Некоторые экологические особенности инкубации куриных яиц [Some ecological peculiarities of incubation of chicken eggs]

Нарушин В.Г.; Романов М.Н. Выводы: Параметры скорлупы куриных яиц являются достаточно информативными показателями при оценке их инкубационных свойств. Очевидно, в первую очередь это обусловлено физическими характеристиками естественной преграды на пути микроорганизмов, которой является скорлупа. Эффект тонкой скорлупы отрицательно влиял на результаты инкубации, так же, как и слишком большая поверхность скорлупы по отношению к величине яйца, что связано с относительно большим количеством пор. Предложенная методика, основанная на анализе расположения измеряемых параметров в исследуемой статистической выборке, позволяет оценить инкубационные свойства куриных яиц до закладки в инкубатор. Использование метода предынкубационного отбора яиц экономически целесообразно. В рамках проведенных исследований количество невыведенных яиц можно сократить почти вдвое при их своевременной оценке и выбраковке

Egg-inspired engineering in the design of thin-walled shelled vessels: a theoretical approach for shell strength

A novel subdiscipline of bionics is emerging in the form of ‘egg-inspired engineering’ through the use of egg-shaped ovoids as thin-walled tanks and building structures. Hügelschäffer’s and Narushin’s models of egg geometry are highly applicable within this proposed subdiscipline. Here we conducted a comparative analysis between the two models with respect to some of the most important egg parameters. These included contents volume, shell volume, and the location of the neutral axis along the shell thickness. As a first step, theoretical studies using the Narushin’s model were carried out due to the lack (or limited amount) of data on the geometric relationships of parameters and available calculation formulae. Considering experimental data accumulated in the engineering and construction industries, we postulate a hypothesis that there is a correlation between location of the neutral axis and the strength of the walls in the egg-shaped structure. We suggest that the use of Narushin’s model is preferable to Hügelschäffer’s model for designing thin-walled shelled vessels and egg-shaped building structures. This is due to its relative simplicity (because of the requirement for only two initial parameters in the basic equation), optimal geometry in terms of material costs per unit of internal capacity, and effective prerequisites for shell strength characteristics

A novel Egg Quality Index as an alternative to Haugh unit score

An unusually popular index reflecting the quality of the egg contents and known as the Haugh unit (HU) score is empirical in nature. Because of that, a number of studies appeared that contradict or try to improve this index. In this regard, we set a study that pursued several goals: (i) to trace the rationale for developing the HU index and give it a theoretical reassessment; and (ii) based on the assumptions of previous studies in this field, to revisit and refine the index by increasing such its components as the mathematical adequacy and information value. As a result, an alternative index was inferred that we called the Egg Quality Index (EQI) and described using the appropriate mathematical dependencies. This novel index, in addition to the egg weight (W), takes into account the physical properties of the thick albumen (by measuring its height, H) and yolk (by identifying its diameter, d, or height, h). We, then, compared the two indices, HU and EQI, using the simulation modelling approach. The results of comparison of the two indices as applied to a various set of parameters characteristic of chicken eggs suggested a wider potential for using EQI due to the inclusion of an additional parameter reflecting the yolk condition as well as a more accurate distribution of the studied eggs in quality grade groups with various gradations of consumer attractiveness

A universal formula for avian egg shape

The bird’s oomorphology has far escaped mathematical formulation universally applicable. All bird egg shapes can be laid in four basic geometric figures: sphere, ellipsoid, ovoid, and pyriform (conical/pear-shaped). The first three have a clear mathematical definition, each derived from expression of the previous, but a formula for the pyriform profile has yet to be inferred. To rectify this, we introduced an additional function into the ovoid formula. The subsequent mathematical model fits a completely novel geometric shape that can be characterized as the last stage in the evolution of the sphere—ellipsoid—Hügelschäffer’s ovoid transformation applicable to any avian egg shape geometry. Required measurements are the egg length, maximum breadth, and diameter at the terminus from the pointed end. This mathematical description is invariably a significant step in understanding not only the egg shape itself, but how and why it evolved, thus making widespread biological and technological applications theoretically possible

[On relationship between chicken egg morphological parameters and chick sex] К вопросу о взаимосвязи морфологических параметров куриных яиц с полом цыплят

Нарушин В.Г.; Романов М.Н.; Богатырь В.П. При комплектовании промышленных стад кур-несушек возникает необходимость в поисковых исследованиях по выявлению взаимосвязи между полом цыплят и параметрами яиц. Использование разработанных ранее методов неразрушающей оценки морфологических признаков яиц (Нарушин, 1993, 1994) позволяет рассчитывать не только внешние, но и внутренние параметры. В опыте измеряли исходные данные (массу, длину и периметр) 643 куриных яиц, полученных от кур породы белый род-айланд (линия 68), красный род-айланд (линия 70) и белый леггорн (линия 01). После завершения инкубации определяли пол цыплят. Проверена рабочая гипотеза о том, что с увеличением массы яиц процентное соотношение вылупившихся петушков и курочек смещается в сторону петушков. Установлено, что достоверных различий в соотношении полов для яиц разных весовых категорий не было. Анализ взаимосвязи между плотностью содержимого яиц и соотношением полов цыплят также не дал достоверных результатов. Учитывая тот факт, что на плотность содержимого (Dc) оказывает влияние плотность всего яйца (D), изучалась корреляция между отношением Dc/D и полом цыплят. Полученный ряд значений Dc/D был условно разбит на три интервала: менее 0,94 (1-я группа); от 0,94 до 0,97 (2-я группа); свыше 0,97 (3-я группа). Если во второй группе соотношение полов приближалось к пропорции 1:1, то в первой на 38% курочек приходилось 62% петушков, а в третьей на 69% курочек приходилось 31% петушков. Уточнить предельные значения Dc/D, начиная с которых вылупляются одни петушки либо одни курочки, не удалось. Тем не менее полученные данные могут являться предпосылкой для дальнейших исследований в области прединкубационной сортировки яиц

Egg Quality Index: A more accurate alternative to the Haugh unit to describe the internal quality of goose eggs

Enhancing goose production for human consumption requires evaluating the quality of goose eggs based on their physical characteristics. Grounded on the theoretical and experimental studies, we developed two calculation formulae that enabled the computation of Egg Quality Index (EQI) as an alternative to the widely used Haugh unit (HU) score in assessing goose egg quality. In addition to the egg weight (W) and the height of thick albumen (H), this computation takes into account the indicators for the yolk, i.e., its diameter (d) and height (h). Depending on the research preferences when measuring d or h, one of the two proposed calculation equations can be employed. Using simulation methods that considered all possible combinations of W, H and d values, we created and analyzed a database of virtual goose eggs. As a result, we found that the use of EQI as compared to HU seems preferable due to the possibility to evaluate a greater number of options and nuances of variation in quality characteristics in goose eggs. The proposed novel index for defining the goose egg quality can be a promising and useful tool for linking structure and functionality in goose eggs and for further application in food and poultry industries

Mathematical progression of avian egg shape with associated area and volume determinations

Development of nondestructive techniques for estimating egg parameters requires a comprehensive approach based on mathematical theory. Basic properties used to solve theoretical and applied problems in this respect are volume (V) and surface area (S). There are respective formulae for calculating V and S of spherical, ellipsoidal, and ovoid eggs in classical egg geometry; however, the mathematical description and calculation of these parameters for pyriform eggs have remained elusive. In the present study, we derived the appropriate formulae and established that this would be not only applicable and valid for the category of pyriform eggs, but also universal and explicit for all other naturally occurring avian egg shapes. Thus, we have demonstrated “mathematical progression” of this natural object, considering the egg as a sequence of geometric figures that transform from one to another in the following sequence of shapes: sphere → ellipsoid → ovoid (whose profile corresponds to Hügelschäffer's model) → pyriform ovoid

A 2-D imaging-assisted geometrical transformation method for non-destructive evaluation of the volume and surface area of avian eggs

Egg volume and surface area are reliable predictors of quality traits for both table and hatching chicken eggs. A new non-destructive technique for the fast and accurate evaluation of these two egg variables is addressed in the present study. The proposed method is based on the geometrical transformation of actual egg contour into a well-known geometrical figure which shape most of all resembles the examined egg. The volume and surface area of an examined egg were recomputed using the formulae appropriate for three figures including sphere, ellipsoid, and egg-shape ovoid. The method of the geometrical transformation includes the measurements of the egg length and the area of the examined eggs. These variables were determined using two-dimensional (2-D) digital imaging and image processing techniques. The geometrical transformation approach is proven to be reliable to turn the studied chicken eggs into the three chosen ovoid models, with the best prediction being shown for the ellipsoid and egg-shape ovoid, whilst the former was slightly more preferable. Depending on the avian species studied, we hypothesise that it would be more suitable to use the sphere model for more round shaped eggs and the egg-shaped ovoid model if the examined eggs are more conical. The choice of the proposed transformation technique would be applicable not only for the needs of poultry industry but also in ornithological, basically zoological studies when handling the varieties of eggs of different shapes. The experimental results show that the method proposed is accurate, reliable, robust and fast when coupled and assisted with the digital imaging and image processing techniques, and can serve as a basis for developing an appropriate instrumental technology and bringing it into the practice of poultry enterprises and hatcheries

Measurement of the neutral axis in avian eggshells reveals which species conform to the golden ratio

Avian eggs represent a striking evolutionary adaptation for which shell thickness is crucial. An understudied eggshell property includes the neutral axis, a line that is drawn through any bent structure and whose precise location is characterized by the k‐factor. Previous studies have established that, for chicken eggs, mean k corresponds to the golden ratio (Φ = 1.618, or 0.618 in its reciprocal form). We hypothesized whether such an arrangement of the neutral axis conforms to the eggshell of any bird or only to eggshells with a certain set of geometric parameters. Implementing a suite of innovative methodological approaches, we investigated variations in k of 435 avian species, exploring which correspond to Φ. We found that mean k is highly variable among birds and does not always conform to Φ, being much lower in spherical and ellipsoid eggs and higher in pyriform eggs. While 21 species had k values within 0.618 ± 0.02 (including four falcon species) and the Falconinae subfamily (six species) revealed a mean of 0.618, it is predominantly domesticated species (chicken, ducks, and geese) that lay eggs whose neutral axis corresponds to the golden ratio. Thus, the study of the mathematical secrets of the eggshell related to the golden ratio of its neutral axis suggests its species‐specific signatures in birds