Amphiascoides sp. was cultured in the laboratory for the first time. Culture method and data on its life cycle are given. Reproductive potential and behaviour (pairing incidence) were studied in relation to population density (i.e. to medium conditioned by a previously dense population) and in relation to food supply. It was found that: (1) conditioned medium reduces the number of ovisacs per f...

Infertility and embryonic mortality are economically important for the commercial broiler industry because they are components of hatchability. Embryonic mortality in chickens is not uniformly distributed over the course of incubation; two phases of embryonic mortality are characteristic of chicken development. The objective of this paper was to develop a mathematical model to assess infertilit...

BACKGROUND Our previous studies have demonstrated the cystic fibrosis transmembrane conductance regulator (CFTR) is important for capacitation and male fertility in mouse and guinea pig spermatozoa. However, the exact function of CFTR on human sperm fertilizing capacity, and correlation with sperm quality has not been established. The present study may shed light on some unexplained male infert...

The aim of this study was to investigate the effects of in ovo injections of albumin, amino acid and dextrose into the amnion on the hatchability, growth performance and slaughter yield of Ross 308 broiler chicks. Fertile eggs (n=360) were assigned to 6 treatment groups (4 replicates of 15 eggs each) including: non-injected eggs (control), and eggs injected with 0.7 ml distilled water (sham), a...

An experiment was conducted to assess how hatching performance is affected by breeder age and egg holding environment during short-term storage. Response variables analyzed were egg weight loss up to 18 d of incubation, viability (hatchability of fertile eggs), embryonic mortality, hatching time, and weight of male and female chicks, at hatching and at the end of incubation. The trials involved...

A hypothesis was tested that the in ovo injection of biological buffers may reinforce the buffering capacity of albumen, thereby withstanding the increase in albumen pH during storage and improving hatchability and chick quality in long-term stored eggs. Hatching eggs (n = 2,420) were randomly assigned to 11 treatment groups (4 replicates of 55 eggs each) and injected (d 1) with distilled water...

The present study was motivated by a recent anomalous finding between individual competitive performance and reproductive output in brown-headed cowbirds (Molothrus ater). White et al. (2002c) found that adult males who were housed with juveniles outcompeted adults who were housed with other adults when they were brought together to compete for mating opportunities. Although the males in groups...