豬隻背脂與腰眼面積超音波即時顯像分析

張秀鑾 嚴世俊 賴永裕 劉錦條 李世昌 黃鈺嘉 吳明哲

台灣省畜產試驗所

應用台灣省畜產試驗所純種藍瑞斯、約克夏、杜洛克與盤克夏豬，於4.0、4.5與5.0月齡時使用Aloka SSD-500 B-模式，進行活體超音波即時顯像掃瞄，測定第十肋骨處腰眼面積(LOIN)與同部位長軸中點1/2處背脂厚度(BF)，並逢機選取90頭達110公斤之完檢豬隻進行屠體分切與測定第十肋骨處的腰眼面積(CLOIN)、瘦肉量(LEAN)、活體瘦肉率(LEAN1%)和溫屠體瘦肉率(LEAN2%)。統計模式係以品種與性別為固定效應，父畜與機差為逢機效應，而豬隻掃描時實際日齡為共變數。BF與LOIN具性別間差異存在(P<0.001)，公豬具較厚的BF與較大的LOIN，且其差異隨著日齡增加而增加(4.0與5.0月齡之BF與LOIN性別差異分別為0.16 cm vs. 0.26 cm 與1.8 cm2 vs. 2.8 cm2)。同時，公豬BF與LOIN的堆積速率亦較女豬者為快。品種比較結果發現：盤克夏較其他豬種具較厚BF與較小LOIN。Pearson相關係數分析發現，LOIN與CLOIN之相關係數為0.55~0.63，而與LEAN相關係數0.43~0.54 (P<0.001）；但與LEAN1%或LEAN2%，則無顯著的相關存在(P>0.05)。至於BF與屠體性狀之相關係數普遍較低，且均未顯著。

關鍵語：豬、超音波影像、腰眼面積。

ASSESSMENT OF BACKFAT AND LOIN MUSCLE AREA IN SWINE
USING REAL-TIME ULTRASOUND SCANS

H. L. Chang, S. C. Yen, Y. Y. Lai, C. T. Liu, S. C. Lee, Y. C. Huang and M. C. Wu

Taiwan Livestock Research Institute

Aloka Model SSD-500 B-mode real-time ultrasound scanner fitted with UST-5011U 3.5 M HZ probe frequency was used to scan Landrace, Yorkshire, Duroc and Berkshire pigs in Taiwan Livestock Research Institute. Pigs were scanned at or near 4.0, 4.5 and 5.0-month-old. Ultrasonic measurements of loin muscle area at the tenth rib (LOIN) and 1/2 point overlying fat (BF) were taken. 90 off-tested pigs were randomly sampled for carcass measures near 110 ㎏ live weight and traits evaluated included tenth rib loin muscle area (CLOIN), lean cuts (LEAN) and percent lean cuts on a live (LEAN1%) and carcass (LEAN2%) weight basis. Statistical model used included sex and breed as fixed effects, sire and scanned age in days as random effects and covariate, respectively. Sex effects were significant for BF and LOIN (P<0.001). Boars showed thicker BF and larger LOIN than gilts. The differences between sexes were increased as age increased (0.16 cm vs. 0.26 cm, and 1.8 cm2 vs. 2.8 cm2 for BF and LOIN at 4.0- vs. 5.0-month-old, respectively). The rates of deposition for both measures in boars were also faster than in gilts. Meanwhile, Berkshire pigs were observed with larger BF and smaller LOIN among breeds studied. Pearson correlation analysis indicated that there were significant correlations between LOIN and CLOIN ranging from 0.55 to 0.63 (P<0.001). Similar results was also found between LOIN and LEAN ranging from 0.43 to 0.54 (P<0.001). However, LOIN was not significantly correlated with LEAN1% or LEAN2%. Correlations between BF and carcass measures were general low and not significantly different from zero.

Key Words: Pigs, Ultrasonography, Loin muscle area.