Effects of Amino Acid-balanced Low-Protein Diet Supplemented with Glutamate and Arginine on Growth and Serum Indicators of Weaned Piglets
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摘要:
目的 探讨较大程度降低饲粮粗蛋白质（Crude protein，CP）水平后添加必需氨基酸、谷氨酸和精氨酸对断奶仔猪生长性能、腹泻率和血液生化指标的影响。 方法 选用192头（26±2 d）健康的杜长大三元杂交断奶仔猪，随机分成4个处理组，每组设6个重复，每个重复8头猪。Ⅰ组为对照组，饲粮CP水平21.16%；Ⅱ组为低CP（15.97%）补充必需氨基酸（L-赖氨酸、DL-蛋氨酸、L-苏氨酸、L-色氨酸、L-缬氨酸、L-异亮氨酸）饲粮；Ⅲ组在Ⅱ组基础上添加1.5%谷氨酸，Ⅳ组在Ⅱ组基础上添加1.5%谷氨酸和1.0%精氨酸。试验期16 d，试验结束时，采集断奶仔猪结束体重、耗料量、腹泻天数和血液样品，测定仔猪日增重、料重比、腹泻率及血浆生化和激素指标。 结果 仔猪平均日增重（ADG）Ⅱ组显著低于Ⅰ组、Ⅲ组和Ⅳ组（P＜0.05），Ⅲ组、Ⅳ组与Ⅰ组间差异不显著（P＞0.05）。平均日采食量（ADFI）各组间差异均不显著（P＞0.05）。料重比Ⅱ组显著高于其他处理组（P＜0.05）。仔猪腹泻率Ⅱ组显著低于Ⅰ组（P＜0.05），Ⅲ组和Ⅳ组均极显著低于Ⅰ组（P＜0.01），显著低于Ⅱ组（P＜0.05）。仔猪血浆乳酸脱氢酶（LDH）、碱性磷酸酶（ALP）、谷丙转氨酶（GPT）和谷草转氨酶（GOT）活性各组间差异均不显著（P＞0.05），仔猪血浆二胺氧化酶（DAO）活性Ⅱ组比Ⅰ组显著升高（P＜0.05），Ⅲ组和Ⅳ组均显著低于Ⅱ组（P＜0.05），Ⅲ组和Ⅳ组与Ⅰ组相比均差异不显著（P＞0.05）。血浆尿素氮（PUN）浓度Ⅱ组显著低于Ⅰ组、Ⅲ组和Ⅳ组（P＜0.05）。血浆CCK浓度Ⅲ组和Ⅳ组均显著高于Ⅰ组和Ⅱ组（P＜0.05），血浆IGF-1浓度Ⅳ组显著高于Ⅰ组和Ⅱ组（P＜0.05），Ⅰ组、Ⅱ组和Ⅲ组间差异不显著（P＞0.05）。 结论 将饲粮CP水平降低至15.97%，断奶仔猪生长性能受到不利影响，肠道屏障通透性受到不同程度影响，但能降低断奶仔猪腹泻率和血浆PUN浓度；添加谷氨酸后，能够恢复断奶仔猪生长性能，提高胃肠激素水平。因此，断奶后饲喂低蛋白质饲粮并添加重要必需氨基酸和谷氨酸可减少断奶仔猪腹泻，降低肠黏膜屏障通透性，是一种可行的饲喂策略。 Abstract:Objective Effects of a forage with reduced protein and a supplement of essential amino acids, glutamate, and arginine on the growth, diarrhea rate, and serum indicators of weaned piglets were studied. Method One-hundred-ninety-two healthy (26±2)-day-old crossbred piglets (Duroc × Landrace ×Large White) were randomly divided into a control and 3 treatment groups. Each group comprised 6 replicates of 8 piglets. They were fed for 16 days with the following forages containing 21.16% crude protein (CP) as control (Group 1), low-protein of 15.97% CP supplemented with the essential amino acids including L-Lys, DL-Met, L-Thr, L-Thr, L-Val, and L-Ile (Group 2), 15.93% CP with the same added essential amino acid plus 1.5% glutamate (Group 3), and 15.95% CP with the added essential amino acids plus 1.5% glutamate and 1.0% arginine (Group 4). At end of the feeding, body weight, forage consumption, number of days with diarrhea, and blood samples of the piglets were collected for daily gain, feed to weight ratio, diarrhea rate, and plasma biochemicals and hormones determinations. Result The average daily weight gain (ADG) of the piglets in Group 2 was significantly lower than those in other groups (P＜0.05). There were no significant ADG differences among those 3 groups, nor the average daily feed intake (ADFI) among all groups (P＞0.05). The feed/gain (F/G) of Group 2 was significant higher than other groups (P＜0.05). The diarrhea rate of Group 2 piglets was significantly lower than that of Group 1; Group 3 and Group 4 extremely significantly lower than that of Group 1; and Group 3 and Group 4 significantly lower than that of Group 2 (P ＜0.05). The activities of serum LDH, ALP, GPT, and GOT among the 4 groups did not differ significantly (P ＞0.05). The DAO of Group 2 animals was significantly higher than that of Group 1; Group 3 and Group 4 significantly lower than Group 2; while Group 3 and Group 4 not significant differed from Group 1 (P＞0.05). The PUN of Group 2 was significantly lower than the other 3 groups (P＜0.05). The CCK of Group 3 and Group 4 were significantly higher than those of Group 1 and Group 2 (P＜0.05). No significant differences on IGF-1 were found among piglets of Group 1, Group 2, and Group 3, but that of Group 4 higher than those of Group 1 and Group 2 (P＜0.05). Conclusion The reduction of CP to 15.97% in forage could adversely affect the growth as well as the intestinal barrier permeability to varying degrees of the weaned piglets. However, it also reduced the diarrhea rate and plasma PUN of the weaned piglets. Since the addition of glutamate in diet restored the growth and improved the levels of gastrointestinal hormones of piglets, feeding piglets an essential amino acid-balanced, low-protein diet with the supplementation of glutamate could be a plausible strategy to mitigate the occurrences of diarrhea and interference on the intestinal mucosal barrier permeability in the animals after weaning. -
Key words:
- Glutamate /
- arginine /
- growth performance /
- serum indicators /
- low-protein diet /
- weaned piglets
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表 1 饲粮组成与营养水平（风干基础）
Table 1. Nutritional composition of basal diets (air-dry basis) （单位： %）
项目
ItemsⅠ组 (CK)
Group ⅠⅡ组
Group ⅡⅢ组
Group ⅢⅣ组
Group Ⅳ原料 Ingredient 玉米 Corn 35.12 48.00 47.00 45.00 豆粕 Soybean meal 15.00 6.30 6.20 6.60 膨化大豆 Extruded soybean 18.00 11.00 12.00 12.00 麦麸 Wheat bran 1.70 鱼粉 Fish meal 7.00 7.00 7.00 7.00 乳清粉 Whey powder 16.00 16.00 16.00 16.00 蔗糖 Sucrose 2.00 2.00 2.00 2.00 柠檬酸 Citric acid 2.00 2.00 2.00 2.00 豆油 Soybean oil 2.50 2.26 2.56 3.15 石粉 Lime stone 0.30 0.32 0.23 0.47 磷酸氢钙 CaHPO4 0.54 0.72 0.82 0.60 食盐 NaCl 0.30 0.30 0.30 0.30 氯化胆碱 Choline chloride (50%) 0.08 0.08 0.08 0.08 L-赖氨酸盐酸盐 L-lysine·HCl 0.03 0.47 0.46 0.46 DL-蛋氨酸 DL-methionine 0.09 0.24 0.24 0.24 L-苏氨酸 L-threonine 0.03 0.23 0.23 0.23 L-色氨酸 L-tryptophan 0.01 0.08 0.08 0.08 L-缬氨酸 L-valine 0.16 0.16 0.15 L-异亮氨酸 L-isoleucine 0.14 0.14 0.14 L-谷氨酸 L-glutamate 1.50 1.50 L-精氨酸 L-arginine 1.00 ①预混料 Premix 1.00 1.00 1.00 1.00 合计 Total 100.00 100.00 100.00 100.00 ②营养水平 Nutrient levels 消化能 Digestible energy/ (MJ·kg−1) 14.99 14.42 14.39 14.39 净能 Net energy/（MJ·kg−1） 10.55 10.54 10.53 10.54 粗蛋白质 Crude protein 21.16 15.97 15.93 15.95 标准回肠可消化氨基酸
Standardized ileal digestible amino acids赖氨酸 Lys 1.30 1.30 1.30 1.30 蛋氨酸 Met 0.46 0.54 0.54 0.54 蛋氨酸+胱氨酸 Met+Cys 0.78 0.78 0.78 0.78 苏氨酸 Thr 0.85 0.85 0.85 0.85 色氨酸 Trp 0.26 0.26 0.26 0.26 缬氨酸 Val 0.97 0.88 0.88 0.88 异亮氨酸 Ile 0.88 0.78 0.78 0.78 亮氨酸 Leu 1.66 1.32 1.32 1.32 谷氨酸 Glu 3.60 2.67 4.15 4.16 精氨酸 Arg 1.36 0.95 0.95 1.95 ①每千克饲粮提供：维生素A 12500 IU，维生素D3 2500 IU，维生素E 80.00 mg，维生素K3 3.00 mg，维生素B1 2.50 mg，维生素B2 10.00 mg，维生素B6 3.00 mg，维生素B12 0.035 mg，烟酸 30.00 mg，泛酸 15.00 mg，叶酸 0.45 mg，生物素 0.50 mg，铁 140 mg，铜15 mg，锌140 mg，锰30 mg， 碘0.50 mg，硒0.25 mg；②粗蛋白质为实测值，其他营养指标为计算值。
① Premix provided following nutrients per kg of forage: VA 12 500 IU, VD3 2 500 IU, VE 80.00 mg, VK3 3.00 mg, VB1 2.50 mg, VB2 10.00 mg, VB6 3.00 mg, VB12 0.035 mg, nicotinic acid 30.00 mg, pantothenic acid 15.00 mg, folic acid 0.45 mg, biotin 0.50 mg, Fe 140.00 mg, Cu 15.00 mg, Zn 140.00 mg, Mn 30.00 mg, I 0.50 mg, Se 0.25 mg；② CP is a measured value; others, calculated.
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表 2 低蛋白质饲粮添加谷氨酸和精氨酸对断奶仔猪生长性能和腹泻率的影响
Table 2. Effect of low-protein diet supplemented with glutamate and arginine on growth and diarrhea rate of weaned piglets
项目
ItemsⅠ组
Group ⅠⅡ组
Group ⅡⅢ组
Group ⅢⅣ组
Group Ⅳ初始体重 IBW/kg 6.95±0.23 6.85±0.26 6.98±0.32 7.07±0.35 结束体重 FBW/kg 12.25±0.57 11.79±0.65 12.32±0.76 12.38±0.72 平均日增重 ADG/（g·d−1） 331.25±38.62 a 308.75±42.13 b 333.75±48.26 a 331.88±47.47 a 平均日采食量 ADFI/（g·d−1） 460.48±37.55 457.62±36.48 460.63±42.39 459.28±51.13 料重比 F/G 1.39±0.25 b 1.48±0.19 a 1.38±0.21 b 1.38±0.22 b 腹泻率 Diarrhea rate/% 5.21±2.35 Aa 3.65±1.04 ABb 1.96±1.62 Bc 2.17±0.98 Bc 同行数据后不同小写字母表示差异显著（P ＜0.05），不同大写字母表示差异极显著（P ＜0.01），相同字母或无字母表示差异不显著（P＞0.05），下表同。
Data with different lowercase letters on same row indicate significant difference at P＜0.05; those with different capital letters, extremely significant difference at P＜0.01; those with same or no letter, no significant difference at P＞0.05. Same for tables below.
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表 3 低蛋白质饲粮添加谷氨酸和精氨酸对断奶仔猪血浆生化指标的影响
Table 3. Effect of low-protein diet supplemented with glutamate and arginine on serum indicators of weaned piglets
项目 Items Ⅰ组 Group Ⅰ Ⅱ组 Group Ⅱ Ⅲ组 Group Ⅲ Ⅳ组 Group Ⅳ 乳酸脱氢酶 LDH/(U·L−1) 2058.12±250.54 2029.82±154.37 1960.14±238.70 2060.04±236.78 碱性磷酸酶 ALP/(U·L−1) 17.06±3.28 21.28±2.50 21.49±1.86 18.85±3.64 谷丙转氨酶 GPT/(U·L−1) 16.51±1.74 19.03±1.02 16.76±1.25 15.77±0.93 谷草转氨酶 GOT/(U·L−1) 8.36±0.48 9.76±0.48 9.58±0.73 10.43±1.13 二胺氧化酶 DAO/(U·L−1) 17.24±2.25 b 20.86±1.34 a 17.07±1.14 b 16.33±1.23 b 尿素氮 PUN/(mmol·L−1) 2.14±0.40 a 1.15±0.29 b 1.95±0.40 a 2.06±0.29 a
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表 4 低蛋白质饲粮添加谷氨酸和精氨酸对断奶仔猪血浆激素指标的影响
Table 4. Effect of low-protein diet supplemented with glutamate and arginine on serum hormone indicators of weaned piglets
项目 Items Ⅰ组 Group Ⅰ Ⅱ组 Group Ⅱ Ⅲ组 Group Ⅲ Ⅳ组 Group Ⅳ 胰岛素样生长因子-1 IGF-1/(ng·mL−1) 93.12±5.57 a 84.35±3.9 b 92.57±3.87 a 96.70±6.86 a 胆囊收缩素 CCK/(ng·L−1) 179.55±12.23 b 182.30±14.91 b 237.32±15.11 a 234.78±15.78 a
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