キール骨折は、家具付きケージに個別に収容された産卵鶏の行動を変化させ、福祉、生産能力、卵の質を低下させた

Keel fracture changed the behavior and reduced the welfare, production performance, and egg quality in laying hens housed individually in furnished cages.

• Haidong Wei
• Yanju Bi
• Hongwei Xin
• Lei Pan
• Runze Liu
• Xiang Li
• Jianhong Li
• Runxiang Zhang
• Jun Bao

抄録

キール骨折は産卵鶏の福祉、行動、健康、生産能力、卵質に悪影響を及ぼす。本研究では、17wk（WOA）時点で正常なキール骨を持つ健康なローマン白産鶏90羽を使用し、家具付きケージに個別に収容した。全ての雌鶏は、5つの時点（22, 27, 32, 37, 42 WOA）で触診を行い、キール骨の状態に基づいて、骨折キール（FK）または正常キール（NK）のマークを付けた。触診後、各時点で2日間連続して行動観察を行い、FK産卵鶏は27-32、32-37、37-42 WOAで、FK産卵鶏は27-32、32-37、NK産卵鶏は37-42 WOAで、総産卵数、汚卵数、破卵数、飼料摂取量を記録した。各行動観察後、新鮮なFK産鶏10羽とNK産鶏10羽を無作為に抽出して、厚生と卵質を判定した。その結果、キール骨折の発生率は産卵鶏の年齢とともに増加していることがわかった。NK 鶏と比較して、FK 鶏では座位・立位行動が有意に増加し（P<0.05）、給餌・歩行・パーチング・跳躍行動が有意に減少した（P<0.05）。飲水行動、前哨行動、慰安行動、ケージ突進行動、営巣行動には NK と FK の間で有意な変化は見られなかった（P>0.05）。実験期間中、FK雌鶏はNK雌鶏と比較して、産卵率、体重、1日の飼料摂取量、卵殻強度、厚さ、重量が減少（P<0.05）し、強直不動の期間が増加（P<0.05）した。27～32WOAでは、FK雌鶏は破卵率が有意に上昇した(P<0.05)。汚れ卵率、卵形指数、蛋白質高さ、Haugh unit、羽毛カバースコア、足指と足パッドの健康スコアには有意な差はありませんでした(P>0.05)。このことから、産卵鶏のキール破壊は行動に変化をもたらし、福祉、生産能力、飼料摂取量、卵殻品質を低下させることがわかった。

Keel fracture has adverse effects on welfare, behavior, health, production performance, and egg quality of laying hens. To investigate this, 90 healthy Lohmann white laying hens with normal keel bones at 17 wk of age (WOA) were used in this study and housed individually in furnished cages. All hens were marked with fractured keel (FK) or normal keel (NK) based on the keel bone status through palpation at 5 time-points (22, 27, 32, 37, and 42 WOA). After the palpation, the behavior was observed for 2 consecutive days at each time-point, and the total number of eggs produced, dirty eggs, broken eggs, and feed intake of FK and NK laying hens were recorded at 27-32, 32-37, and 37-42 WOA, respectively. After each behavioral observation, 10 fresh FK hens and 10 NK hens were randomly selected to determinate the welfare and egg quality. The results showed that the incidences of keel fracture increased with the age of laying hens. Compared with NK hens, the sitting and standing behaviors significantly increased (P < 0.05) while feeding, walking, perching, and jumping behaviors significantly decreased (P < 0.05) in FK hens. There were no significant changes in drinking, preening, comforting, cage pecking, and nesting behaviors between NK and FK hens (P > 0.05). During the experiment period, the egg production rate, body weight, daily feed intake, and eggshell strength, thickness, and weight decreased (P < 0.05) and duration of tonic immobility increased (P < 0.05) in FK hens compared with those in NK hens. At 27-32 WOA, FK hens had significantly elevated broken egg rate (P < 0.05). There were no significant differences in the dirty egg rate, egg shape index, protein height, Haugh unit, feather cover score, and toe and foot pad health score (P > 0.05). Therefore, keel fracture in laying hens caused changes in behavior and reduced the welfare, production performance, feed intake, and eggshell quality.

Copyright © 2020. Published by Elsevier Inc.