Research Report

Extreme Cold Weather and Broiler Chicken Transport
There are many factors that must be considered when evaluating the wellbeing of animals. In the case of broilers the effect of temperature has been of concern for years. However, since most broilers in the U.S. are grown in the southern climates, there has not been much work on extreme cold. Recent climate conditions have made the potential for extreme cold in the south more likely. In Canada where very low temperatures during the winter months are normal, researchers at the University of Saskatchewan recently investigated the effects of these cold temperatures on the core body temperature of broilers in a controlled study.

The objectives of this study were to examine the thermoregulatory responses of birds in drawers under cold conditions typical of those they might experience during transport in winter months in Western Canada. It is very interesting to note the responses of the birds to the temperature. Before the temperatures were lowered, the birds we distributed throughout the transport drawer but during the last 10 minutes, the birds decreased their use of the front portion and grouped into the middle and rear of the drawer. The front was on average, 5°C colder than the middle which was about 2.5°C warmer than the rear. Thus, the birds moved to warmer sections and changed the density of the area to compensate for the temperature reduction.

Huddling, hiding the head and feet to protect them and ruffling their feathers to improve their insulating affect are well known behaviors in cold conditions. In the Canadian study, the broilers also moved away from the cold incoming air stream in the front of the drawer.

The core body temperature (CBT) did change. During the initial exposure to the chamber, the decline in the CBT was quite rapid, but near the end of the period, the decline began to slow down. This suggests that the birds tend to be most affected during the beginning of the journey. The slower rate of decrease in CBT during the latter part of the chamber exposure may also be attributed to the birds’ behavioral and physiological responses.

The results from this study suggest that exposing birds to temperatures at or below −5°C affects the behavior and physiology of broilers, but the CBT response was not as drastic as previously reported. The birds in this study were able to cope with and recover from the conditions to which they were exposed. Other typical transport stressors were eliminated or minimized to isolate the effect of low temperatures. The density used in this experiment is not one that would typically be employed in the commercial setting, and further research is necessary to understand the behavioral and physiological responses of broilers exposed to cold conditions at those higher densities.

The effect of simulated cold weather transport on core body temperature and behavior of broilers. M. L. Strawford , J. M. Watts, T. G. Crowe, H. L. Classen , and P. J. Shand. 2011 Poultry Science 90 :2415–2424.

Dairy Cow Tail Docking
“Tail docking remains a common practice on dairy farms in the United States. This paper describes the results of an online engagement designed to create discussion on tail docking, to document the reasons participants put forward for and against the practice, and to compare these reasons with the literature available on this topic. A total of 178 people responded; 30% were producers, 23% were veterinarians, 25% had no experience with the dairy industry, and 22% included a mixture of teachers, students, and industry professionals. Approximately 79% of participants were opposed to docking. Responses varied with participant demographics (e.g., females were more likely than males to oppose docking), but in every demographic subgroup (e.g., by sex, age, country of origin, and dairy production experience), the majority of respondents were opposed to tail docking. Common reasons for opposition to docking included the lack of scientific evidence that docking improves cleanliness or udder health, that docking is painful for cows, that docking is unnatural, and that tails are important for controlling flies. Some respondents in favor of docking cited cow cleanliness as an issue, despite the scientific evidence showing no positive effect of docking on cow cleanliness or udder health. Additional reasons included protecting producer safety. These results illustrate the range of reasons that are cited for supporting and opposing tail docking. This approach can be used to better target outreach efforts (e.g., improving farmer education on the lack of positive effects of docking on cleanliness and udder health while addressing concerns about producer safety). More generally, this type of online discussion provides a safe and productive format for discussions about contentious issues in the dairy industry and provides a mechanism for producers, industry professionals, and the public to share perspectives on these topics.”

Tail docking dairy cattle: Responses from an online engagement
D. M. Weary, C. A. Schuppli, and M. A. G. von Keyserlingk, J ANIM SCI. November 2011, 89:3831-3837