Effects and mitigation of competition for feed access on the behaviour of lactating dairy cows
Through two independent experiments, utilizing group-housed lactating Holstein cows, this thesis sought to determine, firstly, the effects of increased feed competition on variability in feeding behaviour between individuals, and secondly, whether increased feed delivery frequency improved access to feed, and reduced variability between cows. In the first study, cows were fed at each of 3 competition levels: low (3:3, cows:feed bins), moderate (3:2), and high (3:1). Under the highest competition: cows maintained dry matter intake through increased feeding rate and decreased feeding time; feed was consumed in fewer, larger and longer meals; and greater variability in feeding patterns was observed within groups. The second study delivered feed to competitively-fed cows (2 cows:1 feed bin), at either a lower frequency (2 ×/d) or a higher frequency (6 ×/d). At the higher frequency, first meals after feed delivery were shorter and smaller, while maintaining dry matter intake. Variability in feeding behaviour, in the second study, was more affected by parity than frequency of feed delivery. These studies suggest that reducing competitive pressure while feeding could reduce potentially deleterious behaviour and limit the variability between individuals. Additionally, more frequent feed delivery could improve access to feed during peak periods of feeding activity.