Department of Agricultural, Food and Environmental Sciences, University of Perugia, Borgo XX Giugno, 74, 06121 Perugia, Italy.
Department Veterinary medicine, Università degli Studi di Perugia, via San Costanzo, 4, 06126 Perugia, Italy.
Animal. 2019 Sep;13(9):1934-1942. doi: 10.1017/S175173111900020X. Epub 2019 Feb 18.
Standard feeds are imbalanced in term of n-6/n-3 polyunsaturated fatty acids (PUFA) ratio, with a low proportion of the latter. The reproductive system appears to be strongly affected by administration of n-3 PUFA, and ingredients rich in α-linolenic acid (ALA; i.e. vegetable sources) or EPA and DHA acids (i.e. fish oil) can be included in animal diets to balance PUFA intake. The aim of this study was to evaluate the effect of dietary supplementation with flaxseed (ALA) or fish oil (EPA and DHA) on PUFA metabolism in rabbit does. A total of 60 New Zealand White female rabbits were assigned to three experimental groups: control group, FLAX group fed 10% extruded flaxseed and FISH group fed 3% fish oil. Blood, milk, liver and ovaries were collected from the does to assess the lipid composition; furthermore, FADS2 gene expression was assessed in liver and ovary tissues. Reproductive performance of does was also recorded. The fertility rate and number of weaned rabbits improved with n-3 dietary supplementation: does at first parity showed the lowest reproductive results, but the administration of n-3 reduced the gap between primiparous and multiparous does. Feed consumption and milk production were not affected by the feeding regime. The fatty acid composition of milk, plasma, liver and ovaries were widely influenced by diet, showing higher concentrations of n-3 long-chain PUFA (LCP) in does fed with n-3 enriched diets. FISH diet resulted in the highest n-3 LCP enrichment, whereas in the FLAX group, this increase was lower. Blood and milk showed low levels of LCP, whereas liver and ovaries were the main sites of n-3 LCP synthesis and accumulation. Accordingly, although the liver is the main metabolic centre for LCP synthesis, ovaries also have a prominent role in LCP generation. FADS2 expression in liver and ovary tissue was downregulated by FISH administration. In conclusion, the enrichment of diets with n-3 PUFA could be an effective strategy for improving the reproductive performance of does.
标准饲料在 n-6/n-3 多不饱和脂肪酸（PUFA）比例方面是不平衡的，后者的比例较低。生殖系统似乎受到 n-3 PUFA 给药的强烈影响，并且可以在动物饮食中添加富含 α-亚麻酸（ALA；即植物来源）或 EPA 和 DHA 酸（即鱼油）的成分来平衡 PUFA 摄入。本研究的目的是评估日粮补充亚麻籽（ALA）或鱼油（EPA 和 DHA）对母兔 PUFA 代谢的影响。总共将 60 只新西兰白母兔分配到三个实验组：对照组、饲喂 10%膨化亚麻籽的 FLAX 组和饲喂 3%鱼油的 FISH 组。从母兔身上采集血液、牛奶、肝脏和卵巢来评估脂质组成；此外，还评估了肝脏和卵巢组织中 FADS2 基因的表达。还记录了母兔的繁殖性能。n-3 日粮补充提高了母兔的受胎率和断奶仔兔数量：初产母兔的繁殖效果最低，但 n-3 的给药缩小了初产和经产母兔之间的差距。饲料采食量和产奶量不受饲养方式的影响。日粮广泛影响牛奶、血浆、肝脏和卵巢的脂肪酸组成，饲喂富含 n-3 的日粮的母兔血液中 n-3 长链多不饱和脂肪酸（LCP）浓度更高。FISH 日粮导致 n-3 LCP 富集最高，而在 FLAX 组中，这种增加较低。血液和牛奶中 LCP 水平较低，而肝脏和卵巢是 n-3 LCP 合成和积累的主要部位。因此，尽管肝脏是 LCP 合成的主要代谢中心，但卵巢在 LCP 生成中也起着重要作用。FADS2 在肝脏和卵巢组织中的表达受 FISH 给药的下调。总之，用 n-3 PUFA 丰富饮食可能是提高母兔繁殖性能的有效策略。
