Faculty of Pharmacy, Federal University of Bahia, Salvador, Brazil.
School of Veterinary Medicine and Animal Sciences, Department of Animal Science, Federal University of Bahia, Salvador, Brazil.
J Anim Physiol Anim Nutr (Berl). 2021 Nov;105(6):1173-1178. doi: 10.1111/jpn.13513. Epub 2021 Mar 18.
The aim of this study was to characterize and determine how days in milk (DIM) affect the milk fatty acid (FA) profile of grazing donkeys. Donkey milk is very similar to human milk, containing bioactive molecules such as FA and proteins. However, there is a lack of scientific and technical information on the changes in the FA profile of asinine milk in pasture-feeding systems. Seven multiparous Pega donkeys, maintained in an exclusively extensive system, were used. Milking was undertaken twice a day, once a week for 16 weeks. Milk samples were composed according to the average lactating days as follows: 55, 110, 165, 220 and 275 DIM. A descriptive analysis of the milk fat composition was performed, and the linear and quadratic effects of DIM on the milk FA profile were tested. The milk FA profile of grazing donkeys is influenced by lactation days and is characterized by high concentrations of polyunsaturated FA (PUFA) with a low n-6 to n-3 ratio (0.66 g/100 g), mainly due to the high level of linolenic acid (16.8 g/100 g). Most of the individual FAs did not change during lactation, but stearic and oleic acid linearly decreased (p < .05), and total polyunsaturated FA (PUFA) and n-3 FA increased (p < .05) with DIM. The milk profile of grazing donkeys is influenced by the day of lactation and is characterized by a high concentration of n-3 PUFA (mainly α-linolenic acid) and a lower n-6 to n-3 ratio. As the number of days of lactation increased, the concentration of n-3 PUFA also increased. Therefore, higher milk quality may be associated with higher days in milk.
本研究旨在描述和确定奶牛在泌乳天数（DIM）如何影响放牧驴的乳脂肪酸（FA）谱。驴乳与人类乳非常相似，含有生物活性分子，如 FA 和蛋白质。然而，关于放牧系统中驴乳 FA 谱的变化，缺乏科学和技术信息。使用了 7 头处于完全粗放系统中的多胎母驴。每周挤奶两次，持续 16 周。根据平均泌乳天数将乳样组合如下：55、110、165、220 和 275 DIM。对乳脂组成进行了描述性分析，并测试了 DIM 对乳 FA 谱的线性和二次效应。放牧驴的乳 FA 谱受泌乳天数的影响，并具有高浓度多不饱和 FA（PUFA）和低 n-6/n-3 比值（0.66 g/100 g）的特点，主要是由于亚麻酸水平较高（16.8 g/100 g）。大多数个体 FA 在泌乳期间没有变化，但硬脂酸和油酸呈线性下降（p <.05），总多不饱和 FA（PUFA）和 n-3 FA 随 DIM 增加（p <.05）。放牧驴的乳谱受泌乳天数的影响，其特点是 n-3 PUFA（主要是α-亚麻酸）浓度高，n-6/n-3 比值低。随着泌乳天数的增加，n-3 PUFA 的浓度也增加。因此，更高的乳质量可能与更高的泌乳天数有关。
