Factors influencing calf birth weight in primiparous and multiparous Holstein Friesian cattle on a dairy farm

摘要

A main research focus when studying risk factors for dystocia and stillbirth in dairy cows is the calf birth weight; especially, in primiparous cows. The aim of this cross-sectional study was to assess potential maternal, fetal and management related factors influencing calf birth weight. Between April 1st, 2013 and February 28th, 2014, 1949 calvings were assessed on a northern German dairy farm, calving parameters were recorded from farm protocols, and additional data were added using the computer program DairyComp 305. Six to 8 weeks a. p. (far-off dry cows; TS 1), 2 weeks a. p. (close-up dry cows; TS 2) and on the day of calving (Day 0), back fat thickness was measured using ultrasound and blood samples were taken for assessment of calcium, inorganic phosphorous, non-esterified fatty acids (NEFA) and beta hydroxybutyrate (BHB) concentrations. Associations were assessed using multivariable linear regression analyses, separate for primiparous and multiparous cows. In primiparous cows, four parameters (sex of the calf, length of gestation, duration of TS 2 and BHB at TS 2) and in multiparous cows, seven parameters (sex of the calf, length of gestation, duration of TS 2, NEFA at TS 2, NEFA on Day 0, calf sire, and number of lactations) were retained in the final model to predict calf birth weight, accounting for 26.3 % and 25.5 % of variability in calf birth weights, respectively. Using sexed semen, avoiding extended pregnancy duration, reducing intensity and duration of the close-up period and monitoring BHB and NEFA concentrations are recommended to avoid increased calf birth weights.