1. The effect of biotin supplementation of low-biotin practical diets during rearing and laying stages on performance was studied in White Leghorn-type laying hens. 2. Biotin supplementation during rearing did not have any apparent effect on the condition of the bird at point-of-lay or on subsequent laying performance. 3. Biotin supplementation during lay did not have any beneficial effect upon...

Several studies illustrated that the structure of feed, i.e., the particle size, particle-size distribution, and the physical form of the diet, affects the avian gastrointestinal function and health leading to changes in productive performance. However, investigations concerning the effects of feeding differently processed diets on laying hens are limited and primarily concentrated on bird perf...

The aim of this study was to compare the performance of hens (feed intake, rate of lay, egg weight, and BW gain), egg quality and blood biochemistry (enzymes, electrolytes, proteins, and other plasma constituents) of laying hens fed diets containing hemp products. Forty-eight Lohmann LSL-Classic (white-egg layers; 19 wk of age) were individually caged and fed 1 of 6 wheat-barley-soybean-based d...

Feed deprivation is used in the layer industry to induce molting and stimulate multiple egg-laying cycles in laying hens. Unfortunately, the stress involved increases susceptibility to Salmonella enteritidis (SE), the risk of SE-positive eggs, and incidence of SE in internal organs. Leghorn hens over 50 wk of age were divided into 4 treatment groups of 12 hens each in experiment 1 and 3 treatme...

Photosensitive species undergo neuroendocrine changes during a reproductive season that cause them to gradually become unresponsive to a photoperiod that initially stimulated reproduction. They may first become relatively photorefractory (rPR), when they will cease egg laying only if photoperiod is reduced, and then absolutely photorefractory (aPR), when they will cease laying despite long day ...

The objective of this study was to determine the effects of various levels of dietary black cumin seed on egg production, egg weight, feed conversion ratio, egg shell quality, and egg yolk cholesterol. In this study, eighty 27-wk-old laying hens (Hyline-5 White) were randomly assigned into 4 groups with 4 replicates of 5 birds each (20 laying hens per group) and fed diets supplemented with 1, 2...

The aim of this study was to investigate the differences in production performance, use of nest box, and external appearance of 2 strains of laying hens kept in conventional and enriched cages. Lohmann Brown Classic (LB, n=532) and Lohmann LSL Classic (LW, n=532) hens were housed from 16 to 73 wk in either conventional cages or enriched cages. Enriched cages had a nesting area, scratch pad, per...

Molting is a process by which a hen's reproductive tract is rejuvenated prior to the beginning of a laying cycle. This process is often artificially induced in commercial settings in order to extend the productive life of a flock of hens. The most common method for the induction of molt is feed withdrawal for a period of several days. It has been noted that feed withdrawal, while effective in i...

This experiment was designed to evaluate the effects of different levels of tomato pomace (DTP) with different multi enzymes on the performance and egg quality of laying hens at the first phase of production. In this experiment 432 hens were used in a completely randomized design in a factorial arrangement of 4×4, with four levels of tomato pomace (0, 4, 8 and 12) and different enzymes (without...

Background: The use of IgYs in a variety of methods in different areas of research, diagnostics, medical application and biotechnology should be considered widely. Objectives: Development of antibodies against extra cellular domain of influenza M2 (M2e) protein in egg yolk of laying hens. Methods: A Fusion construct harboring C-terminal of bovine heat shock protein 70 (Hsp70) and influenza M2e ...