Prostaglandins in the foetal pig and prepartum endocrine changes in mother and foetus

Chronically catheterized sows and their foetuses were used to investigate the changes in steroids and prostaglandins in maternal and foetal plasma and in allantoic fluid before and during parturition. A rise in foetal plasma corticosteroid concentration began 5-7 days before delivery. This was accompanied by a rise in oestrogen levels in foetal and maternal plasma and in allantoic fluid. There were a significant venous-arterial differences in oestrogen across both uterine and umbilical circulations. A more gradual decrease in maternal plasma progesterone levels occurred with a pronounced fall 24 hr before parturition; wide arterio-venous (uterine) and venous-arterial (umbilical) progesterone differences were found. Prostaglandin concentrations remained low in the maternal circulation until the day of farrowing, when PGF and its metabolic 13, 14-dihydro-15-oxo prostaglandin (PGFM) rose 10-20 fold. Foetal plasma levels of PGF, PGF and PGFM were higher than those of the sow in the prepartum period, while allantoic fluid concentrations were even greater. A delivery, PGE and PGF in the umbilical vein and allantoic fluid were raised but in the arterial plasma of the piglets at birth only PGFM levels were high. There was a close correlation between the neonatal PGFM levels and those in maternal arterial plasma at the time of delivery

Colostral immunoglobulins absorption in Canchim and Nelore calves Absorção de imunoglobulinas do colostro em bezerros das raças Canchim e Nelore

The efficiency of absorption of colostral immunoglobulins was evaluated in five Canchim and seven Nelore calves. They received colostrum pools with concentration of 70.20 ± 6.14 mg/mL through esofageal feeder at 2, 12, 24 and 36 hours after birth. The immunoglobulins concentrations of the pools were estimated through specific gravity and measured by radial immunodifusion. In the blood collection at birth and during the first 70 days of life, the total protein was assayed by biuret method and the immunoglobulins were assayed by radial immunodifusion. Data were analysed as a randomized split-plot statistical model. The highest concentrations of serum immunoglobulins and total protein were observed at 24 hours of age. No significant differences (P>0.5484) were observed for immunoglobulins concentration at 24 hours, with concentrations of 28.80 ± 7.24 mg/mL for Canchim and 27.32 ± 9.54 mg/mL for Nelore. The efficiency for immunoglobulins absorption was not significantly different (P>0.8715) between breeds, 64.04 ± 7.74% for Canchim and 62.30 ± 6.93% for Nelore. The lack of statistical significance persisted until the fourtieth day of life, period of maternal immunoglobulin predominance in the calves blood circulation. In the following period, from 40 to 70 days of age, phase of establishment of the endogenous production of immunoglobulin, differences in the IgG concentrations between the two groups were detected refflecting a possible breed effect difference. The process of colostral IgG absorption by the newborn calves was not affected by breed. The differences between breeds in the calves serum IgG were related to the phase of endogenous production of antibodies.<br>A eficiência de absorção de imunoglobulinas do colostro foi avaliada em cinco bezerros da raça Canchim e sete bezerros da raça Nelore. Os bezerros receberam colostro de "pools" com concentração média de 70,20 ± 6,14 mg/mL, por sonda esofagiana, às 2, 12, 24 e 36 horas após o nascimento. As concentrações de imunoglobulinas dos "pools" foram estimadas por gravidade específica e quantificadas por imunodifusão radial. No sangue obtido ao nascimento e durante os primeiros 70 dias de idade, a proteína total foi analisada pelo método do biureto e as imunoglobulinas séricas, quantificadas por imunodifusão radial. O delineamento experimental foi inteiramente casualizado em parcelas subdivididas no tempo. As concentrações máximas de imunoglobulinas séricas e de proteína total foram observada às 24 horas de idade. Não foi observada diferença significativa quanto à concentração de imunoglobulinas às 24 horas (P>0,5484), com valores médios de 28,80 ± 7,24 mg/mL para Canchim e de 27,32 ± 9,54 mg/mL para Nelore. A eficiência de absorção das imunoglobulinas não diferiu significativamente (P> 0,8715) entre as raças, sendo 64,04 ± 7,74% para Canchim e 62,30 ± 6,93% para Nelore. A ausência de diferença significativa estendeu-se até o 40º dia, período de predominância de anticorpos maternos na corrente sangüínea do bezerro. No período seguinte, dos 40 aos 70 dias de idade, fase de estabelecimento da produção endógena de anticorpos, verificaram-se diferenças na concentração de IgG entre os dois grupos de animais, refletindo provavelmente o comportamento diferenciado das raças. O processo de absorção das imunoglobulinas provenientes do colostro pelos bezerros recém-nascidos não foi afetado pela raça. As diferenças entre raças na concentração sérica de IgG foram relacionadas à fase endógena de produção de anticorpos