Department of Animal and Food Sciences, University of Kentucky, Lexington, KY 40546, USA.
J Anim Sci. 2012 Aug;90(8):2663-70. doi: 10.2527/jas.2011-4780.
Two experiments were conducted to assess the effects of porcine ST (pST) on the responses to a near-ideal blend of AA for pigs from 22 to 60 kg BW. Eighty Hampshire × Yorkshire gilts (40 gilts/experiment) were individually penned and assigned to a 4 × 2 factorial arrangement of treatments, consisting of 4 diets with and without pST injection. A fortified corn-soybean meal basal diet was formulated to contain 1.50% total Lys and Thr, Met, and Trp were added to obtain a near-ideal blend of these AA relative to Lys. In 3 additional diets, Lys was reduced to 1.25%, 1.00%, or 0.75% by diluting the basal diet with cornstarch, cellulose, and sand, such that the diets also contained the same ratios of AA. Pigs that received pST were administered a daily intramuscular injection of 2 mg of pST. Data from the 2 experiments were pooled. Administration of pST increased ADG (P < 0.01), G:F (P < 0.01), and LM area (P < 0.01), and decreased ADFI (P < 0.03), last rib backfat (P < 0.01), and 10th rib backfat (P < 0.01). Also, estimated carcass muscle and calculated lean gain increased (P < 0.01) in pST-treated pigs. Administration of pST also increased (P < 0.01) the percentage, total gain and accretion rate of water, protein, and ash in the carcass, and decreased (P < 0.01) the percentage, total gain, and accretion rate of carcass fat. Growth rate, G:F, and carcass traits improved (P < 0.01), percentage of carcass protein and water increased (P < 0.01), and carcass fat percentage decreased (P < 0.01) with increasing dietary Lys. The percentage, total gain, and accretion rate of carcass protein increased to a greater extent in pST-treated pigs than in untreated pigs, resulting in a pST × Lys interaction (P < 0.05). The results indicated that pST improves performance, leanness, and protein accretion in pigs from 22 to 60 kg BW, and that these responses to dietary Lys and a near-ideal blend of AA is greater in growing pigs treated with pST than untreated pigs.
进行了两项实验，以评估猪 ST（pST）对 22 至 60 公斤体重猪对近乎理想的 AA 混合物的反应的影响。80 头汉普夏 × 约克郡母猪（每个实验 40 头母猪）单独被安置在 4×2 因子处理的安排中，包括 4 种添加和不添加 pST 注射的饮食。配制强化玉米-豆粕基础日粮，使其含有 1.50%的总赖氨酸和苏氨酸，添加蛋氨酸和色氨酸，以获得相对于赖氨酸的近乎理想的 AA 混合物。在另外 3 种日粮中，通过用玉米淀粉、纤维素和沙子稀释基础日粮，将赖氨酸减少到 1.25%、1.00%或 0.75%，使日粮也含有相同比例的 AA。接受 pST 的猪每天接受一次肌肉内注射 2 毫克 pST。将来自这两个实验的数据汇总。pST 的给药增加了 ADG（P<0.01）、G:F（P<0.01）和 LM 面积（P<0.01），减少了 ADFI（P<0.03）、最后肋骨背膘（P<0.01）和第 10 肋骨背膘（P<0.01）。此外，估计的胴体肌肉和计算的瘦肉增加（P<0.01）在 pST 处理的猪中。pST 的给药还增加了（P<0.01）胴体中水分、蛋白质和灰分的百分比、总增益和积累率，并降低了（P<0.01）胴体脂肪的百分比、总增益和积累率。生长速度、G:F 和胴体性状得到改善（P<0.01），胴体蛋白质和水分的百分比增加（P<0.01），胴体脂肪百分比降低（P<0.01），日粮赖氨酸增加。与未处理的猪相比，pST 处理的猪胴体蛋白质的百分比、总增益和积累率增加幅度更大，导致 pST×赖氨酸相互作用（P<0.05）。结果表明，pST 提高了 22 至 60 公斤体重猪的性能、瘦肉率和蛋白质积累，并且在接受 pST 处理的生长猪中，对日粮赖氨酸和近乎理想的 AA 混合物的反应大于未处理的猪。
