The objective of this study was to compare zinc sources and levels of supplementation on laying hen performance. Bovan White Leghorn hens were fed one of six dietary treatments in a 2x3 factorial arrangement consisting of two zinc sources (Availa®Zn or zinc sulfate) and three levels (40, 80, or 120 ppm). Treatments were randomly assigned to 48 cages with five hens/cage. Blocks provided eight re...

An arrest in egg laying associated with a polycystic ovarian follicle syndrome (PCOF) has been recently reported early in the egg production period in turkey hens photostimulated at 30 wk of age (WOA) with continuous light. When autopsied 2 to 3 wk after laying ceased, the ovaries of PCOF hens contained an increased number of mature size (F1) yolky follicles in comparison with normally laying h...

Freedom from thirst is one of the most undeniable welfare requirements. Nevertheless, the welfare implication of water deprivation because of a particular situation (e.g., transport) or as an involuntary consequence (e.g., sick, injured, or subordinate animals) remains unclear. This experiment investigated the behavioral changes in laying hens following various durations of water deprivation by...

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...

BACKGROUND Newcastle disease virus (NDV) can cause serious damage to the reproductive tracts of egg-laying hens and leads to egg production and quality reduction. However, the mechanism of severe pathological damage in the oviducts of egg-laying hens after NDV infection has not been fully elucidated. In this study, the correlation between the primary pathological lesions and viral load in the o...

Broiler breeder hens are typically provided a restricted amount of feed once a day. This feed is rapidly consumed; therefore, the hens fast for an extended period of time before their next feeding. In the current research, the effects on reproductive performance of implementing a twice-a-day vs. a once-a-day feeding program after photostimulation were investigated. Pullets and cockerels were re...

Aspects related to hatching, life time, number of blood meals to molt, mortality, feeding time and postfeed defecation delay for each instar of Meccus phyllosomus, M. mazzottii, and M. bassolsae, life-cycle were evaluated and compared in two cohorts of each of those three species, fed on hens or rabbits. No significant (p > 0.05) differences were recorded among cohorts fed on hens respect to co...

The specific [3H] progesterone binding per milligram of protein of the cytosolic fraction of the hen uterus was found to have decreased at 1 and 4 h after the injection of progesterone (P4), but increased at 4 and 8 h after the injection of estradiol-17 beta (E2), and at 1 and 4 h after the injection of testosterone (T). The equilibrium dissociation constant obtained by Scatchard analysis was n...

Two experiments were conducted to study the effects of red pepper (Capsicum frutescens) powder or red pepper pigment on the performance and egg yolk color of laying hens. In Exp. 1, 210, thirty-wk old, Hy-line Brown laying hens were fed one of seven diets containing 0.3, 0.6, 1.2, 2.0, 4.8 or 9.6 ppm red pepper pigment or 0.3 ppm carophyll red. Each diet was fed to three replicate batteries of ...

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...