Dairy cows trade-off feed quality with proximity to a dominant individual in Y-maze choice tests

Abstract

In this experiment choice tests were used as a tool to determine how dairy cows perceive their feeding environment with specific emphasis on understanding the challenges that low ranking animals face when forced to feed in the presence of socially dominant cows. It was hypothesised that cows would trade-off proximity to a dominant individual at the feed-face with access to food of a high quality. Thirty Holstein Friesian cows were used in the study. A test pen contained a Y-maze, with one black feed bin placed in one arm of the maze and one white feed bin placed in the other arm. During a training phase half of the cows were trained to make an association between the black bin and high quality food (HQF), and the white bin and low quality food (LQF). The other half was trained with the opposite combination, to prevent any colour bias. The status of each cow was assessed and dominant and subordinate cows were paired. Choice test 1 determined if cows had correctly learned the association between colour (of food bin) and food quality. Cows were presented with one black and one white bin in the two arms of the maze, with the presentation of each coloured bin in the left and right arms randomised. When cows achieved an 80% success rate of HQF preference they proceeded onto the next stage, where two further tests were presented. In choice test 2, the subordinate cow was presented with two bins of HQF, one of which had a dominant cow feeding from it. In test 3, cows had a choice of HQF and LQF, with the dominant cow present at the HQF bin. Cows showed a significant preference for feeding on HQF alone rather than next to a dominant ( P < 0.001). When they were “asked” to trade-off feed quality with feeding next to a dominant, the majority chose to feed alone on LQF ( P < 0.01). These results suggest that social status within a herd could significantly affect feeding behaviour, especially in situations of high competition and for subordinate individuals.