The effect of diet on the milk quality of organic dairy cows

Summary

This report was presented at the UK Organic Research 2002 Conference. Changes in milk quality were evaluated with spring-calving dairy cows and heifers fed organic diets and different levels of concentrates during early lactation. The diets were based on ad libitum forage and either 2 kg of concentrates/day (Diet 1) or concentrates fed according to milk yield up to a maximum of 7 kg/day (Diet 2). Average milk yields during the study for the cows and heifers were 23.1 and 20.1 kg/day (Diet 1) and 25.8 and 24.0 kg/day (Diet 2), respectively. The highest number of samples with a fat to protein ratio of 1.4 or > were found in samples collected from cows and heifers fed Diet 1 (20.9 and 50.0%). The lowest milk protein value of 2.86% was recorded from the heifers fed Diet 1. Low milk lactose values were correlated to high somatic cell counts.