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

Wat kan de pluimveehouderij leren van de productie van krokodillen?

In Nederland denken we bij een commerciële broederij altijd aan pluimvee, en dan meestal aan kippen of eventueel aan kalkoenen of ander pluimvee. In sommige andere landen worden echter ook andere diersoorten commercieel gebroed. Het productiesysteem voor krokodillen lijkt vrij sterk op een productiesysteem voor kippen, met dit verschil dat het een meerleeftijden systeem is en dat zowel vermeerdering, broederij als opfok en mesterij zich op hetzelfde bedrijf afspeelt. In dit artikel wordt kort beschreven hoe een krokodillenfarm in Zuid-Afrika is opgezet, met speciale aandacht voor het proces van vermeerdering en broederij

Verlaging stikstofaanvoer bij opfok vleeskuikenouderdieren

Naast fosfor wordt in toenemende mate ook aandacht besteed aan het terugdringen van de hoeveelheid stikstof in de mest. In dit artikel worden de eerste resultaten weergegeven van een onderzoek naar de mogelijkheden om de hoeveelheid stikstof in de mest bij opfok van vleeskuikenouderdieren te verminderen

Vochtverlies van broedeieren

In de praktijk wordt bij de bewaring van broedeieren de relatieve luchtvochtigheid in de bewaarruimte op een hoog niveau gehouden, om het vochtverlies van de eieren zoveel mogelijk te beperken. Dit wordt gedaan omdat algemeen wordt aangenomen dat een hoog vochtverlies tijdens de bewaring een negatieve invloed heeft op de broedresultaten

Theoretical and empirical studies on temperature and moisture loss of hatching eggs during the pre-incubation period

In the Netherlands, approximately 800 million hatching eggs per year are produced on highly specialized broiler breeder farms. On this farms, the eggs are produced and stored for several days. Normally once or twice a week the eggs are collected from the farms and transported to the hatchery, where they are set and incubated.Between production of the eggs and setting, a certain amount of mortality occurs in the eggs. As a result of this mortality and because some embryos are not able to complete the pipping process in time, about 10% of the fertile eggs do not hatch. A certain percentage of these eggs are not hatching because the conditions in the period before incubation are not set at a level that is optimal for embryo survival. To minimize the number of non hatching fertile eggs, the conditions during the pre-incubation period must be set at a level that meets the demands of the embryo. In commercial situations, the management decisions concerning the egg handling that have to be taken in the pre-incubation period are mainly influencing the effects of tune, temperature and relative humidity.The aim of the studies presented in this thesis was (1) to formulate analytical equations to calculate the temperature development and moisture loss of hatching eggs, (2) to determine the climatic conditions in the pre-incubation period that can occur in field situations and (3) to determine the influence of these conditions on hatchability.In chapter 1 a review of the literature concerning the treatment of eggs in the pre-incubation period is presented. From this review, it can be concluded that the majority of the research on this subject is done in the period before 1970. The availability of experimental results on this subject with eggs produced by the modem type broiler breeder is limited. In chapter 1, some hypothesis are formulated to explain the influence of storage time and storage temperature on hatchability.With the analytical equations formulated in chapter 2, the effect of climatic conditions on the temperature development and moisture loss of eggs can be calculated. Therefore, climatic conditions that occur in field situations can be evaluated on their influence on the eggs. One of the conclusions from these calculations is that air velocity will have a major influence on internal egg temperature in the second half of the incubation process.In chapter 3 and 4, the results of the calculations based on the equations are compared with measurements. The results show that temperature development and moisture loss of eggs can be predicted rather accurate when eggs are placed in litter nests and roll away nests. When birds have access to litter nests, eggs are warmed by the birds. Under these conditions, accurate calculation of temperature and moisture loss is not possible. During storage, no accurate calculation of temperature and moisture loss could be made, because of natural convection in hatching egg containers and protection of the storage system against moisture loss.In chapter 3, the temperature and moisture loss of eggs during their period in the nest boxes is examined. The results indicate that eggs produced in litter nests are warmed by the birds to a temperature above the minimum level for embryo development Eggs produced in roll-away nests are not warmed by the birds and their cooling process starts immediately after production, with the cooling rate and final temperature level depending on the climatic conditions in the house. Moisture loss of eggs in produced in litter nests is higher than in roll-away nests, but relatively low compared to the total moisture loss during incubation.During storage, temperature and moisture loss characteristics are dependent on the position of the eggs in the containers, the method of storage and the storage conditions (chapter 4). Eggs placed in centre position of containers experience a slow warming and cooling process when compared with eggs in side positions. When eggs are stored on incubator trays, cooling and warming of eggs is more rapidly than when eggs are stored on cardboard trays. The rate of cooling and warming of eggs stored on plastic trays is intermediate. When air velocity is increased, the cooling and warming rate of eggs increases. The use of coverages over containers decreases the rate of temperature change.Moisture loss of eggs in containers can not be calculated directly from temperature and relative humidity of the air surrounding the container. The containers provide a protection against moisture loss, probably due to the presence of a boundary layer around the eggs, which forces the eggs to loose less water than is expected from the climatic conditions.The influence of temperature during the pre-incubation period on hatchability is examined in chapter 5. The results indicate that the influence of storage time and pre-incubation temperature on hatchability is related with age of the flock Pre-incubation treatments that can be classified as having a negative influence on hatchability were more detrimental for eggs of older birds than for eggs of younger birds.The results presented in chapter 5 indicate that hatchability of eggs that has experienced a high temperature during the nesting period is lower than of eggs that has experienced a low temperature in this period. This indicates that eggs produced in litter nests will have a lower hatchability than eggs produced in roll away nests, due to differences in egg temperature. From the results presented in this chapter it can be concluded that eggs of younger birds can be stored for longer periods than eggs of older birds. For both age groups, the combination of longer storage periods and low storage temperature is beneficial for hatchability compared to longer storage periods and high storage temperature. According to the results presented in this chapter, low storage temperatures can also be used when eggs are stored for relatively short periods.In chapter 7, some possible explanations for the reported relations between storage time, storage temperature and bird age are discussed. It is suggested that the development of albumen pH determines the suitability of eggs for storage of eggs and that storage conditions can be evaluated on their influence on the albumen pH development.In chapter 6, the influence of moisture loss during storage on moisture loss during incubation and hatchability is reported. The results presented in this chapter indicate that moisture loss during storage influences moisture loss during incubation. As a result relative humidity during storage has a smaller effect on total amount of moisture lost between oviposition and hatching than would be expected from the amount of moisture lost during storage. Moisture loss during storage had no significant effect on hatchability

Coccidiose bij vleeskuikenouderdieren

Coccidiose is bij de opfok van vleeskuikenouderdieren een voortdurende zorg. De problematiek bij deze ziekte ligt duidelijk anders dan bij bijvoorbeeld vleeskuikens. Enting tegen coccidiose met Paracoxe lijkt goede mogelijkheden voor de toekomst te bieden

Voerschema's bij vleeskuikenouderdieren

Hoewel de proef nog niet geheel is afgesloten kunnen een aantal voorlopige en voorzichtige conclusies worden getrokken: R.d de top kan de voergift snel teruggebracht worden, zonder nadelige gevolgen voor de broedeiproductie in deze periode. Hierdoor ka