The effects of supplementing a basal diet with 2 levels of an essential oil mixture and an antibiotic on the growth, laying traits, and egg hatching characteristics of broiler breeders were examined in this study. Nine hundred sixty female and 128 male breeders at an age of 1 d old were randomly allocated to 16 replicates (i.e., 4 replicates of 4 dietary treatments) in a floor pen trial. Two le...

The present study was carried out to determine the sex of the fertilized white layer eggs with using morphological measurements. A total of 300 Super Nick White Layer (54 wks of age) eggs were incubated and sexed in the end of incubation period. Before incubation egg length, width and weight were measured. The egg volume and shape index were estimated with using these measurements for each egg....

Two experiments were conducted to evaluate the efficacy of sodium carbonate peroxyhydrate (SCP) in improving the hatching success of channel catfish Ictalurus punctatus when used as a prophylactic chemotherapeutant during egg incubation. In the first experiment, the efficacy of SCP was evaluated in 379-L aluminum incubation troughs similar to those used in commercial hatcheries. Egg masses trea...

  The aims of the present study were to determine the best time for egg stripping after ovulation and to study oocyte over-ripening in the Caspian brown trout (Salmo trutta caspius). Eggs were retained in the female abdominal cavity for 40 days post ovulation (DPO). Partial volumes of eggs stripped from 10 individually identified females at 10 days intervals and fertilized with a pool of semen ...

in this study, rainbow trout (oncorhynchus mykiss) eggs were treated with effective doses of  daenensis thyme, thymus daenensis (20, 10 and 5 mgl-1) and mentha, mentha longifolia (10, 5 and 2.5 mgl-1), during incubation period (20 days) until hatching for 30 minutes per every other day as constant flow bath treatment method. the mortality level in normal control (without any treatment) was sign...

Accelerated hatching is one of few defences available to embryos, and is effective against many egg-stage risks. We present the first analysis of genetic variation in hatching plasticity, examining premature hatching of American toad embryos in response to pathogenic water moulds. We reared eggs from half- and full-sib families in the presence and absence of water mould. Hatching age and hatchl...

The viability of freshly laid avian eggs declines after several days of exposure to ambient temperatures above physiological zero, and declines occur faster in tropical than temperate ecosystems. Microbial infection during preincubation exposure has recently been shown as a second cause of egg viability decline in the tropics, but whether microbial processes influence the viability of wild bird...

Exposure to olfactory cues during embryonic development can have long term impacts on birds and amphibians behaviour. Despite the vast literature on predator recognition and responses in fishes, few researchers have determined how fish embryos respond to predator cues. Here we exposed four-day-old rainbowfish (Melanotaenia duboulayi) embryos to cues emanating from a novel predator, a native pre...

Egg production of cultivated broodstocks of orange-spotted grouper, Epinephelus coioides and larvae rearing were surveyed in Iran from 2008 to 2012. . Broodstocks were obtained by rearing of 7 wild juveniles (587.57 ± 132.63 g body weight) which were caught from the north of Persian Gulf in October 2008 and reared to December 2012.. Captured juvenile fishes were fed using defrosted trash fish a...