• Title, Summary, Keyword: eggshell

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Effects of Dietary Silicate Based Complex Mineral on Performance, Egg Quality and Immunological Competence in Laying Hens (규산염 복합광물질의 급여가 산란계의 생산능력, 계란품질 및 면역능력에 미치는 영향)

  • Lim, Chun Ik;Park, Jin Ern;Kim, Sang Eun;Choe, Ho Sung;Ryu, Kyeong Seon
    • Korean Journal of Poultry Science
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    • v.44 no.4
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    • pp.267-274
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    • 2017
  • This study was conducted to investigate the effect of feeding with dietary silicate based complex mineral (SCM) on the performance of laying hens. SCM at five levels (0%, 0.2%, 0.4%, 0.6% and 0.8%) was added to commercial diets, and fed to four hundred fifty Hy-Line Brown from fifty four to sixty five weeks of age. Egg production increased as the addition of dietary SCM to basal diets increased up to 0.6% (P<0.05). Furthermore, Feed intake increased in a manner similar to that of egg production (P<0.05). However, there was no difference in feed efficiency among the treatments. Eggshell thickness and breaking strength were significantly higher for the chickens fed with SCM than control from sixty weeks old to the end of experiment (P<0.05). Similarly, albumen height and Haugh unit were significantly higher for the chickens fed with SCM compared to those of control group (P<0.05). AST of birds fed SCM showed significantly higher than control (P<0.05). However, blood neutral fat level tended to increase in SCM treatments. Moreover, bone mineral density increased with SCM addition up to 0.4% (P<0.05). IL-2 (Interleukin-2) and IL-6 (Interleukin-6) levels appeared to be improved in the chickens fed with SCM addition diets, although not statistically different from all treatments. The results of this study indicated that the optimum SCM for improving the performance, egg quality and immunological competence of laying hens from 54 to 65 weeks of age was 0.6%.

Comparison of Production Performances between Early- and Late-feathering Chickens in Parent Stocks of Korean Native Chicken (토종종계에 있어 조우성 개체와 만우성 개체간 생산능력 비교 고찰)

  • Kim, Ki Gon;Cho, Eun Jung;Choi, Eun Sik;Kwon, Jae Hyun;Jung, Hyun Chul;Sohn, Sea Hwan
    • Korean Journal of Poultry Science
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    • v.46 no.4
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    • pp.279-286
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    • 2019
  • Currently, feather-sexing, which is based on differences in feather development at hatching, is a widely used chick sexing method in the poultry industry. For effective chicken feather-sexing, paternal early-feathering (EF) chickens and maternal late-feathering (LF) chickens must be bred. Therefore, it is critical to identify the effect of EF and LF patterns on production traits in chickens. Thus, the purpose of this study is to analyze and compare the production performances between 522 EF and 232 LF chickens in order to establish the Korean native chicken feather-sexing lines. The results showed that the survival rate of the LF group was significantly higher than that of the EF group from hatching to 52 weeks of age (P<0.05). Body weight, however, was not significantly different between the two groups at all ages. LF and EF groups did not significantly differ in age at first egg laying. However, the hen-day and hen-housed egg production of the LF group were significantly higher than those of EF group (P<0.01). No significant differences were found between the EF and LF groups in all egg quality indicators such as egg weight, eggshell color, albumin height and Haugh unit. Because the breeding target of Korean native commercial chicken is meat-type chicken, feather-sexing strains of Korean native chicken should be established using weighing-based paternal EF lines and laying-based maternal LF lines. Therefore, these results are critical for establishing desirable and effective feather-sexing strains.