中国6个地方鸡种蛋壳质量和超微结构的比较

实验测定和观察比较同一饲养条件下6个地方鸡种同一天所产的各30枚蛋的蛋重、蛋形指数、蛋壳颜色、蛋壳厚度、蛋壳强度和蛋壳超微结构。结果表明:蛋形指数以茶花鸡、藏鸡和金湖乌凤鸡较合适,基本维持在1.32~1.34;金湖乌凤鸡的蛋壳厚度和蛋壳强度分别为0.33 mm和4752.20 g/cm2;6品种蛋鸡蛋壳质量由高到低依次为金湖乌凤鸡、边鸡、泰和鸡、北京油鸡、藏鸡和茶花鸡。泰和鸡蛋壳外表面裂隙数分别比金湖乌凤鸡、边鸡、茶花鸡、藏鸡和北京油鸡多4.37%、11.87%、28.75%、43.75%和32.50%;而金湖乌凤鸡蛋壳外表面裂隙宽仅有0.88μm;藏鸡蛋壳栅栏层厚度所占百分比为63.30%;金湖乌凤鸡蛋壳的乳头数和乳头宽分别为10.67个/μm2和36.32μm。蛋壳外表面的裂隙数、乳头层、栅栏层及晶体层厚度百分比和乳头数与蛋壳强度均呈显著或极显著正相关,而裂隙宽和乳头宽与蛋壳强度呈极显著负相关。     

Physical and mechanical properties of eggshell as affected by chicken breed and flock age

ABSTRACT

1. A study was conducted to evaluate the relationship among physical and mechanical properties of the eggshell, as affected by breed and hen’s age.

2. Data on eggshell quality (external characteristics and derived measurements) were obtained from 322 laying hens, from three breeds (Fayoumi, Dandarawi and Hy-Line Brown) during the laying cycle, starting from 38 wks of age for four experimental periods (38, 46, 54 and 62 wks).

3. Eggs obtained from the Fayoumi breed exhibited the highest shell thickness and breaking force. There was a linear improvement in eggshell quality attributes associated with hen’s age up to 54 wks, thereafter a deterioration was found for all breeds.

4. Generally, eggs laid by native breeds (Fayoumi and Dandarawi) had better mechanical properties compared to those produced by the commercial strain (Hy-Line Brown). In addition, the interaction between breed and hen’s age was not significant for any physical property or mechanical attribute. There was a highly significant (P ≤ 0.01) positive correlation between the breaking force and either eggshell toughness or shell thickness, and regression analyses suggested that eggshell toughness was the best predictor for breaking force, followed by shell thickness.     

Quality assessment of chicken eggshell cuticle by infrared spectroscopy and staining techniques: a comparative study

1. The cuticle is a very thin organic layer that coats the eggshell surface and plugs the eggshell pores preventing bacterial penetration. It also reduces eggshell permeability which is important to maintain internal quality of the egg. Thus, the eggshell cuticle quality is crucial to ensure the food safety and quality of eggs.

2. A new methodology to assess eggshell cuticle quality, based on attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), is compared with a more traditional method based on cuticle staining techniques.

3. Both techniques are useful to determine the amount of cuticle; however, the ATR-FTIR technique is independent of egg colour, more sensitive and provides complete information about the cuticle and its composition. Additionally, it provides information about eggshell permeability.

4. The methodology for cuticle quality assessment described in this work can be very useful for genetic selection programmes aimed to improve the safety and quality of eggs.     

固始鹅蛋壳质量性状分析

试验旨在分析固始鹅的蛋壳质量性状，为品种资源普查提供素材。在农户散放饲养的鹅中随机收集56枚鹅蛋，对鹅蛋的蛋壳重占总蛋重的比例和不同部位蛋壳厚度进行测定。结果表明，蛋壳重占总蛋重的比例平均为12.32%；平均蛋壳厚度为0.517 mm，大多数鹅蛋的蛋壳锐端厚度比钝端和中间高。     

不同周龄母鸡鸡蛋及不同蛋壳质地鸡蛋的蛋品质比较

本文比较了同一品种不同周龄(26、40周龄和64周龄)母鸡所产蛋的蛋壳品质和蛋品质,包括蛋重、蛋壳相对重、蛋形指数、蛋壳强度、蛋壳厚度、蛋黄颜色、蛋黄指数、蛋黄比率、哈氏单位、蛋清pH值。之后,还比较了该鸡种不同蛋壳质地鸡蛋(正常蛋和砂壳蛋)之间上述指标的差异。结果表明:在不同周龄母鸡所产蛋之间,蛋重、蛋黄指数、蛋黄比率、哈氏单位等均存在显著差异(p<0.05),而蛋壳厚度之间差异不显著(p>0.05)。此外,蛋重、蛋形指数、蛋黄颜色、蛋黄比率随着母鸡周龄的增加呈上升趋势,而蛋壳强度、蛋壳相对重、哈氏单位、蛋黄指数、蛋清pH值呈下降趋势。最后,蛋壳质地不同的鸡蛋(正常蛋与砂壳蛋)之间,蛋重、蛋壳相对重、蛋壳强度、蛋清pH值之间存在极显著差异(p<0.01),而其他参数之间差异不显著(p>0.05)。     

蛋壳品质营养调控的研究进展

蛋壳不仅可以作为对鸡蛋内容物的支撑、免受外力的侵害,还能保护鸡蛋内部成分免遭微生物的侵袭。蛋鸡生产中常出现蛋壳破损等问题,据统计,全世界由蛋壳质量而导致的损失达6%~10%,我国每年因此也造成5亿多元的损失。因此,提高蛋壳质量是蛋鸡行业亟须解决的重要问题之一。近年来,学者从营养调控方面已开展了大量研究,本文从蛋壳的组成、形成过程、有关因子和调控实践等方面着手,简述国内外在改善蛋壳品质方面的研究进展。     

Comparison of hatchability and some egg quality characteristics in spotted and unspotted partridge (Alectoris chukar) eggs

The current research was conducted to determine the comparison of hatchability and some egg quality characteristics in spotted and unspotted partridge (Alectoris chukar) eggs. The research was carried out on 51 male and 102 female chukar partridges (Alectoris chukar) aged 50 wk, which were raised at the Research and Application Farm of the Faculty of Veterinary Medicine of Selcuk University. In total, 244 spotted and 261 unspotted eggs were used in the research. The hatching eggs were stored at 75% RH and 13°C for 14 d. Thirty spotted and 30 unspotted eggs laid on the same day were used for the evaluation of egg quality characteristics. Egg weight, chick weight, egg weight loss during the hatching period, shape index, hatchability, and some egg quality characteristics were evaluated at the end of the research. Spotted eggs exhibited a higher fertility and hatchability, as well as a lower percentage egg weight loss and embryonic mortality when compared with unspotted eggs. No significant differences were observed between spotted and unspotted eggs for egg weight, chick weight, shape index, specific gravity, albumen height, Haugh unit, yolk color green-red chromaticity (a*), albumen pH, and yolk pH. Spotted eggs had higher eggshell color a*, eggshell color blue-yellow chromaticity (b*), and eggshell strength, as well as a lower eggshell color light-dark chromaticity (L*), yolk color L*, and yolk color b* scores when compared with unspotted eggs. It was demonstrated that spots on the eggshells of chukar partridges (Alectoris chukar) improved their hatchability by affecting various quality characteristics of their eggs. It was concluded that spotted eggs are more suitable for hatching.     

Effect of Monochromatic Light on the Egg Quality of Laying Hens

The chicken eye can discriminate light color, and different light wavelengths affect egg quality. In this study, we used blue (B), green (G), and red (R) light produced by light-emitting diode lamps, as well as incandescent light (W) to illuminate Hy-Line Brown hens from 19 to 52 wk. All light sources were equalized to a light intensity of 15 lx and applied for 16 h daily. The results showed that egg weight in W light (61.1 g) was significantly (P < 0.05) greater than those in R light (59.2 g) throughout the experimental stage. Beginning at the age of 30 wk, egg weight in R light was consistently smaller than those in other lights. The egg length in B light was significantly (P < 0.05) shorter than those in other lights, and its width was significantly (P < 0.05) shorter than those in W light from 38 to 52 wk. The egg width in R light was significantly (P < 0.01) shorter than those in W light and to a lesser extent (P < 0.05) shorter than those in B and G lights from 19 to 52 wk. Similarly, eggshell strength in G light was significantly (P < 0.01) better than those in W and B lights, and eggshell thickness in G light was significantly (P < 0.05) better than those in other lights from 21 to 45 wk. Our results indicate that egg weight in R light was less than those in other lights, the egg length and egg width in B light became shorter, and the egg width in R light became shorter with age; the egg quality in G light was found to be the best.     

Probiotic Bacillus subtilis C-3102 Improves Eggshell Quality after Forced Molting in Aged Laying Hens

This study was carried out to evaluate the effects of probiotic Bacillus subtilis C-3102 feed additive on quality characteristics including strength, thickness, and weight of eggshells of Boris Brown laying hens. The control group (n=64) was fed a basal diet comprised of maize and feed rice, whereas the experimental group (n=64) was fed a basal diet supplemented with B. subtilis C-3102 (3×10⁵ CFU/g) starting at 49 weeks of age. From 67 to 69 weeks, all hens were induced to molt using an anorexic program; then, the birds in both groups returned to their respective diets (from 69 to 82 weeks). Eggshell strength, measured six times with 60 eggs selected before the molting treatment, was significantly greater in the C-3102 group than in the control group at 51, 59, 63, and 66 weeks (3.45, 3.44, 3.28, and 3.13 kg/cm²; P<0.05, 0.05, 0.01, and 0.01, respectively). Moreover, eggshell strength—measured three times after the molting treatment—was significantly greater in the C-3102 group than in the control group at 73 and 77 weeks (3.79 and 3.65 kg/cm²; P<0.01 and 0.01, respectively). Eggshell thickness was also significantly greater in the C-3102 group than in the control group at 73 and 77 weeks (0.400 and 0.390 mm; P<0.01 and 0.01, respectively). Fecal samples collected from eight hens of each group at 70 weeks of age after forced molting, showed a significantly higher proportion of Lactobacillus spp. in the C-3102 group (8.94 log CFU/g) (P<0.05) than in the control group (8.63 log CFU/g). Clostridium spp. abundance was significantly lower in the C-3102 group (2.92 log CFU/g) than in the control group (4.3 log CFU/g). These results suggest that C-3102 supplementation improves eggshell quality in aged laying hens, particularly after forced molting.     

蛋壳表型性状与蛋壳质量间的相关与通径分析

本文旨在研究蛋壳表型性状与蛋壳强度之间的相关与通径分析。试验选用40~43周龄的新鲜珍珠鸡蛋100枚,测定了其蛋重、蛋形指数、蛋壳厚度、蛋壳重、蛋壳比例、单位面积蛋壳重、蛋壳强度6个指标,计算其性状间的相关系数;采用通径分析方法计算以表型性状为自变量对蛋壳强度作因变量的通径系数、决定系数对各性状的影响大小进行分析。从通径分析结果看出,直接影响最大的是蛋壳厚度（P=0.657）,间接影响最大的是蛋壳比例（0.746）,并以蛋壳厚度指标建立回归方程为y=44.145x-9.229。在生产实践中,为获得好的蛋壳质量应着重注意蛋壳厚度和蛋壳比例,同时要协调蛋形指数、蛋重、蛋壳比例、单位面积蛋壳重与蛋壳强度之间的关系。     

固始鸡蛋壳质量性状分析

实验对56个固始鸡鸡蛋的蛋壳颜色、蛋壳重占总蛋重的比例和蛋不同部位蛋壳厚度进行测定。结果表明,浅褐色和灰色蛋壳颜色占绝大多数,没有灰白色和白色;蛋壳重占总蛋重的比例平均为10.97%;平均蛋壳厚度0.339mm,大多数鸡蛋锐端蛋壳厚度比钝端和中间高。     

番鸭蛋壳气孔数、壳厚对出雏效果的研究

本试验分别测定新鲜番鸭种蛋 ;一照健胚蛋、死胚蛋 ;三照死胚蛋、正常出雏蛋和毛蛋的大端、中部和小端的气孔数及厚度。结果表明 :一照、三照死胚蛋和毛蛋与一照健胚蛋和正常出雏蛋气孔数差异极显著 (P <0 .0 1) ;而三照死胚蛋和毛蛋的蛋壳厚度均极显著高于正常出雏蛋 (P <0 .0 1)。并对新鲜种蛋、毛蛋和正常出雏蛋蛋壳进行扫描电镜观测 ,结果显示蛋壳结构与其它禽蛋相似 ,同时也证实了死胚蛋蛋壳厚度 (0 .395～ 0 .4 0 1mm)极显著高于正常出雏蛋(0 .36 3mm)。     

单色光对产蛋鸡蛋品质的影响

试验采用红(660nm)、绿(560nm)、蓝(480nm)3种发光二极管(处理组)和白炽灯(400～700nm)(对照组),对180羽海兰褐蛋鸡进行人工光照,研究了单色光对蛋重、蛋形指数、蛋长径、短径和蛋壳质量的影响。试验期为19～52周,光强度均为15lx,光照时间为16h。结果表明:在整个试验期,白光组蛋重最高(61.1g),红光组最低(59.2g),二者之间差异显著(P<0.05);38～52周龄,蓝光组蛋长径显著小于其他组,而其短径显著(P<0.05)小于白光组,另外,红光组蛋短径极显著(P<0.01)小于其他组;19～37周龄,绿光组蛋形指数(1.303)显著大于其他组,而38～52周龄,红光组蛋形指数(1.343)极显著(P<0.01)大于其他组;21～45周龄,绿光组蛋壳强度(3.54kg/cm2)极显著(P<0.01)高于白光和蓝光组而绿光组蛋壳厚度(0.368mm)显著(P<0.05)大于其他组;蓝光组蛋壳颜色值(31.6)显著(P<0.05)小于白光组(33.1)。结果提示:蓝光使蛋长、径变短而红光使蛋短径变短,从而使蓝光和红光组蛋重随产蛋周龄而增长的趋势小于白光和绿光组。单色光可影响蛋壳质量,其中绿光组的蛋壳质量最好。     

槲皮素对蛋鸡蛋壳品质的影响

试验旨在研究槲皮素对蛋鸡蛋壳品质的影响。选择体重和产蛋率相近的240只29周龄蛋鸡,随机分4组,每组6个重复,每个重复10只。对照组饲喂基础日粮,试验1、2、3组分别在基础日粮中添加0.02%、0.04%、0.06%槲皮素。结果表明:①与对照组相比,产蛋高峰期试验2组的蛋壳相对重极显著提高(P<0.01);在产蛋后期各试验组的蛋壳厚度均显著提高(P<0.05),试验2、3组的蛋壳相对重分别提高0.27%(P<0.05)和0.48%(P<0.01),试验1、2组的鸡蛋破软壳率极显著降低(P<0.01)。②产蛋高峰期各试验组的蛋壳钙含量均显著升高(P<0.05);产蛋后期试验2、3组的蛋壳钙含量显著提高(P<0.05),试验3组蛋壳磷含量显著降低(P<0.05)。③产蛋高峰期和后期各试验组的血清钙含量均极显著提高(P<0.01);在产蛋高峰期试验2组的血清碱性磷酸酶(ALP)含量极显著提高(P<0.01);在产蛋后期试验1组的血清ALP含量极显著降低(P<0.01),试验2、3组的血清羟脯氨酸(Hyp)含量均显著降低(P<0.05)。因此,0.04%槲皮素可有效改善产蛋后期蛋壳品质。     

鸡蛋壳质量与超微结构关系的研究

研究使用常规方法测定蛋形指数、蛋壳相对重量、蛋壳强度和蛋壳厚度等蛋壳质量指标,使用X射线能谱仪测定蛋壳断面各层钙的相对含量,使用环境扫描电子显微镜观察蛋壳断面各层和内外表面的超微结构。结果表明:蛋壳强度与蛋壳相对重量、蛋壳强度与蛋壳厚度以及蛋壳相对重量与蛋壳厚度之间相关分别达到0.444(P<0.01)、0.700(P<0.01)和0.611(P<0.01),各相关系数不在同一水平。蛋壳各层钙的相对含量分别达到32.68%±8.62%、33.13%±6.58%和32.35%±.97%,之间差异不显著(P>0.05),几近匀质。环境扫描电子显微镜的观察发现不同强度的蛋壳,其各层和内外表面超微结构存在明显差异。由此得出:蛋壳超微结构的差异是蛋壳质量变化的重要影响因素。     

Changes in eggshell structure and predisposition of broilers to health problems: is there a common pathophysiology?

1. A study of broiler breeder eggs differing in eggshell matrix optical density was conducted to determine the association of eggshell structural quality and the risk of disease in broilers.

2. A total of 10 000 eggs from a broiler breeder flock were examined according to the pre-established criteria, and allocated to groups classified as having a high or low density shell matrix.

3. The eggs from respective groups were incubated and hatched in a commercial hatchery. Samples of unhatched eggs from each group were subjected to detailed examination to establish the cause of reproductive failure. First, quality chicks from each group were raised as separate flocks in a commercial broiler barn. Group performance, morbidity, and mortality were monitored throughout the growth period. All birds were processed in a commercial plant, and condemnation data were compiled.

4. There were significantly more unhatched eggs, and fewer quality chicks in the group classified as having a low density eggshell matrix, in comparison to the high-density group.

5. Embryo pathology accounted for a large proportion of the overall reproductive failure in both groups, with a large proportion of embryos showing anatomical anomalies. The eggs and embryos from the low-density eggshell matrix group were three times more likely to be infected.

6. Significantly higher production losses associated with mortality/morbidity, and condemnations of carcasses at processing were observed in broilers from the low-density eggshell group compared with the high-density eggshell group.

7. It is concluded that common metabolic/physiological changes in breeder hens associated with eggshell pathology may be also risk factors linked with predisposition of broiler chicks to some health problems.

     

Effects of dietary probiotic inclusion on performance, eggshell quality, cecal microflora composition, and tibia traits of laying hens in the late phase of production

Ninety-six White laying hens (64 weeks old) were used to investigate the effect of dietary inclusion of Bacillus subtilis on performance and eggshell quality. Hens were randomly distributed into three treatment groups and fed basal diet (control), basal diet plus 0.5 g/kg B. subtilis (Probiotic-0.5), or basal diet plus 1 g/kg B. subtilis (Probiotic-1) for 10 weeks. Probiotic-1 group exhibited the maximum (P?<?0.05) increase in egg production, egg weight, egg mass, eggshell weight, and eggshell thickness, compared with Probiotic-0.5 and the control groups. During the last week of the study, eggshell densities were 94.9, 88.7, and 65.6 mg/cm² in Probiotic-1, Probiotic-0.5, and the control group, respectively. The average unmarketable eggs were 1.3 %, 2.2 %, and 6.4 % in Probiotic-1, Probiotic-0.5, and the control group, respectively. Tibia weight, density, and ash content increased significantly. The average time required by B. subtilis to establish a significant effect was 3 weeks for Probiotic-1and 6 weeks for Probiotic-5. B. subtilis improved gut microflora balance, which has the potential to improve gut health and absorption efficiency. It should be possible to improve egg performance and eggshell quality of aged laying hens by dietary inclusion of B. subtilis, which will be of importance for farmers.     

Influence of strain and flock age on geometrical and mechanical attributes of eggs produced from Japanese quail birds

We investigated how the geometrical and mechanical properties of eggshell of Japanese quail are affected by strain and flock age. Two strains of quail (white and gray) were used in the current experiment. The results showed that there was no significant difference for all geometric measurements due to strain effect. Eggs produced from the older birds showed significantly higher (P < 0.01) values compared with younger age for all studied traits. Eggs produced from quails at 22 weeks had a significantly (P < 0.01) darker yolk color than that of the younger age. Superiority in shell thickness, shell weight, and breaking force was detected in eggs of gray quails compared with white quails. On the other hand, the eggs from white quails had significantly higher values for static stiffness and Young's modulus as compared with those of gray counterparts. A significant decrease (P < 0.01) was found for fracture toughness and Young's modulus in eggs of aged birds. A significant negative relationship was found between the breaking force and both static stiffness and Young's modulus. A significant positive relationship was observed between breaking force and both shell thickness and shell percentage. The phenotypic correlation between eggshell breaking force and toughness was relatively high.     

改善产蛋后期鸡蛋蛋壳质量研究进展

蛋壳质量是评价蛋品质的重要指标,和鸡蛋的运输和保存过程中的破损率相关,且直接与种蛋的合格率、孵化率和鸡苗的健康密切相关,是影响蛋鸡生产效益的要素之一。蛋鸡老龄化是导致产蛋后期蛋壳质量下降的主要因素。特别是近年来,商品蛋鸡的产蛋周期大大延长,蛋鸡老龄化程度更高,这导致产蛋后期面临的蛋壳质量下降的问题更为严峻。本文对蛋壳的形成过程和钙代谢过程引起产蛋后期蛋鸡蛋壳质量下降的原因进行了概述,并对提高产蛋后期蛋壳质量的调控措施进行了总结和展望。     

Predatory activity of Pochonia chlamydosporia fungus on Toxocara (syn. Neoascaris) vitulorum eggs

Toxocara (Neoascaris) vitulorum is a gastrointestinal nematode parasite of young ruminants, responsible for high mortality rates in parasitized cattle and buffalo calves. The objective of this work was to compare the predatory capacity under laboratory conditions of four fungal isolates of the nematophagous fungus Pochonia chlamydosporia (VC1, VC4, VC5 and VC12) on T. vitulorum eggs in 2% water-agar (2% WA). T. vitulorum eggs were plated on 2% WA Petri dishes which contained cultured fungal isolates and control plates without fungi. After 10 and 15 days one hundred eggs were removed and classified according to the following parameters: type 1, biochemical and physiological effect without morphological damage to the eggshell, type 2, lytic effect with morphological alteration of the eggshell and embryo and type 3, lytic effect with morphological alteration of eggshell and embryo in addition to hyphal penetration and internal egg colonization. The fungal isolates were effective in the destruction of T. vitulorum eggs presenting the type 3 effect at 10 and 15 days after contact with the fungus. No nematophagous fungi were observed in the control group during the experiment. There was no variation in the predatory capacity of the fungal isolates (P?>?0.01) at the intervals of 10 and 15 days. These results indicate that P. chlamydosporia (VC1, VC4, VC5 and VC12) negatively influenced the development of T. vitulorum eggs and can be considered a potential candidate for the biological control of nematodes.