Field notes: Diary at a Dairy

There are approximately 9 million dairy cattle in the United States [1] as of 2019, with almost half of all farms in the United States having cattle or calves of some kind [2]. With such a large population of cattle being used as food sources in our country (either as beef or dairy products), it is imperative that we improve our understanding of their welfare on farms. There are a variety of ways that welfare can be studied in animals, including pain, fear and physical health. In my lab at UC Davis, we focus on looking at the behaviors that these animals perform, and what this ultimately can tell us about their welfare.

Figure 1: Jersey cow performing the abnormal repetitive behavior of tongue rolling.

In summer of 2021 I completed my first project (woo!) for my PhD in Animal Behavior at UC Davis. I am interested in examining dairy cattle’s abnormal repetitive behaviors (ARBs). An ARB, as defined by animal scientist Joseph Garner, is a behavior that is “inappropriate, repetitive and unvarying in either goal or motor pattern” [3]. In dairy cattle specifically, there are three primary ARBs that are examined: cross-sucking, tongue rolling [Figure 1], and non-nutritive oral manipulation. These ARBs all involve some kind of mouth movement or manipulation by the individual. Part of the reason that we are interested in looking at these behaviors is because dairy cattle spend a large portion of their day eating [Figure 2], so it is likely that the performance of ARBs is associated with feeding. For example, when dairy calves are fed less hay, they perform tongue rolling more [4].

Figure 2: Dairy cows spend a large amount of time eating and ruminating throughout their day! Dairy cattle diet can consist of components like hay, alfalfa, almond hulls, grains, corn, soybean meal, and byproducts.

My goal for the 2021 project was to create a sampling system that captured the prevalence of ARB performance within a group of dairy cattle, and examine the variability of these performances across days. In order to accomplish this, my intern and I observed one pen of dairy cows across a 14-hour time period and across two consecutive or semi-consecutive days. In order to maximize the amount of data we could collect, we repeated this in seven different pens of animals. Three of the pens had lactating cows, which are typically the oldest animals on the farm, and the remaining four pens contained heifers, which are the “teens” of the farm (older than calves, but not yet lactating). All of these cows are female and range from a few days to about 8 years! By examining both ages, we were also able to look at any potential differences in performance based on age.

Figure 3: Some sleepy little heifers basking in the early morning sun.

Sampling 40 cows at one time is no simple task, as it is important to keep all of the animals within your view when possible. This meant that we would often bring a stepladder outside the pen, so that we could peek over the high fencing. We also used binoculars, so that we could record the ID of the individual performing the behavior. The process of sampling consisted of long days. These entailed either myself or my intern arriving to the farm before 6 am to set up for a 2 hour observation. Then, every 2 hours we would switch off, swapping until we were finished at 8 pm. Although 2 hours doesn’t sound very long for observing cows, when sitting in a concrete feed bunk [Figure 4] in 40 degrees F, it could feel like forever! One of my favorite things to do during observations was to listen to my favorite podcasts to stay focused.

Figure 4: A curious cow gets a little too close during observations!

After several warm days and cold evenings of observing cattle, we were finally finished in September 2021. After analyzing the data, it seems like dairy cattle do in fact show distinct patterns[1] [2] in their ARB performance! This is an exciting discovery, as once we understand more about the prevalence of ARBs on farms, and when they are performed, then we can help to predict and potentially prevent them from happening. This is critical in order for us to fully understand and improve their welfare. For future studies, we plan to continue to study these adorable animals and the strange things they do with their mouths!

Isabelle McDonald-Gilmartin is a PhD student in the Animal Behavior Graduate Group. She studies welfare behavior in dairy cattle. She loves painting, reading and playing with her dog.

References:

[1] U.S. Department of Agriculture. Milk Production. By National Agricultural Statistics Service. February 2020. https://www.nass.usda.gov/Publications/Todays_Reports/reports/mkpr0220.pdf

[2] U.S. Department of Agriculture. Overview of U.S. Livestock, Poultry and Aquaculture Production in 2017. By Animal and Plant Health Inspection Service. November 2017. https://www.aphis.usda.gov/animal_health/nahms/downloads/Demographics2017.pdf

[3] Garner, J. P. (2006). Perseveration and stereotypy: systems-level insights from clinical psychology. Stereotypic animal behaviour: fundamentals and applications to welfare, 121, 142.

[4] Kooijman, J., Wierenga, H. K., & Wiepkema, P. R. (1991). Development of abnormal oral behaviour in group-housed veal calves: effects of roughage supply. New trends in veal calf production, 54-58.

[Edited by Josie Hubbard and Maggie Creamer]