Prediction of pathologic disorders of the reproductive system based on the time of occurrence of the first estrus after calving

Abstract

Reasons for performing this study: Cows becoming pregnant in an efficient manner and at a profitable interval after calving is the goal of reproduction management in dairy cattle. Post-partum bacterial infections of the genital tract and post-partum ovarian cysts can lead to a prolonged interval calving-first ovulation. Being able to predict pathologic disorders of the reproductive system, based on the time of occurrence of first heat after calving, detected with a sensor, could make it possible to intervene early. The early diagnosis and treatment of reproductive problems after calving is very important, because it influences herd profitability and is, therefore, of great economic importance. Objective: Determine if the moment, at which the first estrus after calving, detected with a sensor, occurs, could predict whether the cow has problems in the reproductive tract or not. Materials & methods: Leg movement activity was obtained of 3107 mostly Holstein-Friesian cows with a pedometer between day 12-30 post-partum. A heat-attention was given if the number of steps for three consecutive 2 h time period exceeded a threshold, i.e. the mean plus 1.4 (x-factor) times the standard deviation of the preceding 4 days. Data of disease registration was available for every cow. Cows were housed in 18 farms, spread over the Netherlands. A bivariate Pearson Correlation in SPSS 24 was applied for statistical analysis. Results: 59,6 % of all cows received a heat-attention between day 12-30 after calving and 4,2 % of all cows had reproductive problems, mainly located in the uterus. 4 % of the cows who showed no heat-attention, had reproductive problems. Of the cows who showed a heat-attention, 4,3 % had reproductive problems. 59,6 % of the cows who had no reproductive problems, showed a heat-attention. Of the cows who had reproductive problems, 61,5 % showed a heat-attention. 59,5 % of the cows who had no uterine problem, showed a heat-attention. 62,7 % of the cows who had a uterine problem, showed a heat-attention. 59,7 % of the cows who had no ovarian problem, showed a heat-attention. 20