scholarly journals EFFECT OF HEAT TREATMENTS DURING HATCHING EGGS STORAGE ON HATCHABILITY TRAITS AND CHICK QUALITY

2019 ◽  
Vol 39 (4) ◽  
pp. 791-808
Author(s):  
Mohamed El-Menawey
Author(s):  
M. K. Singh ◽  
Shive Kumar ◽  
R. K. Sharma ◽  
S. K. Singh ◽  
Brijesh Singh ◽  
...  

A study was conducted to determine the effects of pre-incubation egg parameters on post-incubation parameters in Uttara breeder hens. A total of 2,890 hatching eggs were classified according to three egg weight groups viz. small (44-52 g); medium (53-57 g) and large (58-68 g). Results indicated that large-sized eggs produced chicks with higher hatch-weight than medium and small-sized eggs. However, no differences were observed for fertility and hatchability rates but significant differences were found for chick quality and chick weight. It was therefore concluded from the results of the present study that sorting of eggs by weight prior to incubation might be advantageous in producing uniform size hatchlings to meet specific market demands with focus on breeding for obtaining maximum number of saleable chicks.


Animal Review ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 20-29
Author(s):  
Sherif Kh. El ◽  
El-Gogary M. R ◽  
Hasan R.A ◽  
Ismail F Radwa

This study investigated the effects of pre-storage heating and storage period of hatching eggs on hatchability traits and chick quality of Dokki-4 (Egyptian local strain of chickens) laying hens. A total of 3600 eggs were collected from 46-week-old laying hens. Eggs were distributed in a 3x4 factorial arrangement, with three storage times (4, 8 and 12 days at 18°C and 75% RH) and four heat treatments prior to storage (0, 3, 6 and 9 hours at 37.5°C and 56% RH). Eggs were distributed to twelve treatments of 20 replicates. After storage, eggs were incubated under the normal conditions of incubation at the same time. The results showed that the long storage period increased egg weight loss. Hatchability and chick quality results from 8-12 days stored eggs were lower than eggs stored for 4 days. The 6-hour pre-storage heating system substantially improved egg hatchability and chick quality relative to non-heated or 9-hour heating. Important interactions were observed during pre-storage heating × egg storage time for loss in egg weight, hatchability of total and fertile eggs, embryonic mortality and chick quality. When eggs were stored for more than four days, pre-storage heating of hatching eggs for six hours improved hatchability and chick quality compared to unheated eggs or heated for 9 hours. Conclusively, pre-storage heat treatment beneficially affects hatchability traits and chick quality, especially when hatching eggs are stored for long periods.


Author(s):  
İsmail Durmuş ◽  
Serdar Kamanlı ◽  
Yeliz Kaşko Arıcı ◽  
Mehmet Akif Özcan

This study was conducted to investigate the hatching parameters differences between the hatching eggs which were controlled or not for fertility at 18th day of embryo development in the hatchery unit. Hatching was conducted with hatching eggs of Atak-S commercial layers parent stocks. Four treatment groups were constituted; 1) 95% fertility, fertility control at 18th day, 2) 95% fertility, no fertility control at 18th day, 3) 75% fertility, no fertility control at 18th day and 4) 50% fertility, no fertility control at 18th day. There were no significant differences between the groups in terms of fertility rate, hatching efficiency hatchability of fertile eggs and early-, middle and late period embryo mortality. Chick quality according to Pasgar score chick quality assessment differed significantly between the treatment groups. The results of the present study indicate that transferring of eggs to the hatcher without fertility control at 18th day of embryo development did not affect the hatching results, but chick quality decreased when the fertility rate decreased below 45%.


Author(s):  
S. Mahajan ◽  
M. R. Pinnel ◽  
J. E. Bennett

The microstructural changes in an Fe-Co-V alloy (composition by wt.%: 2.97 V, 48.70 Co, 47.34 Fe and balance impurities, such as C, P and Ni) resulting from different heat treatments have been evaluated by optical metallography and transmission electron microscopy. Results indicate that, on air cooling or quenching into iced-brine from the high temperature single phase ϒ (fcc) field, vanadium can be retained in a supersaturated solid solution (α2) which has bcc structure. For the range of cooling rates employed, a portion of the material appears to undergo the γ-α2 transformation massively and the remainder martensitically. Figure 1 shows dislocation topology in a region that may have transformed martensitically. Dislocations are homogeneously distributed throughout the matrix, and there is no evidence for cell formation. The majority of the dislocations project along the projections of <111> vectors onto the (111) plane, implying that they are predominantly of screw character.


Author(s):  
A. W. West

The influence of the filament microstructure on the critical current density values, Jc, of Nb-Ti multifilamentary superconducting composites has been well documented. However the development of these microstructures during composite processing is still under investigation.During manufacture, the multifilamentary composite is given several heat treatments interspersed in the wire-drawing schedule. Typically, these heat treatments are for 5 to 80 hours at temperatures between 523 and 573K. A short heat treatment of approximately 3 hours at 573K is usually given to the wire at final size. Originally this heat treatment was given to soften the copper matrix, but recent work has shown that it can markedly change both the Jc value and microstructure of the composite.


Author(s):  
P. J. Lee ◽  
D. C. Larbalestier

Several features of the metallurgy of superconducting composites of Nb-Ti in a Cu matrix are of interest. The cold drawing strains are generally of order 8-10, producing a very fine grain structure of diameter 30-50 nm. Heat treatments of as little as 3 hours at 300 C (∼ 0.27 TM) produce a thin (1-3 nm) Ti-rich grain boundary film, the precipitate later growing out at triple points to 50-100 nm dia. Further plastic deformation of these larger a-Ti precipitates by strains of 3-4 produces an elongated ribbon morphology (of order 3 x 50 nm in transverse section) and it is the thickness and separation of these precipitates which are believed to control the superconducting properties. The present paper describes initial attempts to put our understanding of the metallurgy of these heavily cold-worked composites on a quantitative basis. The composite studied was fabricated in our own laboratory, using six intermediate heat treatments. This process enabled very high critical current density (Jc) values to be obtained. Samples were cut from the composite at many processing stages and a report of the structure of a number of these samples is made here.


2008 ◽  
Vol 128 (4) ◽  
pp. 289-297 ◽  
Author(s):  
Tsutomu Mizuno ◽  
Shigemi Enoki ◽  
Takashi Asahina ◽  
Takayuki Suzuki ◽  
Hiroyuki Maeda ◽  
...  

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