Relationship between hatchling length and weight on later productive performance in broilers

Hatchling length and weight are used as tools to measure hatchling quality. However, the relationship between these parameters and later performance are not well known. This review evaluates the relationship between hatchling length or weight and slaughter weight, breast meat yield and feed conversion ratio (FCR) in both male and female broilers. Datasets from two trials were compared. In the first, hatchling length and weight of 100 male and 100 female broilers were measured and body weight and breast meat yield were determined at 38 days of age. In experiment 2, hatchling length of 187 female and 230 male broilers was measured and body weight was determined at 21 and 42 days of age. Feed intake was determined between 21 and 42 days of age. In both experiments, male broilers showed a positive relationship between hatchling length and slaughter weight or breast meat yield, but no relationship was found with hatchling weight. The relationship between hatchling length and performance in female broilers differed between the two experiments. In female broilers, a negative relationship between hatchling weight and breast meat yield was found. No relationship between hatchling length and FCR in both male and female broilers was found. From this limited dataset, it can be concluded that hatchling length seems to be a better parameter to predict subsequent chick performance, excluding FCR, than hatchling weight, but gender needs to be taken into accoun

Meeting embryonic requirements of broilers throughout incubation: a review

During incubation of chicken embryos, environmental conditions, such as temperature, relative humidity, and CO2 concentration, must be controlled to meet embryonic requirements that change during the different phases of embryonic development. In the current review, the effects of embryo temperature, egg weight loss, and CO2 concentration on hatchability, hatchling quality, and subsequent performance are discussed from an embryonic point of view. In addition, new insights related to the incubation process are described. Several studies have shown that a constant eggshell temperature (EST) of 37.5 to 38.0 degrees C throughout incubation results in the highest hatchability, hatchling quality, and subsequent performance. Egg weight loss must be between 6.5 and 14.0% of the initial egg weight, to obtain an adequate air cell size before the embryo internally pips. An increased CO2 concentration during the developmental phase of incubation (first 10 days) can accelerate embryonic development and hatchability, but the physiological mechanisms of this acceleration are not completely understood. Effects of ar increased CO2 concentration during late incubation also need further investigation. The preincubation warming profile, thermal manipulation, and in ovo feeding are new insights related to the incubation process and show that the optimal situation for the embryo during incubation highly depends on the conditions of the eggs before (storage duration) and during incubation (environmental conditions) and on the conditions of the chickens after hatching (environmental temperature)

The chicken embryo and its micro environment during egg storage and early incubation

When egg storage periods are prolonged (>7 days), hatchability and chick quality declines. The reason for this decline has been investigated, but is still not completely understood. At oviposition the developmental stage of the chicken embryo varies and so do the total number of viable cells. During storage, changes can occur in the embryo. Embryo viability at the end of storage seems to be dependent on the number of viable cells and the developmental stage of the embryo at oviposition. When the hypoblast is completely formed (during the quiescent developmental stage), the embryo seems to be more able to endure prolonged storage periods than embryos that are less or more advanced. During storage, changes also occur in egg characteristics such as albumen viscosity, albumen pH and yolk pH. There appears to be an interaction between albumen pH and embryo viability during early incubation and perhaps also during storage. An albumen pH of 8.2 seems to be optimal for embryo development. Albumen pH may influence embryo viability, but embryo viability may in turn, affect albumen pH. It has been hypothesised that an embryo in which the hypoblast is completely formed is better able to provide an effective barrier between the internal embryo and the exterior (yolk and albumen) and/or is better able to produce sufficient amount of carbon dioxide, which will reduce the pH level in the micro environment of the embryo to the optimal pH of 8.2. It appears that, to maintain hatchability and chick quality after prolonged storage periods, embryonic development should be advanced to the stage in which the hypoblast is completely formed or the atmosphere during storage and early incubation should be altered in such a way that albumen pH is maintained at the optimal level of 8.2

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO–Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ ≲ 4×10−15. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models

Performance analysis of a palletizing system

When designing the layout of the material handling system for a warehouse there is a need for the analysis of overall system performance. Since warehouses are typically very large and complex systems it is infeasible to build a simulation model for the entire system. Our approach is to divide the system into subsystems that are small enough to be captured in simulation models. These models can then later be assembled to acquire a simulation model of the entire system. In this case study we assess the feasibility of this approach by creating a simulation model of a part of a warehouse and verify whether it can be used to embed it in a larger simulation model. The subsystem we use for our case study is a container unloading and automatic palletizing system. This system is chosen because it has already been studied extensively using another simulation tool. We also do a performance analysis of this system in order to come to an optimal layout for this subsystem as well as to reproduce the results of the earlier study for validation. For our performance analysis we created a chi model of the unloading and palletizing area. The process algebra chi has been extensively used for modeling and simulation of real-time manufacturing systems. Our case study is also used as a means to assess the suitability of chi for modeling and simulation in a logistics environment. Our experiments resulted in roughly the same outcomes as the earlier study. It turns out that for the required throughput the layout chosen in that study is optimal. We also concluded that chi is perfectly suitable for modeling logistic systems. Considering the extensive time it takes to run simulations of a rather small part of a warehouse using chi, we conclude that it is infeasible to perform simulations of entire warehousing systems by integrating the simulation models of all subsystems into one simulation model. To overcome this problem, aggregate modeling can be used

Effects of eggshell temperature pattern during incubation on tibia characteristics of broiler chickens at slaughter age

This study was designed to determine effects of eggshell temperature (EST) pattern in week 2 and week 3 of incubation on tibia development of broiler chickens at slaughter age. A total of 468 Ross 308 eggs were incubated at an EST of 37.8°C from incubation day (E) 0 to E7. Thereafter, a 2 × 2 factorial arrangement with 2 EST (37.8°C and 38.9°C) from E8 to E14 and 2 EST (36.7°C and 37.8°C) from E15 till hatch was applied. After hatching, chickens were reared until slaughter age with the 4 EST treatments and 8 replicates per treatment. At day 41 and 42, one male chicken per replicate per day was selected, and hock burn and food pad dermatitis were scored. Rotated tibia, tibia dyschondroplasia, epiphyseal plate abnormalities, bacterial chondronecrosis with osteomyelitis, and epiphysiolysis were assessed. Tibia weight, length, thickness, head thickness, and robusticity index were determined. X-ray analyses (osseous volume, pore volume, total volume, volume fraction, mineral content, and mineral density) and a 3-point bending test (ultimate strength, yield strength, stiffness, energy to fracture, and elastic modulus) were performed. A high EST (38.9°C) in week 2 of incubation, followed by a normal EST (37.8°C) in week 3 resulted in higher mineral content (P = 0.001), mineral density (P = 0.002), ultimate strength (P = 0.04), yield strength (P = 0.03), and stiffness (P = 0.05) compared with the other 3 EST groups (week 2 × week 3 interaction). A high EST (38.9°C) in week 2 of incubation, regardless of the EST in week 3, resulted in a higher tibia weight (P < 0.001), thickness (P = 0.05), osseous volume (P < 0.001), and total volume (P < 0.001) than a normal EST (37.8°C). It can be concluded that 1.1°C higher EST than normal in week 2 of incubation appears to stimulate tibia morphological, biophysical, and mechanical characteristics of broiler chickens at slaughter age. Additionally, a 1.1°C lower EST in week 3 of incubation appears to have negative effects on tibia characteristics, particularly in interaction with the EST in week 2 of incubation.</p

Evidence for virtual Compton scattering from the proton

In virtual Compton scattering an electron is scattered off a nucleon such that the nucleon emits a photon. We show that these events can be selected experimentally, and present the first evidence for virtual Compton scattering from the proton in data obtained at the Stanford Linear Accelerator Center. The angular and energy dependence of the data is well described by a calculation that includes the coherent sum of electron and proton radiation

Self-referring patients at the emergency department: appropriateness of ED use and motives for self-referral

© 2014, van der Linden et al.; licensee Springer. Background: Nearly all Dutch citizens have a general practitioner (GP), acting as a gatekeeper to secondary care. Some patients bypass the GP and present to the emergency department (ED). To make best use of existing emergency care, Dutch health policy makers and insurance companies have proposed the integration of EDs and GP cooperatives (GPCs) into one facility. In this study, we examined ED use and assessed the characteristics of self-referrals and non-self-referrals, their need for hospital emergency care and self-referrals' motives for presenting at the ED. Methods: A descriptive cohort study was conducted in a Dutch level 1 trauma centre. Differences in patient characteristics, time of presentation and need for hospital emergency care were analysed using χ2 tests and t tests. A patient was considered to need hospital emergency care when he/she was admitted to the hospital, had an extremity fracture and/or when diagnostic tests were performed. Main determinants of self-referral were identified via logistic regression. Results: Of the 5,003 consecutive ED patients registering within the 5-week study period, 3,028 (60.5%) were self-referrals. Thirty-nine percent of the self-referrals had urgent acuity levels, as opposed to 65% of the non-self-referrals. Self-referrals more often suffered from injuries (49 vs. 20%). One third of the self-referrals presented during office hours. Of all self-referrals, 51% needed hospital emergency care. Younger age; non-urgent acuity level; chest pain, ear, nose or throat problems; and injuries were independent predictors for self-referral. Most cited motives for self-referring were ‘accessibility and convenience’ and perceived ‘medical necessity’. Conclusions: A substantial part of the self-referrals needed hospital emergency care. The 49% self-referrals who were eligible for GP care presented during out-of-hours as well as during office hours. This calls for an integrative approach to this health care problem

A study of the neglected Galactic HII region NGC 2579 and its companion ESO 370-9

The Galactic HII region NGC 2579 has stayed undeservedly unexplored due to identification problems which persisted until recently. Both NGC 2579 and its companion ESO 370-9 have been misclassified as planetary or reflection nebula, confused with each other and with other objects. Due to its high surface brightness, high excitation, angular size of few arcminutes and relatively low interstellar extinction, NGC 2579 is an ideal object for investigations in the optical range. Located in the outer Galaxy, NGC 2579 is an excellent object for studying the Galactic chemical abundance gradients. In this paper we present the first comprehensive observational study on the nebular and stellar properties of NGC 2579 and ESO 370-9, including the determination of electron temperature, density structure, chemical composition, kinematics, distance, and the identification and spectral classification of the ionizing stars, and discuss the nature of ESO 370-9. Long slit spectrophotometric data in the optical range were used to derive the nebular electron temperature, density and chemical abundances and for the spectral classification of the ionizing star candidates. Halpha and UBV CCD photometry was carried out to derive stellar distances from spectroscopic parallax and to measure the ionizing photon flux.Comment: To be published in Astronomy & Astrophysic