This study was conducted to determine effects of dietary NaHCO supplementation on egg 3 production and egg quality during the late laying period. Hisex Brown layers, 54 wks of age, were blocked according to the cage location and then assigned randomly to receive one of four diets containing 0, 0.1, 0.2, or 0.4% NaHCO for 75 d. Each diet was replicated in 6 groups; each consisting of 2 cages con...

During recent decades productivity of laying hens increased substantially (Elliot, 2008). Not only egg number, egg mass, and feed conversion has increased but also persistency of lay has improved. As such, this must have implications on the optimal amino acid nutrition of current laying hen strains. Simply stated, increasing egg mass output per hen means an increased amino acid output which has...

Free-living hens roost on branches in trees at night, and laying hens in aviary systems or cages provided with perches also make extensive use of these for night-time roosting. It is therefore suggested that roosting on perches is important to the hens and that domestic hens should be provided with perches in order to promote welfare. However, no study has addressed the question of motivation f...

An experiment was performed to investigate the effect of animal vs. vegetable protein sources in the diet of laying hens on the development of hen performance. A diet containing protein sources of only vegetable origin was compared with 4 diets, each containing 1 of 4 processed animal proteins (PAP). Two PAP (Daka-58 and Sonac-60) were classified as meat meals, and the remaining 2 (Daka-40 and ...

The objectives of this study were to compare the behaviors, postures, and heterophil-to-lymphocyte ratios (H:L) of laying hens housed in a cage system when offered a Ca premolt treatment and low-energy molt diets vs. a traditional feed withdrawal (FW) treatment during and after molt. A total of 144 Hy-Line W-36 hens (85 wk of age), housed 3 hens/cage (413 cm(2)/hen), were used. Hens were allott...

Juvenile turkey hens were actively immunized against vasoactive intestinal peptide (VIP) prior to photostimulation to evaluate its effect on enhancing egg production. VIP antibody titers were generated in the VIP immunized hens and a greater rate of egg production per hen was observed compared to controls. In addition, the first egg laying cycle was extended for an additional 7 wk without a sig...

A majority of laying hens fracture their keel bones during the laying cycle. It is not easy for a farmer to identify hens with fractures and hen survival rate seems high. Thus, the effect of both recent and healed fractures on bird welfare is unclear. We aimed to investigate the impact of these keel-bone fractures on hens’ production and behaviour. The egg production, mobility and behaviour of ...

In this experiment, the effects of fennel and thyme extracts with and without flaxseed were investigated on performance and egg quality of Leghorn-type laying hens (Hy-Line W-36). 200 laying hens from 26 to 38 weeks of age were assigned to five dietary treatments with five replications. The treatment groups were: 1) Control (a diet without any additives); 2) control diet plus fennel (40 mg/kg f...

Severe feather pecking (SFP) in laying hens is a detrimental behavior causing loss of feathers, skin damage and cannibalism. Previously, we have associated changes in frontal brain serotonin (5-HT) turnover and dopamine (DA) turnover with alterations in feather pecking behavior in young pullets (28-60 days). Here, brain monoamine levels were measured in adult laying hens; focusing on four brain...

The purpose of this study was to evaluate cytologically the bone marrow (and peripheral blood) of adult laying hens affected with lymphoid leukosis. Diagnosis of the neoplasm was made on the basis of clinical history, signs and symptoms and pathology. Only histologically confirmed cases were included in the study. Examination of blood smears revealed +2 heterophil toxicity and the presence of l...