J. Poultry Sci. 和文要旨 61巻　2024年

DOI： https://doi.org/10.2141/jpsa.2024008

総説：ニワトリにおける感染防御機能改善のための自然免疫系の訓練

吉村幸則1,2・新居隆浩1・磯部直樹1

1広島大学統合生命科学研究科　東広島市739-8528
2放送大学広島学習センター　広島市730-0053

家禽の生産において、免疫系は良好な生産性と安全で高品質な生産物を得るために重要な役割を果たす。 歴史的には、ワクチン接種の主なターゲットは適応免疫であった。 しかし、過去 約10 年にわたり、さまざまな動物においてワクチン接種や飼料添加物により自然免疫も強化されることが報告されている。 この強化はtrained immunity（免疫の訓練）と呼ばれる自然免疫記憶によるもので、エピジェネシスや代謝性のリプログラミングが重要な役割を果たす。 家禽のtrained immunityに関する報告は限られているが、ワクチン接種と飼料添加物が自然免疫に影響を与えることが示唆されている。 この総説では、哺乳類のtrained immunityに関する情報も参考にしながら、家禽の感染防御機能を強化するための戦略として、ワクチン接種とβ-グルカンが自然免疫系に影響を及ぼす可能性について検討する。

Innate Immune Training in Chickens for Improved Defense against Pathogens: A Review

Yukinori Yoshimura, Takahiro Nii, Naoki Isobe

抄録 The avian immune system plays a vital role in poultry production to obtain good productibility and products that are safe and of high quality. Historically, adaptive immunity has been the main target of vaccination. However, over the past decade, innate immunity has been reported to be enhanced in different animals through vaccination and feed additives. This enhancement is due to innate immune memory termed “trained immunity,” in which epigenetic and metabolic reprogramming play significant roles. Although reports on trained immunity in poultry are limited, several studies have suggested that vaccinations and feed additives affect the innate immunity. This review discusses the possible effects of vaccination and β-glucan on innate immunity for potential incorporation in advanced strategies to enhance the defense function in poultry while considering the information on trained immunity in mammals.

DOI： https://doi.org/10.2141/jpsa.2024008

DOI： https://doi.org/10.2141/jpsa.2024012

ニワトリの摂食調節機構に関する近年の研究

實安隆興

神戸大学大学院農学研究科　神戸市　657-8501

家禽産業において、飼料摂食量は生産性に影響を及ぼす。それゆえ、その調節機構の全容を解明することは、生産性を改善するための新しい方法を提供し得る。飼料摂取は中枢神経系、消化管、ホルモン、および栄養素といった多くの因子が関与する複雑な機構によって調節されている。これまでにニワトリにおける摂食調節機構を明らかにするために数多くの研究が行われてきたが、未だ完全には明らかにされていない。ニワトリにおける摂食調節機構に関する知識をアップデートすることを目的に、この総説ではこれまでの総説で触れられていない最近の知見に着目した。すなわち、スペキシン、アディポカイン、中枢の細胞内シグナル伝達因子、および神経分泌タンパク質GLとGMについて取り上げる。
キーワード： ニワトリ、摂食、視床下部、延髄

Recent Research on Mechanisms of Feeding Regulation in Chicks

Takaoki Saneyasu

Food intake affects poultry productivity. A complete understanding of these regulatory mechanisms provides new strategies to improve productivity. Food intake is regulated by complex mechanisms involving many factors, including the central nervous system, gastrointestinal tract, hormones, and nutrients. Although several studies have been conducted to elucidate regulatory mechanisms in chickens, the mechanisms remain unclear. To update the current knowledge on feeding regulation in chickens, this review focuses on recent findings that have not been summarized in previous reviews, including spexins, adipokines, neurosecretory proteins GL and GM, and central intracellular signaling factors.
Keywords: chicken, food intake, hypothalamus, medulla oblongata

DOI： https://doi.org/10.2141/jpsa.2024012

DOI： https://doi.org/10.2141/jpsa.2024001

ブロイラー前期へのトレハロース給与効果：高密度飼育における生産成績改善効果の検討

Takawan Sooksridang1・Chantaluk Rachatapibul1・Saksit Srinongkote1・向井和久2・喜久里基3

1Bangkok Animal Research Center Co. Ltd.・2㈱林原・3東北大学大学院農学研究科

これまで、著者らのグループはブロイラー前期飼料にトレハロース（Tre）を0.5%添加すると出荷体重や飼料要求率（FCR）、腸管形態が改善することを報告している。本研究では、高密度で群飼育したブロイラーの飼育成績、腸管絨毛形態、趾蹠皮膚炎（FPD）におよぼすTreの給与効果を調べた。0日齢Ross 308ブロイラー雄を400羽供試し、4区に分けた後、2つの異なる密度（標準：11羽/m2、高密度：14羽/m2）において、対照およびTre 0.5%添加飼料を各々給与した（各8反復）。飼料は、0-10日齢はスターター（クランブル）、11-24日齢はグロワー（ペレット、3 mm径）、25-42日齢はフィニッシャー・仕上げ飼料（ペレット、同上）を用いた。スターター・グロワー飼料にのみTreを添加し、25日齢以降はいずれのニワトリも対照飼料で飼育した。なお、いずれの飼料にもサリノマイシンを500 ppm添加した。データは密度および飼料（Tre）を主効果とした二元配置の分散分析で統計解析した。スターター／グロワー期（前期）では、増体量、飼料摂取量、FCRに対する密度、飼料の影響は認められなかった。25日齢の空腸絨毛形態は、絨毛高および陰窩深に対しては密度、飼料の影響は認められなかったが、絨毛高／陰窩深比に対しては有意ではないものの、飼料の影響が認められる傾向が示された（P = 0.07）。フィニッシャー／仕上げ期では、増体量、飼料摂取量、FCRが密度の影響を受け、さらにFCRは飼料による影響が認められた（密度×飼料の影響はなし）。解体成績では手羽が密度の影響を受けたが、他の部位に対する密度、飼料の影響は認められなかった。出荷日齢時のFPDスコアは密度による影響が、盲腸内容物中Clostridium perfringens数は飼料による影響が認められた（いずれもP < 0.05）。飼育密度にかかわらず、ブロイラー前期のみにTreを給与することで出荷体重やFCRが改善することが確認された。この効果はC. perfringensの増殖抑制が一因である可能性が考えられる。

キーワード：プレバイオティクス作用；Clostridium perfringens; 乳酸菌；飼料要求率；バクテリオシン

Full Paper

DOI： https://doi.org/10.2141/jpsa.2024001

ブロイラー前期へのトレハロース給与効果：高密度飼育における生産成績改善効果の検討

Takawan Sooksridang1・Chantaluk Rachatapibul1・Saksit Srinongkote1・向井和久2・喜久里基3

1Bangkok Animal Research Center Co. Ltd.・2㈱林原・3東北大学大学院農学研究科

これまで、著者らのグループはブロイラー前期飼料にトレハロース（Tre）を0.5%添加すると出荷体重や飼料要求率（FCR）、腸管形態が改善することを報告している。本研究では、高密度で群飼育したブロイラーの飼育成績、腸管絨毛形態、趾蹠皮膚炎（FPD）におよぼすTreの給与効果を調べた。0日齢Ross 308ブロイラー雄を400羽供試し、4区に分けた後、2つの異なる密度（標準：11羽/m2、高密度：14羽/m2）において、対照およびTre 0.5%添加飼料を各々給与した（各8反復）。飼料は、0-10日齢はスターター（クランブル）、11-24日齢はグロワー（ペレット、3 mm径）、25-42日齢はフィニッシャー・仕上げ飼料（ペレット、同上）を用いた。スターター・グロワー飼料にのみTreを添加し、25日齢以降はいずれのニワトリも対照飼料で飼育した。なお、いずれの飼料にもサリノマイシンを500 ppm添加した。データは密度および飼料（Tre）を主効果とした二元配置の分散分析で統計解析した。スターター／グロワー期（前期）では、増体量、飼料摂取量、FCRに対する密度、飼料の影響は認められなかった。25日齢の空腸絨毛形態は、絨毛高および陰窩深に対しては密度、飼料の影響は認められなかったが、絨毛高／陰窩深比に対しては有意ではないものの、飼料の影響が認められる傾向が示された（P = 0.07）。フィニッシャー／仕上げ期では、増体量、飼料摂取量、FCRが密度の影響を受け、さらにFCRは飼料による影響が認められた（密度×飼料の影響はなし）。解体成績では手羽が密度の影響を受けたが、他の部位に対する密度、飼料の影響は認められなかった。出荷日齢時のFPDスコアは密度による影響が、盲腸内容物中Clostridium perfringens数は飼料による影響が認められた（いずれもP < 0.05）。飼育密度にかかわらず、ブロイラー前期のみにTreを給与することで出荷体重やFCRが改善することが確認された。この効果はC. perfringensの増殖抑制が一因である可能性が考えられる。

キーワード：プレバイオティクス作用；Clostridium perfringens; 乳酸菌；飼料要求率；バクテリオシン

Trehalose Supplementation Effects on Growth, Intestinal Morphology, Gut Bacteria, and Footpad Dermatitis of Broiler Chickens Reared at High Density

Takawan Sooksridang, Chantaluk Rachatapibul, Saksit Srinongkote, Kazuhisa Mukai, Motoi Kikusato

This study aimed to measure the effects of trehalose (Tre) supplementation on the growth, intestinal morphology, gut bacteria, and footpad dermatitis (FPD) of broiler chickens reared at different stocking densities (SD). Four hundred newly hatched Ross 308 male chicks were randomly allocated to four groups of eight, following a 2 × 2 factorial arrangement in a randomized complete block design using two SDs (normal, 11; high, 14 birds/m2) and two diets: basal with and without 0.5% Tre. Tre supplementation was provided during the starter/grower phase, but not the finisher phase. Data were analyzed using a two-way analysis of variance. We observed no significant effects of SD or Tre, individually or combined, on body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) during the starter/grower period. However, high SD decreased both BWG (P < 0.001) and FI (P < 0.05), and increased FCR (P < 0.001), during the finisher period. Whereas Tre reduced FCR (P < 0.05) as a main effect, no combined effect was observed on FCR. Over the total period, high SD negatively affected BWG and FCR (P < 0.001), and Tre significantly reduced FCR, with its effect unaffected by SD. No significant effects of SD or Tre were observed on jejunal morphology. The ileal abundance of Clostridium perfringens (P > 0.05) was not affected by high SD but was significantly reduced by Tre. Neither high SD nor Tre altered Lactobacillus spp. counts; however, high SD increased FPD lesion scores, whereas Tre had no effect. The study showed that Tre supplementation during the starter/grower period improved FCR during the finisher period, possibly by decreasing the abundance of C. perfringens in broiler chickens.

DOI： https://doi.org/10.2141/jpsa.2024001

DOI： https://doi.org/10.2141/jpsa.2024003

Effect of Dietary Puerarin Supplementation on Growth Performance, Immune Response, Antioxidant Capacity, and Intestinal Morphology in Domestic Pigeons (Columba livia)

Runzhi Wang1, Tingting Li2, Zaixu Pan3, Hui Chen3, Shanjin Xu3, Xixue Lu4, Kai Shi4, Bang Bian1 and Guansuo Wu1

1Nanjing Institute of Animal Husbandry and Poultry Science, Nanjing 210036, China
2Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325011, China
3Nanjing Dongchen Pigeon Industry Co., Ltd., Nanjing 210000, China
4College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China

Puerarin is an isoflavone extracted from Gegen (Pueraria lobata) and has been widely utilized to treat various human diseases; however, information regarding its benefits in animal production is limited. In this study, we aimed to investigate the influence of dietary puerarin supplementation on growth performance, immune organ index, immunoglobulin profile, antioxidant capacity, and intestinal morphology in pigeons. In total, 375 healthy 28-day-old White King pigeons were randomly divided into five groups, each consisting of five replicates and 15 pigeons per replicate. Each group was administered one of five dietary treatments: the basal diet, or the basal diet supplemented with 40, 80, 120, or 160 mg/kg puerarin. Treatment duration was 30 days following a 7-day acclimation period. Puerarin treatment did not significantly alter the growth performance of pigeons but afforded a significant linear enhancement in the thymus index (P < 0.05). Additionally, puerarin supplementation significantly increased serum immunoglobulin A and immunoglobulin M levels in pigeons in a linear manner (P < 0.05). Similarly, puerarin significantly and linearly increased the activities of total antioxidant capacity, superoxide dismutase, glutathione, and catalase in the serum and liver, and decreased the malondialdehyde content (P < 0.05). Moreover, the villus height(VH), crypt depth (CD), and VH/CD ratio of the small intestine (including the duodenum, jejunum, and ileum) increased linearly upon puerarin supplementation (P < 0.05). Collectively, these results indicate that puerarin supplementation could improve the immune response, antioxidant capacity, and intestinal morphology of pigeons.

Key words: antioxidant capacity, immune response, intestinal morphology, pigeon, puerarin

DOI： https://doi.org/10.2141/jpsa.2024003

DOI： https://doi.org/10.2141/jpsa.2024004

暑熱環境下での飼育がブロイラー鶏肉のイミダゾールジペプチド含量に及ぼす影響

Takawan 片渕歩美1・亀川みずき1・後藤芹里菜2・桑原大知3・大澤友紀子3・島元紗希4・石原慎矢5・大塚彰1,2・井尻大地1,2

1 鹿児島大学農林水産学研究科、鹿児島市郡元1-21-24 890-0065
2 鹿児島大学農学部、鹿児島市郡元1-21-24 890-0065
3 ENEOS株式会社、神奈川県横浜市中区千鳥町8番地 231-0815
4 新潟大学自然科学研究科、新潟市西区五十嵐2の町8050 950-2181
5 日本獣医生命科学大学応用生命科学部、武蔵野市境南町1-7-1 180-8602

夏季の高温多湿な暑熱環境は, ブロイラーの飼料摂取量, 体重および鶏肉収量を低下させ, 鶏肉中の脂質過酸化度やドリップロスを増加させる。本研究では, 猛暑日（35℃）を想定した暑熱感作が, ブロイラー鶏肉の遊離アミノ酸およびイミダゾールジペプチド含量に及ぼす影響を調べた。ブロイラーヒナ（ROSS308）16羽を0日齢で導入し, 14日齢まで予備飼育した。14日齢時点で8羽ずつ適温区と暑熱区に分け, 42日齢まで適温（25±1℃）または暑熱（1日あたり35±1℃ 8時間）の各温度条件で飼育した。飼料および水は自由摂取とした。42日齢時点で解体し, 頸部より血液を採取した。次いで, 剖検し, 浅胸筋、深胸筋、大腿部、腹腔内脂肪、心臓および肝臓を採取した。暑熱感作は, 飼養成績（終体重, 増体量, 総飼料摂取量）および組織重量（浅胸筋, 深胸筋, 大腿部, 肝臓, 心臓）を有意に減少させた。また, 4℃, 48時間保存後の暑熱区の浅胸筋のドリップロスは, 暑熱感作により有意に増加した。加えて, 浅胸筋の遊離アミノ酸を分析した結果, 暑熱感作はアンセリンおよびカルノシンの含量を減少させた。さらに, 暑熱感作は, 浅胸筋中のカルノシン合成酵素のmRNA発現量を減少させ, カルノシン分解酵素のmRNA発現量を増加させた。暑熱環境下では, 浅胸筋のカルノシン合成酵素のmRNA発現量の減少とカルノシン分解酵素のmRNA発現量の増加により, 浅胸筋のイミダゾールジペプチド含量が減少することが示唆された。

キーワード：キーワード:　イミダゾールジペプチド, アンセリン, カルノシン, カルノシン合成酵素, カルノシン分解酵素, 肉用鶏

Effects of Cyclic High Ambient Temperature on Muscle Imidazole Dipeptide Content in Broiler Chickens

Ayumi Katafuchi1, Mizuki Kamegawa1, Serina Goto2, Daichi Kuwahara3, Yukiko Osawa3, Saki Shimamoto4, Shinya Ishihara5, Akira Ohtsuka1,2 and Daichi Ijiri1,2

1 Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan
2 Department of Agricultural Sciences and Natural Resources, Kagoshima University, Korimoto, Kagoshima 890-0065, Japan
3 Biotechnology Group, Innovation Technology Center, Central Technical Research Laboratory, ENEOS Corporation, Chidori-Cho 8, Naka-ku, Yokohama 231-0815, Japan
4 Graduate School of Science and Technology, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata 950-2181, Japan
5 Graduate School of Applied Life Science, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino, Tokyo 180-8602, Japan

Imidazole dipeptides possess important bioregulatory properties in animals. This study aimed to evaluate the effect of high ambient temperature on muscle imidazole dipeptides (carnosine, anserine, and balenine) in broiler chickens. Sixteen 14-day-old male broiler chickens were divided into two groups, which were reared under thermoneutral (25 ± 1 °C) or cyclic high ambient temperature (35 ± 1 °C for 8 h/day) for 4 weeks. Chickens exposed to cyclic high ambient temperatures displayed lower skeletal muscle anserine and carnosine content than control chickens. Balenine could not be detected in the pectoral muscle of either group. The pectoral muscles of broiler chickens kept under cyclic high-temperature exhibited significantly lower mRNA expression of carnosine synthase 1, which synthesizes carnosine and anserine; but a significantly higher mRNA expression of carnosinase 2, which degrades carnosine and anserine. Our results suggest that heat exposure decreases pectoral imidazole dipeptide content in broiler chickens. This may be attributed to a lower expression of imidazole dipeptide-synthesizing genes, but higher levels of genes involved in their degradation.

Key words: anserine, broiler chicken, carnosinase, carnosine, carnosine synthase, imidazole dipeptide

DOI： https://doi.org/10.2141/jpsa.2024004

DOI： https://doi.org/10.2141/jpsa.2024005

Expression of Relaxin Family Peptide Receptors 1 and 3 in the Ovarian Follicle of Japanese Quail

Khoi X. Hoang1*, Mei Matsuzaki2*, Tetsuya Kohsaka3 and Tomohiro Sasanami1, 4

* These authors contributed equally to this work.

1United Graduate School of Agricultural Science, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan
2Program of Food and AgriLife Science, Graduate School of Integrated Sciences for Life, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima City, Hiroshima 739-8528, Japan
3Faculty of Health Science, Butsuryo College of Osaka, 3-33 Otorikita-machi, Sakai, Osaka 593-8328, Japan
4Department of Applied Life Sciences, Faculty of Agriculture, Shizuoka University, 836 Ohya, Shizuoka, Shizuoka 422-8529, Japan

In our previous studies, we demonstrated that the primary source of relaxin 3 (RLN3) in Japanese quail is ovarian granulosa cells. Although several relaxin family peptide (RXFP) receptors have been sequenced, the intricacies of these receptors in avian species remain insufficiently clarified. Therefore, we assessed the expression of RXFP receptors, RXFP1 and 3, in Japanese quail. Using RT-PCR, we found that both RXFP1 and 3 were ubiquitously expressed. The expression level of RXFP1 is significantly higher in the ovarian theca layer, indicating that it is the primary receptor for RLN3 in the ovary. During follicular development, there was an elevation in thecal RXFP1 expression, but it declined after the luteinizing hormone(LH) surge. We found that the protease activity of the 60 kDa band increased after the LH surge, suggesting the involvement of RLN3 signaling in ovulation. These results suggest a paracrine role of RLN3, involving its binding with RXFP1 in ovarian theca cells. This interaction may elicit biological actions, potentially initiating ovulation after the LH surge.

Key words: follicle, Japanese quail, ovulation, relaxin, relaxin family peptide receptor

DOI： https://doi.org/10.2141/jpsa.2024005

DOI： https://doi.org/10.2141/jpsa.2024006

ブロイラー成長や屠体成績、腸内健康、肉質ならびに免疫特性に対するコリアンダー、アジュワン、ディルの各種子からの抽出エッセンシャルオイルの添加の影響

これまで多くの研究によって、セリ科などを含めた植物から抽出されたエッセンシャルオイル（EOs）の添加が成長促進抗生剤（AGPs）の代替物として有益かどうか、またその最適な投与量について検討されてきた。しかし、植物の抽出条件や特性の違いによってEOsの化学組成が変動するとの事実があるにもかかわらず、その実測値に基づいた結論にまでは至っていない。そのため、本研究では、セリ科の植物のうち、主成分として56.8％のリナロール、68.2％のチモール、41.1％のカルボンをそれぞれ含有するコリアンダー(C)、アジュワン(Aj)、ディル(D)の各種子のEOs（CEO、AjEO、DEO）を用いて、肉用鶏の成長成績、腸の健全性、免疫状態に及ぼす影響を評価した。660羽の1日齢の肉用鶏を供試し、11の試験区、すなわち、コントロール区、リンコマイシンを500mg/kg添加したAGP区、および3種のEOをそれぞれ200、400、600mg/kg添加した9区を設定し、35日間給与した。その結果、最終体重は、AGP区ならびにAjEO 600mg/kg区を除くすべてのEO添加区で改善され、各EO添加区内ではCEO 400mg/kg、AjEO 200mg/kg、DEO 200mg/kgの添加区で最も成長成績が優れていることが示された。EOsの添加により、総じて、十二指腸、空腸、回腸の絨毛高は増加し、腸の形態学に改善効果が認められ、大腸菌やサルモネラなどの有害微生物が減少し、腸内環境にも良好な影響を与えた。さらに、これらEOは、その抗酸化能の働きによると考えられるが、体液性免疫を向上し、ドリップロスを軽減し肉質を改善した。本研究は、CEO、AjEO、DEOの各EOがAGPの代替物として重要な役割を果たしうること、また肉用鶏における最適な投与量について提案する。

キーワード：アジュワン、コリアンダー、ディル、エッセンシャルオイル、成長成績、腸内健康

Effects of Supplemented Coriander, Ajwain, and Dill Seed Essential Oils on Growth Performance, Carcass Characteristics, Gut Health, Meat Quality, and Immune Status in Broilers<

Usman Ali1, Saima1, Shafqat Nawaz Qaisrani1, Athar Mahmud2, Zafar Hayat3 and Masaaki Toyomizu1,4

1Department of Animal Nutrition, Faculty of Animal Production and Technology, University of Veterinary and Animal Sciences, Lahore 54000, Pakistan
2Department of Poultry Production, Faculty of Animal Production and Technology, University of Veterinary and Animal Sciences, Lahore 54000, Pakistan
3Department of Animal Sciences, Faculty of Agriculture, University of Sargodha, Sargodha 40100, Pakistan
4Animal Nutrition, Life Sciences, Graduate School of Agricultural Science, Tohoku University, Sendai 980-8572, Japan

Numerous studies have assessed the benefits and optimal dosage of supplementation with essential oils (EOs), including extracts from plants of the Apiaceae family, as an alternative to antibiotic growth promoters (AGPs) in broilers. However, little consideration has been given to the actual chemical composition of the evaluated EOs when drawing critical conclusions, even though EO composition can vary with different extraction conditions and plant characteristics. Therefore, the present study was conducted to evaluate the effects of EOs from seeds of plants of the Apiaceae family: coriander (CEO), ajwain (AjEO), and dill (DEO), containing 56.8% linalool, 68.2% thymol, and 41.1% carvone, respectively, on the growth performance, gut health, and immune status of broilers. In total, 660 one-day-old broiler chicks were divided into 11 experimental diet groups and fed for 35 days with either the control diet, basal diet with added AGP (lincomycin, 500 mg/kg), or one of nine EO diets supplemented with CEO, AjEO, or DEO at 200, 400, and 600 mg/kg. Final body weights were improved by supplementation with not only AGP but also any EO except AjEO at 600 mg/kg; within each EO, supplementation of CEO at 400 mg/kg, AjEO at 200 mg/kg, and DEO at 200 mg/kg afforded the best growth performance. EO supplementation had beneficial effects on gut morphology, such as increased villus height in the duodenum, jejunum, and ileum, and against harmful microbiota, such as reduction of Escherichia coli and Salmonella spp. populations. Furthermore, EOs enhanced humoral immunity and improved meat quality by reducing drip loss, likely consequent to their antioxidant properties. Overall, this study presents evidence that CEO, AjEO, and DEO can each play a pivotal role in replacing AGPs, as well as providing information regarding optimal doses for broilers.

Key words: ajwain, coriander, dill, essential oil, growth performance, gut health

DOI： https://doi.org/10.2141/jpsa.2024006

DOI： https://doi.org/10.2141/jpsa.2024010

Antioxidant Status, Lipid Metabolism, Egg Fatty Acids, and Nutritional Index of White-Egg Laying Hens Fed Flaxseed Cake

Youssef A. Attia1, Ahmed A. Al Sagan2, El-sayed O. S. Hussein3, Marai J. Olal4, Tarek A. Ebeid5, Rashed A. Alhotan3, Mohammed M. Qaid3, Fulvia Bovera6, Heba A. Shehta7 and Vincenzo Tufarelli8

1Animal and Poultry Production Department, Faculty of Agriculture, Damanhour University, Damanhour 22516, Egypt
2King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia
3Department of Animal Production, College of Food and Agricultural Sciences, King Saud University, Riyadh 11451, Saudi Arabia
4Admin & Animal Nutrition Technical Services, Danisco Animal Nutrition & Health (IFF), Riyadh 11411, Saudi Arabia
5Department of Poultry Production, Faculty of Agriculture, Kafrelsheikh University, Kafr El-Sheikh 33516, Egypt
6Department of Veterinary Medicine and Animal Production, University of Napoli Federico II,, Napoli 80137, Italy
7Regional Centre for Food and Feed, Agricultural Research Center, Giza 12619, Egypt
8Department of Precision and Regenerative Medicine and Jonian Area, Section of Veterinary Science and Animal Production, University of Bari ‘Aldo Moro’,, Bari 70010, Italy

Flaxseed cake contains high levels of phenolic compounds, which have numerous biological activities, as well as a considerable amount of omega-3 fatty acids, such as α-linolenic acid, which remains after oil extraction. In this study, we examined the effects of flaxseed cake meal (FSCM) on the antioxidative status, lipid metabolism, egg fatty acid profile, and egg health index of white-egg laying hens. A total of 63 Hisex White laying hens were divided into three experimental treatment groups and fed diets containing 0, 5, or 10% FSCM from 48 to 58 weeks of age. Feeding with 5 and 10% FSCM did not significantly (p>0.05) influence total lipid, triglyceride, total cholesterol, very low-density lipoprotein-cholesterol, or low-density lipoprotein-cholesterol concentrations, or the high-/low-density lipoprotein ratio in the serum and egg yolk; however, 10% FSCM significantly (P<0.05) increased serum high-density lipoprotein. Dietary FSCM also did not affect (P>0.05) antioxidant markers in the eggs and blood plasma. Notably, dietary inclusion of FSCM significantly increased (P<0.05) total n-3 polyunsaturated fatty acids (PUFAs), α-linolenic acid, docosahexaenoic acid, and eicosapentaenoic acid levels in egg yolk, whereas the n-6:n-3 PUFAs ratio was markedly (P<0.05) decreased in a dose-dependent manner. Moreover, including 5–10% FSCM improved (P<0.05) egg health indices, with 10% being the most beneficial. Together, these findings indicated that the inclusion of up to 10% FSCM in laying hen diets improved egg yolk lipid and fatty acid profiles, as well as egg quality and nutritional and metabolic indices.

Key words: antioxidant status, fatty acids, flaxseed cake, health index, laying hens

DOI： https://doi.org/10.2141/jpsa.2024010

Sex differences in COL1A1 Expression and Collagen Content in Skeletal Muscle of Mature and Juvenile Shamo Chickens

Shotaro Nishimura1, Mizuki Ohtani2, Grendah Mpundu Kabunda2, Sayaka Arai2, Haruka Nishimura2 and Yoshinao Z. Hosaka1

1 Faculty of Agriculture, Kyushu University, Fukuoka, Japan
2 Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan

Collagen content is an important parameter affecting meat consistency. Sex differences in collagen were therefore studied in mature and juvenile Shamo chickens. The pectoral (PT), lateral iliotibial (ITL), medial part of puboischiofemoral (PIF), and lateral part of gastrocnemius (GCL) muscles were weighed, and their COL1A1 expression levels and total collagen content were analyzed. Body and muscle weights were significantly higher in males than in females of all ages. Muscle/body weight ratios were also higher in mature males than in females, but this difference was not observed in juveniles. In mature chickens, COL1A1 expression was higher in the PIF and GCL muscles; this was not the case in juvenile chicken muscles. Sex differences in collagen content were observed only in the ITLs of mature chickens. A positive correlation between muscle weight and intramuscular collagen content was found for PT and GCL, but not for ITL and PIF, muscles. These results suggest that the sex difference in intramuscular collagen content only occurs in specific muscles and that COL1A1 expression is not necessarily related to collagen content in mature chickens. Factors that determine the intramuscular collagen content likely differ by muscle type.
Key words: collagen, sex difference, Shamo chicken, skeletal muscle

DOI： https://doi.org/10.2141/jpsa.2024011

低タンパク質飼料へのアミノ酸の添加がブロイラーヒナの成長成績とタンパク質代謝関連因子に及ぼす影響

Asmaa S. El-Far1, 2・神谷真帆1・實安隆興1・本田和久1

1 神戸大学大学院農学研究科　神戸市　657-8501
2 Faculty of Veterinary Medicine, Damanhour University, Damanhour, Egypt

低タンパク（LP）飼料は窒素とアンモニアの排出を抑制することにより、鶏肉生産が環境に与える影響を緩和する可能性がある。本研究では、15％低タンパク質飼料におけるアミノ酸（AA）補填の有無が10～35日齢のブロイラーヒナの成長成績に及ぼす影響と骨格筋量減少の機構について調べた。36羽の雄ブロイラーヒナを体重に基づき、対照群、LP群、および必須AA添加LP群（LP+AA）にわけた。体重増加量および飼料要求率は給餌期間終了時にLP群においてのみ有意に低い値を示した。むね肉およびももの重量もLP群で有意に減少した。さらに、血漿尿酸濃度はLP+AA群で有意に低下した。LP群では、LC3BのmRNA量は浅胸筋で有意に増加し、artogin-1、MuRF-1、およびMyoDはのmRNA量は大腿二頭筋で有意に増加した。肝臓や骨格筋のIGF-1 mRNA量には群間で有意差は見られなかった。これらの結果から、ブロイラーヒナの成長成績に対するLP飼料の悪影響は必須AA補填によって改善されること、および骨格筋のタンパク質分解関連遺伝子の発現変動がLP飼料の悪影響と関係する可能性が示された。
キーワード：ニワトリ，飼料効率，インスリン様成長因子，骨格筋量，筋形成，タンパク質分解

DOI： https://doi.org/10.2141/jpsa.2024014

Effects of Amino Acid Supplementation to a Low-Protein Diet on the Growth Performance and Protein Metabolism-related Factors in Broiler Chicks

Asmaa S. El-Far1, 2, Maho Kamiya1, Takaoki Saneyasu1 and Kazuhisa Honda1

1 Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan
2 Faculty of Veterinary Medicine, Damanhour University, Damanhour, Egypt

A low-protein (LP) diet may alleviate the environmental impact of chicken meat production by reducing nitrogen excretion and ammonia emissions. Thus, this study investigated the effect of a 15% reduced protein diet with or without amino acid(AA) supplementation on the growth performance of broiler chicks from 10 to 35 days of age and the underlying mechanism for loss of skeletal muscle mass. Thirty-six male broiler chicks were allocated to three experimental groups based on body weight: control, LP, and essential AA-supplemented LP (LP+AA). The body weight gain, feed conversion ratio, and weight of breast muscles and legs significantly decreased only in the LP group at the end of the feeding period. Plasma uric acid levels were significantly lower in the LP+AA group than those of the other groups. In the LP group, mRNA levels of microtubuleassociated protein 1 light chain 3 isoform B were significantly higher in the pectoralis major, whereas those of atrogin-1, muscle RING-finger protein-1, and myoblast determination protein 1 were significantly higher in the biceps femoris compared to those in the control group. There were no significant differences in insulin-like growth factor 1 mRNA levels in the liver or skeletal muscle between groups. These findings suggested that supplementation with essential AAs ameliorated the impaired effects of an LP diet on growth performance in broiler chicks, and that the transcriptional changes in proteolytic genes in skeletal muscles might be related to the impaired effects of the LP diet.
Key words: chicken, feed efficiency, insulin-like growth factor, low-protein diet, myogenesis, proteolysis

DOI： https://doi.org/10.2141/jpsa.2024014

DOI： https://doi.org/10.2141/jpsa.2024015

Expression and Mutation of SLC45A2 Affects Iris Color in Quail

Linke Huo1, Xiaohui Zhang1,2, Youzhi Pang1,2, Yanxia Qi1, 2, Shiwei Ren1, Fanghu Wu1, Yuanyuan Shang1 and Jinquan Xi1

1College of Animal Science, Henan University of Science and Technology, Luoyang, 471003 He’nan, P.R. China
2Luoyang Key Laboratory of Animal Genetics and Breeding, Luoyang 471003, P.R. China

Iris color is a prominent phenotypic feature of quail. To understand the mechanism of melanin deposition related to quail iris color, iris tissues were selected from Beijing white and Chinese yellow quail for transcriptome analysis. Differentially expressed genes (DEGs) associated with pigmentation were identified using RNA sequencing and validated by quantitative real-time polymerase chain reaction (RT-qPCR). The identified single nucleotide polymorphisms were studied using bioinformatics and iris color correlation analyses. A total of 485 DEGs were obtained, with 223 upregulated and 262 downregulated.
Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed. Thirty-two genes were annotated using the GO database. Three important pigment synthesis pathways (Notch signaling, melanogenesis, and tyrosine metabolism) were identified in quail iris tissue (P < 0.05). The expression levels of solute carrier family 45 member 2 (SLC45A2), tyrosinase-related protein 1, vitamin D receptor, opsin 5, and docking protein 5 were significantly different between Beijing white and Chinese yellow quail, as verified by RT-qPCR. The c.1061C>T mutation in SLC45A2, which caused a single amino acid change at position 354 (threonine to methionine), was significantly associated with iris color in Beijing white and Chinese yellow quail, and might be the main reason for the different iris colors between these two quail species.
Key words: iris color, quail, RNA-Seq, RT-qPCR, SLC45A2

DOI： https://doi.org/10.2141/jpsa.2024015

ブロイラーのそ嚢におけるCampylobacter jejuniの生存時間

西井真理1・安富政治2

1京都府農林水産技術センター畜産センター　京都府綾部市位田町桧前　623‐0221
2ヤストミ　京都府綾部市味方町　623‐0031

Lactobacillus spp.は、in vitroの条件下においてCampylobacter jejuniの増殖を阻害することが確認されている。しかし、Lactobacillus spp.が優勢な細菌叢を形成している生きた鶏のそ嚢中において、C. jejuniに対する生育阻害は確認されていない。我々の以前の研究において、ブロイラーに籾米主体の飼料を給与するとそ嚢中の飼料の滞留時間が増加することを明らかにした。このことは、そ嚢中に滞留する細菌の殺菌活性の観察が可能になると考えられた。そこで本研究では、ブロイラーのそ嚢に残存しているC. jejuniに対する殺菌活性を評価した。その方法は、籾米主体の飼料を給与した26日齢のブロイラーにC. jejuniと二酸化チタン（TiO₂）を混合した接種用懸濁液を経口接種し、そ嚢内容物を20分間隔で80分まで採取した。そ嚢内容物中のTiO₂残存率は接種後時間の経過とともに徐々に減少したが、60分後においても接種量の57%のTiO2がそ嚢中に残存していた。他方、そ嚢中の C. jejuni は 40 分後以降は接種時に比べて有意に少なくなり、接種菌量に対して 40分後に11%、60 分後に1%、そして80 分後には検出できなくなった。 このことは、接種された C. jejuni のほとんどが次の消化管セグメントに移行する前にそ嚢内で死滅したことを示している。さらに、細菌死滅すなわち死滅事象は 30—40 分の間に集中的に発生していた。そ嚢内におけるC. jejuni の平均生存時間は 37.1 分と求められた。本研究の結果より、C. jejuni がそ嚢内に 40 分以上残留すると、死滅に至ることが示された。
キーワード：そ嚢、Campylobacter、死滅事象、滞留時間、生存率、全粒籾米

DOI： https://doi.org/10.2141/jpsa.2024016

Survival Time of Campylobacter jejuni in Broiler Crops

Mari Nishii and Masaharu Yasutomi

Kyoto Prefecture Agriculture Experiment Station, Ayabe-Shi 623-0221, Japan

Lactobacillus spp. inhibit the growth of Campylobacter spp. in vitro. However, in chicken crops, in which Lactobacillus spp. predominate, such inhibition of Campylobacter has not been confirmed. In our previous study, feeding paddy rice to broiler chicks increased the residence time of the food, which might enhance the bactericidal activity of the crop. Here, the bactericidal activity against the remaining Campylobacter spp. in broiler crops was evaluated. A suspension prepared by mixing Campylobacter jejuni and titanium dioxide (TiO₂) was inoculated into the pharynx of 26-day-old broiler chicks fed a paddy rice-based diet. The crop contents were sampled at 20-min intervals. The TiO₂ residual ratio in the crop gradually decreased with time after inoculation, with 57% of the inoculated TiO2 remaining in the crop 60 min after inoculation. The survival fraction of C. jejuni in the crops was 11% at 40 min, only 1% at 60 min, and was undetectable at 80 min. Most of the inoculated C. jejuni died in the crop before entering the next segment. These data indicated that bacterial death occurred between 30 min and 40 min after inoculation. The average survival time of C. jejuni in the crop was calculated to be 37.1 min. Thus, C. jejuni remaining in a chicken crop for more than 40 min died.
Key words: broiler crop, Campylobacter, lethal event, retention time, survival fraction, whole-grain paddy rice

DOI： https://doi.org/10.2141/jpsa.2024016

胚時期のカダベリンシグナル伝達：初生ヒナにおける血漿遊離アミノ酸および骨格筋エネルギー代謝への影響

白石純一・島倉奈緒子・木村一輝・江草（雜賀）愛・太田　能之

日本獣医生命科学大学応用生命科学部　武蔵野市境南町　180-8602

カダベリンは、リジン脱炭酸酵素を介したリジン分解に由来する生理活性物質であり、その生理作用が注目されている。げっ歯類を用いた研究では、特に腸内細菌が産生するカダベリンにおいて、細胞成長調節因子としての役割が明らかにされている。しかし、胎生期におけるカダベリンの栄養学的・生理学的役割については、特にこの時期の腸内細菌叢や消化機能が未熟であることを考慮すると、不明な点が多い。本研究では、ニワトリの胚発生期における栄養および代謝シグナルとしてのカダベリンの栄養生理的機能を探索することを目的とした。18日目のニワトリ胚にカダベリンをin ovo投与した結果、孵化直後のヒナの体重や臓器重量に変化は見られなかったが、血漿中のトリプトファン、N-メチルヒスチジン、N-メチルヒスチジン濃度が低下し、骨格筋におけるインスリン／インスリン様成長因子1のシグナル伝達因子の遺伝子発現が上昇した。これらの結果は、カダベリンが胚時期のトリプトファン代謝および骨格筋異化に影響を与えることを示唆しており、骨格筋におけるエネルギー代謝シグナル伝達に寄与する生理活性因子としての役割を示唆している。
キーワード：カダベリン、胚、初生ヒナ、ポリアミン、骨格筋異化

DOI： https://doi.org/10.2141/jpsa.2024017

Embryonic Cadaverine Signaling: Implications for Plasma Free Amino Acid and Skeletal Muscle Energy Metabolism in Newly Hatched Chicks

Jun-ichi Shiraishi, Naoko Shimakura, Kazuki Kimura, Ai-Saiga Egusa and Yoshiyuki Ohta

Faculty of Applied Life Science, Nippon Veterinary and Life Science University, Musashino 180-8602, Japan

Cadaverine is a bioactive substance derived from lysine degradation by lysine decarboxylase and has gained attention for its physiological effects. Studies in rodents have revealed its role as a cell growth regulator, particularly intestinal bacterial-produced cadaverine. However, the nutritional and physiological roles of cadaverine during the embryonic period remain unclear, especially considering the immature state of the gut microbiota and digestive functions during this stage. This study explored the potential functions of cadaverine as a nutritional and metabolic signal during chicken embryonic development. Experiments were conducted using an in ovo administration method to evaluate the effects of nutritional bioactive substances on developing chicken embryos. Although there were no observable changes in body or organ weights of newly hatched chicks following in ovo cadaverine administration to day 18 chick embryos, plasma tryptophan, Nτ-methylhistidine, and Nπ-methylhistidine concentrations decreased and the gene expression of insulin/insulin-like growth factor 1 signaling in skeletal muscle was upregulated. These findings imply that cadaverine influences tryptophan metabolism and skeletal muscle catabolism during the embryonic period, suggesting its role as a bioactive factor contributing to energy metabolism signaling in skeletal muscle.
Key words: cadaverine, embryo, newly hatched chicks, polyamine, skeletal muscle catabolism

DOI： https://doi.org/10.2141/jpsa.2024017

DOI： https://doi.org/10.2141/jpsa.2024018

Ovary Transcriptome Profiling in Broody and Egg-laying Chahua Chickens

Yanli Du, Huang Wei, Meiquan Li, Xiao Wang, Jinshan Ran, Jing Wang, Cuilian Dong and Na Zhu

College of Agronomy and Life Sciences, Kunming University, Kunming 650200, Yunnan Province, People’s Republic of China

Broodiness in egg-laying hens (EHs) leads to ovarian atrophy, resulting in reduced egg-laying performance. However, the ovarian regulatory mechanisms in broody hens (BCs) remain elusive. Therefore, ovaries were removed from 300-day-old BCs and EHs for RNA sequencing. Ovarian morphology and histological characteristics of the BC and EH groups were compared and analyzed. The EH group had significantly more hierarchical follicles (HFs) and small yellow follicles (SYFs) than that of the BC group. Although several secondary follicles (SFs) and primary follicles were observed in the ovaries of the EH group, only a few SFs were observed in the ovaries of the BC group. Subsequently, RNA-sequencing analysis was conducted to determine the ovarian expression profiles of the two groups. Transcriptome sequencing identified 259 differentially expressed genes (DEGs) between the BC and EH groups. Of the 259 DEGs, 136 were upregulated and 123 were downregulated. The DEGs were mapped to 22 gene ontology terms and 4 Kyoto Encyclopedia of Genes and Genomes pathways for ovarian tissue. The analysis showed that matrix metalloproteinases 11/13 (MMP11/MMP13) were enriched in the extracellular matrix. The extracellular matrix mediated by MMP13 is affected by follicle-stimulating hormone, prolactin, and estrogen, which are critical signaling pathways that may affect ovarian follicle development to regulate the large yellow follicle reserve process and the ovulation cycle of broody Chahua chickens. These findings indicate that understanding differences in gene expression between the ovarian tissues of BCs and EHs could serve as a valuable reference point for enhancing egg-laying performance in Chahua chickens.
Key words: broody hens, ovary, transcriptome analysis, reverse transcription-qPCR, western blot

DOI： https://doi.org/10.2141/jpsa.2024018

採卵鶏のアニマルウェルフェア飼養システム導入における将来予測：生産性と価格に与える影響

加藤博美・嶋崎知哉・矢用健一

農研機構　畜産研究部門　茨城県つくば市池の台２　305-0901

アニマルウェルフェア生産システムの導入は、日本における持続可能な畜産生産の将来戦略として大きな価値がある。しかし、単位面積あたりの生産性が低下することで農家に経済的負担をかけ、農家の心身の健康状態にも負の影響を及ぼすと言われている。また普及には、消費者の意識を向上させる必要もある。特に、単位面積あたりの生産性の低下は、農家への影響だけではなく経済活動や国民が必要とする鶏卵量の確保に不安をもたらし，結果として食料安全保障に対する懸念が高まると予測されている。 本研究では、日本の鶏卵必要量を分析し，2050年をベンチマークターゲットとして、鶏卵生産量、飼養羽数、農場面積、生産コストおよび小売価格が４つの鶏卵生産施設の移行割合に関してどのように変化するかを5つのシナリオでシミュレーションした。 その結果、①日本の採卵鶏生産システムは、生産効率が高く、生産量を最大化し、小売価格を最小化することを目的としたコンベンショナルケージで構築されていたことが確認された。②日本が必要とする鶏卵量を最適なレベルで確保することが、アニマルウェルフェア施設移行時の課題であることを示し，過不足を防ぐためには、生産施設の計画的な移行が必要であることを明らかにした。さらに、③生産コストおよび小売価格の上昇、飼養羽数および農場面積の増加の予測値を提示した。 よって、アニマルウェルフェアシステムの導入を考える際には、その移行方法と移行期間を慎重に検討することが不可欠である。本研究は、政策立案者が食料安全保障、アニマルウェルフェア，日本の農業特性および農業者福祉を考慮しながら，最適な鶏卵生産方法を選択する意思決定プロセスにおいて、貴重な資料を提供するものである。
キーワード：アニマルウェルフェア、年次推移、鶏卵生産、シミュレーション

DOI： https://doi.org/10.2141/jpsa.2024019

Simulations of Future Trends in Welfare-Centric Egg Production Systems: Impacts on Productivity and Prices

Hiromi Kato, Tomoya Shimasaki and Ken-ichi Yayou

National Agriculture and Food Research Organization, Tsukuba 305-0901, Japan

The implementation of more animal welfare-centric livestock production systems holds considerable potential for achieving sustainable production in Japan. However, such systems generally reduce productivity per unit area, impose financial burdens on farmers that adversely affect their physical and mental health, and require increased consumer awareness. In particular, declines in productivity per unit area substantially affect the farming economy, giving rise to concerns about the sufficient egg production for the population, which consequently exacerbates Japan’s food security concerns. In this study, our goal was to predict temporal trends in the Japanese transition to welfare-centric facilities by analyzing desired egg consumption. We formulated five scenarios, ending in 2050, to assess the future impact of changing the proportions of types of egg production on total production, numbers of hens, total farm area, production costs, and retail prices. Multiple issues were identified in our analysis. First, Japanese production uses conventional caging, which provides high efficiency, maximum output, and decreased prices. Our simulations suggest that ensuring optimal production is likely to present challenges as animal welfare is addressed. They also suggest that the poultry industry or the Japanese government will likely need to plan changes in production methods will likely be necessary to prevent egg surpluses and/or shortages. Additional issues were identified, including price increases, numbers of hens, total farm area, and production costs. This study offers valuable insights for policymakers in their decision-making processes to help optimize production methods while considering food security, animal welfare, and farmers’ welfare.
Key words: animal welfare, annual trends, egg production, simulation.

DOI： https://doi.org/10.2141/jpsa.2024019

ホロホロチョウ（Numida meleagris）における小規模な平飼い条件下で形成されたつつき順位

寺田知功1,2・下田美月（co-first）1・和久大介1,3・小川博1,4

1 東京農業大学農学部，神奈川県厚木市船子1737　243-0034
2 東京大学大学院総合文化研究科，東京都目黒区駒場3-8-1　153-0041
3 東京農業大学国際食料情報学部，東京都世田谷区桜丘1-1-1　156-8502
4 山階鳥類研究所，千葉県我孫子市高野山115　 270-1145

野生下において，ホロホロチョウはオスのみつつき順位を形成することが知られている。平飼いはホロホロチョウの効率的な繁殖において有益であるが，平飼い条件下でも順位を形成する場合，劣位個体が十分な給餌時間を確保できなくなる可能性が考えられる。本研究では，小規模な平飼い条件下において，つつき順位が形成されるのかを調べた。実験群はオス群（雄4羽），メス群（雌4羽），雌雄混合群（雄2羽，雌2羽）の3種類を，それぞれ3回ずつ設定した。なお，各実験群は基本的に異なる個体を対象とした。オス群は130時間52分間，メス群は89時間11分間，雌雄混合群は98時間46分間行動を記録した。その結果，オスのホロホロチョウは他のオスをつつく一方，メスはほとんどつつき行動を示さなかった。また，オスのつつき回数は各実験群内で個体によって偏りがみられた。これらのことから，オスにはつつき順位がある一方，メスにはつつき順位がないことが示唆された。多くの実験群において，つつき行動の回数は実験開始日の20分経過後に減少した。雌雄混合群では劣位個体3羽は摂餌時間がほとんどなかった一方，他の個体は摂餌時間を確保していた。そのため，ホロホロチョウの小規模な平飼い飼育は可能であるが，オスの健康管理には注意をする必要があることが示唆された。ただし，雌雄混合での小規模な平飼い飼育は避けるべきであると考えられる。本研究は，小規模な平飼い飼育におけるホロホロチョウの動物福祉の向上に寄与するものである。
キーワード：群れ，ホロホロチョウ，つつき行動，つつき順位

DOI： https://doi.org/10.2141/jpsa.2024020

Formation of the Pecking Order during Small-Scale Floor Feeding in Helmeted Guinea Fowl (Numida meleagris)

Tomoyoshi Terada1,2, Mitsuki Shimoda1, Daisuke Waku1,3 and Hiroshi Ogawa1,4

1 Faculty of Agriculture, Tokyo University of Agriculture, 1737 Funako, Atsugi, Kanagawa 243-0034, Japan
2 Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan
3 Faculty of International Agriculture and Food Studies, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
4 Yamashina Institute for Ornithology, 115 Konoyama, Abiko, Chiba 270-1145, Japan<

Helmeted guinea fowl are social animals and only males form a hierarchy in the wild. Non-cage husbandry systems benefit the reproductive health of guinea fowl; however, there are concerns that the feeding duration of subordinate individuals is insufficient. Here, the pecking orders formed during small-scale floor feeding were investigated. There were three experimental categories: male-only (four males), female-only (four females), and mixed category (two males, two females). Each experimental category was set up three times and included different individuals. Behaviors were recorded for 130 h 52 min, 89 h 11 min, and 98 h 46 min in the male, female, and mixed categories, respectively. Male helmeted guinea fowls pecked other males, whereas females exhibited little pecking behavior. Male pecking behavior was not homogeneous within each experimental group. It has been suggested that males form a pecking order, whereas females have no hierarchy under small-scale floor-feeding conditions, as observed in the wild. In most cases, on the first day the number of pecking behaviors was low 20 min after the start of the experiment. The three subordinate individuals in the mixed category had little time to feed, whereas the other birds in the mixed category and all helmeted guinea fowl in the male- and female-only categories had longer feeding durations. We suggest that helmeted guinea fowl may be reared under small-scale floor feeding, and that the health of males should be managed. However, rearing females and males under small-scale floor feeding conditions should be avoided. This study contributes to improving the welfare of helmeted guinea fowl reared under small-scale floor feeding.
Key words: flocking type, Numida meleagris, pecking behavior, pecking order

DOI： https://doi.org/10.2141/jpsa.2024020

Egg Quality, Sensory Attributes, and Protein Metabolites of Laying Hens Fed Whole Flaxseed, Fish Oil, and Different Sources of Trace Elements

Youssef Attia 1, Ahmed A. Al Sagan 2, El-Sayed O.S. Hussein 3, Marai J. Olal 4, Tarek A. Ebeid 5, Abdulaziz A. Alabdullatif 3, Rashed A. Alhotan 3, Gamaleldin M. Suliman 3, Mohammed M. Qaid 3, Vincenzo Tufarelli 6, Heba A. Shehta 7 and Marco Ragni 8

1 Animal and Poultry Production Department, Faculty of Agriculture, Damanhour University, Damanhour 22713, Egypt
2 King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia
3 Department of Animal Production, College of Food and Agricultural Sciences, King Saud University, Riyadh 11451, Saudi Arabia
4 Admin & Animal Nutrition Technical Services, Danisco Animal Nutrition and Health (IFF), Riyadh 11451, Saudi Arabia
5 Department of Poultry Production, Faculty of Agriculture, KafrEl-Sheikh University, KafrEl-Sheikh 33516, Egypt
6 Department of Precision and Regenerative Medicine and Jonian Area (DiMePRe-J), Section of Veterinary Science and Animal Production, University of Bari ‘Aldo Moro’, Bari 70010, Italy
7 Regional Center for Food and Feed, Agricultural Research Center, Giza 12619, Egypt
8 Department of Soil, Plant and Food Science, University of Bari ‘Aldo Moro’, Bari 70125, Italy

This study evaluated the effects of whole flaxseed (WFS), fish oil (FO), and different sources of Se, Zn, and Fe(inorganic, organic, and nano-source) on egg production, quality, sensory attributes, and serum protein metabolites in laying hens. A total of 144 hens were divided into six groups with six replicates of four hens each. Hens were fed six diets as follows: 1)control diet; 2) 7.5%WFS+1.5%FO; 3) 7.5%WFS+1.5%FO+175 mg/kg vitamin E (VE); 4) 7.5%WFS+1.5%FO+175 mg/kg VE + inorganic sources of Se, Zn, and Fe (ISeZnFe); 5)7.5%WFS+1.5%FO+175 mg/kg VE + organic sources of Se, Zn, and Fe (OSeZnFe); 6) 7.5%WFS+1.5%FO+175 mg/kg VE + nano-source of Se, Zn, and Fe (NSeZnFe) from 40–50 weeks of age. Laying hens fed 7.5% WFS, 1.5% FO, and different sources of trace elements in their diets had no negative effects on laying rate, egg weight, egg mass, feed intake, feed conversion ratio, body weight change, or survival rate compared to that of hens fed the control diet. Dietary treatments did not negatively affect the external and internal egg characteristics or egg sensory attributes. Feeding 7.5%WFS+1.5%FO+VE+ISeZnFe positively influenced yolk color in fresh eggs. Dietary treatments had a significant impact on egg nutritional composition, with the highest levels of macronutrients found in eggs from hens fed the 7.5%WFS+1.5%FO+VE+NSeZnFe treatment. The highest plasma globulin concentrations were observed in hens fed organic and nano-source trace elements. The same diets reduced plasma uric acid levels. Based on these findings, the inclusion of organic or nano-source trace minerals in diets containing WFS and FO positively affected egg quality and hen protein metabolites.
Key words: egg quality; laying hens; protein metabolites; trace elements; whole flaxseed.

DOI： https://doi.org/10.2141/jpsa.2024021

ニワトリ初生ヒナにおける気質とストレス関連遺伝子発現量との関連<

石川明1・高沼朋香1・橋本典和2・都築政起3

1名古屋大学大学院生命農学研究科　名古屋市千種区不老町　464-8601，
2和歌山県畜産試験場養鶏研究所　和歌山県日高郡日高川町船津644-1111，
3広島大学大学院統合生命科学研究科　東広島市鏡山　739-8528

商業孵化場管理下における初生ヒナのストレスは成鶏の問題行動と関連することが知られている。最近、我々は初生ヒナ用の新しい行動ハンドリングテストを開発し、このテストが日本鶏および外国鶏の7つ品種間の気質の違いを評価できることを示した。これらの7品種のうち、特徴的な気質を示す5品種を選んで本研究を行った。本研究では、これら5品種の2日齢雄ヒナを用いて、気質特性と視床下部-下垂体-副腎（HPA）軸に関与する3つのストレス関連遺伝子（NR3C1、CYP11A1、HSD3B2）のmRNA発現量との関係を検討した。ハンドリングテストにおける10の行動形質を主成分分析した結果、ファヨウミ品種とチャボ広島ラインは、騒々しい気質を示すニワトリとして他の品種と区別された。NR3C1発現量のみが、2つの行動形質（一般的な発声と壁への接近）と有意な正の相関を示したが、移動とは負の相関を示した。これらの結果は、初生ヒナの複雑な気質は、HPA軸のストレス関連遺伝子によって部分的に制御されている可能性を示唆した。
キーワード：ニワトリ，遺伝子発現，HPA軸，ストレス，気質

DOI： https://doi.org/10.2141/jpsa.2024022

Association between Temperament and Stress-related Gene Expression in Day-old Chickens

Akira Ishikawa1, Tomoka Takanuma1, Norikazu Hashimoto2 and Masaoki Tsudzuki3

1 Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
2 Livestock Experiment Station, Wakayama Prefecture, Hidaka-Gun 644-1111, Japan
3 Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima 739-8525, Japan

Stress in day-old chickens from commercial hatcheries is associated with problematic behavior in adult animals. Recently, we developed a new behavioral handling test for day-old chickens and demonstrated that it assessed temperament differences between seven breeds of native Japanese and Western chickens. In this study, we used 2-day-old male chicks from five of the above breeds to investigate the relationship between temperament and mRNA levels of three stress-related genes (nuclear receptor subfamily 3 group C member 1 (NR3C1), cytochrome P450 family 11 subfamily A member 1, and hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 1) involved in the hypothalamic-pituitary-adrenal axis. Principal component analysis of 10 behavioral traits for the handling test revealed that the Fayoumi breed and Hiroshima line of the Chabo breed, both of which exhibited boisterous temperament, clustered separately from the other breeds. Only NR3C1 expression showed a significant positive correlation with two behavioral traits (general vocalization and approaching the wall), and a negative correlation with movement. These results suggest that the complex temperament of day-old chickens is regulated, in part, by stress-related genes along the hypothalamic-pituitary-adrenal axis.
Key words: chickens, gene expression, hypothalamic-pituitary-adrenal axis, stress, temperament

DOI： https://doi.org/10.2141/jpsa.2024022

ビワ葉混合発酵茶製造加工残渣の給与が対馬地鶏肉用交雑鶏の発育成績および肉質に及ぼす影響

松永将伍1,2・深川　聡2・中村桐子3・大塚　彰2,3・井尻大地2,3
1長崎県農林技術開発センター畜産研究部門　島原市有明町湯江丁3600　859-1404
2鹿児島大学大学院連合農学研究科　鹿児島市郡元1-21-24　890-0065
3鹿児島大学大学院農林水産学研究科　鹿児島市郡元1-21-24　890-0065

本研究では，未利用資源であるビワ葉混合発酵茶製造加工残査の飼料としての可能性を明らかにし，対馬地鶏肉用交雑鶏の発育および肉質に及ぼす影響について調査した。ビワ葉混合発酵茶製造加工残査は，緑茶粕と比べて，βカロテン含量，α-トコフェロール含量および総カテキン含量は有意に低い値（P < 0.01）であったが，総ポリフェノール含量が有意に高く（P < 0.01），DPPHラジカル消去活性が有意に高い傾向（P < 0.10）にあったことから，高い抗酸化機能を有することが明らかとなった。ビワ葉混合発酵茶製造加工残査を1.0 %添加した飼料を対馬地鶏肉用交雑鶏の仕上げ期4週間に給与すると，ビワ葉混合発酵茶製造加工残査を添加していない対照区と比べて，発育成績や解体成績に影響を及ぼさず，浅胸筋中のα-トコフェロール含量を高め，肉の鮮度の指標となるK値の上昇を抑制し，ドリップロスを低減できることから，肉質の改善効果が期待できることが示された。
キーワード：対馬地鶏肉用交雑鶏，ビワ葉混合発酵茶製造加工残渣，肉質，α-トコフェノール, K値, ドリップロス

DOI： https://doi.org/10.2141/jpsa.2024024

Effect of a Mixed Fermented Loquat Leaf Tea By-Product on the Growth Performance and Meat Quality of Tsushima-Jidori Crossbred Chicken

Shogo Matsunaga1,2, Satoru Fukagawa1, Kiriko Nakamura3, Akira Ohtsuka2,3 and Daichi Ijiri2,3

1 Nagasaki Agricultural and Forestry Technical Development Center, 3600 Yue-tei, Ariake-cho, Shimabara, Nagasaki 859-1404, Japan
2 The United Graduate School of Agricultural Sciences, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan
3 Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan

In the present study, the effects of dietary supplementation with a mixed fermented loquat leaf tea residue (MFL) were evaluated on muscle α-tocopherol concentration and drip loss of Tsushima-Jidori crossbred chicken. MFL contained significantly less β-carotene, α-tocopherol, and total catechin than that of residues of green tea leaf infusion, although total polyphenol was significantly higher and 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity tended to be higher, indicating increased antioxidant properties. A total of 120 male Tsushima-Jidori crossbred chickens were divided into two groups at 62 days of age. The control group was fed a basal diet (commercial finisher diet containing 16.5% crude protein and 12.77 MJ/kg metabolizable energy) and the test group was fed a basal diet supplemented with MFL at a concentration of 1.0% until 90 days of age. Body mass, body mass gain, feed intake, and tissue mass did not significantly differ between the two groups. Dietary supplementation with MFL significantly increased breast muscle α-tocopherol concentration and reduced muscle drip loss. This was accompanied by a lower muscle K-value, which indicated the freshness of the meat. These results suggested that dietary supplementation with MFL improved the shelf life and water-holding capacity of breast muscles of Tsushima-Jidori crossbred chickens.
Key words: α-tocopherol, drip loss, K-value, meat quality, mixed fermented loquat leaf tea residue, Tsushima-Jidori crossbred chicken

DOI： https://doi.org/10.2141/jpsa.2024024

DOI： https://doi.org/10.2141/jpsa.2024002

ニワトリinterleukin-5の発現と抗原特異的な抗体産生に与える影響

渡邊天海1，寺田拓実1，江崎僚1，松崎芽衣1，古澤修一1，堀内浩幸1,2

1広島大学大学院統合生命科学研究科　東広島市鏡山　739-8528
2ゲノム編集イノベーションセンター　東広島市鏡山　739-0046

養鶏産業における感染症の脅威を最小限に抑えるためには，効果的なワクチン接種が重要である．ワクチン接種による免疫の増強効果を得るためには，ニワトリの抗体産生に関与するサイトカインに関する知見は欠かすことができない．本研究では，マウスにおいて抗体産生に関わるサイトカインの１つであるinterleukin-5（IL-5）に着目し，ニワトリIL-5の発現，抗体産生に与える影響について調査した．ニワトリ脾臓からリンパ球を分離し，マイトゲンとして知られるconcanavalin Aによる刺激培養を行った．その後，細胞から抽出したtotal RNAを用いてRT-PCRを行い，ニワトリIL-5の発現の有無を確認した．その結果，ニワトリIL-5は脾臓リンパ球で発現しており，哺乳類と同様にT細胞サブセットから発現することが示唆された．また，タンパク質のコーディング領域をクローニングし，シークエンス解析を実施したところ，予想されるIL-5と一致していた．このクローニングされた配列をもとに組換えタンパク質を作製し，抗原と共に点眼投与を隔週で２回実施した．その結果，ニワトリIL-5は血清中の抗原特異的なIgY産生を増強し，IgA産生を抑制することが見出された．このことから，ニワトリIL-5は抗体産生において重要な機能を有しており，これはニワトリ特有の機能である可能性が示唆された．
キーワード：抗体産生，IgA産生，インターロイキン-5，脾臓リンパ球

Chicken Interleukin-5 is Expressed in Splenic Lymphocytes and Affects Antigen-Specific Antibody Production

Tenkai Watanabe1, Takumi Terada1, Ryo Ezaki1, Mei Matsuzaki1, Syuichi Furusawa1 and Hiroyuki Horiuchi1,2

1Laboratory of Immunobiology, Graduate School of Integrated Sciences for Life, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima, 739-8528, Japan
2Genome Editing Innovation Center, Hiroshima University, 3-10-23 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-0046, Japan
Vaccination is important for reducing disease incidence in the poultry industry. To enhance immunity and vaccine efficacy, chicken cytokines associated with antibody production must be identified. In this study, we focused on interleukin-5(IL-5), involved in antibody production in mice, measuring its expression and effects on antibody production. Concanavalin A-stimulated splenocytes were used for RT-PCR to clone IL5 cDNAs. Recombinant IL-5 was prepared from the clone and administered to chickens with antigen via the ocular-topical route twice every alternate week. IL-5 enhanced antigen-specific IgY and inhibited antigen-specific serum IgA production in serum. Our findings suggest that IL-5 plays an important role in chicken antibody production, with possible unique functions.
Key words: antibody production, IgA production, interleukin-5, splenic lymphocyte

DOI： https://doi.org/10.2141/jpsa.2024002

DOI： https://doi.org/10.2141/jpsa.2024007

玄米と酒粕の給与がブロイラーの成長と肉質に及ぼす影響

西川幸樹1, 宮﨑香綸1, 平井猛博2, 實安隆興1, 本田和久1

1 神戸大学大学院農学研究科　神戸市　657-8501
2 白鶴酒造株式会社研究室　神戸市　658-0041

日本は酒と高タンパク質な酒粕の原料である米の生産地である。本研究では、玄米と酒粕が輸入飼料原料であるトウモロコシと大豆粕に置換できるかどうかを調べた。実験1では、24羽の21日齢のブロイラーヒナを2群に分け、トウモロコシ大豆粕飼料、或いは玄米大豆粕飼料を21日間給与した。その結果、トウモロコシの玄米への置換は体重を増加させ、飼料要求率を改善した。また、もものL*値（明るさ）を上昇させ、もものa*値（赤さ）とb*値（黄色さ）、および脂肪組織のb*値を有意に低下させた。実験2では、36羽の21日齢のブロイラーヒナを3群に分け、トウモロコシ大豆粕飼料を3週間、トウモロコシ大豆粕飼料を2週間給与後、玄米酒粕飼料を1週間、或いは玄米酒粕飼料を3週間、それぞれ給与した。その結果、玄米酒粕飼料の3週間給与は飼料要求率を有意に改善し、むね肉、もも、および脂肪組織のa*値とももと脂肪組織のb*値を有意に低下させた。また、玄米酒粕飼料の1週間給与はむね肉と脂肪組織のa*値を有意に低下させた。これらの結果から、玄米と酒粕は成長成績に悪影響を及ぼすことなくブロイラー用の輸入飼料原料の代替品として利用できることが示唆された。これらの国産飼料原料は日本における地産地消の家禽生産システムの構築に役立つと考えられる。

Effects of Dietary Brown Rice and Sake Lees on the Growth Performance and Color of Meat in Broiler Chicks

Koki Nishikawa1, Karin Miyazaki1, Takehiro Hirai2, Takaoki Saneyasu1 and Kazuhisa Honda1

1 Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan
2 Research & Development Department, Hakutsuru Sake Brewing Co., Ltd., Kobe 658-0041, Japan
In this study, we examined whether brown rice and sake lees (domestic feed ingredients) could replace corn and soybean meal (major imported feed ingredients) in broiler chick feed. In Experiment 1, 21-day-old broiler chicks were assigned to two groups and fed a corn-soybean- or a brown rice-soybean-based diet for three weeks (3 birds × 4 replicates/group). Dietary brown rice significantly improved body weight gain and feed conversion ratio. Brown rice feeding also significantly increased L* (lightness) in the thigh and significantly decreased a* (redness) and b* (yellowness) in the thigh and b* in the fat. In Experiment 2, 21-day-old broiler chicks were assigned to three groups and fed either a corn-soybean-based diet for 3 weeks, a corn-soybean-based diet for the first 2 weeks followed by a brown rice sake lees-based diet for the last week, or a brown rice sake lees-based diet for 3 weeks (3 birds × 4 replicates/group). Replacement of the imported feed ingredients significantly improved the feed conversion ratio. The a* values for the breast, thigh, and fat, and the b* values for the thigh and fat were significantly decreased by rice and sake lees feeding for 3 weeks. The a* values for the breasts and fat were significantly decreased by rice and sake lees feeding for 1 week. These results suggest that brown rice and sake lees can be used as replacements for imported feed ingredients such as corn and soybean meal in broiler chicks without detrimental effects on growth performance. These domestic feed ingredients may benefit local production and consumption of poultry in Japan.
Key words: chicken, color, hulled rice, maize, unpolished rice

DOI： https://doi.org/10.2141/jpsa.2024007

DOI： https://doi.org/10.2141/jpsa.2024009

定期的・局所的なLED照明の切り替えはブロイラーの移動を誘導する

楠田慎吾1, 大島用三2, 實安隆興1, 本田和久1

1 神戸大学大学院農学研究科　神戸市　657-8501
2 株式会社イシイフーズ　徳島県名西郡石井町　779-3224

Wooden breastと脚弱は現代のブロイラー生産において深刻な問題となっている。最近の知見から、運動にはブロイラーのWooden breastと脚弱を改善する可能性がある。照明色はニワトリヒナの行動に影響し、移動を誘導することが明らかにされている。本研究では、定期的・局所的な照明の切り替えが、ブロイラーの移動を誘導し、脚弱とWooden breast に影響するかどうか明らかにするために実施した。30羽の5日齢のブロイラーヒナを2つの囲い（4.72 m × 0.73 m）に分けた。対照群は白色LED照明下で42日齢まで飼育した。試験群では、中央に白色LED照明を点灯し、囲いの何れかの端に青色か赤色のLED照明を点灯した。21日齢まで、青色と赤色の照明を3時間毎に、それぞれ赤色と青色の照明に切り替えた。21日齢時に全ての照明を白色LEDに変え、35日齢まで、いずれかの側の照明のみを3時間毎に点灯して飼育した。35日齢以降は全てのLED照明を白色に変えて飼育した。その結果、照明の定期的・局所的切り替えは、ブロイラーヒナの移動を有意に誘導した。Wooden breastのスコアは照明処理によって改善する傾向を示した。一方、ゲートスコア、浅胸筋の剪断力価、及び脛骨の長さ、直径、並びに破断強度には有意な影響は見られなかった。本研究は、定期的・局所的な照明の切り替えがブロイラーの移動を誘導することを示す始めての証拠であり、ブロイラーの健康状態の改善に役立つシステムとなる可能性がある。

Periodic and Local LED Light Switching Induces Broiler Locomotion

Shingo Kusuda1, Chikamitsu Oshima2, Takaoki Saneyasu1, Kazuhisa Honda1

1 Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan
2 Ishiifoods Co., Ltd., Tokushima 779-3224, Japan
Wooden breast myopathy and leg weakness are serious problems in the broiler chicken industry. The color and intensity of light in the chicken habitat affect behavior, including walking of chicks. The present study was conducted to determine whether periodic and local light switching induces locomotion and affects wooden breast myopathy and leg weakness in broiler chicks. Thirty five-day-old broiler chicks were assigned to two pens (4.72 m × 0.73 m each). In the control pen, chicks were reared under three white-light emitting diode (LED) lights until they were 42 days old. In the other pen, chicks were reared under a white LED light located in the center, supplemented with blue or red LED lights on either side of the pen. The color of the LED lights changed every 3 h, from blue and red to red and blue. From 21 d of age, all LED lights were changed and only one of the side lights was turned on every 3 h. From 35 d of age, all three white lights were turned on until 42 d of age. Periodic and local color switching and on-off switching significantly induced locomotion in broiler chicks. Wooden breast scores tended to improve with light-switching treatment. The tibia length, diameter, and breaking strength were not significantly affected. This is the first report showing that locomotion may be induced in broiler chicks by periodic and local lighting switching, and may be useful for improving the health status of broiler chicks.
Key words: bone, light emitting diode, myopathy, shear force, walking

DOI： https://doi.org/10.2141/jpsa.2024009

DOI： https://doi.org/10.2141/jpsa.2024013

初生ヒナにフルオロキノロンを投与した種鶏とその子孫ブロイラーにおけるフルオロキノロン耐性大腸菌の分布

川崎　武志

人と鳥の健康研究所，網走市鱒浦，099-3119

本研究では，ヒナが鶏舎に到着してから 5 日間オフロキサシンを投与したブロイラー種鶏群 (PS) とその子孫ブロイラーにおけるオフロキサシン耐性大腸菌 (OFXR-EC) の分布について調査した。 OFXR-ECは，鶏舎に到着した種鶏の初生ヒナ群（PSN）の22.95％から検出された。 鶏舎で飼育中のPS における OFXR-EC の検出率は 72.49% であり，PSN よりも有意に高かった。 さらに，子孫ブロイラーの初生ヒナ群 (CSN) では OFXR-EC の検出率がPS よりも有意に低く，7.06% であったが，約 6 週齢のブロイラー群 (CS) では 24.62% であった。 すなわち，CSNからCSまでの飼育期間では一貫してオフロキサシンを含む治療用抗菌薬が使用されなかったにもかかわらず，OXR-ECの検出率はCSNよりもCSで有意に高かった。 OFXR-ECが検出されたサンプルから分離された大腸菌における OFXR-EC の割合は，PSN 63.85%，PS 10.52%，CSN 62.00%，CS 8.25% であり，PSNとCSN，PSとCSの間ではほとんど差がなかった。
キーワード：ブロイラー，大腸菌，フルオロキノロン耐性，オフロキサシン，種鶏

Distribution of Fluoroquinolone-Resistant Escherichia coli in Parent Flocks Treated with Fluoroquinolones on Chick Stage and their Broiler Offspring

Takeshi Kawasaki

Research Office Concerning the Health of Humans and Birds, Abashiri, 099-3119, Japan
This study investigated the distribution of ofloxacin-resistant Escherichia coli (OFXR-EC) in broiler parent flocks (PS) treated with ofloxacin for 5 days from the time the chicks arrived at the poultry house, and their broiler offspring. OFXR-EC was detected in 22.95% of neonatal parent stock chicks (PSN) arriving at the poultry house. The detection rate of OFXR-EC in PS rearing was 72.49%, which was significantly higher than that detected in PSN. In addition, the detection rate of OFXREC was significantly lower in neonatal chicks of their offspring broilers (CSN) at 7.06% than that of PS, but was 24.62% in offspring broiler flocks (CS) at approximately 6 weeks of age. The OFXR-EC detection rate was significantly higher in CS than that in CSN, even though no therapeutic antimicrobials, including ofloxacin, were used from CSN to CS. In addition, the proportions of OFXR-ECs in E. coli isolated from samples in which OFXR-ECs were detected were 63.85% for PSN, 10.52% for PS, 62.00% for CSN, and 8.25% for CS. There was little difference in the composition ratio of OFXR-EC between PSN and CSN, or between PS and CS.
Key words: broiler, Escherichia coli, fluoroquinolone-resistant, ofloxacin, parent stock

DOI： https://doi.org/10.2141/jpsa.2024013