The effect of age on egg production was investigated in the domestic fowl. The rate of egg production was reduced with increasing age and the incidence of thin-shelled and cracked eggs was markedly increased. Older hens which remained in lay produced fewer but larger eggs than the younger birds. The ovaries of these two groups of hens were of similar appearance but the largest preovulatory foll...

Data from ten sources comprising 3,851 flocks were modelled to identify variation in levels of mortality in laying hens. The predicted increase with age was curvilinear with significant variation between the seven breed categories. Mortality was higher in loose housing systems than in cages and variable within system, confirming previous reports. Cumulative mortality (CM) was higher in flocks w...

An experiment was conducted to assess how hatchability performance of eggs is affected by line and age female broiler breeders. Response variables analyzed were hatchability, infertility, pipping (i.e., pipped shell but not emerged), embryonic mortality (1st, 2nd, 3rd wk), malposition. The trials involved a total 2,880 fertile from two breeder lines (Ross 308 Cobb 500) at different ages (30 50 ...

The effects of Different Levels Alhaji Maurorum L. on Egg Production, Traits and Blood Parameters Commercial Laying Hen (Line W63)

BACKGROUND The ovaries are the primary targets of senescence effects in mammalian and avian species. In the present study, relationships between reproductive aging, sex steroids and the growth pattern of the pre-ovulatory follicle wall were investigated using young hens with long clutch (YLC), old hens with long clutch (OLC), old hens with short clutch (OSC), and old hens with interrupted long ...