Traditional poultry production has changed to a considerable industry after few decades. Now, poultry industry is one of the main sectors to obtain the required protein for human consumption. Prediction of the weight and number of eggs according to economic traits can improve the efficiency of production and the profit of producers. In present study, the weight and number of eggs in Mazandaran ...

Traditional poultry production has changed to a considerable industry after few decades. Now, poultry industry is one of the main sectors to obtain the required protein for human consumption. Prediction of the weight and number of eggs according to economic traits can improve the efficiency of production and the profit of producers. In present study, the weight and number of eggs in Mazandaran ...

Traditional poultry production has changed to a considerable industry after few decades. Now, poultry industry is one of the main sectors to obtain the required protein for human consumption. Prediction of the weight and number of eggs according to economic traits can improve the efficiency of production and the profit of producers. In present study, the weight and number of eggs in Mazandaran ...

In the Mongolian gerbil, vaginal opening occurs at 40 to 60 days of age (Nakai, Nimura, Tamura, Shimizu & Nishimura, 1960; Schwentker, 1963; Marston & Chang, 1965), whilst the age of sexual maturity has been given as 9 to 12 weeks (Schwentker, 1963; Marston & Chang, 1965). Recently, Norris & Adams (1972a) estimated that the mean age at first conception was 75 days under the most favourable cond...

Background: In this study, we report the first case of a male reef manta ray, Mobula alfredi, becoming sexually mature in captivity and present its reproductive characteristics. Methods: We investigated changes in external morphology, behavior, and levels of steroid hormones in a male M. alfredi during its sexual maturation process. Results: At 2 years and 6 months of age, the male exceeded 300...

Information on aging, maturation, and growth is important for understanding life histories of organisms. In extinct dinosaurs, such information can be derived from the histological growth record preserved in the mid-shaft cortex of long bones. Here, we construct growth models to estimate ages at death, ages at sexual maturity, ages at which individuals were fully-grown, and maximum growth rates...

Performance of three generation (G0,G1 and G2)of indigenous chicken was evaluated to assess the effect of breeding strategies on the productivity. Data on age at sexual maturity (ASM), body weight at sexual maturity (BWM), body weight at one year of age (BWY), eggs per clutch (EGC), clutches per year (CLY), hatchability on set eggs basis (HAT) and survivability of baby chicks up to sexual matur...