The effects of stocking density on the performance, egg quality, leukocyte concentration, blood biochemistry, corticosterone levels, bone mineral density, and noxious gas emission of laying hens were investigated. Eight hundred 34-week-old Hy-Line Brown laying hens (Gallus gallus domesticus) were randomly assigned to one of 4 treatments, each of which was replicated 4 times. Four stocking densi...

Previously we showed that free-range hens fed diets supplemented with diatomaceous earth (DE) were significantly heavier, laid more eggs, and consumed more feed than hens fed the control diet, with no differences in feed efficiency. In the present study, we compared plasma calcium concentrations, and bone mineralization of the hens from our previous study to test the effect of DE on these param...

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...

Fatty liver is a common energy metabolic disorder in caged laying hens. Considering that the egg industry is shifting from conventional cages to alternative housing systems such as enriched cages, the objective of this study was to determine the effects of perches on fat deposition and liver health in laying hens. Three hundred twenty-four 17-wk-old White Leghorn hens were housed in 1 of 4 trea...

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...

Heat-stress remains a costly issue for animal production, especially for poultry as they lack sweat glands, and alleviating heat-stress is necessary for ensuring animal production in hot environment. A high γ-aminobutyric acid (GABA)-producer Lactobacillus strain was used to investigate the effect of dietary GABA-producer on laying performance and egg quality in heat-stressed Hy-line brown hens...

This research aimed to compare the effects of pigments extracted from dried petal meal of marigold flower and synthetic pigments on productive performance of laying hens, egg quality and antioxidant properties of the egg. A total of 64 laying hens, aged 75 weeks, were distributed in a completely randomized design in 4 treatments and 4 replications containing 4 hens per cages. Experimental group...

Different types (light to heavy) of laying hens are used in practice. There are questions about the optimum level of balanced protein (BP) supply in feed for different types of hens. Therefore, a broad range of amino acids intake levels [550 to 800 mg of true fecal digestible (TFD) Lys/hen per d] was tested on heavy (Lohmann Brown Classic) and light (Lohmann LSL Classic) laying hens from 24 to ...

an experiment was conducted to investigate the effects of using different levels of ginger rhizome powder (grp) and turmeric rhizome powder (trp) on production performance and some blood metabolites in laying hens. ninety 103-week old laying hens were divided into 5 treatments in a completely randomized design with 3 replicates and 6 birds in each cage. the birds were fed a corn-soybean meal ba...

An experiment was conducted to study the effects of carbon tetrachloride (CCl4) on post-peak performance and serum enzymes of Hy-Line W-36 laying hens from 32-36 weeks of age. The experiment was carried out with a total of 192 laying hens in a completely randomized block design. During the experiment laying hens were allocated to 4 groups consisted of T1) no CCl4 as control diet, T2, T3 and T4)...