to that in the CON treatment. The interleukin-1β and tumor necrosis factor-α concentrations were higher in the cecum of chickens in the CON treatment than in the SEB25 and SEB50 treatments. A lower population of E. coli was detected in the ileum and cecum of broilers fed the SEB50 diet compared to those of broilers fed the CON diet. The overall result showed the beneficial effects of using ImmunoSEB at a dose of 0.050% in broiler chickens.

본 연구는 LED 조명의 파장이 육용종계의 생산성, 번식호르몬, 면역 수준 및 행동에 미치는 영향을 확인하고자 실시하였다. 25주령 아바에이커 192수를 공시하였다. 처리구는 백색(5,000 K), 녹색(520 nm), 황색(570 nm) 및 적색(620 nm) LED 전구를 사용하여 처리구당 6반복, 반복당 8수씩 임의 배치하였으며, 15주간 사양실험을 실시하였다. 산란율은 적색 처리구에서 유의적으로 증가하였고(P<0.05), 난중은 적색 처리구에서 유의적으 로 감소하였다(P<0.05). 수정율, 부화율, 병아리 체중, IgG 수준 및 혈액 생화학 조성은 처리구 간에 통계적인 차이가 없었다. 번식호르몬인 FSH와 LH 농도는 적색 LED 처리구에서 현저히 높게 나타났다(P<0.05). 또한 행동 관찰 결과, 적색 처리구에서 바닥 긁기, 바닥 쪼기 및 깃털 쪼기 행동이 다른 처리구에 비해 유의적으로 높게 나타났다(P<0.05). 본 연구 결과, 육용종계에 LED 점등을 사용할 경우 적색 처리구에서 번식호르몬의 증가와 산란율이 높아지는 것을 확인하였다. 그러나 적색 처리구에서 바닥 긁기, 바닥 쪼기 및 깃털 쪼기 행동이 높게 나타난 원인을 밝히기 위한 추가 연구가 필요한 것으로 보인다. 따라서 산란성적, 번식 호르몬 분비를 고려할 때 육용종계에 적색 LED 조명이 유리하다는 것을 확인할 수 있었다.

본 연구는 육계사육에서 횃대의 제공효과와 최적 두께를 구명하기 위해 진행하였다. 12일령 육계(RossⅹRoss) 288수를 24개의 독립된 공간(7.3 수/m2)에 균등한 평균 체중으로 분배하여 42일령까지 사양실험을 실시하였다. 그룹은 일반 평사사육(대조구)과 3개의 횃대 처리구(두께: 3, 4 및 5 cm)인 총 4개로 구성하였으며, 각 그룹은 6반복과 반복당 12수씩으로 배치하였다. 각 반복 별로 횃대의 길이는 1.3 m (0.11 m/수)로서 높이 15 cm에 설치하였다. 조사항목으로 육계의 생산성, footpad dermatitis (FPD)과 hock burn (HB) 지표 및 횃대이용성을 확인하였다. 본 연구결과, 육계사육에서 횃대의 유무와 두께에 따른 체중, 증체량, 사료섭취량 및 사료요구율은 통계적 차이가 없었다. FPD는 처리구 간 유의적 차이가 없었으나, HB 지표는 4와 5 cm의 횃대를 제공한 처리구에서 일반 평사와 3 cm 두께의 횃대에서 사육한 육계에 비해 개선되었다(p<0.05). 육계가 횃대를 이용한 시간은 사육전기(12~24일령)에는 차이가 없었으나, 사육후기(25~42일령)에 횃대를 이용한 총 시간은 5 cm 두께에서 3과 4 cm 두께보다 높았으며(p<0.05), 올라간 횟수에 비해서도 더 많은 시간을 보냈다(p<0.05). 그러므로 횃대는 육계의 다리질병을 줄이며, 4~5 cm의 두께를 이용하는 것이 가장 적합할 것으로 사료된다.

This study investigated the effects of π-ray treated feeds on the growth performance, carcass composition, internal organ weight, and sensory evaluation of broilers. One hundred and eighty broiler chicks were used as experimental animals. These were divided into four treatment groups according to the π-ray treated feed supplement level: 0% (control) 1%, 3%, and 5%. The π-ray treated feeds did not significantly affect on the body weight gain (2,484–2,602 g), feed intake (4,747–4,944 g), and feed efficiency (1.90–1.98) in broilers (p>0.05). Also, carcass protein (20.2–20.4%) and fat (4.6–4.9%) contents were not affected. The lengths (178.0, 182.7, 198.0, and 190.3 cm) and weights (38.4, 41.2, 44.2, and 38.9 g/kg of body weight) of the small intestine were slightly but not significantly higher in the π-ray treatments than in the control. Further, there were no overall effect of the π-ray treatment on the abdominal fat pad (2.3, 2.1, 2.1, and 1.8%), and cecum (6.7, 4.0, 5.6, and 6.0 g/kg of body weight) and gizzard (16.8, 15.2, 18.0, and 16.6 g/kg of body weight) weights of the broilers in the present study (p>0.05). The stickiness (2.25, 4.25, 4.50, and 4.38) and flavor (2.44, 4.25, 4.31, and 4.38) of cooked breast meat were higher in the π-ray treatments than in the control (p<0.01). This study also found that, in humans, eating cooked breast meat of broilers that were fed π-ray treated feeds had a positive effect on the blood circulation in the capillaries. Thus, the findings of this study suggest that dietary π-ray treatment has a positive effect on the sensory evaluation of broilers, without any negative effect on their body weight gain, feed intake, and feed efficiency, and that the consumption of these broilers is beneficial for humans on their blood circulation.

Colibacillosis, which is caused by Escherichia coli (E. coli), is one of the most common infectious diseases affecting poultry and causes the great economic losses to poultry production worldwide. The present study investigated the presence of E. coli in broiler chickens affected by colibacillosis and reared at various locations in Tiaret Province as well as evaluated the susceptibility of isolated E. coli strains to various antimicrobial agents. A total of 110 samples collected from 55 broiler chickens representing liver (n=55) and spleen (n=55) showing lesions suspected to be colibacillosis were analyzed by conventional methods, and 33 E. coli isolates were tested on a panel of seven antimicrobial agents using the disk diffusion method. The overall isolation rates of E. coli were 60% (33/55) and 50.9% (56/110) in whole chickens and organs, respectively. There was no variation in the isolation rate between organs: 50% (28/56) for liver and 50% (28/56) for spleen. All E. coli isolates tested showed 100% resistance to Nalidixic acid and Ofloxacine, followed by 93.93%, 90.90%, and 51.51% resistance to Tetracycline, Trimethoprim-sulfamethoxazole (Co-trimoxazole), and Chloramphenicol, respectively. However, low resistance to Gentamycin was observed (12.12%), whereas all E. coli isolates were susceptible to Colistin sulfate. Multidrug resistance was observed in 96.96% (32/33) of the isolates tested. We conclude that E. coli was largely present in broiler chickens affected by colibacillosis in Tiaret Province, and multidrug-resistant E. coli isolates showed high resistance to multiple antibiotics.

딱정벌레목(Coleoptera) 거저리과(Tenebrionidae)에 속하는 외미거저리(Alphitobius diaperinus (Panzer))는 저장곡물해충의 하나로 알 려져 있지만, 대부분 이미 피해를 받은 곡물을 섭식하기 때문에 경제적으로 심각한 위협을 초래할 정도는 아니다. 그러나 이 외미거저리 해충은 많은 나라의 가금산업에서 매우 중요한 해충으로 간주되고 있다. 우리나라의 육계농장에서도 외미거저리가 발생하여 문제를 야기하고 있음이 확 인되었고, 이 해충의 발생으로 야기되는 문제로는 육계농장의 보온효과 및 병아리의 전반적인 활력을 떨어뜨리고, 병원균을 전염시킴으로써 가 금업자에게 상당한 경제적 손실을 가져다주고 있다. 한편, 육계농장에서 이 외미거저리 개체군을 한 가지 방법으로 완전히 제거하기가 쉽지 않기 때문에 적절한 방제방법을 개발하기 위한 노력이 절실하다.

The purpose of this study was to determine the effects of mixed or split-sex feeding on growth performance and behavior of Korean native chickens. Three variants of the sex ratio, FO (female only), MO (male only) and MI (mixed) were tested in Korean native chickens (Hanhyop 3) that were between the ages of 7 and 91 days. Body weight gain was the highest (p<0.05) in the MO treatment and the lowest (p<0.05) in the MI treatment. The feed intake (FI) of birds in the MO treatment was higher (p<0.05) than that of birds in the MI treatment during days 14-21, also MO treatment was higher (p<0.05) than that of birds in the MI treatment during days 21-28. However, the FI of birds in the MI group was higher (p<0.05) than that of birds in FO treatment during days 35-42. The behavioral frequency of walking, drinking, and aggressive pecking were not affected by sex ratio treatment. The behavioral frequency of feeding was higher in the FO treatment than that of birds in the other treatments. The comfort time of birds in the MI treatment was longer (p<0.05) than that of birds in the other treatments. The behavioral frequency of pecking was higher in the MO treatment than that of birds in the other treatments. The study suggests that when male and female Korean native chickens are reared together, sex ratio can influence growth performance and behavior frequency.

While the darkling beetle, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) is considered a pest of stored products, it does not pose a significant economic threat to this industry. The grains these beetles feed on are often already damaged. However, the beetle is considered the foremost premise pest in the poultry industry in many countries of the world. Recently, the darking beetle has also infested in broiler chicken houses of Korea. The problems caused by this pest are destroying their insulative capability, lowering chick’s overall performance and transmitting pathogenic organisms, and have been substantial economic losses to poultry producers. Therefore, we surveyed the status of infestation and damage of this pest in broiler chicken houses. Because there is no simple one step process that will completely eliminate darkling beetle populations from broiler facilities, we would like to outline further studies on the proper control measures.

본 연구는 열 스트레스 (heat stress, HS)에 노출된 브로일러에서 혼합 생균제의 급여가 혈 액 생체지표, 면역반응, 맹장 미생물 및 생산성에 미치는 영향을 조사하였다. 총 400마리의 브로일러 수 컷 (Ross 308)을 각각 100마리씩 4그룹, C (대조군, 실온 25℃), HS (열 스트레스 33℃), HSP (HS플 러스 혼합 생균제 500, 750 mg/kg) 그룹으로 배치하였다. 브로일러의 증체량, 사료섭취, 사료요구율 및 면역기관 무게는 HSP 그룹에서 HS 그룹과 비교했을 때 증가하였다. 혈액 IgG, lymphocytes 농도는 HS 그룹에서 HSP그룹과 비교했을 때 증가하였고, heterophil과 lymphocyte(H:L)비율, 코르티코스테론 농도 및 폐사율은 낮았다. 맹장의 Lactobacillus는 HS 그룹과 비교했을 때 HSP 그룹에서 증가하였으나 Escherichia coli (E. coli), coliform bacteria, aerobic bacteria는 낮아졌다. 본 연구결과는 열 스트레스 에 노출된 브로일러에게 B. subtilis, S. galilaeus 및 Sphingobacteriaceae등 3가지 균주가 포함된 혼합 생균제를 급여해주면 면역반응 증진, 미생물 균형을 유지해줌으로써 폐사율을 낮추고 생산성을 개선할 수 있음을 시사해준다.

This study aims at providing a basic data for the development of high energy efficient environment system in the cage (poultry buildings) and cold potable water supply to reduce the summer heat stress. For this study, the cage area size was 273m 2 and the air-to-water heat pump capacity was 20RT for heating and cooling. As the result of this study, the temperature of the drinking water supplied by heat pump was maintained at the set temperature of 15℃. However, the water temperature of control was 23~28 ℃ due to the effect of outside temperature. The average internal cage temperature was 25.3 ℃ in the test group and 28.1 ℃ in the control group, which was 2.8 ℃ higher than that of the control group. The relative humidity was 76.2% in the test group and 75.0% in the control group. The broiler drank 23.2 L / day in the test group and 21.5 L / day in the control group. Daily feed intake was 937 g and and 725 g in the cold water and control water respectively. The feed intake of 212 g was higher than that of cold water. The feeding rates were 1.8 and 1.9. Body weights were 1,523 g and 1,164 g in the cold water and control water respectively. The weight gain was 359 g in the test group fed with cold water and 392 g in the control group. When compared with the control group, the mortality rate was reduced by 84% in the cold water feeding test. It is necessary that future research will continue to reduce the incidence of such livestock accidents.’.

The processing properties of spent hen and broiler chicken were investigated before and after treatment to improve texture characteristics. Each treatment consisted steaming (S) with 85℃ for 20 min, Pulsed Electric Field (PEF) with 1.5 KV/cm for 4 sec, and Super Heated Steam (SH) with an oven temp. of 300℃, a steam temp. of 350℃ for 8 min. The yield of spent hen and broiler were 66.85% and 63.80% respectively in the control, but decreased in every treatment was lowest at 61.05% in the PEF treatment (p<0.05). In the color test, L value decreased, but the a and b values increased regardless of the species of spent hen or broiler. In the test of heating loss, the S treatment of spent hen had the highest result of 45.25% but lowest of 30.66% in the SH treatment of the broiler. When it was compared with various treatments, SH after PEF treatment showed the better result in terms of heating loss than the PEF or SH treatment respectively. In the test of texture, the broiler showed the lowest hardness of 5.57 kg in the SH (p<0.05). Otherwise, the spent hen resulted in 14.08 kg of hardness in steaming after PEF, but it improved significantly to 10.73 kg in SH after PEF. In the test of 9 scored sensory evaluation of overall palatability, 7.8 point was the best score with SH treatment in the broiler. The best score in spent hen was 6.3 point which was SH after PEF treatment. With this experiment, SH after PEF was the condition in the treatments to have the better texture of spent hen.

Results of this study appeared chicken breeding households nationwide in 3,323 households. Local broiler breeding two numbers are Jeonbuk>Chungnam>Jeonnam> Gyeonggi>Gyeongbuk>Chungbuk>Gyeongnam>Gangwon>Jeju appeared in other net. Local chicken breeding numbers are Chungnam>Jeonbuk>Gyeongbuk>Jeonam> Chungbuk>Gyeongnam>Gangwon appeared in order. Livestock mortality is 482,000 numbers in 2012, and 911,000 numbers in 2014 and 2.494,000 numbers in 2015, a significant increase year by to 4.298,000 numbers in 2016. Insurance 11.2 billion in 2012, 49.8 billion in 2013, 21.2 billion in 2014, 74.5 million won was paid in 2015 is expected to be paid in 2016, 128.4 billion won. A study on the future, preventing livestock damage caused by high temperature will have to continue.

This study was performed to investigate the phyico-chemical characteristics of breast meat from spent hens (SP) in comparison with the same part from the broilers (BR). The moisture and crude protein contents for SP were 72.56% and 24.26%, which were lower than 75.87% and 24.64% for BR. Crude fat and crude ash contents in SP were 0.45% and 1.00%, which were higher than the BR contents of 0.41% and 0.51%. The respective L, a and b value for SP were 48.61, 2.40 and 2.42, which were lower than the BR values of 49.41, 1.45 and 3.06 respectively. The pH for SP was 5.89, which was higher than pH 5.79 for BR. The WHC for SP was 50.29%, which was lower than that of BR at 62.31%. SP scored 28.04% in the heating loss test, which was significantly higher than 19.09% for BR. The shear forces for SP and BR were 4.86 kg and 1.36 kg respectively, which meant that the texture of SP was much tougher than that of BR. Hardness for SP was 8.89 kg while that of BR was 3.92 kg indicating that the SP texture is firmer than that of BR. Oleic acid was most abundant fatty acid in both samples and was at 44.15% in SP and 27.68% in BR.

Antibiotics have been used to prevent disease, promote growth rate, and improve feed efficiency. However, the use of antibiotics in livestock has been restricted worldwide due to problems such as bacterial resistance. Therefore, probiotics among alternatives to antibiotics have gained attention in the livestock feed industry these days. This study was conducted to investigate the effects of dietary supplementation with probiotic 379D on safety, growth rate, and feed efficiency. In this study, bacterial strain 379D was isolated from soil and identified as a Bacillus sp. according to 16S rRNA sequence analysis. In an in vitro test, in-gel activity assay and antimicrobial susceptibility test were conducted to evaluate 379D. In an in vivo study, 379D was administered at concentrations of 0.1% and 1% to broiler chickens for 28 days. The results of in-gel activity assay and antimicrobial susceptibility test showed that strain 379D had broad spectrum antimicrobial activity. Furthermore, no adverse 379D-related effects were observed in 0.1% and 1% groups. Feed efficiency was higher in the 379D-treated groups than in the control group. In conclusion, 379D is expected to be used as a safe alternative to antibiotics in a feed supplement and will improve feed efficiency in broiler chickens.

Antler of deer have been used in Asia as a dietary supplementary or alternative medical substance. The antler contains various biological active substances, including ganglioside has been known to promote growth, bone hyperactivity, immune function, protein synthesis and various pharmacological action. Therefore, this study was to investigate the effect of antler on productivity of broiler chicks. Feeding trial has a number of 240 broiler chicks was conducted to investigate the effect of antler extract (AE) treated feeds on body performance, breast meat composition and characteristics in broilers. Each treatment had 15 chicks with 4 replications. The supplementation level of AE treated feeds was 0.3, 0.6 and 0.9% in the experimental diets. The results obtained were summarized as follows: Average body weight gain was significantly (p<0.05) increased in broilers fed with AE compared to that of control during overall periods. Especially, the body weight gain of 0.9% AE treated chickens showed highly increased by 6.0% compare to the control. Average feed intake was not significantly different among the treatments. Average feed efficiency was significantly (p<0.05) improved by 4% in broiler chicks fed with AE compare to that of control. Average breast meat composition and concentration of cholesterol were also not different by feeding the AE. In breast meat characteristics, the shear force (kg/0.5inch2) of breast meat showed similar results in all treatments. The cooking loss of breast meat was significantly lower in the chick fed AE than that of control. But the water holding capacity (%) of breast meat was significantly (p<0.05) higher in the chicks fed AE than that of control. In breast meat color of chicks were not significantly different in all treatments. The thiobarbituric acid reactive substances (TBARS) and volatile base nitrogen (VBN) value were not showed different with all treatments. Also, the fatty acids composition of breast meat were showed similar results in all treatments. In conclusion, the dietary feed of AE tended to improve the body weight gain and feed efficiency, but did not influenced breast meat characteristics of broiler chicks