Daytime pasture vs. free-stall barn access: What do dairy cows with year-long outdoor experience prefer?

Abstract Text:

Provision of regular exercise to dairy cows is a topic that has received an increasing amount of interest in recent years. Pasturing cows not only addresses the current issue of restricted movement found in many production units, but also has positive effects on health and welfare. The objective of the current study was to investigate cow preference for day-pasture access or a free-stall barn under Eastern Canadian summer climatic conditions. Two important components were introduced in the current study: the use of a herd with year-round outdoor experience and the provision of the same feed options (fresh forage and silage) inside and on pasture. 32 lactating organic Holstein cows were submitted to a 6-d preference cycle comprised of three 2-d phases. Cows were restricted to a free-stall barn (forced-indoor), restricted to pasture (forced-outdoor), or provided the choice between staying in a free-stall barn or? going to pasture (free-choice) for a 7-h period in between a.m. and p.m. milking. Live observations of activities (feeding from the feeder, grazing, lying down, and other) were conducted every 2 min by scan sampling during the forced-outdoor and choice phases. A group level t-test was used to test whether preference of cows to be outdoors differed from 0 % (choice to stay in free-stall), 50 % (indifference), and 100 % (choice to go to pasture). An independent 2-sample t-test was used to compare time spent in conducting the observed activities inside to those outside. Cows spent more time at pasture when provided the choice (range h1 to h6 across weeks: 68.4 to 87.4 %), displaying partial preference for the outdoors in h1, and h3 to h6 (difference from 0 %; P < 0.01) and complete preference for outdoor in h2 (difference from 0 and 50 %; P < 0.01), when the percentage of cows choosing to be outside was the highest. Cows conducted the same levels of activities on pasture as in the free-stall barn (P > 0.05), with cows grazing more than eating silage from the feeder on pasture (33.1 vs. 10.2 %, respectively) and eating fresh forage over silage when indoors (33.6 vs 4.2 %, respectively). This study showed that when provided with year-long outdoor access, dairy cows chose day-time pasture access over free-stall barn, and freshly-cut forage or pasture over silage. 

Keywords: dairy cow, preference test, outdoor access