Metzler-Zebeli Barbara U, Sener-Aydemir Arife, Sharma S, Lerch Frederike
Unit of Nutritional Physiology, Department of Biomedical Sciences, University of Veterinary Medicine Vienna, 1210 Vienna, Austria.
Christian-Doppler Laboratory for Innovative Gut Health Concepts of Livestock, University of Veterinary Medicine Vienna, 1210 Vienna, Austria.
J Anim Sci. 2021 Jul 1;99(7). doi: 10.1093/jas/skab171.
Despite their anti-inflammatory properties, role in barrier function, absorption and microbial balance in the gut, knowledge on maturational and dietary effects on intestinal short-chain fatty acids (SCFA) in neonatal piglets is scarce. Moreover, little information exists whether SCFA and lactic acid (LA) modulates gut motility at this age. The present study aimed (1) to investigate the maturational changes in the SCFA profile with and without creep feeding of piglets in the first 3 wk of life; and (2) to examine the effects of SCFA and LA on muscle contractibility in jejunal tissue from neonatal piglets ex vivo. SCFA concentrations were measured in fecal samples of 52 piglets from 10 litters collected on days 2, 6, 13, and 20 of life using gas chromatography. Half of the litters were fed a commercial creep feed from day 10 of life. The organ bath system was used to test the effect of SCFA (acetate, propionate, butyrate, isobutyrate, valerate, isovalerate, and caproate) as well as of LA and the combination of LA and SCFA on muscle contractibility in piglet's jejunum. Average daily gain of piglets was similar between groups before and after introduction of creep feed. SCFA were detectable in feces in relevant concentrations from day 2 of life and increased on day 6 in males by 3.0-fold and on day 13 in females by 1.6-fold but decreased again on day 20 in both sexes compared with day 2 (P < 0.05). Creep feeding reduced fecal SCFA by 0.6-fold on day 13 without largely modifying molar proportions, whereas it increased fecal SCFA by 0.8-fold on day 20 of life compared with the sow-reared only piglets (P < 0.05). Applying SCFA ex vivo increased the muscle contraction of the jejunum by 30% (P < 0.05). Likewise, addition of LA and the combination of LA and SCFA increased the jejunal muscle contractibility by 34.9% and 32.2%, respectively, compared with the muscle tension preaddition (P < 0.05). In conclusion, the present results for fecal SCFA in first days of life suggest high bacterial activity on milk components and emphasize the importance of SCFA for intestinal development and function. After a lag phase, creep feeding promotes fermentation in the distal colon, which may be beneficial for the gut homeostasis. Results further demonstrate the stimulating effect of SCFA and LA for jejunal motility, suggesting a role for mixing of digesta (segmentation) and digestion and absorption of nutrients as well as passage in the jejunum of neonatal piglets.
尽管短链脂肪酸具有抗炎特性，在肠道屏障功能、吸收及微生物平衡方面发挥作用，但关于新生仔猪肠道短链脂肪酸（SCFA）成熟及饮食影响的知识却很匮乏。此外，关于这个年龄段SCFA和乳酸（LA）是否调节肠道蠕动的信息也很少。本研究旨在：（1）调查出生后前3周有或没有补饲的仔猪SCFA谱的成熟变化；（2）体外研究SCFA和LA对新生仔猪空肠组织肌肉收缩性的影响。使用气相色谱法测定了来自10窝52头仔猪在出生第2、6、13和20天采集的粪便样本中的SCFA浓度。一半的仔猪从出生第10天开始喂商业补饲饲料。采用器官浴系统测试SCFA（乙酸盐、丙酸盐、丁酸盐、异丁酸盐、戊酸盐、异戊酸盐和己酸盐）以及LA和LA与SCFA组合对仔猪空肠肌肉收缩性的影响。在引入补饲饲料前后，各组仔猪的平均日增重相似。从出生第2天开始就能在粪便中检测到相关浓度的SCFA，雄性仔猪在第6天SCFA浓度增加了3.0倍，雌性仔猪在第13天增加了1.6倍，但与第2天相比，两性在第20天又再次下降（P<0.05）。补饲在第13天使粪便SCFA减少了0.6倍，且未大幅改变摩尔比例，而与仅由母猪饲养的仔猪相比，在出生第20天补饲使粪便SCFA增加了0.8倍（P<0.05）。体外应用SCFA使空肠肌肉收缩增加了30%（P<0.05）。同样，与添加前的肌肉张力相比，添加LA以及LA与SCFA的组合分别使空肠肌肉收缩性增加了34.9%和32.2%（P<0.05）。总之，本研究关于出生后最初几天粪便SCFA的结果表明，细菌对乳成分具有高活性，并强调了SCFA对肠道发育和功能的重要性。经过一个滞后期后，补饲促进远端结肠的发酵，这可能有利于肠道内环境稳定。结果进一步证明了SCFA和LA对空肠蠕动的刺激作用，表明其在新生仔猪空肠中对食糜混合（分节运动）、营养物质消化吸收以及通过方面发挥作用。
