Morphological characteristics of foetal membranes of swamp buffaloes of Assam

The present investigation was undertaken to study the morphological characteristics of foetal membrane of swamp buffaloes of Assam. Animals were calved normally and no cases of retention of placenta were recorded. The average expulsion time, weight, length, width and number of cotyledons of foetal membranes were 241.20+ 22.05 minutes, 3.47+0.12 kg, 171.87+2.99 cm, 30.83+ 0.73 cm and 114.83+ 5.56 respectively. A highly significant (P<0.01) positive correlation between birth weight of the calf and weight and width of the foetal membranes and a significant (P<0.05) positive correlation between birth weight and number of small cotyledons of foetal membranes were recorded in the present study. There was no significant effect of parity on various characteristics of foetal membranes except the number of large cotyledons. The number of large cotyledons was significantly (P<0.05) higher in animals of third to fifth lactation than in animals of first and second lactation. The sex of calves had no significant effect on various characteristics of foetal membranes.

A method for obtaining chimaeric mouse blastocysts with two separate inner cell masses: a preliminary report

Pairs of zona-free mouse blastocysts aggregated in the presence of inactivated Sendai virus and subsequently cultured in vitro will fuse to form a chimaeric blastocyst with one common blastocoelic cavity. Depending on the relative position of the inner cell masses in the apposed ‘parental’ blastocysts, the resulting chimaeric blastocyst contains either a single inner cell mass (ICM) of dual origin or two discrete ICMs each originating from one embryo. In the present experiments, fusion between the two aggregated blastocysts occurred in 23% of the pairs and 64% of these chimaeric blastocysts contained two ICMs. Blastocysts of the latter type could potentially give rise to pairs of embryos which as regards the topography of the foetal membrane would resemble spontaneous identical twins, although they would be genetically dissimilar. Possible applications of the described method are discussed.

Live-weight, total body-water and maternal body-solid changes in pregnant and lactating beef cows

SummaryLive weight and total body water (TBW; measured as tritiated water space) were measured in eight pregnant cross-bred beef cows from the 6th month of gestation to approximately 1 month after calving. Using the values from these measurements and by estimating foetal, foetal fluid and foetal membrane weights from previously established prediction equations, the maternal live weight, maternal body water and maternal body solids were calculated.Live weight, TBW, maternal body water and maternal live weight increased during gestation, whereas maternal body solids decreased. The TBW percentage of live weight increased from 74·8 to 79·6% during gestation and remained at about 79·5% during the first month of lactation.It was concluded that live-weight changes alone could be misleading in assessing the energy balance of pregnant ruminants not only because of development of the foetus and associated structures but also because of maternal hydration.