@article{oai:obihiro.repo.nii.ac.jp:00000246,
 author = {Kuchida, Keigo and 口田, 圭吾 and 菊地, 彩 and Kato, Kohji and 加藤, 浩二 and Hidaka, Satoshi and 日高, 智 and 鈴木, 三義 and Miyoshi, Shunzo and 三好, 俊三},
 issue = {1},
 journal = {日本畜産学会報, Nihon Chikusan Gakkaiho},
 month = {Feb},
 note = {application/pdf, 胸最長筋の皮下脂肪側において，筋間脂肪が胸最長筋内に大きく入り込んでくぼみのあるもの（いわゆる‘ハート芯’）は，枝肉の価値を低下させる一因であるとされる．本研究では，画像解析による新たなハート芯評価方法について提案すること，ならびに黒毛和種のハート芯形成に対する種雄牛の影響を検討することを目的とした．枝肉横断面撮影装置によって撮影された第6～7肋骨間の胸最長筋画像を2値化した．2値画像について胸最長筋の境界線を検出し，膨張処理ならびに細線化処理を行い，なめらかな胸最長筋の輪郭線を得た．胸最長筋の長径より上部（皮下脂肪側）について，凸部を結んだ凸多角形を描き，凸多角形と胸最長筋の輪郭線が作る領域について，その面積，パターン幅等を測定した．得られた画像解析形質のうちから3変数を用い，肉眼で判定したハート芯の程度を分類変数とする線形判別分析を行ったところ，その判別率は，97.0％と極めて高く，画像解析によりハート芯の程度を数値化することを可能とした．237頭（種雄牛32頭）の黒毛和種産肉能力検定間接法の材料牛について，ハート芯の程度を肉眼で調査したところ，38頭においてハート芯が確認された．画像解析により評価したハート芯の程度に対する種雄牛の効果は高度に有意（P＜0.01）であり，特定の種雄牛からの後代にハート芯の出現度が多い傾向が認められ，ある1頭の種雄牛については，後代6頭すべてがハート芯の形状を呈した．
A depression formed by intermuscular fat ingrowing greatly into the upper side of the M. longissimus
thoracis (i.e. 'heart-shaped ribeye') causes a decrease in the carcass value in Japan. The purpose of this
research was to propose a new method to evaluate the level of the heart-shaped ribeye by computer image
analysis and to investigate the influence of sire on the appearance of the heart-shaped ribeye in Japanese
Black. Digital images of the M. longissimus thoracis (ribeye) between the 6th and 7th ribs were taken by an
equipment developed by the authors. The resolution of the image was 1，800 X 1，200 pixels with a file size of
800 to 900 KB in JPEG format. A five times dilation and thinning process were performed to smooth the
contour line of the ribeye，which was semi-automatically detected from the binary image using computer
software programmed by the authors. The area，
maximum length，pattern width and length of hairline were
measured in an area structured with a convex polygon and the contour line of the upper side over the major
axis of the ribeye. The level of the heart-shaped ribeye has been assigned into 4 levels (None，Small，Middle，Large) by several researchers. Discriminate analysis for the level of heart-shaped ribeye assigned by
researchers as the classified variable was performed with 10 covariates associated with image analysis traits.
The percentage of the difference between the level by researchers and by discriminate analysis within土0 was 97.0%. The level of the heart-shaped ribeye was progeny tested with 237 (32 sires) Japanese Black
steers by image analysis. The heart-shaped ribeye was confirmed in 37 cattle. The effect of the sire on the
level of the heart-shaped ribeye was highly significant (P<0.01). A trend towards a high appearance
frequency of heart-shaped ribeyes from several sires was found. Heart-shaped ribeyes were recognized in
all six steers from one sire.},
 pages = {23--29},
 title = {画像解析による黒毛和種の牛胸最長筋形状評価法と種雄牛の影響},
 volume = {74},
 year = {2003}
}