Epsilon Archive for Student Projects

Abstract

Cattle make extensive use of their sense of smell and are highly motivated to explore their surroundings. They have more than twice as many active olfactory genes as humans and use their sense of smell for, among other things, foraging, socialization and assessing predation risks. Despite this, there is very limited knowledge about cattle’s sense of smell and olfactory test regimes are scares. The immediate reactions of cattle when exploring new and thus novel odors have never been studied before, to the best of my knowledge.
In this experiment, 20 heifers were allowed to investigate the following 10 odors: orange, cedarwood, anise, pepper, eucalyptus, lemongrass, lemon, ginger, thyme and basil. The heifers were exposed to all the odors twice over two consecutive tests. The odors were placed on a cotton strip that was taped to the bottom of a feed bucket. The bucket was then fastened to a wall with cable ties. During the second test, an odor-free control bucket was also provided. The control bucket was added to be able to compare the reactions affected by different odors to reactions that were not affected by odors. The reactions of the heifers were recorded using video cameras and then interpreted using a curiosity scale. The results showed that the most common reaction was to sniff, regardless of the odor. The second most common reactions were Leaves and Turns. The odor of lemon induced the most curiosity (highest reaction on the scale) in the heifers. The odors which the heifers were the least curious about were ginger in Test 1 and basil in Test 2. The results also showed an increased expression of the reactions Head-shaking, Other behaviors and No approach over time. This suggests the possibility that the number of repetitions of the experiment may have influenced the heifers’ reactions to the odors. During the execution of the experiment, some disturbances occurred. Therefore, the results are to be interpreted with caution. The experiments were carried out in the heifers’ home environment and are therefore considered to show realistic results for how heifers investigate new odors during normally occurring disturbances. The disturbances included a feed wagon passing by, other heifers disturbing by sticking their heads into the test area, and other cattle being moved around in the barn. Future researchers are advised to work on the method and conduct more pilot studies before conducting their experiments.