Department of Animal Science, Aarhus University, Tjele, Denmark.
Food Funct. 2021 Nov 15;12(22):11625-11640. doi: 10.1039/d1fo02092g.
The increasing world population with improved living conditions has increased the demand for food protein. This has intensified the search for sustainable alternative plant-derived high-quality protein sources for human nutrition. To study the effect of plant and milk proteins on growth in weaned pigs as a model for humans, 96 weaned pigs were divided into 48 pens and fed one of 4 different diets for 3 weeks. The dietary protein originated from either 50% rice + 50% 00-rapeseed protein (RICE + RAPE), 50% milk protein (MPC) + 50% 00-rapeseed protein (MPC + RAPE), 50% milk + 50% rice protein (MPC + RICE), or 100% MPC, and were supplemented with crystalline amino acids to meet the amino acid requirements. Weekly feed intake and body weights were recorded and after 3 weeks, a blood sample was taken 1 hour after a fixed meal, while organ weights were measured, and liver- and muscle tissue, and bone samples were collected at euthanasia. All pigs had a high daily gain and a low feed-to-gain ratio (F : G, feed intake per kg weight gain), but feed intake and daily gain was lowest and F : G highest in the RICE + RAPE diet. Metacarpal bones were longer and heavier in MPC + RICE and MPC fed pigs compared to pigs fed diet RICE + RAPE ( < 0.05), and intermediate in MPC + RAPE fed pigs, with no differences in bone thickness ( > 0.05). Plasma levels of all essential amino acids except Cys and Lys decreased markedly when fed a diet containing only plant protein. The differences were not associated with differences in plasma insulin or IGF-1, nor in the abundance of mRNA related to growth in liver and longissimus dorsi muscle. In conclusion, the growth of piglets fed a combination of milk and rice protein did not differ from the pure dairy-based diet, whereas the pure plant-based diet consisting of rice and rapeseed protein led to reduced growth. This was most likely caused by a lower feed intake and a lower than expected amino acid digestibility of the 00-rapeseed protein. There were no indications that the milk protein, beyond a favourable amino acid composition and high digestibility, specifically stimulated growth factors or other biomarkers of growth the IGF-1 and insulin signalling pathways.
随着生活条件的改善，世界人口不断增加，人们对食物蛋白质的需求也在增加。这使得人们更加迫切地需要寻找可持续的、替代植物来源的高质量蛋白质资源，以满足人类营养需求。为了研究植物蛋白和牛奶蛋白对断奶仔猪生长的影响，我们以断奶仔猪为模型进行了这项研究。将 96 头断奶仔猪分为 48 个栏，用 4 种不同的日粮喂养 3 周。日粮中的蛋白质分别来源于 50%大米+50%00-油菜籽蛋白（RICE+RAPE）、50%牛奶蛋白（MPC）+50%00-油菜籽蛋白（MPC+RAPE）、50%牛奶+50%大米蛋白（MPC+RICE）或 100%MPC，并用结晶氨基酸进行补充，以满足氨基酸的需求。每周记录饲料摄入量和体重，3 周后，在固定膳食 1 小时后采集血样，同时测量器官重量，并在安乐死后采集肝脏、肌肉组织和骨骼样本。所有仔猪的日增重和饲料增重比（F：G，每公斤体重的饲料摄入量）都很高，但在 RICE+RAPE 日粮中，仔猪的采食量和日增重最低，F：G 最高。与饲喂 RICE+RAPE 日粮的仔猪相比，饲喂 MPC+RICE 和 MPC 日粮的仔猪的掌骨更长、更重（<0.05），而饲喂 MPC+RAPE 日粮的仔猪的掌骨长度则处于中间水平，且骨厚度无差异（>0.05）。只饲喂植物蛋白的日粮会显著降低所有必需氨基酸（除 Cys 和 Lys）的血浆水平。这些差异与血浆胰岛素或 IGF-1 水平的差异无关，也与肝脏和背最长肌中与生长相关的 mRNA 丰度的差异无关。总之，饲喂牛奶和大米蛋白组合日粮的仔猪的生长情况与纯牛奶基日粮没有差异，而仅由大米和油菜籽蛋白组成的纯植物基日粮则导致生长速度下降。这很可能是由于采食量较低，以及油菜籽蛋白的氨基酸消化率低于预期。没有迹象表明，牛奶蛋白除了具有良好的氨基酸组成和高消化率外，还能特异性地刺激生长因子或 IGF-1 和胰岛素信号通路等其他生长标志物。
