نتایج جستجو برای: laying hens

تعداد نتایج: 15944  

2012
P. Y. Zhao H. Y. Baek I. H. Kim

An experiment was conducted to evaluate the effects of bacteriophage supplementation on egg performance, egg quality, excreta microflora, and moisture content in laying hens. A total of 288 Hy-line brown commercial laying hens (36-wk-old) were randomly allotted to 4 treatments in this 6-wk trial and dietary treatments included: i) CON, basal diet; ii) T1, CON+0.020% bacteriophage; iii) T2, CON+...

2017
Meng Zhang Feng-Bin Yan Fang Li Ke-Ren Jiang Dong-Hua Li Rui-Li Han Zhuan-Jan Li Rui-Rui Jiang Xiao-Jun Liu Xiang-Tao Kang Gui-Rong Sun

Poultry meat quality is associated with breed, age, tissue and other factors. Many previous studies have focused on distinct breeds; however, little is known regarding the epigenetic regulatory mechanisms in different age stages, such as DNA methylation. Here, we compared the global DNA methylation profiles between juvenile (20 weeks old) and later laying-period (55 weeks old) hens and identifi...

Journal: :Poultry science 2005
W K Kim L M Donalson P Herrera L F Kubena D J Nisbet S C Ricke

A study was conducted to evaluate skeletal quality and eggshell parameters of molted hens at the end of the second laying cycle. Sixty Single Comb White Leghorn hens were used for this study. There were 2 controls and 4 molting treatments: full-fed control 1 (82 wk old; FF1), full-fed control 2 (122 wk old; FF2), feed withdrawal (FW), 100% alfalfa (A100), 90% alfalfa/10% layer ration (A90), and...

2013
L. E. Edwards G. J. Coleman P. H. Hemsworth

The quality of human contact that hens are exposed to will determine the degree of fear of humans that they experience. This has consequences for the welfare of commercial laying hens, as hens that are afraid of humans will be regularly exposed to a fear-provoking stressor. Hens can be habituated to human presence using positive or neutral human–animal interactions, although the specific human ...

Journal: :Reproductive biology 2005
Monika Proszkowiec-Weglarz Janusz Rzasa Maria Słomczyńska Helena Paczoska-Eliasiewicz

The present study was designed (i) to assess the changes in the activity of 3beta-hydroxysteroid dehydrogenase (3beta-HSD) and cytochrome P450 aromatase (P450arom) in the ovaries of hens which are subjected to a pause in egg laying by fasting, and (ii) relate these changes with progesterone (P(4)) and estradiol (E(2)) production in the ovary. Hy-Line Brown laying hens (n=90) were fasted for 5 d...

L.D. Abd El-Samee S.M. Hashish,

This study aimed to decrease the cholesterol content of egg yolk of laying hens through inclusion of barley malt rootlets in the diets. Forty-two, 54-week-old, Lohman laying hens were fed for a 12 weeks laying period on 3 iso-caloric and iso-nitrogenous diets contained 0 (control), 25.5 or 51.1g barley malt rootlets/kg. Inclusion of barley malt rootlets at 25.5 or 51.1g/kg diet significantly de...

Journal: :Behavioural brain research 2014
Marjolein S Kops Joergen B Kjaer Onur Güntürkün Koen G C Westphal Gerdien A H Korte-Bouws Berend Olivier J Elizabeth Bolhuis S Mechiel Korte

Severe feather pecking (FP) is a detrimental behavior causing welfare problems in laying hens. Divergent genetic selection for FP in White Leghorns resulted in strong differences in FP incidences between lines. More recently, it was shown that the high FP (HFP) birds have increased locomotor activity as compared to hens of the low FP (LFP) line, but whether these lines differ in central seroton...

2012
X. Y. Guo I. H. Kim

This experiment was conducted to evaluate the effects of single or multi-particle size limestone on the egg shell quality, egg production, egg quality and feed intake in laying hens. A total of 280 laying hens (ISA brown) were used in this 10-wk trial. Laying hens were randomly assigned to 4 treatments with 14 replications per treatment and 5 adjacent cages as a replication (hens were caged ind...

2016
Yaxiong Jia Minghui Yang Kuanfeng Zhu Liang Wang Yukun Song Jing Wang Wenxiang Qin Zhiyuan Xu Yu Chen Guoshi Liu

The egg-laying rates of hens approximately 470 days of age exhibited a positive correlation to blood melatonin levels. The hens with an egg-laying rate <30%, 30~90% and ≥90% had blood melatonin levels of 5.8 ± 2.6, 74.0 ± 32.9 and 445.9 ± 115.3 ng/ml, respectively. When 10 mg of melatonin was implanted into the hens at 300, 360, 470 and 550 days of age, the egg-laying rates increased 4.63 ± 0.4...

2017
Yizhe Cui Qiuju Wang Shengjun Liu Rui Sun Yaqiang Zhou Yue Li

Free range feeding pattern puts the chicken in a mixture of growth materials and enteric bacteria excreted by nature, while it is typically unique condition materials and enteric bacteria in commercial caged hens production. Thus, the gastrointestinal microflora in two feeding patterns could be various. However, it remains poorly understood how feeding patterns affect development and compositio...

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