Effect of Milking Frequency on Body Condition Score, Somatic Cell Count, and Reproductive Performance of Dairy Cows Milked by An Automatic Milking System

Abstract

The objective of this study was to determine the effect of milking frequency using an Automatic Milking System (AMS) on body condition scores (BCS), somatic cell count (SCC), and reproductive performance of Holstein cows. The study was conducted in Hiroshima University Farm. Eight multiparous cows and four primiparous cows were divided into two treatments of groups (2 and 4 times milking frequency). Cows were fed by Partial Mixed Ration (PMR) ad libitum and concentrate diet (5-8 kg) at every milking. The PMR consisted of Italian ryegrass silage 35% dry matter (DM), oat hay (8% DM), alfalfa hay (8% DM), pellet bit pulp (8% DM), formula feed (39% DM), minerals and vitamin. The PMR nutrients contents were 13.6% crude protein (CP) and 70% total digestible nutrient (TDN), while concentrate contained 20.6% CP and 82.4% TDN. On days 20, 35, and 50 postpartum, BCS was observed, and milk samples were collected for SCC analysis. Reproductive performance data collected were S/C, calving interval, and postpartum mating. The MIXED model for repeated measures (SAS 2004) was used for testing the difference in BCS and SCC. Significance was declared at P < 0.05, and tendency at P < 0.10. The research showed that no difference on BCS and SCC between 2 and 4 times milking by AMS, but the probability of occurrence of high SCC (> 100,000) was lower for four times milking cows than 2 times milking cows (6% vs 59%). The effect of milking frequency did not show any difference on S/C, calving interval, and postpartum mating. Increasing milking frequency may positively affect on SCC without any effects on BCS and reproductive performance in this experiment.