Partanen K H, Mroz Z
Institute for Animal Science and Health (ID-DLO), Department of Nutrition of Pigs and Poultry, PO Box 65, 8200 AB Lelystad, The Netherlands. kirsi.partanen@mtt
Nutr Res Rev. 1999 Jun;12(1):117-45. doi: 10.1079/095442299108728884.
Organic acids and their salts appear to be potential alternatives to prophylactic in-feed antibiotics and growth promoters in order to improve the performance of weaned piglets, fattening pigs and reproductive sows, although their growth-promoting effects are generally less than that of antibiotics. Based on an analysis of published data, the growth-promoting effect of formates, fumarates and citrates did not differ in weaned piglets. In fattening pigs, formates were the most effective followed by fumarates, whereas propionates did not improve growth performance. These acids improved the feedgain ratio of both weaned piglets and fattening pigs. In weaned piglets, the growth-promoting effects of dietary organic acids appear to depend greatly on their influence on feed intake. In sows, organic acids may have anti-agalactia properties. Successful application of organic acids in the diets for pigs requires an understanding of their modes of action. It is generally considered that dietary organic acids or their salts lower gastric pH, resulting in increased activity of proteolytic enzymes and gastric retention time, and thus improved protein digestion. Reduced gastric pH and increased retention time have been difficult to demonstrate, whereas improved apparent ileal digestibilities of protein and amino acids have been observed with growing pigs, but not in weaned piglets. Organic acids may influence mucosal morphology, as well as stimulate pancreatic secretions, and they also serve as substrates in intermediary metabolism. These may further contribute to improved digestion, absorption and retention of many dietary nutrients. Organic acid supplementation reduces dietary buffering capacity, which is expected to slow down the proliferation and|or colonization of undesirable microbes, e.g. Escherichia coli, in the gastro-ileal region. However, reduced scouring has been observed in only a few studies. As performance responses to dietary organic acids in pigs often varies, more specific studies are necessary to elucidate an explanation.
有机酸及其盐类似乎是预防性饲料抗生素和生长促进剂的潜在替代品，可用于提高断奶仔猪、育肥猪和繁殖母猪的生产性能，尽管它们的促生长效果通常不如抗生素。基于对已发表数据的分析，在断奶仔猪中，甲酸盐、富马酸盐和柠檬酸盐的促生长效果没有差异。在育肥猪中，甲酸盐最有效，其次是富马酸盐，而丙酸盐并不能提高生长性能。这些酸提高了断奶仔猪和育肥猪的料重比。在断奶仔猪中，日粮有机酸的促生长效果似乎很大程度上取决于它们对采食量的影响。在母猪中，有机酸可能具有防止无乳的特性。要在猪日粮中成功应用有机酸，需要了解它们的作用方式。一般认为，日粮中的有机酸或其盐类会降低胃内pH值，从而导致蛋白水解酶活性增加和胃内停留时间延长，进而改善蛋白质消化。胃内pH值降低和停留时间延长很难得到证实，而在生长猪中观察到蛋白质和氨基酸的回肠表观消化率有所提高，但在断奶仔猪中未观察到。有机酸可能会影响黏膜形态，还会刺激胰腺分泌，并且它们也可作为中间代谢的底物。这些可能会进一步有助于改善许多日粮营养物质的消化、吸收和保留。补充有机酸会降低日粮的缓冲能力，这有望减缓胃肠道区域中不良微生物（如大肠杆菌）的增殖和/或定殖。然而，只有少数研究观察到腹泻减少。由于猪对日粮有机酸的生产性能反应往往各不相同，因此需要更具体的研究来阐明原因。
