圈养条件下麻鸭日粮中添加菹草对产蛋率和蛋黄着色的影响

Effect of dietary supplements of Potamogeton crispus on laying rate and color of egg yolk in Ma duck under confinement feeding condition

菹草是一种富含胡萝卜素的眼子菜科水生植物,广泛分布在河北白洋淀湖区。就菹草不同添加方式对蛋鸭产蛋率和蛋黄颜色等蛋品质的影响进行了研究。结果表明,在产蛋率方面,B日粮组(52.6%鲜菹草+47.3%基础日粮)和C日粮组(20%风干菹草+80%基础日粮)相比差异不显著,但二者比对照组(基础日粮)分别显著提高7.9%和4.2%(P<0.05);试验各组日粮蛋重、蛋形指数、蛋比重指标无显著差异;C日粮组蛋壳强度、厚度与对照组相比差异不显著,但B日粮组蛋壳强度、厚度显著低于对照组(P<0.05);B日粮组鸭蛋哈氏单位显著低于对照组(P<0.05),但C组与对照组相比差异不显著;B日粮组和C日粮组蛋黄色度分别比对照组显著增加76.5%和67.3%(P<0.05)。总之,采用避光风干制备菹草粉是有效保留其类胡萝卜素最为经济的干燥方式。蛋鸭日粮中添加风干菹草粉可有效提高蛋鸭生产性能,并显著增加蛋黄色度等蛋品质性状,上述结果为科学合理使用白洋淀菹草来实现常年生产天然红心鸭蛋提供了实践指导依据。

Abstract： Potamogeton crispus is a carotene-rich Potamogetonaceae aquatic plant that is widely distributed in the Baiyangdian Lake in Hebei province, China. Laying rate, egg yolk color and egg quality of Chinese Ma duck was investigated in response to dietary supplements of P. crispus powder. Fresh P. crispus was harvested on May 12, 2009 and dehydrated with different drying methods. Total carotenoids in dried samples were ranked as freeze dried powder （846.3 mg/kg DM）〉air-dried powder （617.5 mg/kg DM）〉sun-dried powder （362.7 mg/kg DM）〉oven dried powder （268.2 mg/kg DM）. Nutritive composition of air-dried P. crispus powder was analyzed. Sixty 330 day old Chinese Ma laying duck （body weight： 1.5±0.1 kg） were randomly arranged into A, B, and C groups （n=20 for each group）. All ducks were daily fed on a fixed amount of 165 g corn-soyabean-meal basal ration before the start of this feeding trial. During the 12-d feeding trial period, the ducks in A group （control group） were still fed daily with the basal diet, while the ducks in B group were fed with fresh P. crispus ration （52.6% fresh P. crispus＋47.3% basal ration）, and the ducks in C group with air-dried P. crispus ration （20% dry basis P. crispus4-80% basal ration）. In both B and C ration groups the egg laying rate significantly increased by 7.9% and 4.2% respectively compared with that in A group （P〈0.05）, hut there were no significant differences between B and C groups. There were no significant differences for egg shape index and egg weight between the three groups. Eggshell strength and thickness between C and A groups did not differ, but the eggshell strength and thickness of B group were significantly lower than those of A group （P〈0.05）. Harvey unit of egg in B group was significantly lower than that in A and C group （P〈 0.05）, but there was no difference between the C and A groups. The egg yolk color of B and C groups significantly increased by 76.5% and 67.3%, respectively （P〈0.05）. Overall, air drying of fresh P. crispus effectively retained total carotenoids content. Dietary supplementation of air-dried P. crispus powder can effectively improve laying rate and significantly increase the color of egg yolk as well as other quality traits. These results may provide a reference guide of a rational use of Baiyangdian P. crispus to achieve a routine production of eggs with a red color in the yolk in laying ducks.