The objective of this study was to evaluate the effects of supplementing low-protein diets with sodium dichloroacetate (DCA) and glucose on growth performance, carcass traits, and meat quality of growing-finishing pigs. A total of 80 crossbred (Duroc × Landrace × Large White) growing barrows (27 ± 0.4 kg body weight) were allocated randomly to one of the five treatments during three successive 4-wk periods. There were five diets in each phase. Diet 1 was the control diet with normal protein levels (CON) where protein levels in the three phases were 18%, 16.5%, and 15.5%, respectively. The dietary protein levels of Diets 2, 3, 4, and 5 (the low-protein diets, LP) were decreased by 4.5% compared to Diet 1. Additionally, Diets 3 and 4 were supplemented with an extra 120 mg/kg DCA (LP + DCA) or 1.8% glucose (LP + GLUC), respectively. Diet 5 was further supplemented with an extra 120 mg/kg DCA and 1.8% glucose (LP + DCA + GLUC). The LP + DCA diet increased the average daily weight gain of pigs compared to the CON and LP diet in phase 3 and the overall experimental period (P < 0.001). The LP diet reduced the gain:feed ratios of the pigs compared to the CON, LP + DCA, and LP + DCA + GLUC diets in phase 1 and the overall experimental period (P < 0.001). Furthermore, gain:feed ratios in LP + DCA and LP + DCA + GLUC groups did not differ from that of the CON group (P > 0.10). Pigs fed the LP + DCA diet had higher pH values of meat at 24 h post-mortem than the CON group (P < 0.05). The LP + DCA + GLUC diet increased the total protein content in the longissimus dorsi (LD) muscle of pigs, compared to the other dietary treatments (P < 0.05), and increased the Arg and Leu contents in the LD muscle compared to the LP + DCA diet (P < 0.05). Moreover, the LP + DCA diet induced a higher C18:1n9t percentage in the LD muscle of pigs compared to other groups (P < 0.05). In conclusion, an LP diet reduced the feed efficiency in pigs and barely affected meat quality, whereas 120 mg/kg DCA supplementation in an LP diet improved the growth performance of growing-finishing pigs, showed modest effects on carcass traits, and improved the muscle protein content with the addition of glucose.

中文翻译：

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低蛋白日粮添加二氯乙酸钠和葡萄糖对生长肥育猪生长性能、胴体性状和肉品质的影响

本研究的目的是评估在低蛋白日粮中添加二氯乙酸钠 (DCA) 和葡萄糖对生长肥育猪生长性能、胴体性状和肉质的影响。在三个连续的 4 周期间，将总共 80 头杂交（杜洛克×长白×大白）生长的公猪（体重 27±0.4 千克）随机分配到五种处理中的一种。每个阶段有五种饮食。饮食 1 是具有正常蛋白质水平 (CON) 的对照饮食，其中三个阶段的蛋白质水平分别为 18%、16.5% 和 15.5%。与饮食 1 相比，饮食 2、3、4 和 5（低蛋白饮食，LP）的膳食蛋白质水平降低了 4.5%。此外，饮食 3 和 4 额外补充了 120 mg/kg DCA（ LP + DCA）或 1.8% 葡萄糖（LP + GLUC）。饮食 5 进一步补充了额外的 120 mg/kg DCA 和 1.8% 葡萄糖 (LP + DCA + GLUC)。在第 3 阶段和整个实验期间，与 CON 和 LP 饮食相比，LP + DCA 饮食增加了猪的平均日增重 (P < 0.001)。在第 1 阶段和整个实验期间，与 CON、LP + DCA 和 LP + DCA + GLUC 饮食相比，LP 饮食降低了猪的增重：饲料比 (P < 0.001)。此外，LP + DCA 和 LP + DCA + GLUC 组中的增重：饲料比与 CON 组没有差异（P > 0.10）。饲喂 LP + DCA 日粮的猪在死后 24 小时肉的 pH 值高于 CON 组 (P < 0.05)。与其他日粮处理相比，LP + DCA + GLUC 日粮增加了猪背最长肌 (LD) 肌肉中的总蛋白质含量 (P < 0.05)，与 LP + DCA 饮食相比，增加了 LD 肌肉中的 Arg 和 Leu 含量（P < 0.05）。此外，与其他组相比，LP + DCA 饮食在猪的 LD 肌肉中诱导了更高的 C18:1n9t 百分比 (P < 0.05)。总之，LP 日粮降低了猪的饲料效率并且几乎不影响肉质，而在 LP 日粮中添加 120 mg/kg DCA 改善了生长肥育猪的生长性能，对胴体性状表现出适度的影响，并改善了肌肉蛋白质含量加上葡萄糖。