Animal Nutrition, Institute of Agrifood Research and Technology (IRTA), E-43120 Constantí, Spain.
Animal Health-CReSA, Institute of Agrifood Research and Technology (IRTA), E- 08193 Bellaterra, Spain.
Animal. 2024 Oct;18(10):101317. doi: 10.1016/j.animal.2024.101317. Epub 2024 Aug 23.
Weaning is a decisive event in piglets' life. This study aimed to evaluate whether the inclusion of fish oil, rich in eicosapentaenoic and docosahexaenoic acids (EPA and DHA), in sow and piglet diets, increased the concentration of anti-inflammatory molecules in the blood of weaned piglets and whether the effect was dependent on the pigs being born with either low or a high birth BW (bBW). Thirty-six sows in four consecutive batches were randomly distributed between a control diet with animal fat (15 g/kg in gestation and 30 g/kg in lactation) or a n-3 long-chain fatty acid diet (LCFA; totally or half replacing animal fat by fish oil during gestation and lactation, respectively) from service until weaning (ca. 28 days). At birth, the two lightest (LBW) and the two heaviest (HBW) piglets in each litter were identified and, at weaning, grouped in pens by pairs prioritising their bBW. Pens were further distributed into a control (30 g/kg animal fat) or n-3 LCFA diet (totally replacing animal fat by fish oil) for 28 days. At the end of the trial, blood was collected from piglets in the first batch (n = 48). Serum fatty acids (FAs) were quantified by GC, plasma oxylipins by ultra-HPLC-MS, and plasma immune indicators by ELISA. An interaction between piglet diet and bBW for average daily gain (P = 0.020) and average daily feed intake (P = 0.014) during the whole postweaning indicated that dietary n-3 LCFA-promoted LBW piglets to have a similar growth and intake than HBW piglets reaching 1.5 kg average BW more at the end of the postweaning period than LBW control piglets. Fish oil in piglet diets also increased the concentrations of total n-3 FA, EPA and DHA (all P < 0.001), their resultant oxylipins, particularly their hydroxy derivatives from lipoxygenase enzymatic pathway (all P < 0.001) and tended to increase immunoglobulin M (P = 0.067) in blood. Regarding the bBW category, LBW piglets tend to increase tumour necrosis factor α in plasma (P = 0.083) compared to HBW. It is concluded that fish oil in postweaning diets could enhance the daily gain and feed intake of LBW piglets, increasing the concentration of serum n-3 FAs and their derived oxylipins in plasma.
断奶是仔猪生命中的一个决定性事件。本研究旨在评估在母猪和仔猪日粮中添加富含二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）的鱼油是否会增加断奶仔猪血液中的抗炎分子浓度，以及这种效果是否取决于仔猪出生时的低出生体重（bBW）或高出生体重（HBW）。
从配种到断奶（约 28 天），36 头母猪在连续 4 批中被随机分配到含有动物脂肪的对照组（妊娠 15g/kg，哺乳期 30g/kg）或含有 n-3 长链脂肪酸的日粮组（LCFA；分别在妊娠和哺乳期通过鱼油完全或部分替代动物脂肪）。在出生时，每个窝中体重最轻的（LBW）和体重最重的（HBW）的两头仔猪被识别出来，并在断奶时按 bBW 优先配对分组。每个围栏进一步分配到对照组（30g/kg 动物脂肪）或 n-3 LCFA 日粮（完全用鱼油替代动物脂肪），持续 28 天。在试验结束时，从第一批仔猪（n=48）中采集血液。血清脂肪酸（FA）通过 GC 定量，血浆氧化脂质通过超高效液相色谱-质谱法，血浆免疫指标通过 ELISA 定量。仔猪日粮和 bBW 之间的相互作用表明，在整个断奶后阶段，平均日增重（P=0.020）和平均日采食量（P=0.014）存在差异，表明日粮中的 n-3 LCFA 促进了 LBW 仔猪的生长和采食量，与 HBW 仔猪相比，在断奶后阶段结束时，体重增加了 1.5kg，比 LBW 对照组仔猪多 1.5kg。
仔猪日粮中的鱼油还增加了总 n-3 FA、EPA 和 DHA 的浓度（均 P<0.001），以及它们的氧化产物，特别是来自脂氧合酶酶途径的羟基衍生物（均 P<0.001），并倾向于增加血液中的免疫球蛋白 M（P=0.067）。关于 bBW 类别，LBW 仔猪的血浆肿瘤坏死因子 α 有增加的趋势（P=0.083）。
综上所述，断奶后日粮中的鱼油可以提高 LBW 仔猪的日增重和采食量，增加血清 n-3 FA 的浓度及其在血浆中的衍生氧化脂质。
