The effects of milking cows three times daily

Abstract

The experiment assessed the effects on performance from calving to the 20th week of lactation of milking cows three times daily (3 × ) compared to milking twice daily (2 × ). After 20 weeks all cows were milked 2 ×. Each treatment consisted of 18 cows and 11 heifers. The mid-calving date was 21 September 1979.Complete diets of the same composition were offered separately to each group in quantities equivalent to 1040 g/kg of their previous intake. The diet for the first 18 weeks of lactation was estimated to have an energy concentration within the range 11·0 to 11·3 MJ metabolizable energy per kg dry matter. After 18 weeks, the diet was reformulated to reduce the energy concentration to 10·3 MJ per kg dry matter. Total food intakes for the 20 weeks of treatment were 2352 kg dry matter (3 ×) and 2241 kg dry matter (2 ×). From 8 April 1980 the cows were turned out to grass to complete their lactations.During the 20 weeks the mean daily milk yields of heifers were 19·3kg (3×) and 171kg (2×) (P<005). Cow yields were 28·4 (3×) and 23·9 kg (2×) (P< 0·001) during the same period. After 3× daily milking ceased, there were some positive carry-over effects on milk yield and food intake.Lactation yields from heifers were 4881 (3 ×) and 4498 kg (2×), whilst for cows the equivalent yields were 6485 (3 ×) and 5694 kg (2 ×) (P<0·01). There were no significant differences in milk quality. At 20 weeks after calving the cows milked 3 × daily had gained less weight, but by 44 weeks from calving the weight gains were similar at 42 (3 ×) and 45 kg (2 ×).