Feeding motivation on the incidence of floor eggs and extraneously calcified eggs laid by broiler breeder hens

1. Commercial broiler breeder hens lay many eggs on the floor rather than in nest boxes provided. A study was conducted to determine whether feeding feed-restricted broiler breeder hens during the sitting phase of nesting results in a higher incidence of floor eggs and/or retained eggs. 2. Sixty broiler breeder females (Ross 308) were randomly assigned to 6 deep litter pens containing 10 nest-boxes. At 35 weeks of age and for 9 weeks, feed was distributed to all pens at lights-on every second day (fed normally, FN). On alternate days (feeding delay, FD), feed was distributed when 2-3 hens/pen were sitting in a nest box. Behaviour was sampled at 41 weeks of age, for 26 d. Eggs and egg location data were collected daily, and eggs were scored for extra-cuticular calcium. 3. Of 81 instances in which the hen was sitting firmly in a nest box at the time of feeding, on 80 instances the hen left the nest-box to feed, and on one instance the hen laid her egg then exited to the feeder. Of these 80 instances, on 58 occasions the hen returned to a nest-box to lay her egg; on 12 the hen returned to the nest-box but laid no egg; on 7 the hen did not return to the nest box and laid no egg; and on three the hen laid her egg on the floor. 4. Mean floor egg percentage was 13·3 ± 3·2% on FN and 13·3 ± 4·7% on FD days; these did not differ significantly. 5. The mean extra-cuticular calcium score over all pens was 0·9 ± 0·06 on FN days and 1·2 ± 0·06 on FD days; these differed significantly. 6. In conclusion, feeding broiler breeder hens during nesting results in a conflict between feeding and nesting motivation and higher numbers of extraneously calcified eggs, but does not result in a significant increase in floor eggs even though nesting hens will leave the nest box for food.     

Abnormal characteristics of eggs laid by hens fed with high levels of cottonseed meal

In China, consumers sometimes get special eggs, which are characterized by the pasty, firm, and elastic texture of yolk from hard-boiled eggs and are usually called “rubber eggs” by Chinese customers. Consumers do not like the texture of rubber eggs and often associate the odd texture of the yolk to food safety risks. The objective of this study was to assess the physical and chemical characteristics of these eggs. A total of 200 46-week-old Hy-Line Brown laying hens were divided into 2 groups and were fed for 2 weeks. One group was fed on a corn-soybean meal based diet (BD) and served as control whereas the second group’s diet contained 6% cottonseed meal (CSM), which was in replacement of the SBW. The yolks of hard-cooked eggs of the CSM group had harder and more elastic yolks than those of the control group (P < 0.05). Also, the levels of stearic and myristic acids in the yolk of the CSM group also were increased (P < 0.01), while the myristoleic, pentadecanoic, arachidic, cis-11-eicosenoic and cis-11, 14-eicosadienoic acids and crude protein, fat, phospholipids, chloride, calcium, and iron were decreased (P < 0.05). In conclusion, hens fed a diet that was incorporated with 6% cottonseed meal laid eggs that had unique physical and chemical characteristics and lower nutritional values. These results might help to guide limited incorporation of CSM in laying hen diet, and provide some evidences on the mechanism of the observed physical and chemical changes.     

Influence of dietary osteolathyrogens on the ultrastructure of shell and membranes of eggs from laying hens

1. Laying hens were fed osteolathyrogens, either semicarbazide hy‐drochloride at 0.3 g/kg or β‐aminopropionitrile fumarate at 0.6 g/kg, to examine their effects upon the ultrastructure of shell and shell membranes by scanning electron microscopy.

2. Effects of the 2 lathyrogens were similar. Compared with the highly‐branched network of fine fibres in normal membranes, there is widespread lack of separation of fibres in lathyritic specimens and hence, uneven distribution of nucleation sites. Pores are also uneven in size and distribution, which can account for increased permeability.

3. Establishment between shell and membranes is reduced. Within the cone layer both type A and type B mammillary bodies occur. Large interstitial spaces and late fusion of the palisade layer indicate reduced resistance to fracture.     

Learning ability of 1-d-old partridges (Alectoris rufa) from eggs laid by hens fed with different n-3 fatty acid concentrations

1.?The diets of commercial strains of laying partridge are usually lower in polyunsaturated fatty acids (PUFA) and n-3 fatty acids than the diets of wild partridges. The aim of this experiment was to examine the effects of three different PUFA and n-3 concentrations in partridge laying diets.

2.?Offspring learning ability (passive avoidance test of 1-d-old chicks) was used to assess the effect of three different maternal diets (144 chicks were tested for each diet). A negative experience, allowing the bird to peck a bead bathed in a bitter liquid (methyl anthranilate—MA), was used for this purpose. The adults had been fed one of three different diets with n-3 contents of 0·48, 4·04 or 7·60 g/kg.

3.?There was better memory retention in the offspring of adults fed the intermediate n-3 content compared to those fed the lower content. Discrimination ratio (DR) of the latency time toward the wrong (red) bead was less for the lower n-3 content (0·48) than for the middle n-3 PUFA content (0·43). DR of the number of pecks toward the wrong beads was greater for the lower n-3 content (0·51) than for the middle n-3 PUFA content (0·71).

4.?The partridges fed the diet containing the lowest concentration of n-3 and PUFA were unable to express the expected behavioural score (neural embryo development index) given the genetic characteristics of the animals.     

Colonization of specific regions of the reproductive tract and deposition at different locations inside eggs laid by hens infected with Salmonella enteritidis or Salmonella heidelberg

Internal contamination of eggs by Salmonella Enteritidis has been a significant source of human illness for several decades and is the focus of a recently proposed U.S. Food and Drug Administration regulatory plan. Salmonella Heidelberg has also been identified as an egg-transmitted human pathogen. The deposition of Salmonella strains inside eggs is apparently a consequence of reproductive tissue colonization in infected laying hens, but the relationship between colonization of specific regions of the reproductive tract and deposition in different locations within eggs is not well documented. In the present study, groups of laying hens were experimentally infected with large oral doses of Salmonella Heidelberg, Salmonella Enteritidis phage type 13a, or Salmonella Enteritidis phage type 14b. For all of these isolates, the overall frequency of ovarian colonization (34.0%) was significantly higher than the frequency of recovery from either the upper (22.9%) or lower (18.1%) regions of the oviduct. No significant differences were observed between the frequencies of Salmonella isolation from egg yolk and albumen (4.0% and 3.3%, respectively). Some significant differences between Salmonella isolates were observed in the frequency of recovery from eggs, but not in the frequency or patterns of recovery from reproductive organs. Accordingly, although the ability of these Salmonella isolates to colonize different regions of the reproductive tract in laying hens was reflected in deposition in both yolk and albumen, there was no indication that any specific affinity of individual isolates for particular regions of this tract produced distinctive patterns of deposition in eggs.     

Selection for egg shell strength in laying hens using shell membrane characteristics

1. Divergent selection for attachment strength between the shell membrane and the calcium shell was performed in a White Leghorn strain. Multivariate analysis was used to estimate genetic parameters for shell membrane measurements and shell thickness. The aim was to investigate the possibility of improving shell strength in laying hens by selecting for increased attachment strength.

2. A significant direct selection response for attachment strength was achieved. There was a favourable correlated selection differential in the frequency of cracked eggs which resulted in a nonsignificant but favourable, correlated response. Selection for a strong attachment resulted in a thinner egg shell, and vice versa. Heritabilities were all relatively high (0.30 to 0.70). Most of the genetic correlations were in agreement with the achieved correlated responses.

3. Two factors that probably contributed to the responses in egg shell thickness were an unfavourable genetic correlation between attachment strength and shell thickness, and natural selection against changes in attachment strength, in the form of increased mortality during incubation and hatching. Problems connected with breeding for increased shell strength are discussed.     

绿壳蛋土鸡若干种质特性的研究

实验对绿壳蛋土鸡生长发育等有关特性进行观测，结果表明：公鸡的生长速度比母鸡快，到13周龄时公母鸡体重分别为1355g和1067g；公鸡的胫长、胫围、龙骨长、胸角测定值高于母鸡，而体斜长、胸围、胸宽、胸深公母鸡相差不大；上述各体尺与体重的相关系数分别为-0．623、0．278、0．868、-0．013、-0．081、0．585、0．608和0．108：13周龄公母鸡在屠宰性状方面存在差异，公鸡的腿肌率、胸肌率、翅膀率、全净膛率和半净膛率分别为26．2％、18.3％、13．8％、89．2％和70．9％，母鸡为19．4％、13．9％、11．0％、90．4％和72．5％，公鸡的腿肌率、胸肌率和翅膀率高于母鸡，而半净膛率和全净膛率却比母鸡低。     

Deposition of phage type 4 and 13a Salmonella enteritidis strains in the yolk and albumen of eggs laid by experimentally infected hens

Because egg yolk and albumen differ substantially in their abilities to support bacterial growth, the initial level and location of Salmonella enteritidis deposition are critical for determining whether proposed standards for refrigerating eggs are likely to protect public health by preventing extensive microbial multiplication. In the present study, three groups of laying hens were infected with oral doses of approximately 10(9) cells of different S. enteritidis strains (two were phage type 4 and one was phage type 13a) in two replicate trials. For all three S. enteritidis strains, the incidence of yolk contamination (approximately 2.5% overall) was significantly greater than the incidence of albumen contamination (approximately 0.5% overall). The phage type 13a strain was less often isolated from fecal samples at 2 wk post-inoculation than were the phage type 4 strains, but no significant differences between strains were observed in the incidence of egg contamination. Most freshly laid contaminated eggs contained fewer than 1 S. enteritidis cell/ml of egg yolk or albumen, and no sample contained more than 67 S. enteritidis cells/ml.     

关于温度影响蚕种产附的体会

蚕种产附是指平附种的外观性状,主要包括蚕种卵面分布的整齐度,卵色一致性等。产附好的蚕种,蚕卵均匀平整地分布于整张蚕种纸,卵色一致,生种、不受精卵少,即生产上讲的产附平整。反之,蚕卵分布疏密相间,卵面有堆叠或空缺,生种、不受精卵多,即蚕种产附差。蚕种     

Exogenous estradiol improves shell strength in laying hens at the end of the laying period

Background

Cracked shells, due to age related reduction of shell quality, are a costly problem for the industry. Parallel to reduced shell quality the skeleton becomes brittle resulting in bone fractures. Calcium, a main prerequisite for both eggshell and bone, is regulated by estrogen in a complex manner. The effects of estrogen, given in a low continuous dose, were studied regarding factors involved in age related changes in shell quality and bone strength of laying hens. A pellet containing 0.385 mg estradiol 3-benzoate (21-day-release) or placebo was inserted subcutaneously in 20 birds each of Lohmann Selected Leghorn (LSL) and Lohmann Brown (LB) at 70 weeks of age. Eggs were collected before and during the experiment for shell quality measurements. Blood samples for analysis of total calcium were taken three days after the insertion and at sacrifice (72 weeks). Right femur was used for bone strength measurements and tissue samples from duodenum and shell gland were processed for morphology, immunohistochemical localization of estrogen receptors (ERα, ERβ), plasma membrane calcium ATPase (PMCA) and histochemical localization of carbonic anhydrase (CA).

Results

Estrogen treatment increased shell thickness of both hybrids. In addition, shell weight and shell deformation improved in eggs from the brown hybrids. The more pronounced effect on eggs from the brown hybrid may be due to a change in sensitivity to estrogen, especially in surface epithelial cells of the shell gland, shown as an altered ratio between ERα and ERβ. A regulatory effect of estrogen on CA activity, but not PMCA, was seen in both duodenum and shell gland, and a possible connection to shell quality is discussed. Bone strength was unaffected by treatment, but femur was stronger in LSL birds suggesting that the hybrids differ in calcium allocation between shell and bone at the end of the laying period. Plasma calcium concentrations and egg production were unaffected.

Conclusions

A low continuous dose of estrogen improves shell strength but not bone strength in laying hens at the end of the laying period.     

Correlations between shape index and shell deformation of hens’ eggs over a laying year

The egg shape index and shell deformation of 2466 pullet and 2214 hen eggs have been studied each week over a period of 45 weeks. The weekly and 5‐week averages were utilised for correlation analysis.

A pronounced negative correlation between shape index and shell deformation variations was found for both pullet and hen eggs. The pullet egg correlation coefficient, determined on the basis of the weekly and 5‐week averages, was ‐0.605 and ‐0.885, respectively; while the corresponding values for hen eggs were ‐0.433 and ‐0.510.

It has been pointed out that although a correlated variation of shape index and shell deformation with time might be due to specific conditions, it is reasonable to assume that if the time‐dependent changes of the relevant properties were taken into account in the investigations, an improved correlation might be expected.     

Influence of the type of management system on corticosterone transfer into eggs in laying hens

The effect of free-range versus cage management system on corticosterone transfer into the eggs was studied in laying hens. Hungarian Yellow laying hens (age: 21 weeks, body weight: 2.0 +/- 0.5 kg) were divided into two groups in the spring: Group I, free-range keeping (n=15 layers, density: > 0.5 bird/m2) in outdoor runs, with continuous access to a commercial layer feed; Group II, hens kept in battery cages (n=17 layers, density: 2 birds/m2, natural light, continuous access to feed and water). Eggs were collected after a one-week adaptation period on days 2, 7 and 16. Corticosterone (CST) was extracted from homogenised egg samples using an ASE-200 Accelerated Solvent Extractor and then assayed by liquid chromatography linked with tandem mass spectrometry (LC-MS/MS) [Thermo Quest Surveyor high-performance liquid chromatography (HPLC) interfaced via Atmospheric Pressure Chemical Ionisation (APCI) ion source to Finnigan/Thermo Quest LCQ Deca MS/MS] using dexamethasone as internal standard with positive APCI ionisation. CST concentrations of whole eggs laid by free-range hens on days 2, 7 and 16 were 0.370 +/- 0.218, 0.259 +/- 0.066 and 0.915 +/- 0.745 ng x g(-1), respectively, while those of eggs laid by caged hens were 0.206 +/- 0.157, 0.223 +/- 0.165 and 0.184 +/- 0.110 ng x g(-1) at the above sampling times. It is concluded that in free-range laying hens the sharp changes of environmental weather conditions significantly increased the corticosterone content of eggs, while the environmentally controlled and closed battery cage management technology resulted in relatively uniform corticosterone concentrations in the whole eggs.     

Production of Salmonella enteritidis-contaminated eggs by experimentally infected hens

Laying hens of three different ages were experimentally infected with a strain of Salmonella enteritidis by either oral inoculation or contact transmission. Total egg production was depressed in exposed hens of all three age groups. Persistent intestinal shedding was observed in a small number of hens. Eggs with contents contaminated by S. enteritidis were produced by exposed hens at a high frequency, but only during a fairly short period of time that extended through approximately 1 week postinoculation for older hens and through 2 weeks for younger hens. S. enteritidis was recovered from whole yolks and albumen of these eggs at similar frequencies, but not from the content of yolks. Eggs with contaminated shells were also produced, but at a lower frequency. Contaminated eggs were produced by orally inoculated and contact-exposed hens at similar frequencies. S. enteritidis was not isolated from the contents of eggs laid by hens infected with other S. enteritidis strains.     

Effect of a single injection of adrenaline on shell ultrastructure in a series of eggs from domestic hens

1. Adrenaline (1 mg in 1 ml water) was administered subcutaneously to three hens to determine whether any changes in the shell ultrastructure of subsequent eggs would occur. 2. The egg shells were examined in a scanning electron microscope after plasma etching. 3. The first three eggs laid by each bird after adrenaline injection were compared with previously-collected normal eggs from the same birds and also with control eggs collected over the same period from three hens which had received no adrenaline. 4. The first egg laid following adrenaline treatment was essentially normal but both the second and third eggs showed severe structural disorganisation at all levels, from the mamillary caps up to the cuticular layer. 5. Eggs laid 20 d or more after adrenaline treatment had reverted to normal. 6. The findings suggest that the abnormal eggs laid after hens have been exposed to disturbance or stress are likely to be affected in not only their external appearance but also to be of poor structural quality.     

不同蛋壳颜色鸡蛋品质的比较研究

通过对不同蛋壳颜色蛋品质的比较研究,探讨蛋壳颜色与蛋品质的关系。连续3 d收集新扬州鸡蛋,从中随机选取120只,测定其蛋壳颜色、蛋重、蛋形指数、蛋壳强度、蛋白高度、蛋黄颜色、蛋白重、蛋黄重、蛋壳重和蛋壳厚度,分析蛋壳颜色与蛋品质各指标的关系。结果表明,不同蛋壳颜色的蛋品质间存在着一定差异。不同蛋壳颜色组间蛋重、蛋白重、蛋黄重、蛋形指数、哈氏单位和蛋黄颜色之间差异不显著（P〉0.05）,蛋壳颜色为30～34.9的蛋壳强度、蛋壳厚度与其他各组存在显著差异（P〈0.05）;蛋壳颜色与蛋壳强度、蛋壳重呈显著负相关（P〈0.05）,与蛋壳厚度呈极显著负相关（P〈0.01）。     

Changes in the average weight and shell thickness of eggs produced by hens exposed to high environmental temperatures—A review

Summary The decline in egg weight which occurs at high environmental temperatures (above 26°C) is due mainly to the effect of heat stressper se and not to the effect of diminished feed intake. This is particularly true in the case of the egg shell component, the reduction in thickness of which is apparently due to alkalosis of the blood caused by the loss of excessive amounts of carbon dioxide by panting. The reduction in weight of albumen and yolk is also due mainly to heat stressper se but the explanation of the mechanism involved awaits further investigation.

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Résumé La diminution de poids d'oeufs observée lorsque la température ambiante dépasse 26°C est essentiellement due au choc thermique,per se et n'est pas le résultat de la diminution de la quantité de nourriture ingérée. Pour la réduction de l'épaisseur de la coquille, il appara?t que la modification de ses composants résulte de l'alcalinité du sang elle-même due à une perte considérable de bioxyde de carbone résultant de la précipitation des mouvements respiratoires. La diminution constatée tant de l'albumine que du jaune est également due au choc thermique par lui-même, mais des études complémentaires seront encore nécessaires pour en déterminer le mécanisme.

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Sumario La disminución del peso, de los huevos que ocurre en temperaturas ambientales altas (por encima de 26°C), se debe más que todo a la carga fisiológicaper se debida a la temperatura y no a la disminución en la ingestión de alimentos. Esto es particularmente cierto en el caso de los componentes de la cascara. La reducción del grosor, de la misma, se debe aparentemente, a la alcalosis de la sangre causada por la peridida excesive de dióxido de carbono al respirar agitadamente. La reducción de peso de la albúmina y de la yema, también se debe principalmente a la carga fisiológicaper se debida a la temperatura. La explicación del mecanismo de este ultimo fenómeno, requiere una investigación más profunda.

     

A comparison of the shell strength of eggs from battery and deep‐litter units

The investigation involved 966 light‐hybrid pullets, 366 accommodated in battery cages and 600 kept on deep litter. Samples of their eggs were taken at four stages during the laying year for measurement of shell strength by the deformation technique. The results of these measurements were very similar for eggs produced under the two systems of housing.     

Bone structure and strength at different ages in laying hens and effects of dietary particulate limestone,vitamin K and ascorbic acid

1. A range of bone structural and strength characteristics was determined in laying hens at 15, 25, 50 and 70 weeks of age. The birds were fed up to 25 weeks on diets supplemented with additional vitamin K (10 mg menadione/kg) or ascorbic acid (250 mg/kg) or up to 70 weeks on diets containing limestone in powder or particulate form. 2. There were important effects of age on all bone characteristics. Between 15 and 25 weeks there was a rapid loss of cancellous bone and a rapid accumulation of medullary bone in the proximal tarsometatarsus (PTM). These changes continued at a slower rate up to 70 weeks. Cancellous bone content of the free thoracic vertebra (FTV) also declined after 15 weeks. 3. Breaking strengths of tibia and humerus did not change between 15 and 25 weeks but decreased later in lay. 4. None of the nutritional treatments affected bone characteristics at 15 weeks of age. 5. Increasing the dietary vitamin K supplement from 2 to 12 mg menadione/kg increased cancellous bone volume in the PTM at 25 weeks. 6. Dietary ascorbic acid did not affect any of the bone characteristics measured up to 25 weeks. 7. Particulate limestone resulted in a smaller loss of cancellous bone between 15 and 25 weeks and increased accumulation of medullary bone in the PTM. Breaking strength of the tibia and radiographic densities of tibia and keel were also improved. 8. It is concluded that patterns of bone loss over the lifetime of laying hens vary, depending upon the bone type. Feeding a particulate source of calcium can help to alleviate some of the characteristics of osteoporosis. Supplementation with extra vitamin K may also be beneficial.     

Assessing the breeding efficiency of broiler breeder flocks by measuring sperm transfer into laid eggs

1. The breeding efficiency of broiler flocks was assessed by estimating the numbers of spermatozoa trapped in a 5.5 mm² area of the perivitelline layer of laid eggs.

2. In samples of approximately 60 eggs taken from flocks on the same day, the numbers of spermatozoa ranged from 0 to several hundred.

3. Within each sample of eggs, there appeared to be two distinct populations: eggs in which perivitelline spermatozoa could not be found; and eggs containing spermatozoa for which the logarithm of the number of perivitelline spermatozoa can be approximated by a normal distribution.

4. When data from 15 flocks were considered, the overall flock fertility was linearly correlated with: the median of the number of spermatozoa per 5.5 mm of perivitelline layer (r = 0.678); the mean of positive values of the logarithm of the number of spermatozoa (r = 0.620); and the proportion of sampled eggs in which the number of perivitelline spermatozoa was greater than 0 (r = 0.714).

5. Flock age was the major factor influencing fertility and all the variables of perivitelline sperm distribution.