The Carcass Characteristics, Meat Qualities and Fatty Acid Profile of Longissimus dorsi in Relation to Sex and Slaughter Weight between Taiwanese Black Pigs and LYD Crossbred Pigs

• Main Authors: Hoang Vu Khanh Vo, 黃扶康
• Other Authors: 譚發瑞
• Format: Others
• Language: en_US
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/65872269560498708122

碩士 === 中興大學 === 動物科學系所 === 99 === This study was conducted to evaluate the effects of breeds (Taiwanese Black Pigs, TBP vs. LYD crossbred pigs, LYD), sexes (gilts vs. barrows), and different slaughter weight (light weight – under 90 kg, medium weight – arranged from 90 to 100 kg, and heavy weight – above 100 kg) on carcass performance and meat quality (Exp1), and on the fatty acid profile for both triglyceride and phospholipids (PL) which were extracted from Longissimus dorsi muscles (Exp 2). A total of 75 pigs were evaluated in this study. In exp 1, carcass weight, dressing percentage, carcass length and backfat thickness were not significantly different between the two breeds (P > 0.05) and two sexes (P > 0.05). As expected, carcass weight, carcass length increased with increasing of slaughter weight. However, dressing percentage and backfat thickness were not affected by slaughter weight. Lean percentage was slightly affected by breed, sex, and slaughter weight with LYD was higher than TBP, and barrows were fewer than gilts, and heavy pigs were higher than medium weight and light weight groups. There were no significant differences on fat percentage and lean/fat ratio due to the effects of breed, sex, and slaughter weight. TBP had higher yield of bone but lower yields of shoulder, loin, ham, and back part fat than that of LYD. LYD had a tendency higher lean percentage than in TBP (47.48 vs. 46.30 %, respectively, P < 0.1). The yield of leg, shoulder and loin of gilts were higher than that of barrows. With increasing slaughter weight, heavy pigs had more lean meat yields of leg, loin, belly and ham, and central part fat yield than that of lighter pigs. TBP was shown to be tender and had lower cooking loss than that of LYD. In addition, pH values at 24 hour postmortem of ham and loin of LYD were higher than that of TBP. Gilts had larger loin eye areas when compared to that of barrows. However, drip loss, shear force, cooking loss, objective muscle color value (L* - lightness, a* - redness, and b* - yellowness), subjective muscle color score, marbling score and pH 45 min postmortem both in ham and loin were not affected by sexes. With increasing slaughter weight, loin eye area was increased and cooking loss was decreased. In experiment 2, for the triglyceride fatty acid part, a significantly higher total MUFA (monounsaturated fatty acid) (P < 0.01), notably on C18:1 (P < 0.001) was observed in LYD crossbred compared to that of TBP. In contrast, TBP had significantly higher total PUFA (polyunsaturated fatty acid) and most individual PUFAs (C18:2, C18:3, C20:4) and tended to have higher SFA (saturated fatty acid) than LYD pigs. Barrows had significantly higher SFA, and tended to have lower MUFA and PUFA than gilts, even though without significant differences. No significant difference was detected by the effect of slaughter weight on SFA. However, with increasing the slaughter weight, MUFA tended to decrease the proportion that contrasted with PUFA. For the phospholipid fatty acids, LYD had higher proportion of total MUFA and no significant difference was detected by the effect of breeds on total MUFA, even thought LYD crossbred had significantly higher on C18:1 than in TBP. On the other hand, a significantly higher total SFA, notably on C16:0 was observed in LYD crossbred when compared to TBP. In contrast, TBP had significantly higher total PUFA and several individual PUFAs such as C18:2 n-6, C20:2 n-6, C20:3 n-6, C20:4 n-6, C22:5 n-3 than LYD crossbred pigs. Barrows had significantly higher SFA, but lower PUFA than gilts. Event thought barrows had more total MUFA than gilts, but no significant differences were detected. With increasing the slaughtered weight, the heavy pigs had less proportion of SFA and MUFA than light pigs. In contrast, total PUFA was increased with the same tendency of increasing in slaughter weight. In conclusion, there were no significant differences on carcass traits due to the breed and sex. Breed and sex slightly affected on the carcass composition. LYD produced more lean meat yield but less bone yield than TBP. Gilt had higher lean meat yield than barrows. In total, only lean percentage was influenced by slaughter weight. Breed, sex and slaughter weight slightly affected meat quality traits. The results demonstrated some differences in total fatty acid and individual fatty acids both in triglyceride and phospholipid fractions by the effects of breeds, sexes, and slaughter weights.