Abstract
Automated feeding systems for dairy cows offer the benefits of ‘little and often’ feeding. Published data were collected and analysed to establish the extent of such benefits. Twenty-three publications reporting the results of 35 experiments were examined. Several statistically significant positive responses indicated that milk fat concentration, and to a lesser extent yield of milk, could sometimes be increased by increasing the feeding frequency. However, for ail experiments the average proportional increases (± s.e.) in milk fat concentration and milk yield were fairly small at 7·3 (± 3·3) % and 2·7 (± 1·3) %, respectively. The responses of milk fat concentration and milk yield were apparently correlated (r= 0·43, s.e. = 0·20), and the mean proportional response of milk fat yield was 8·3 (± 3·1) %. There was no evidence that milk protein concentration, lactose concentration or changes in body weight were affected by changes in feeding frequency. Increases in food intake were sufficient to explain some, but not all, instances of increased milk fat production. All statistically significant responses to increased feeding frequency occurred when the milk fat concentration was originally depressed, milk fat depression generally being due to feeding pelleted or highly concentrated diets. Increases in milk fat concentration through increased feeding frequency were generally insufficient to bring the milk fat concentration up to a commercially acceptable level. All statistically significant responses were observed on moving from one or two to three or more meals per day, but the possibility of further responses beyond four meals per day could not be ruled out. It was concluded that cows producing milk of commercially acceptable milk fat concentrations were unlikely to benefit from increased feeding frequency.