Observations on neonatal calves’ urine excretion during the first week of life

Proteinuria is known to occur shortly after birth in calves, since the kidneys are partly immature. Therefore, low molecular weight proteins can be found in the postnatal urine. This study aimed to investigate urine excretion patterns in neonatal calves with regard to a change in feedstuff. Twenty brown swiss calves were separated from their dams at birth and housed individually for the first week of life. All were fed their dams colostrum for 6 feedings following either transition milk (n=10) provided twice daily with unlimited volume or calves were transitioned to milk replacer (MR) (n=10) from the 7th to the 14th feeding onward. Urine was quantitatively collected using canisters. The weight of milk ingested and urine excreted was then divided and the ratio statistically analysed using a two factorial ANOVA with time and treatment as fixed factors. The urine excretion of newborn calves exhibited a polynomic trend, gradually tapering off towards an asymptote where the volume of urine excreted approached approximately half the amount of milk ingested by the end of the week. Directly after birth, the ratio of ingested milk and excreted urine is very broad with only small amounts of urine excreted compared to the amount of milk ingested. From the 7th feeding onward a significant effect of treatment on the milk-urine ratio was found (p=0.04) where the ratio was more narrow for MR fed calves. Neonatal calves show a high fluid disappearance rate immediately after birth, indicating a dehydration. This state rapidly disappears within the first days and towards the end of the first week, nears a constant excretion of urine of about half the amount of milk ingested.     «

Proteinuria is known to occur shortly after birth in calves, since the kidneys are partly immature. Therefore, low molecular weight proteins can be found in the postnatal urine. This study aimed to investigate urine excretion patterns in neonatal calves with regard to a change in feedstuff. Twenty brown swiss calves were separated from their dams at birth and housed individually for the first week of life. All were fed their dams colostrum for 6 feedings following either transition milk (n=10...     »