The relation between first oestrus postpartum and reproductive disorders 4 weeks postpartum in dairy cattle

Abstract

Fertility problems are one of the main culling reasons on dairy farms and therefore, there seems to be room for improvement. Generally, the first heat postpartum (FH) is not important to a farmer, due to the voluntary waiting period a farmer chooses. But in addition to focussing on the first heat after this waiting period, it might also be worthy to put more emphasis on the resumption of cyclicity after calving much earlier. Diseases such as reproductive disorders (RDs) can be the cause for a delayed resumption of cyclicity and therefore, a relatively late first ovulation postpartum. At the same time, more and more sensors are developed to detect oestrus in dairy cattle, for example the pedometer. Perhaps, the pedometer could be used to detect cows with a RD in an early stage. Early diagnoses can lead to a fast and adequate intervention and therefore less costs due to decreased calving to insemination intervals and thus shorter calving intervals for example. The objective of this study is to investigate if there is a relationship between the moment of FH, measured with a pedometer, and various RDs (such as clinical endometritis, metritis, decreased tone and involution of the uterus and cystic ovaria). Furthermore, to investigate if it is possible to use the calving to first heat interval (CFHI) to predict the manifestation of RDs. In this experiment 605 cows (138 primiparous and 467 multiparous), of eight different farms were equipped with a Nedap Smarttag Leg pedometer. The average CFHI is defined for cows with the various RDs. A significant relation was detected between cystic ovaria and the CFHI (P=0.005). Contrary to what was expected, cows with a cystic ovarium had a 1.49 times shorter CFHI (mean 17,62 days) compared to cows without a RD (mean 30,88 days). Furthermore, the difference in the CFHI between the participating farms, was significant (P=0.000). Further research is needed to determine if the FH, detected with a pedometer, is an accurate predictor of RDs. However, the outcome of this study is a promising result, regarding the use of the pedometer in this area.