The reproductive tract of the male Cape porcupine is morphologically and histologically similar to that of New World hystricomorph rodents. Males are reproductively active throughout the year and attained sexual maturity (complete spermatogenesis) at an age of 8-18 months. Testes weight, epididymides weight and seminiferous tubule diameter attained asymptotic values at the age of 23-30 months. ...

Step-Up Protein (SUP) rearing regimens can reduce Feed Consumption (FC) and Body Weight (BW), while still resulting in pullets with equal or superior egg production and egg mass to pullets grown on a Step-Down Protein (SDP) program. Egg weight has been reduced due to SUP programs, presumably due to the reduced BW at sexual maturity. Because BW is reduced by SUP regimens and a slight lowering of...

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 ...

  Estimates of age, growth parameters, length-weight relationship and length and age at first maturity of the otolithes ruber are required for fishery management. We used counting annuli on the section of sagittal otoliths to age O.ruber from the Northwest Persian Gulf in south of Iran. Estimated ages ranged from 0 to 6 years, and maximum frequency of fishes was observed in age-group 1. The val...

Size at maturity, fecundity, and reproductive periodicity were estimated for the spotted ratWsh, Hydrolagus colliei (Lay and Bennett, 1839), oV the coast of California, Oregon, and Washington. Maximum body size and size at median maturity were greater for females than males. Skeletal muscle concentrations of the steroid hormones testosterone (T) and estradiol (E2) predicted similar, but slightl...

the present research was conducted to analyze the genetic structure of egg quality traits in japanese quail. external and internal egg quality traits were assessed on 1706 eggs of laying japanese quail. eggs were collected for 4 days at the quaits 10 weeks of age. the investigated traits were analyzed through univariate as well as multivariate animal models employing restricted maximum likeliho...

The article describes the problems, which are of greatest interest for formation fish broodstock, such as process gameto- and gonadogenesis duration spawning cycles in broodstock reared artificial conditions. Under Research Experimental Aquaculture Complex BIOS CaspNIRKH formed paddlefish 63 females matured 2020. There were studied 11 born 2002 2003, whose roe was taken food purposes. following...