A13STRACT.--We studied the nesting biology of the Green-rumped Parrotlet (Forpus passerinus) in the llanos of Venezuela. Clutch size averaged 7 eggs (range: 5-10), and eggs were typically laid daily or every other day over 7-16 days (• = 10). Incubation began with the first egg. Clutches hatched over 2-14 days (œ = 8.6) and fledged over 4-17 days (œ = 9.7). An average of 5.7 chicks hatched (ran...

Buergeria japonica is one of a few frogs that breed in coastal areas. To understand why this species can breed in coastal areas, I tested the salinity tolerance of eggs of B. japonica collected from a coastal area of Okinawa Island, Japan. All eggs hatched within four days after oviposition. At 0%. salinity (control), over 94% of eggs hatched normally, and even at 1 per thousand salinity over 8...

This study compared the effect of using either CZB or TCM 199 media on both the development of 1-2 cell ovine embryos from superovulated ewes to the blastocyst stage (Experiment 1), and the hatching process of ovine blastocysts developed in vitro (Experiment 2). For the first 5 d, the CZB medium showed higher rates of embryo development than the TCM 199 medium (p < 0.001). The embryos reaching ...

In vitro-fertilized bovine embryos were incubated in Menezo's B2 medium (MB2) supplemented with 2 mg/mL of BSA. In Exp. 1, eight-cell stage embryos were allotted to one of the following groups: control medium (MB2), MB2 with 20 ng/mL of platelet-activating factor (PAF), 1 x 10(7) bovine blood platelets (Platelets), oviductal cells (BOEC), BOEC and 20 ng/mL of PAF (BOEC+PAF), or BOEC and 1 x 10(...

Previous investigations conducted in our laboratory have shown that the arginase system and, consequently, the Krebs ornithine cycle, is reactivated in baby chicks experimentally infected with Salmonella pullorum (Ross et al., 1956). A similar reactivation, as evidenced by an alteration in the nitrogen excretion pattern, was demonstrated in chicks treated with the endotoxin of S. pullorum (Dool...

The development of assisted reproductive technologies such as embryo transfer (ET), artificial insemination (AI) and in vitro fertilization (IVF) in South American camelids is considerably behind that of other livestock species. Poor success of the embryo transfer technique has been related to a lack of an effective superstimulatory treatment, low embryo recovery rate, and the recovery of hatch...

Excellent fertility and prolificacy have been reported after non-surgical deep uterine transfers of fresh in vivo-derived porcine embryos. Unfortunately, when this technology is used with vitrified embryos, the reproductive performance of recipients is low. For this reason and because the embryos must be stored until they are transferred to the recipient farms, we evaluated the potential applic...

As the current poultry production system stands, there is a period of time when newly hatched chicks are prevented from access to feed for approximately 48-72 h. Research has indicated that this delay in feeding may result in decreased growth performance when compared to chicks that are fed immediately post-hatch. To remedy this issue, in ovo methodology may be applied in order to supply the em...

Recent decades were characterized by genetic selection of broiler and layer chickens for enhanced growth rate and meat yield or intensified egg production, respectively. It is to be expected that genetic selection for various traits would also influence embryo development and growth patterns that affect metabolism. The objective of the present study was to examine the effects of broiler (Cobb a...