Influence of estrus on milking parameters in dairy cows

Abstract

Accurate estrus detection is a crucial component of reproductive management in dairy cows, influencing successful fertilization and pregnancy [1]. Effective reproductive management directly impacts milk production and the economic performance of dairy farms. In recent years, automated technologies have become increasingly common in the dairy industry [2]. One of the most significant advancements is the implementation of automatic milking systems (AMS). AMS allows cows to enter milking stalls voluntarily, individually, and without guidance from farm staff [3]. Consequently, understanding how cows interact with their environment and how this influences their behavior and movement through the AMS is essential for the system’s success [4, 5]. The objective of this study was to assess the influence of estrus on various milking parameters, including milk yield (kg), milk flow rate (kg/min), and electrical conductivity of milk (μS). The study was conducted in Lithuania using data from 25 Holstein cows in their second lactation and fresh milk cows. Data were collected through the GEA “DairyPlan C21” (Germany) herd management system and the GEA Dairy Robot R9500 automated milking system, which milks the cows 2–4 times per day, based on need. Estrus detection was performed using the GEA CowScout system. The results showed that during the estrus period, the average daily milk yield per cow was 42.8 ± 1.38 kg, which was 9.95% lower (P < 0.05) than the period before estrus and 7.41% lower than after estrus. A 2.32% decrease in milk production was observed after estrus. On the day before estrus, the average electrical conductivity peaked at 477.68 ± 5.18 μS, 8.6% higher (P > 0.05) than the estrus day. The average milk flow rate during the study was 2.76 ± 0.14 kg/min, which was 10.9% lower (P > 0.05) than the day before estrus. No direct correlation between the milk flow rate and estrus was found. However, estrus had a direct influence on the average milk yield. Comparison of the average milk production on the day of estrus to the day before estrus showed a decrease of 4.78 kg (P < 0.05).