________________________________________________________________________________ Abstract Male broiler breeders were photostimulated at different ages (56, 77, 98, 119, 147 and 161 d) during the period of growth prior to achieving sexual maturity to observe their response to photoperiod stimulation. Birds were sampled at regular intervals to measure the average testis weight these values respon...

Size and age estimates at sexual maturity were determined for 162 male and 273 female little skates Leucoraja erinacea collected from the western Gulf of Maine. Maturity ogives suggest that 50% maturity in females occurs at age 9.5 years and 480 mm total length (LT), whereas 50% maturity in males occurs at a slightly younger age of 7.7 years and smaller size of 460 mm LT. Age estimates were mad...

The harbour porpoise is the only cetacean species native to German waters. Since human pressures are suggested to shorten their reproductive lifespan, basic knowledge on reproduction is strongly required. One parameter is the onset of sexual maturity in female harbour porpoises. Therefore, we investigated the first signs of sexual maturity for a period of almost two decades (1990-2016). Ovaries...

From studies of both wild and captive animals, gibbons are thought to reach sexual maturity at about 6 to 8 years of age, and the siamang (Hylobates syndactylus) at about 8 to 9 years. However, a review of the literature reveals that in most cases the exact age of the maturing animals was not known and had to be estimated. This study presents seven case reports on captive gibbons of known age. ...

Twenty four farmed great sturgeon, Huso huso (including 8 males and 16 females) over 6 years old were used to develop a method for determination of sex and maturity stages. Seasonal gonadal tissue and blood samples were collected from farmed great sturgeon for three years. The sex and stages of maturity were determined by histology and laparoscopy at the beginning and end of experiment. Plasma ...

Egg-laying strains of chickens are highly susceptible to osteoporosis, a noninfectious disease characterized by a decrease in structural bone as hens age. To minimize the onset of osteoporosis, it was hypothesized that a delay in sexual maturity may allow a pullet to develop a stronger skeletal frame before egg laying, leading to improved skeletal mineralization at end of lay. One management to...

size at sexual maturity and patterns of somatic growth are important aspects of reproductive history of crab. the main purpose of this study is to provide an estimate for the onset of morphological sexual maturity in mangrove crab, opusia indica from a population located in korangi creek intertidal mud flat (karachi, pakistan) based on relative growth. the crabs were monthly collected through q...

The influences of age (4 to 12 wk), sexual maturity status, and sex on hypothalamic-pituitary-adrenal (HPA) axis responsiveness were investigated by measuring changes in peripheral basal levels of corticosterone (B) and responses to 10 min of physical restraint in a crush cage or injection of 1-24 adrenocorticotropic hormone (ACTH) in 2 genotypes of Japanese quail divergently selected for long ...