Animal Nutrition and Welfare Service, Department of Animal and Food Science, Facultat de Veterinària, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona, Spain.
Nutrition, Food Science and Gastronomy Department - XaRTA-INSA, Facultat de Farmàcia i Ciències de l'Alimentació, Universitat de Barcelona, Joan XXIII, 27-31, E-08028 Barcelona, Spain.
Poult Sci. 2019 Mar 1;98(3):1341-1353. doi: 10.3382/ps/pey458.
The aim of the present study is to evaluate the effect of the dietary fat saturation degree and age on the lipid class (TAG, DAG, MAG, and FFA) composition and fatty acid digestibility along the gastrointestinal tract (GIT) and excreta in broiler chickens. A total of 120 one-day-old female broiler chickens were randomly distributed in 2 dietary treatments (6 cages/treatment), which resulted from the supplementation of a basal diet with 6% of soybean oil or palm oil. Two digestibility balances were carried out at 14 and 35 d and fatty acid digestibility and lipid class composition were determined in the gizzard, duodenum, jejunum, ileum, and excreta. Along de GIT, both fatty acid digestibility and lipid class composition were influenced by the dietary fat source and the age of the chickens. The absorption of the unsaturated fat was more efficient and faster than it was for the saturated fat. The ability of adult chickens to absorb fat was higher than for young chickens. The results show that the duodenum is the main place of fat digestion (hydrolysis), and the jejunum the main place of fat absorption. The role of the ileum on fat absorption is very important, as it is the last segment of the GIT where the absorption of fatty acids has been described. Thus, it was the contribution of the ileum that was responsible for the higher fat utilization observed for animals fed the unsaturated diet than for those fed the saturated diet at 14 d, and it was also responsible for the improvement on the utilization of the saturated diet between 14 and 35 d. All the results suggest that the absorption of fatty acids is more limiting than is hydrolysis, because the main differences were observed in the jejunum and ileum, where the absorption of fatty acids takes place.
本研究旨在评估饲粮脂肪饱和度和鸡龄对肉鸡胃肠道（GIT）和粪便中脂质（TAG、DAG、MAG 和 FFA）组成和脂肪酸消化率的影响。共将 120 只 1 日龄雌性肉鸡随机分为 2 个饲粮处理（每个处理 6 个重复），饲粮中分别添加 6%大豆油或棕榈油。14 和 35 日龄时进行 2 次消化平衡试验，测定肌胃、十二指肠、空肠、回肠和粪便中脂肪酸消化率和脂质组成。沿 GIT，脂肪酸消化率和脂质组成均受饲粮脂肪源和鸡龄的影响。不饱和脂肪的吸收比饱和脂肪更有效和更快。成年鸡吸收脂肪的能力高于雏鸡。结果表明，十二指肠是脂肪消化（水解）的主要部位，空肠是脂肪吸收的主要部位。回肠在脂肪吸收中的作用非常重要，因为它是 GIT 的最后一段，已经描述了脂肪酸的吸收。因此，14 日龄时，与饲喂饱和脂肪饲粮的动物相比，饲喂不饱和脂肪饲粮的动物的脂肪利用率较高，这主要是由于回肠的贡献，而在 14-35 日龄之间，饱和脂肪饲粮利用率的提高也是由于回肠的作用。所有结果均表明，脂肪酸的吸收比水解更具限制性，因为主要差异出现在空肠和回肠，而脂肪酸的吸收发生在这两个部位。
