Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna, Austria.
Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna, Austria.
Poult Sci. 2022 Dec;101(12):102173. doi: 10.1016/j.psj.2022.102173. Epub 2022 Sep 9.
Betaine is a well-known component of poultry diets with various effects on nutritional physiology. For example, increased water retention due to the osmolytic effect of betaine increases the volume of the cell, thereby accelerating the anabolic activity, integrity of cell membrane, and overall performance of the bird. Betaine is a multifunctional component (trimethyl derivative) acting as the most efficient methyl group donor and as an organic osmolyte, which can directly influence the gastrointestinal tract integrity, functionality, and health. So far, nothing is known about the effect of betaine on the intestinal barrier in chickens. In addition, little is known about comparing natural betaine with its synthetic form. Therefore, an animal study was conducted to ascertain the effects of betaine supplementation (natural and synthetic) on performance and intestinal physiological responses of broilers. One hundred and five 1-day-old broiler chicks were randomly assigned into 3 groups with 35 birds each: control, natural betaine (1 kg active natural (n)-betaine/ton of feed) and synthetic (syn)-betaine-HCL (1 kg active betaine /ton of feed). Histological assessment showed lower jejunal crypt depth and villi height/crypt depth ratio in syn-betaine-HCL group compared with natural n-betaine fed birds. Furthermore, it was found that syn-betaine-HCL negatively affects the integrity of the intestine by increasing the intestinal paracellular permeability in both jejunum and cecum as evidenced by a higher mannitol flux. Additionally, syn-betaine-HCl significantly upregulated the IFN-γ mRNA expression at certain time points, which could promote intestinal permeability, as it plays an important role in intestinal barrier dysfunction. Body weight (BW) and body weight gain (BWG) did not differ (P > 0.05) between the control birds and birds supplemented with syn-betaine-HCL. However, the BW and BWG were significantly (P < 0.05) improved by the dietary inclusion of n-betaine compared with other treatments. Altogether, the dietary inclusion of n-betaine had a positive effect on performance and did not negatively affect gut paracellular permeability. Furthermore, our results show that syn-betaine-HCl induces changes in the intestine, indicating an alteration of the intestinal histology and permeability. Thus, natural or synthetic betaine has different effects, which needs to be considered when using them as a feed supplement.
甜菜碱是家禽日粮中一种众所周知的成分，对营养生理学有多种影响。例如，由于甜菜碱的渗透调节作用导致的水潴留增加了细胞体积，从而加速了鸟类的合成代谢活性、细胞膜的完整性和整体性能。甜菜碱是一种多功能成分（三甲基衍生物），可作为最有效的甲基供体和有机渗透物，直接影响胃肠道的完整性、功能和健康。到目前为止，还没有关于甜菜碱对鸡肠道屏障影响的报道。此外，关于比较天然甜菜碱和其合成形式的信息也很少。因此，进行了一项动物研究，以确定甜菜碱（天然和合成）补充对肉鸡性能和肠道生理反应的影响。将 105 只 1 日龄的肉鸡随机分成 3 组，每组 35 只：对照组、天然甜菜碱（饲料中添加 1 公斤活性天然（n）-甜菜碱/吨）和合成（syn）-甜菜碱-HCL（饲料中添加 1 公斤活性甜菜碱/吨）。组织学评估显示，与喂食天然 n-甜菜碱的鸟类相比，syn-甜菜碱-HCL 组的空肠隐窝深度和绒毛高度/隐窝深度比值较低。此外，研究发现 syn-甜菜碱-HCL 通过增加空肠和盲肠的肠细胞旁通透性来损害肠道的完整性，这可以通过甘露醇通量的增加来证明。此外，syn-甜菜碱-HCl 在某些时间点显著上调 IFN-γ mRNA 表达，这可能促进肠道通透性，因为它在肠道屏障功能障碍中起重要作用。体重（BW）和体重增重（BWG）在对照组和补充 syn-甜菜碱-HCL 的鸟类之间没有差异（P > 0.05）。然而，与其他处理相比，日粮中添加 n-甜菜碱显著提高了 BW 和 BWG（P < 0.05）。总之，日粮中添加 n-甜菜碱对性能有积极影响，并且不会对肠道细胞旁通透性产生负面影响。此外，我们的结果表明 syn-甜菜碱-HCl 会引起肠道变化，表明肠道组织学和通透性发生改变。因此，天然或合成甜菜碱具有不同的作用，在将其用作饲料添加剂时需要考虑这些作用。
