Egg and embryo abnormalities in the ostrich (Struthio camelus).

Ostrich hens reach sexual maturity at approximately 2.5 years, remaining fertile for about 40 years. Each hen commonly lays about 50 eggs a season. Selective breeding, good breeder nutrition, hygiene and correct incubator settings are important for good productivity (1). Unbalanced nutrition may result in mutifaceted nutrient deficiencies in embryo, including yolk sac pathology (2) and leg abnormalities (3)

Egg and embryo abnormalities in the ostrich (Struthio camelus).

Ostrich hens reach sexual maturity at approximately 2.5 years, remaining fertile for about 40 years. Each hen commonly lays about 50 eggs a season. Selective breeding, good breeder nutrition, hygiene and correct incubator settings are important for good productivity (1). Unbalanced nutrition may result in mutifaceted nutrient deficiencies in embryo, including yolk sac pathology (2) and leg abnormalities (3)

The embryocidal effect of Zinc (Zn) and Cadmium (Cd) in pregnant Mona strain rats

OBJECTIVE: To investigate the toxicity of zinc and cadmium on pregnant Mona strain rats. METHODS: A total of 21 female rats, divided into 3 groups of 7 rats each, were mated, and on the 8th day of gestation, these pregnant rates were injected subcutaneoulsly with 3 mg/kg Zinc sulphate, Group 1:3 mg/kg Cadmium sulphate, Group II, and normal saline, Group III. Animals were fed purina lab chow and given water ad libitum. On the 15th day, animals were sacrified with ether, the uteri were removed and examined. Observations on embryocidal effects and foetal abnormalities were recorded. RESULTS: Zinc at a dose of 3 mg/kg administered subcutaneously on the 8th day of gestation had a marked embryocidal effect (13.8 percent). This was observed to a much lesser degree (1.5 percent) with Cd treatment. CONCLUSION: The results demonstrate the need for further research and a degree of caution in recommending the liberal use of zinc as a dietray supplement (especially in pregnancy). Further detailed analysis of the degree of air pollution and the vegetable material grown in areas with high concentrations of heavy metals is recommended.(Au)

Second trimester placental volumes predict birth size

OBJECTIVE: To investigate the ability of second trimester placental volume to predict birth size. DESIGN AND METHODS: Prospective study of women attending the antenatal clinic of the University Hospital of the West Indies. SUBJECTS: 561 women were recruited from the antenatal clinic. Placental volume and foetal biometry at 14, 17 and 20 weeks' gestation were measured. At birth, placental and newborn's weight, lengths and circumferences were measured. MAIN OUTCOME MEASURES: Birth and placental weight, head, chest, abdominal, and mid-upper-arm circumferences, crown-heel and crown-rump length and placental volume. RESULTS: Placental volume in the second trimester showed a positive association to birth measurements. Ponderal index and head: length ratio showed no significant associations with placental volume, but there was a significant relationship between placental volume at 20 weeks' gestation and head: abdominal circumference ratio. The placental volume at 20 week gestation had the greatest effect on birth weight, and when placental volume was compared to foetal biometry in predicting birth outcome, placental volume was superior. CONCLUSION: In this study, second trimester placental volume has been shown to be an independent predictor of birth outcome, at a time when foetal biometry was not. It was not until the third trimester that foetal biometry became important. Identification of the growth retarded foetus is desirable in obstetrics for proper management. Earlier indication of this process is presumably important. It appears that in the second trimester, placental volume may be a more reliable predictor than foetal biometry.(AU)

Effects of protein deficiency on implantation and embryogenesis in the rat

Dietary protein depletion causes a significant incidence of resorption in pregnant rats when compared to rats fed a complete diet. Histologically, this resorption consists of an extravasation of blood into the implantation crypt on day 9, dilating the crypt and causing necrosis and sloughing of the embryo and decidua. Embryonic death and fragmentation appears subsequent to the appearance of blood and debris in the crypt on day 9 1/2 (AU)