PRID insertion increased embryo survival rate
Elevating progesterone levels in beef heifers, by inserting a PRID device shortly after insemination, has no effect on embryo survival rates on day five or day seven and it can actually increase embryo survival rate and embryo length at day 13 and day 16, according to a study led by Fiona Carter at University College, Dublin.
Her team investigated progesterone profiles and embryo development in beef heifers with elevated progesterone concentrations and she presented their findings at the British Society of Animal Science’s international conference entitled: Fertility in dairy cows – bridging the gaps.
“To examine the effect of increasing progesterone from day three on embryo survival and development with ‘supplemented’ heifers by inserting a PRID to elevate progesterone levels,” said Ms Carter.
The trial involved two groups of beef cross heifers – one inseminated and one non-inseminated. And each group was also split into two – high progesterone and normal progesterone levels. PRID devices were inserted into heifers to create the high progesterone groups on day three of the oestrus cycle – three days after insemination for those high progesterone heifers in the inseminated group.
“On day five and day seven, we saw no significant difference in embryo survival rate between the high progesterone level and normal group.
“At day 13 and 16, however, we saw an increase in both embryo survival and embryo length in the high progesterone group, compared to the group of inseminated heifers with ‘normal’ progesterone levels,” added Ms Carter.
In the high progesterone group, embryo length was around 2.2mm, compared to around 1.2mm for the normal progesterone group. At day 16, embryo length was around 15mm for the high progesterone group, compared to around 6mm for the normal group – a significant difference.
summary (pdf) Presentation 008_carter_orig (pdf)
