Department of Animal Sciences and Industry, College of Agriculture, College of Veterinary Medicine, Kansas State University, Manhattan 66506-0201, USA.
J Anim Sci. 2011 Feb;89(2):404-13. doi: 10.2527/jas.2009-2737.
A total of 144 barrows and gilts (initial BW = 44 kg) were used in an 82-d experiment to evaluate the effects of dietary fat source and duration of feeding fat on growth performance, carcass characteristics, and carcass fat quality. Dietary treatments were a corn-soybean meal control diet with no added fat and a 2 × 4 factorial arrangement of treatments with 5% choice white grease (CWG) or soybean oil (SBO) fed from d 0 to 26, 54, 68, or 82. At the conclusion of the study (d 82), pigs were slaughtered, carcass characteristics were measured, and backfat and jowl fat samples were collected. Fatty acid analysis was performed, and iodine value (IV) was calculated for all backfat and jowl fat samples. Pigs fed SBO tended to have increased (P = 0.07) ADG compared with pigs fed CWG. For pigs fed SBO, increasing feeding duration increased (quadratic, P < 0.01) ADG and G:F. For pigs fed CWG, increasing feeding duration improved (quadratic, P < 0.01) G:F. For pigs fed SBO or CWG, increasing feeding duration increased carcass yield (quadratic, P < 0.04) and HCW (quadratic, P < 0.02). Dietary fat source and feeding duration did not affect backfat depth, loin depth, or lean percentage. As expected, barrows had greater ADG and ADFI (P < 0.01) and poorer G:F (P = 0.03) than gilts. Barrows also had greater last-rib (P = 0.04) and 10th-rib backfat (P < 0.01) and reduced loin depth and lean percentage (P < 0.01) compared with gilts. Increasing feeding duration of CWG or SBO increased (P < 0.10) C18:2n-6, PUFA, PUFA:SFA ratio, and IV in jowl fat and backfat. Pigs fed SBO had greater (P < 0.01) C18:2n-6, PUFA, PUFA:SFA ratio, and IV but decreased (P < 0.01) C18:1 cis-9, C16:0, SFA, and MUFA concentrations compared with pigs fed CWG in jowl fat and backfat. Barrows had decreased (P = 0.03) IV in jowl fat and backfat compared with gilts. In summary, adding SBO or CWG increased the amount of unsaturated fat deposited. Increasing feeding duration of dietary fat increases the amount of unsaturated fatty acids, which leads to softer carcass fat.
总共使用了 144 头阉公猪和母猪（初始 BW=44kg）进行了 82 天的实验，以评估日粮脂肪来源和脂肪饲养时间对生长性能、胴体特性和胴体脂肪质量的影响。日粮处理为不含添加脂肪的玉米-豆粕对照日粮和 5%选择白色油脂（CWG）或大豆油（SBO）的 2×4 因子安排处理，从 0 至 26、54、68 或 82d 饲喂。在研究结束时（第 82 天），对猪进行屠宰，测量胴体特性，并采集背脂和颈肩肉脂肪样品。对脂肪酸进行分析，并计算所有背脂和颈肩肉脂肪样品的碘值（IV）。与饲喂 CWG 的猪相比，饲喂 SBO 的猪 ADG 有增加的趋势（P=0.07）。对于饲喂 SBO 的猪，随着饲养时间的延长，ADG 和 G:F 呈增加趋势（二次，P＜0.01）。对于饲喂 CWG 的猪，随着饲养时间的延长，G:F 得到改善（二次，P＜0.01）。对于饲喂 SBO 或 CWG 的猪，随着饲养时间的延长，胴体产肉率（二次，P＜0.04）和 HCW（二次，P＜0.02）增加。日粮脂肪来源和饲养时间对背脂深度、腰肉深度或瘦肉百分比没有影响。正如预期的那样，阉公猪的 ADG 和 ADFI（P＜0.01）更大，G:F 更差（P=0.03）。与母猪相比，阉公猪的最后肋骨（P=0.04）和第 10 肋骨背脂（P＜0.01）更大，腰肉深度和瘦肉百分比更小（P＜0.01）。饲喂 CWG 或 SBO 的时间延长增加了颈肩肉和背脂中的 C18:2n-6、PUFA、PUFA:SFA 比值和 IV（P＜0.10）。饲喂 SBO 的猪 C18:2n-6、PUFA、PUFA:SFA 比值和 IV 更大（P＜0.01），但 C18:1 cis-9、C16:0、SFA 和 MUFA 浓度更小（P＜0.01），与饲喂 CWG 的猪相比，颈肩肉和背脂中的 C18:2n-6、PUFA、PUFA:SFA 比值和 IV 更大。与母猪相比，阉公猪的颈肩肉和背脂的 IV 更小（P=0.03）。总之，添加 SBO 或 CWG 增加了不饱和脂肪的沉积量。增加日粮脂肪的饲养时间增加了不饱和脂肪酸的数量，从而使胴体脂肪更柔软。
