Heat stress (HS) is a major problem experienced by the poultry industry during high-temperature conditions. The ability to manage the detrimental effects of HS can be attributed to multiple factors, including genetic background of flocks. The objective of the present study was to determine the genetic variation in HS effects on laying hens' physiological homeostasis. Ninety 28-wk-old White Legh...

this experiment was conducted to evaluate the effects using of different levels of rosemary hydro-alcoholic extract (rosmarinus officinalis l.) on productive performance and egg quality indicators, in laying hens. the levels of rosemary hydro-alcoholic extract in this experiment were 0, 500, 1000 and 1500ppm. this experiment was conducted in a blok completely randomized design with 160 “hy-line...

Natural antibodies (NAb) are important humoral components of innate immunity. As the first line of defense, NAb provide protection against infection and support adaptive immunity. An earlier study indicated that serum levels of NAb isotypes IgM and IgG at a young age were predictive for survival in non-beak-trimmed purebred laying hens during the laying period. In the present study, genetic par...

Induced molting of laying hens is a practice used by commercial egg producers to increase the productive lifetime of their flock. However, the conventional method of inducing molt, which involves removal of feed, water, or both as well as a reduction in photoperiod to less than a natural day has drawn criticism due to animal welfare and food safety concerns. The objective of this study was to e...

The present paper provides new experimental data on the biochemical and haematological profile of blood in pheasant hens, and points out the changes in both biochemical and haematological parameters that occur during the laying period. Significant effects of egg laying on both the biochemical and the haematological blood parameters of pheasant hens were found. Biochemical analyses revealed a si...

Many laying hen producers are transitioning from conventional cages to new housing systems including multi-tier aviaries. Aviary resources, such as litter areas, are intended to encourage hens' expression of natural behaviors to improve their welfare. Little research has examined the influence of laying hen strain on distribution and behavior inside aviaries, yet differences could influence a s...

This experiment was conducted to evaluate the effects of different levels of dried aerial parts powderand extract of pennyroyal­ (Mentha pulegium) medicinal plant on performance, egg traits, blood biochemical and immunity parameters of laying hens. Two-hundred-fifty-two Hi-line (W36 strain) laying hens from 46 until 58 weeks of age were used in a completely randomized design in 7 treatments and...

The present study was conducted to evaluate the effect of chilled drinking water on the productivity of laying hens under constant high ambient temperature. A total of seventy-two, 123-day-old Hy-line brown layers was divided into two equal groups. The first group (UDWG) was given unchilled water (23.0±2.5°C) as a control, and the second group (CDWG) was given chilled water (16.0±0.5°C). The la...

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 ...

Several dietary alternatives to feed withdrawal have been proposed to induce a molt in laying hens. This study compared the behavior of laying hens on an alfalfa crumble diet (ALC) to hens that were either on a conventional layer diet (FF) or hens that had feed withdrawn (FW) during a 9-d trial. Each treatment consisted of 24 hens (3 hens per battery cage), and treatment began after a 2-week ac...