• Korean Journal of Poultry Science
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• v.24 no.4
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• pp.199-206
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• 1997

In this experiment, three kinds of autoclaved poultry by-product meals, P1 (head+feet+viscera), P2(P1+blood), and P3(P2+feathers), mixed as to the yielding ratios, and three kinds of autoclaved hatchery by-products meals, H1 (male d-old chicks of egg strain), H2(dead embryos ＆ infertile eggs), and H3(H1+H2, 2:1) were formulated into the layer diets each at 5％ level, respectively, and compared with the control diets(C) containing fishmeal on laying performances and egg qualifies. The egg production, average egg weight, feed intake and feed conversion were not significantly affected by the poultry or hatchery by-product meals. The egg shell qualities, such as the egg specific gravity, egg breaking strength and shell thickness, were not different among treatments. The egg yolk colour was improved by the feeding of hatchery by-products meals (P<0.05). In conclusion, pultry and hatchery by-product meals could be used in layer diets without any adverse effects on laying performances to substitute for fishmeal at about 5％ level.

• Korean Journal of Agricultural Science
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• v.46 no.2
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• pp.361-368
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• 2019

The objective of the current study was to determine calcium (Ca) and phosphorus (P) utilization in 4 different hatchery by-products (HBPs) for broiler chickens. The four different HBPs included infertile eggs (IFE), unhatched eggs (UHE), low grade and dead chicks (LDC), and a mixture (MIX) of 55% IFE, 10% UHE, and 10% LDC with 25% hatched eggshells. A total of sixty four 50-day-old Ross 308 broiler chickens were randomly allotted to 1 of 4 dietary treatments with 8 replicates per treatment. Two birds were placed together in one metabolic cage. Additional 16 birds were used to measure the endogenous losses of Ca and P. A forcefeeding procedure (i.e., crop intubation) was used to measure the apparent and true total tract retention (ATTR and TTTR, respectively) of Ca and P in the 4 HBPs. The results showed that the TTTR of Ca in the UHE was less (p < 0.05) than that in the IFE, LDC, and MIX. The amounts of available Ca in the MIX were greater (p < 0.05) than those in the IFE and UHE, which were greater (p < 0.05) than those in the LDC. The TTTR of P was not different among the 4 HBPs. However, the amounts of available P in the LDC were greater (p < 0.05) than those in the IFE and UHE, which were greater (p < 0.05) than those in the MIX. In conclusion, HBPs contain high amounts of available Ca and P because of high concentrations of total Ca and P with a high utilization rate. Therefore, the use of HBPs in broiler diets can reduce costs on Ca and P supplements.

• Korean Journal of Poultry Science
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• v.24 no.4
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• pp.193-198
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• 1997

This study was conducted to obtain the basic information for hatchery by-products as feed resources. Four kinds of by-products from a commercial hatchery, i. e., autoclaved day-old broiler or egg type chicks, dead embryos ＆ infertile eggs of both chicks were used for chemical composition and bioavailability test. Chemical compositions were obtained by AOAC (1990) method, and amino acid and energy bioavailabilities were determined by the method of Sibbald (1976). The crude protein contents of day-old chicks (60.27∼62.59) were higher than those of dead embryos ＆ infertile eggs (39.24∼40.09) , whereas the crude fat contents of all by-products were not different. The crude ash contents were higher in dead embryos ＆ infertile eggs (29.18∼34.49％) than in day-old chicks (6.50∼6.71％). The Ca contents of dead embryos ＆ infertile eggs (8.79∼10.82％) were higher than those of day-old chicks (1.29∼l.30％). The total amino acid contents, overall amino acid availabilities and ME contents were higher in day-old chicks than in dead embryos ＆ infertile eggs. It seems that the day-old chicks of egg strain can be used as a high protein - high energy feed resources and the dead embryos ＆ infertile eggs of broiler or egg type as a high protein-high calcium feed ingredients.

• Journal of Magnetics
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• v.7 no.3
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• pp.63-71
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• 2002

Three fabrication techniques for forming thin barrier layer with uniform thickness and large barrier height in magnetic tunnel junction (MTJ) are discussed. First, the effect of immiscible element addition to Cu layer, a high conducting layer generally placed under the MTJ, is investigated in order to reduce the surface roughness of the bottom ferromagnetic layer, on which the barrier is formed. The Ag addition to the Cu layer successfully realizes the smooth surface of the ferromagnetic layer because of the suppression of the grain growth of Cu. Second, a new plasma source, characterized as low electron energy of 1 eV and high density of $10^{12}$ $cm^{-3}$, is introduced to the Al oxidation process in MTJ fabrication in order to reduce damages to the barrier layer by the ion-bombardment. The magnetotransport properties of the MTJs are investigated as a function of the annealing temperature. As a peculiar feature, the monotonous decrease of resistance area product (RA) is observed with increasing the annealing temperature. The decrease of the RA is due to the decrease of the effective barrier width. Third, the influence of the mixed inert gas species for plasma oxidization process of metallic Al layer on the tunnel magnetoresistance (TMR) was investigated. By the use of Kr-O$_2$ plasma for Al oxidation process, a 58.8 % of MR ratio was obtained at room temperature after annealing the junction at $300{^{\circ}C}$, while the achieved TMR ratio of the MTJ fabricated with usual Ar-$0_2$ plasma remained 48.4%. A faster oxidization rate of the Al layer by using Kr-O$_2$ plasma is a possible cause to prevent the over oxidization of Al layer and to realize a large magnetoresistance.