Production, egg quality, and intestinal morphometry of laying hens fed marine microalga

ABSTRACT The objective of the present study was to evaluate production and egg quality as well as the intestinal morphometry of laying hens fed diets supplemented with marine microalga Dunaliella salina. Six hundred laying hens were allocated based on a completely randomized design into five treatments (0, 0.25, 0.50, 0.75, and 1% inclusion of D. salina biomass) with 12 replicates of 10 hens per treatment. The experiment was divided into three periods of four weeks each, totaling 84 days. During this period, the productive performance of laying hens, the physical-chemical quality of the eggs, and the morphometric alterations of the small intestine and liver were determined. The inclusion levels of D. salina biomass had a linear effect on the performance (egg weight, egg mass, and feed conversion), qualitative parameters (yolk weight and yolk index), and physicochemical parameters of eggs (total carotenoids, TBARS, and yolk color). At the same time, villi lengths and the villus:crypt ratio of the duodenum and ileum segments and the metabolization of carotenoids in the liver were increased as an effect of Dunaliella salina dietary supplementation. Thus, the inclusion of marine microalgae D. salina biomass in experimental diets for laying hens improves the performance, the intestinal health, the physical-chemical quality of the eggs, and at the same time increases carotenoid content and improves egg oxidative stability.

摘要
本研究旨在评估饲喂添加海洋微藻杜氏盐藻（Dunaliella salina）的日粮对产蛋鸡生产性能、蛋品质以及肠道形态学的影响。本试验采用完全随机设计，将600羽产蛋鸡分为5个处理组，每组日粮中杜氏盐藻生物质添加水平分别为0、0.25%、0.50%、0.75%和1%，每个处理组设12个重复，每个重复10羽产蛋鸡。试验周期分为3个阶段，每个阶段4周，总时长共计84天。试验期间，测定了产蛋鸡的生产性能、鸡蛋的理化品质以及小肠与肝脏的形态学变化。杜氏盐藻生物质的添加水平对产蛋鸡生产性能（蛋重、总蛋重、饲料转化率）、蛋品质参数（蛋黄重量、蛋黄指数）以及鸡蛋的理化参数（总类胡萝卜素含量、硫代巴比妥酸反应物（TBARS）、蛋黄颜色）均产生线性影响。同时，日粮添加杜氏盐藻可提升十二指肠、回肠段的绒毛长度以及绒毛高度/隐窝深度比值，同时增强肝脏中类胡萝卜素的代谢能力。因此，在产蛋鸡试验日粮中添加海洋微藻杜氏盐藻生物质，可改善产蛋鸡生产性能与肠道健康，提升鸡蛋的理化品质，同时增加鸡蛋中类胡萝卜素含量并改善其氧化稳定性。