Effect of non-genetic factors on milk yield in a Romanian Spotted dual purpose breed

Abstract

The objective of the current study was to establish the possible impact of several non-genetic factors on milk yield. Data from 1120 lactations were collected between 2019 and 2022 regarding cows’ milk yield (MY) and 305-d MY, under the influence of year, calving season, lactation order, type of calving, and calving ease. MY proved to be influenced by the season of calving, being higher in summer (5745.5 ± 156.24 kg) compared to spring (5448.9 ± 108.1 kg) or winter (5327.35±200.6 kg). A marked influence of the rank of lactation and type of calving were found. The maximum MY was found in the 4th lactation (6211.8 ± 210.18 kg), whereas the lowest MY was recorded in the 6th lactation (5535.8 ± 116.6 kg). No substantial effects for year and calving ease were recorded (6003.71 ± 174.23 vs. 5712.14 ± 163.9 for eutocic vs. dystocic births). Season, lactation order, and twinning substantially influenced 305-d MY. In conclusion, MY and 305-d MY proved to be highly dependent on environmental and management factors. By ensuring good management practices pre- and post-partum, the farmers can maintain the milk production at a high level.