A study of 1231 first cycle and 887 second cycle table egg flocks (by Bell and Adams) in the early 1980’s in California revealed a series of very important relationships. These relationships are essential to the decision of whether or not flocks should be molted and if so, when? If molting is to pay, the second cycle of production must yield high performance compared to a one cycle option. The ...

We evaluated the in vitro effects of estradiol, progesterone, and testosterone on the molting process, which is the initial and crucial step in the development of the muscular larvae (ML or L1) to adult worm. Testosterone had no significative effect on the molting rate of the parasite, however, progesterone decreased the molting rate about a 50% in a concentration- and time-independent pattern,...

20-Hydroxyecdysone (20E) and juvenile hormone (JH) control a variety of physiological events during insect development and metamorphosis. To understand how 20E and JH developmentally regulate energy metabolism in insects, we performed a genome-wide microarray analysis of fat body tissues isolated from the silkworm, Bombyx mori. Many genes involved in energy metabolism, including genes in the gl...

Th e energetically challenging periods of molting and breeding are usually temporally separated in temperate birds, but can occur simultaneously in tropical birds, a condition known as molt – breeding overlap. Here, we document great variation in the timing and duration of molting and breeding, and in the extent of molt – breeding overlap, among 87 species of understory passerines in central Am...

Recent studies have indicated that egg yolk immunoglobulins (Ig) can be used for therapeutic purposes and that yolk Ig levels are increased after molting of laying hens. The present study was performed to compare between the effects of two methods of induced molting namely alfalfa and zinc methods on serum and yolk IgY concentrations as well as their effects on the egg quality and immune status...

Migratory species employ a variety of strategies to meet energetic demands of postbreeding molt. As such, at least a few species of western Neotropical migrants are known to undergo short-distance upslope movements to locations where adults molt body and flight feathers (altitudinal molt migration). Given inherent difficulties in measuring subtle movements of birds occurring in western mountain...

Induced molting improves egg producing functions in hens. We investigated the mechanism of oviducal regression during induced molting. Involvement of apoptosis and autolysis in the oviducal regression process was analyzed by terminal deoxynucleotidyl transferase (Tdt)-mediated biotinylated deoxyuridine triphosphates (dUTP) nick end-labeling (TUNEL) and an enzyme histochemistry for acid phosphat...

26-Hydroxyecdysone, which is the major free recoverable ecdysteroid of older age groups of embryonated eggs of the tobacco hornworm was also the major component in 4- to 18-hour-old embryonated eggs. The other 3 beta-ecdysteroids, ecdysone, 20-hydroxyecdysone, and 20,26-dihydroxy-ecdysone, were also present and accounted for all the molting hormone activity; 26-hydroxyecdysone was devoid of mol...