In ovo sexing of eggs from brown breeds with a gender-specific color using visible-near-infrared spectroscopy: effect of incubation day and measurement configuration

Estimating yolk weight of duck eggs using VIS-NIR Spectroscopy and RGB images and whole egg weights

Duck eggs are widely-consumed food and cooking ingredient. The heavier yolk weight (YW) corresponds to a larger size and greater value. However, there is no nondestructive method available to estimate the weight of the yolk. Accurate weight prediction of duck egg yolks must combine both phenotypic and internal information. In this research, we used Visible-Near Infrared (VIS-NIR) spectroscopy to obtain internal information of duck eggs, and a high-definition camera to capture their phenotypic features. YW was predicted by combining the reduced spectral and RGB image information with the whole egg weight. We also investigated the impact of color and thickness of the duck egg on spectral transmittance (ST), as these factors can influence the extent of ST. The results showed that the spectral curves of duck eggs produced 2 peaks and 1 valley, which may be caused by the dual-frequency absorption of the C-H group and O-H group, and can be used to symbolize the internal information of duck eggs. The ST was somewhat affected by the color and thickness of the duck eggshell. Before modelling, Principal component analysis (PCA) was used to significantly reduce the dimensionality of the RGB image with spectral data. A partial least squares regression (PLSR) model was utilized to fit all the features. The test set yielded a coefficient of determination (R2) of 0.82 and a Root Mean Squared Error (RMSE) of 1.05 g. After removing the eggshell's color and thickness features, the model showed an R2 of 0.79 and an RMSE of 1.11 g. This study demonstrated that the yolk weight of duck eggs can be estimated using VIS-NIR spectroscopy, RGB images and whole egg weight. Furthermore, the effects of shell color and thickness can be neglected.

Allantoic Fluid-Based qPCR for Early Onset In Ovo Sexing

The day-old male chick culling remains a welfare issue in the poultry industry. Several governments have prohibited this practice, pushing hatcheries to seek alternatives. Although different solutions exist for solving this problem, sex determination during the embryo's incubation (in ovo sexing) is considered the most suitable one among the consumers and industry. However, to be industrialized, in ovo sexing technologies must meet several requirements: compatibility with all egg colors and early developmental stages while maintaining a high hatchability rate and accuracy at low cost and high throughput. To meet these requirements, we studied the use of the sexual genes HINTW (female-specific) and DMRT-1 (both sexes) at incubation days 6-9. By utilizing the quantitative polymerase chain reaction in allantoic fluid (AF) samples, our study confirmed female-specific HINTW detection on all days without any significant detrimental effects on embryo development. We achieved 95% sexing accuracy using the HINTW cycle threshold (Ct) alone and 100% accuracy rate when using Δλ values (difference between the HINTW and DMRT-1 Ct). In conclusion, the developed assay can provide information about AF as a sample for in ovo sexing and open new industrial possibilities for faster and cheaper assays.

Sex-specific transcriptome of the chicken chorioallantoic membrane

Dimorphism between male and female embryos has been demonstrated in many animal species, including chicken species. Likewise, extraembryonic membranes such as the chorioallantoic membrane (CAM) are likely to exhibit a sex-specific profile. Analysis of the previously published RNA-seq data of the chicken CAM sampled at two incubation times, revealed 783 differentially expressed genes between the CAM of male and female embryos. The expression of some of these genes is sex-dependant only at one or other stage of development, while 415 genes are sex-dependant at both developmental stages. These genes include well-known sex-determining and sex-differentiation genes (DMRT1, HEGM, etc.), and are mainly located on sex chromosomes. This study provides evidence that gene expression of extra-embryonic membranes is differentially regulated between male and female embryos. As such, a better characterisation of associated mechanisms should facilitate the identification of new sex-specific biomarkers.

The British Ixworth: individual growth and egg production of a purebred dual-purpose chicken

1. Killing male one-day-old chicks, especially from layer lines, is banned in some European countries. Therefore, dual-purpose chickens, where each sex is used for meat and egg production, respectively, offer an alternative production solution. This study evaluated the British purebred breed Ixworth as a dual-purpose chicken for meat and egg production.2. Ixworth chicks (n = 167) were hatched and reared mixed-sex in a floor housing system, with two groups receiving a commercial pullet diet (treatment 1) and two groups receiving a diet composed for males of layer lines (treatment 2). Individual chick performance data were recorded. Males were slaughtered at 12 weeks of age, and their growth rate and carcase variables were analysed. All hens were continuously reared on the pullet diet and kept in a free-range system from 20 weeks old for one laying period (52 weeks). In addition, group-based feed consumption and mortality were recorded.3. Cockerels in treatment 1 and 2 showed significantly different [T(88) = -2.846, P = 0.003] growth rates (25.3 vs. 27.4 g/day) and average final weights (2166 g vs. 2344 g). The hens in treatment 1 (n = 41) laid an average of 193 eggs per hen housed (mean egg weight: 56.9 g), whereas those in treatment 2 (n = 35) laid 195 eggs per hen housed (mean egg weight: 56.5 g). Nest acceptance was >97.5% and feed consumption was up to 140 g/bird/day.4. The results showed that the Ixworth may be a suitable breed for dual-purpose use and could be improved through selective breeding, offering potential for preservation of this local breed as well as general biodiversity in poultry farming.

Sustainable animal production: exploring the benefits of sperm sexing technologies in addressing critical industry challenges

The sex of the animals is of paramount importance in many animal production systems. This is particularly evident in the production of milk or in breeding programs focused on the production of female animals. In some cases, slaughter or euthanasia of animals of the unwanted sex becomes the only solution, highlighting ethical and economic concerns. As global demand for food continues to rise, the importance of addressing these issues becomes more evident. Reproductive technologies, such as sperm sexing techniques, may hold the key to addressing both animal welfare and the sustainability of animal production. The use of semen enriched with sperm capable of producing offspring of the desired sex can serve as a valuable tool for producers to exert greater control over production outcomes, not only helping to mitigate welfare issues related to the unnecessary premature death of unwanted offspring but also providing a possible ally in the face of stricter animal welfare guidelines. In addition, sexed semen can also contribute to financial gains and reduce greenhouse gas emissions and food waste associated with the less profitable part of the herd. This paper explores the positive impacts that sperm sexing can have on animal welfare, economy, and environment. It also discusses currently available options and strategies for more successful implementation of sexed semen. Partnerships between companies and scientists will be essential to find innovative ways to adapt current production systems and develop sperm sexing technologies that apply to most livestock industries.

Non-destructive optical sensing technologies for advancing the egg industry toward Industry 4.0: A review

The egg is considered one of the best sources of dietary protein, and has an important role in human growth and development. With the increase in the world's population, per capita egg consumption is also increasing. Ground-breaking technological developments have led to numerous inventions like the Internet of Things (IoT), various optical sensors, robotics, artificial intelligence (AI), big data, and cloud computing, transforming the conventional industry into a smart and sustainable egg industry, also known as Egg Industry 4.0 (EI 4.0). The EI 4.0 concept has the potential to improve automation, enhance biosecurity, promote the safeguarding of animal welfare, increase intelligent grading and quality inspection, and increase efficiency. For a sustainable Industry 4.0 transformation, it is important to analyze available technologies, the latest research, existing limitations, and prospects. This review examines the existing non-destructive optical sensing technologies for the egg industry. It provides information and insights on the different components of EI 4.0, including emerging EI 4.0 technologies for egg production, quality inspection, and grading. Furthermore, drawbacks of current EI 4.0 technologies, potential workarounds, and future trends were critically analyzed. This review can help policymakers, industrialists, and academicians to better understand the integration of non-destructive technologies and automation. This integration has the potential to increase productivity, improve quality control, and optimize resource management toward sustainable development of the egg industry.

A review of the recent advances for the in ovo sexing of chicken embryos using optical sensing techniques

The culling of day-old male chicks has caused ethical and economic concerns. Traditional approaches for detecting the in ovo sex of chicken embryos involve opening the eggshell and inner membrane, which are destructive, time-consuming, and inefficient. Therefore, noncontact optical sensing techniques have been examined for the in ovo sexing of chicken embryos. Compared with traditional methods, optical sensing can increase determination throughput and frequency for the rapid sexing of chicken embryos. This paper presented a comprehensive review of the different optical sensing techniques used for the in ovo sexing of chicken embryos, including visible and near-infrared (Vis-NIR) spectroscopy, hyperspectral imaging, Raman spectroscopy, fluorescence spectroscopy, and machine vision, discussing their advantages and disadvantages. In addition, the latest research regarding different detection algorithms and models for the in ovo sexing of chicken embryos was summarized. Therefore, this paper provides updated information regarding the optical sensing techniques that can be used in the poultry industry and related research.

Trends in in ovo sexing technologies: insights and interpretation from papers and patents

Numerous researchers and institutions have been developing in ovo sexing technologies to improve animal welfare by identifying male embryos in an early embryonic stage and disposing of them before pain perception. This review gives a complete overview of the technological approaches reported in papers and patents by performing a thorough search using Web of Science and Patstat/Espacenet databases for papers and patents, respectively. Based on a total of 49 papers and 115 patent families reported until May 2023 worldwide, 11 technology categories were defined: 6 non-optical and 5 optical techniques. Every category was described for its characteristics while assessing its potential for application. Next, the dynamics of the publications of in ovo sexing techniques in both paper and patent fields were described through growth curves, and the interest or actual status was visualized using the number of paper citations and the actual legal status of the patents. When comparing the reported technologies in papers to those in patents, scientific gaps were observed, as some of the patented technologies were not reported in the scientific literature, e.g., ion mobility and mass spectrometry approaches. Generally, more diverse approaches in all categories were found in patents, although they do require more scientific evidence through papers or industrial adoption to prove their robustness. Moreover, although there is a recent trend for non-invasive techniques, invasive methods like analyzing DNA through PCR or hormones through immunosensing are still being reported (and might continue to be) in papers and patents. It was also observed that none of the technologies complies with all the industry requirements, although 5 companies already entered the market. On the one hand, more research and harmony between consumers, industry, and governments is necessary. On the other hand, close monitoring of the market performance of the currently available techniques will offer valuable insights into the potential and expectations of in ovo sexing techniques in the poultry industry.

Highly sensitive and quick in ovo sexing of domestic chicken eggs by two-wavelength fluorescence spectroscopy

The in ovo sexing of chicken eggs is a current task and a prerequisite to overcome the mass killing of male day-old chicks from laying lines. Although various methods have been developed and tested in recent years, practicable methods for sex determination are still missing which can be applicated in poultry hatcheries before the chicken embryo is capable of nociception and pain sensation. Optical spectroscopic methods enable an early determination of the sex. In this study, a novel method based on two-wavelength in ovo fluorescence excitation is described. More than 1600 eggs were examined. In ovo fluorescence was sequentially excited at 532 nm and 785 nm. The fluorescence intensities of the spectral regions behave inversely with respect to sex. It is shown that the observed sex-related differences in the fluorescence intensities are based on the embryonic hemoglobin synthesis. The accuracy of sex determination is 96% for both sexes. The hatching rate is not reduced compared to an equivalent reference group.