ABSTRACT

Lactation is a crucial reproductive stage in eutherian mammals and the most energetically and nutritionally expensive part of the life cycle. However, data on lactation parameters in cetaceans remain scattered and incomplete. In this paper, we present novel information on the nutritional compositions and fatty acid (FA) profiles of the milks of two small odontocete species that inhabit coastal waters of the southwest Atlantic Ocean: the endangered Franciscana dolphin (Pontoporia blainvillei) and the Burmeister's porpoise (Phocoena spinipinnis). Milk samples were collected from the fresh carcasses of two lactating females stranded in Argentina. The milk profiles of both species were consistent with existing knowledge on odontocetes worldwide, being characterised by low proportions of carbohydrates and high proportions of proteins and lipids. The FA profiles exhibited a predominance of long-chain FAs (≥18 C), with monounsaturated FAs representing nearly 50% of the total FAs. In both species, the main FAs were 18:1n9 and 16:0, which are common FAs in coastal prey species in this region. These findings are particularly relevant for the conservation of Franciscana dolphins, which are at risk of extinction throughout their distribution range.

摘要

哺乳期是真兽类哺乳动物的关键生殖阶段，也是生命周期中能量和营养最昂贵的部分。然而，关于鲸类动物泌乳参数的数据仍然分散且不完整。在本文中，我们提供了有关栖息在大西洋西南部沿海水域的两种小型齿鲸类动物乳汁的营养成分和脂肪酸 (FA) 特征的新信息：濒危的弗朗西斯卡纳海豚 (Pontoporia blainvillei) 和伯迈斯特海豚(海豚). 牛奶样本是从两只滞留在阿根廷的哺乳期雌性动物的新鲜尸体中采集的。这两个物种的乳汁概况与世界范围内关于齿鲸的现有知识一致，其特征是碳水化合物比例低，蛋白质和脂质比例高。FA 概况显示长链 FA (≥18 C) 占优势，单不饱和 FA 占总 FA 的近 50%。在这两个物种中，主要的 FA 是 18:1n9 和 16:0，这是该地区沿海猎物物种的常见 FA。这些发现与弗朗西斯卡纳海豚的保护特别相关，因为它们在整个分布范围内都面临灭绝的危险。