Department of Animal Science, Iowa State University, Ames 50011.
Department of Animal and Poultry Science, Virginia Tech, Blacksburg 24061.
Poult Sci. 2017 Jun 1;96(6):1791-1799. doi: 10.3382/ps/pew462.
When laying hen diets are enriched with omega-3 polyunsaturated fatty acids to generate value-added eggs for human consumption markets, concentrations of alpha-linolenic (ALA), eicosapentaenoic (EPA), and docosahexaenoic acids (DHA) in the yolk can reach 250 mg/50 g whole egg. Flaxseed, a rich source of ALA, is commonly used for omega-3 enrichment; however, the impact of dietary flaxseed source (extracted oil vs. milled seed) on fatty acid transfer to egg yolk in laying hens is unknown. Therefore, transfer of ALA, EPA, and DHA into egg yolk from extracted flaxseed oil or milled flaxseed was evaluated in Hy-Line W-36 laying hens over an 8-week feeding period (25 to 33 wk old). Hens (n = 132) were randomly housed with 3 birds/cage (4 replicates/treatment) for each of the 11 treatment groups. Diets were isocaloric and consisted of a control diet, 5 flaxseed oil diets (0.5, 1.0, 2.0, 3.0, or 5.0% flaxseed oil), and 5 milled flaxseed diets (calculated flaxseed oil concentration from milled flaxseed 0.5, 1.0, 2.0, 3.0, 5.0%). Increasing dietary concentrations of flaxseed oil and milled flaxseed resulted in increased ALA, EPA, and DHA concentration in egg yolk, and fatty acid deposition from flaxseed oil was 2 times greater compared to milled flaxseed when fed at the same dietary inclusions (P < 0.01). Egg yolk EPA and DHA concentrations were not different due to oil or milled source (P = 0.21); however, increasing dietary inclusion rates of flaxseed oil from either source increased yolk EPA and DHA (P < 0.01). Hens fed either flaxseed oil or milled flaxseed resulted in reduced BW change as dietary concentrations increased (P = 0.02). Feed efficiency increased as flaxseed oil increased in concentration, while feeding milled flaxseed decreased feed efficiency (P = 0.01). Analysis of the nitrogen corrected apparent metabolizable energy of flaxseed oil resulted in 7,488 kcal/kg on an as-fed basis. Dietary flaxseed oil improved feed efficiency and increased ALA deposition into yolk compared to a milled source, demonstrating flaxseed oil to be a viable alternative for ALA egg enrichment.
当在产蛋母鸡的饮食中添加欧米伽-3 多不饱和脂肪酸，以生产供人类食用的高附加值鸡蛋时，蛋黄中α-亚麻酸（ALA）、二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）的浓度可达到 250mg/50g 全蛋。亚麻籽是 ALA 的丰富来源，通常用于欧米伽-3 富集；然而，日粮亚麻籽来源（提取油与磨碎籽）对产蛋母鸡蛋黄中脂肪酸转移的影响尚不清楚。因此，在 33 周龄前（25 至 33 周龄），通过在海兰 W-36 产蛋母鸡中进行 8 周的喂养试验，评估了从提取亚麻籽油或磨碎亚麻籽中 ALA、EPA 和 DHA 向蛋黄中的转移。母鸡（n=132）随机分组饲养，每 3 只母鸡/笼（每个处理 4 个重复）。日粮等热量，由对照日粮和 5 种亚麻籽油日粮（0.5%、1.0%、2.0%、3.0%和 5.0%）和 5 种磨碎亚麻籽日粮（从磨碎亚麻籽计算的亚麻籽油浓度 0.5%、1.0%、2.0%、3.0%、5.0%）组成。日粮中添加亚麻籽油和磨碎亚麻籽的浓度增加，导致蛋黄中 ALA、EPA 和 DHA 的浓度增加，与相同日粮添加量相比，从亚麻籽油中获得的脂肪酸沉积是磨碎亚麻籽的 2 倍（P<0.01）。由于油或磨碎源，蛋黄 EPA 和 DHA 浓度没有差异（P=0.21）；然而，增加日粮中任何来源的亚麻籽油添加量都会增加蛋黄中的 EPA 和 DHA（P<0.01）。母鸡饲喂亚麻籽油或磨碎亚麻籽，随着日粮浓度的增加，体重变化减少（P=0.02）。随着亚麻籽油浓度的增加，饲料效率增加，而饲喂磨碎亚麻籽则降低了饲料效率（P=0.01）。对亚麻籽油氮校正表观代谢能的分析表明，基础饲粮中为 7488kcal/kg。与磨碎来源相比，日粮亚麻籽油提高了饲料效率并增加了 ALA 在蛋黄中的沉积，表明亚麻籽油是 ALA 蛋富集的可行替代品。
