褐壳蛋鸡蛋壳颜色的形成机理及其泛白原因分析

褐壳蛋鸡蛋壳颜色的深浅与蛋的销路密切相关。所以，很多养殖户对蛋壳颜色非常关注，很在意观察蛋壳颜色的变化，并常常把它的变化与所喂饲料联系在一起。常有养殖户发问：“鸡蛋壳又变白变浅了，是饲料的毛病?还是鸡又闹什么病呢?”。针对这些情况，现就蛋壳颜色的问题和大家作一交流。     

褐壳蛋蛋壳颜色及其调控

1褐壳蛋蛋壳色素的形成、沉积 　　褐壳蛋蛋壳中的色素主要是原卟啉— IX(protoporphyrin IX)，来源于血红蛋白的分解物，即与衰老、受损及形态异常的红细胞的破坏有关。当红细胞在肝、脾和其它部分的网状内皮系统被吞噬破坏后，释放出血红蛋白，并很快被分解为珠蛋白、胆绿素和铁。其中珠蛋白和铁可重新参加体内代谢，只有胆绿素被还原为胆红素，经血液转运至肝脏后结合生成葡萄糖醛酸胆红素，随胆汁排入十二指肠，大部分作为废物随粪便排出体外。还有小部分又在肠道重新吸收，经血液入肝或转 送至输卵管等部分，作为合成蛋壳色素的原料…     

褐壳蛋鸡的蛋壳颜色(综述)(续2)

正上期回顾:上一期介绍了褐色蛋壳和壳腺中的原卟啉Ⅸ、原卟啉Ⅸ的代谢途径,以及饲养系统、营养对蛋壳颜色的影响。5蛋壳颜色的遗传学为了确定蛋壳颜色所涉及的基因,褐壳蛋鸡中褐色色素合成的分子基础及其可能的代谢途径需要进一步的研究(Wang等,2013)。蛋壳的颜色被认为受编码蛋白质和酶的一些基因的调控,调节色素的生成和在蛋壳中的     

褐壳蛋鸡的蛋壳颜色(综述)(续1)

上期回顾:上一期介绍了褐壳蛋鸡所产鸡蛋的蛋壳中色素主要成分是原卟啉Ⅸ,但也存在微量的胆绿素及其锌螯合物,并介绍了计算蛋壳颜色的方法。     

褐壳蛋蛋壳颜色的形成、褪色及调控

鸡蛋的蛋壳颜色是受多基因控制的性状,具有较高的遗传力.因此,蛋壳颜色不仅是蛋鸡品种的重要标志之一,也是蛋鸡子宫内环境优劣的表征.     

蛋鸡蛋壳颜色变浅的原因

季节性白壳蛋 夏季持续高温,鸡体散热困难,为加速排泄散热,鸡大量饮水,加上采食量较低,造成营养流失和不足,使蛋壳颜色变浅。秋冬季,气温突然下降,鸡体一时难以适应,使钙磷代谢受影响,使其变浅变白。     

蛋壳颜色形成的机理探讨

禽蛋蛋壳颜色的遗传力为0.58～0.76,它取决于胆绿素—IX、胆绿素的锌螯合物、原卟啉—IX三者间的比例。本文对蛋壳颜色的形成机理、影响因素及其调控方法进行了阐述。     

褐壳蛋蛋壳颜色与鸡蛋品质相关性分析

研究旨在分析褐壳鸡蛋蛋壳颜色与鸡蛋各品质性状的相关性。选取北京市华都峪口禽业有限责任公司培育的褐壳蛋鸡纯系4个品系为试验材料,测定36周龄和56周龄时鸡蛋的蛋壳颜色、蛋壳强度、蛋壳厚度、蛋形指数、蛋重、蛋黄颜色、蛋白高度和哈夫单位,研究蛋壳颜色深浅与鸡蛋品质的相关性。结果表明:4个品系在36周龄和56周龄时,蛋壳颜色与蛋壳强度、蛋壳厚度呈中低度相关,且不同品系、不同周龄相关程度不同,蛋壳强度和蛋壳厚度随着蛋壳颜色变浅呈现降低的趋势。而蛋壳颜色与蛋形指数、蛋重、蛋黄颜色、蛋白高度和哈夫单位不相关。     

强太阳光会导致褐壳蛋鸡所产蛋的蛋壳颜色变白

看来当蛋鸡饲喂含高水平维生素D3的日粮时,紫外线似乎会影响蛋壳的颜色。因此,蛋鸡生产者可能需要更加地关注日粮中维生素D3的水平了,以避免光线对蛋壳造成的麻烦。     

玉米糖渣对罗曼蛋鸡蛋色的影响

选择43周龄罗曼褐商品蛋鸡450羽,随机分成5组,每组90羽。对照组饲喂基础日粮;试验Ⅰ,Ⅱ,Ⅲ,Ⅳ组分别饲喂含有4%,8%,12%,16%的玉米糖渣,并测定蛋壳、蛋黄的L值(亮度)、a值(红度)和b值(黄度),研究日粮中不同玉米糖渣组成对罗曼蛋鸡蛋壳颜色和蛋黄颜色的影响。试验结果表明:试验Ⅰ,Ⅱ,Ⅲ,Ⅳ组在蛋壳的L值、a值、b值和蛋黄的L值、a值与对照组比较差异不明显(P>0.05)。试验Ⅱ,Ⅲ,Ⅳ组的b值较对照组分别提高了9.7%,7.2%,6.1%,差异显著(P<0.05)。说明蛋鸡日粮中添加8%~16%的玉米糖渣能显著提高蛋黄的黄度。     

Effects of an induced pause in egg production and supplementation of the diet with iron on egg shell colour,quality and performance of brown egg layers

1. A pause in egg production was induced in brown‐egg laying hens, aged 68 weeks, by feeding them whole oats for 7 d. Subsequently, these hens, together with control groups, were given laying diets with either 400 or 600 mg/kg iron. The 200 mg/kg of supplemental iron was added in the form of either ferrous sulphate or iron proteinate (chelated iron).

2. The feeding of whole oats halted egg production in 5.7 ±0.22 d and the duration of the pause was 8.3 ±0.78 d.

3. The induction of a pause improved the subsequent rate of egg production, egg output, efficiency of food utilisation, albumen quality, egg specific gravity and shell colour. It also increased food intake and body weight gain but neither egg weight nor the rate of mortality were affected.

4. Neither supplementation of the diet with iron nor its source had any significant effect on laying performance, egg quality or shell colour.     

Effect of probiotic supplementation on serum/yolk cholesterol and on egg shell thickness in layers

1. The effect of probiotic supplementation on egg production, on serum and yolk cholesterol and on egg shell thickness in 24 White Leghorn layers was studied from 28–38 weeks of age.

2. In 3 treatments the diet was supplemented with 0, 100 and 150 mg probiotic/kg food.

3. In the 100 mg probiotic group, egg production improved by 5%, and shell thickness improved slightly, with fewer thin‐shelled eggs than in the control (8.6% compared to 18.6%).

4. The initial serum cholesterol concentration of 170.2 mg/dl in control birds remained similar throughout the 10‐week experimental period, whereas in the 150 mg group the initial value of 176.5 mg/dl decreased to 114.3 mg by week 10.

5. Yolk cholesterol concentration was 14.69 mg in the control group and 11.28 and 11.37 mg/g in the 100 and 150 mg probiotic groups respectively. Overall mean total egg cholesterol was thus reduced by probiotic supplementation.     

Studies on egg shell strength,shell stiffness,shell quantity,egg size and shape

Physical properties which included shell stiffness, egg weight, width and length, shell weight and thickness, percentage shell, shell weight per unit area, shape index and roundness were studied in relation to maximum force and energy absorbed at failure in 2733 eggs produced by sixty SCWL pullets. Pooled‐egg, bird‐average and individual‐bird bases were used for correlation and regression analyses.

All physical properties in combination accounted for 61.9 and 88.2 per cent of the variation in force and 19.6 and 59.5 per cent of energy absorbed at failure in pooled‐egg and bird‐average analyses respectively. The non‐destructive measurements of shell stiffness, egg size and shape gave R ² values of 60.5 and 86.9 per cent with force and 16.2 and 55.0 per cent with energy in corresponding analyses.

Shell stiffness proved to be the most important predictor of force at failure. Analyses in which variation of shell stiffness was explained by other physical properties supported the conclusion based on theories of elasticity applied to shell structures that shell stiffness was largely an indirect measurement of egg shell quantity together with lesser effects of egg size and shape.

Bird‐to‐bird variation in relations between physical properties and shell strength was evident from individual bird analyses. Coefficients of determination from force at failure regressed on shell stiffness had a mean value of 0.455 with a standard deviation of 0.178 (n = 60).     

褐色种蛋壳色深浅与其孵化率的关系

在种鸡饲养实践中发现 :壳色较深的鸡蛋破损少 ,种蛋合格率高。测量表明 ,浅色蛋的蛋壳比深色蛋的壳薄。蛋壳的厚度又对种蛋的孵化过程有一定的影响 ,如蛋内水份的散失 ,胚胎的气体交换和矿物质的吸收利用等。为此 ,做了褐色种蛋壳色深浅与其孵化率关系的试验。１试验方法１ １测量蛋壳厚度从４１周龄艾维茵肉用种鸡所产合格种蛋中随机取１５０个 ,按照标准取３０个深色蛋和３０个浅色蛋。用螺旋测微器（０ ０１～２５ｍｍ）分别测量每个蛋的钝端、锐端和中间部位的蛋壳厚度。壳色深浅标准为 :深色∶中间色∶浅色＝２０ %∶６０ %∶２０ % ,…     

添加碳酸氢钠对豫州褐蛋种鸡生产(繁殖)性能及种蛋品质的影响

1材料与方法1.1试验鸡的选择与分组选取豫州褐壳蛋鸡Ⅲ系蛋种鸡684只,随机分为3组,每组228只。每笼3只鸡,随机抽取两组作为试验组,另一组为对照组,各组饲喂的日粮分别为:对照组只喂给基础日粮;试验Ⅰ组即0.3%组,在基础日粮中添加0.3%的NaHCO3;试验Ⅱ组即0.5%组,在基础日粮中添加0.5%的NaHCO3。其中基础日粮的主要营养成分含量为:粗蛋白17.30%,代谢能11.25MJ/kg,钙3.38%,磷0.79%,赖氨酸0.84%,蛋氨酸0.29%,食盐0.35%。1.2饲养管理试验鸡各组饲养在同一鸡舍、同排的3层全阶梯笼内,专人饲养。每日定时喂干粉料,自动饮水器供水,每日保持16h光…     

The hen's egg: Density of egg shell and egg contents

One hundred eggs were used, from hens of seven widely differing strains: two commercial brown‐egg hybrids (one British, one American), two commercial white‐egg hybrids (one British, one Canadian), one broiler strain, one highly inbred strain of laboratory White Leghorns and one laboratory strain of Brown Leghorns. The volume occupied by the shell of each egg was estimated from its surface area—itself estimated by means of a three‐parameter model (Carter, 1968)— and its mean thickness, measured with an anvil micrometer. The volume occupied by the egg contents was estimated by subtracting the shell volume from the egg volume, which was also estimated by means of the three‐parameter model. Mean overall shell density (counting as “shell” all mineral matter and spaces between the outer surface of the mineral shell and a surface through the tips of the mammillae) was estimated, by regressing shell weight on shell volume, to be 2.241 ±0.004 g./cm.³; covariance analysis showed that the strains were homogeneous in this respect. Mean incremental shell density (i.e. the density of shell distal to the mammillary region) was estimated, by regressing shell weight per unit surface area on shell thickness, to be 2.386±0.004 g./cm.³; the strains were homogeneous in this respect too. The mean depth of the intermammillary spaces was estimated to be 19.9 μ. All the residual deviation from the common regression line can be attributed to measurement error. The estimated density of incremental shell is lower than that of calcite; the packing fraction of the crystals in the shell aggregate and/or the atoms in the crystals was estimated to be 92.8 per cent. The density of the egg contents (at the temperature of the bird) was estimated by regressing weight of contents on volume of contents; covariance analysis revealed significant differences between strains, one of the brown‐egg hybrids having the highest density of egg contents, 1.045 g/cm.³, and the laboratory Brown Leghorns the lowest, 1.033; both commercial white‐egg hybrid strains gave a value of 1.040 g./cm.³.     

蛋鸡饲喂芽孢杆菌制剂对鸡蛋蛋品质及营养成分的影响

本试验旨在研究芽孢杆菌制剂对"京粉一号"蛋鸡蛋品质及蛋营养成分的影响。选择健康、产蛋均匀的259日龄的"京粉一号"蛋鸡3 600只,随机分为2组,每组6个重复,每个重复300只鸡。对照组饲喂基础日粮,试验组在基础日粮中添加3%的芽孢杆菌制剂,进行为期40 d的试验。结果表明:与对照组相比,试验组蛋壳硬度、哈夫单位以及蛋黄颜色均有不同程度地提高(P>0.05);在反映蛋的物理指标上,试验组蛋黄重和蛋黄相对重显著高于对照组(P<0.05),蛋清相对重显著低于对照组(P<0.05),蛋黄蛋白比有升高的趋势(P>0.05);同时,试验组蛋黄中脂肪和水分含量显著降低(P<0.05),蛋白含量显著升高(P<0.05)。试验表明:在蛋鸡日粮中添加芽孢杆菌制剂,对蛋品质具有一定的改善作用;可显著提高蛋黄重、蛋黄相对重,降低蛋清相对重。同时,可减少蛋黄中脂肪和水分含量,增加蛋白的含量。     

The hen's egg: Evidence on the mechanism relating shell strength to loading rate

1. The decrease in strength of an egg shell which is known to accompany an increase in the period of time over which a load is applied might come about by either of two mechanisms: a decrease in the strength of the material constituting the strong, outer layer of the mineral shell, or a decrease in the thickness of this layer brought about by deepening of the crevices that are normally present between adjacent crystal columns in the weak, inner layer of the shell.

2. Experiments designed to discriminate between these mechanisms are described: the results indicate the second mechanism.

3. This mechanism offers explanations for various other shell phenomena, including delayed fracture under a static, cyclical or recurrent load.

4. The main implication for the poultry industry is that any external insult to a shell is likely to weaken it by doing damage that is local, internal, irreparable and cumulative, even though it may be invisible from the outside.