This study investigated the effects of amino acids (AA) supplementation in low-crude protein (CP) diets on the growth performance and carcass characteristics in late-finishing gilts. Ninety gilts (93.8 ± 5.5 kg) were randomly allotted to one of the five diets which consisted of a normal-CP (137 g/kg) or four low-CP (105 g/kg) diets for 28 days. The low-CP diets were supplemented with lysine + threonine + methionine (LCM), LCM + tryptophan (LCT), LCT + valine (LCV) or LCV + isoleucine (LCI), respectively. Non-significant difference in average daily gain (ADG) was obtained in gilts receiving the control and LCV diet, which was higher than that of gilts fed the LCM diet (p < .05). The additions of crystalline AA in the low-CP diet resulted in the improvements in ADG (linear and quadratic effect, p < .05) and fat-free lean gain (quadratic effect, p < .05) and influenced the valine concentration (linear and quadratic effect, p < .05) and proportion of saturated fatty acid (linear effect, p < .05) in longissimus muscle. The results indicated that the valine supplementation could further improve the performance in 94 to 118 kg gilts fed the 105 g/kg CP diet.

中文翻译：

---

补充结晶氨基酸可改善饲喂低蛋白日粮的后期育成后备母猪的生产性能和胴体性状。

本研究调查了在低粗蛋白 (CP) 日粮中添加氨基酸 (AA) 对后期育肥后备母猪生长性能和胴体特性的影响。90 头母猪 (93.8 ± 5.5 kg) 被随机分配到五种饮食中的一种，其中包括正常 CP (137 g/kg) 或四种低 CP (105 g/kg) 饮食，持续 28 天。低 CP 饮食分别补充了赖氨酸 + 苏氨酸 + 蛋氨酸 (LCM)、LCM + 色氨酸 (LCT)、LCT + 缬氨酸 (LCV) 或 LCV + 异亮氨酸 (LCI)。接受对照和 LCV 日粮的后备母猪的平均日增重 (ADG) 没有显着差异，高于饲喂 LCM 日粮的后备母猪 (p < .05)。在低 CP 饮食中添加结晶 AA 导致 ADG（线性和二次效应，p < .05）和无脂肪瘦肉增重（二次效应，p < .05) 并影响最长肌中的缬氨酸浓度（线性和二次效应，p < .05）和饱和脂肪酸的比例（线性效应，p < .05）。结果表明，缬氨酸补充剂可进一步提高 94 至 118 公斤后备母猪的生产性能，这些后备母猪饲喂 105 克/公斤 CP 日粮。