Development of a Ca,le Shedding Phenotype Recording Protocol for Oklahoma K. McKinney, K. Allwardt, A. Broocks, K. Branham, D. Lalman, and M. Rolf Department of Animal Science, Oklahoma State University
Abstract
Ability of ca,le to shed their hair in the summer likely affects animal well-‐being and reduces heat stress. Conversely, ability of ca,le to regrow winter coats should protect them from weather variability and cold stress in the winter. Because these stresses are unfavorable for both animal performance and for the well-‐being of beef ca,le, it is important to develop tools that allow us to study hair shedding in beef ca,le. Our objecBve is to develop a hair shedding phenotype recording protocol for commercial ca,le in Oklahoma. Preliminary work to build a scoring schemaBc have already been performed at Mississippi State University. Within Mississippi, collecBon of data is performed from March to July. Because weather condiBons are warmer and more humid in Mississippi than in Oklahoma, our objecBve is to determine which months of the year data should be collected to capture shedding differences for ca,le in Oklahoma. To achieve this objecBve, we are collecBng and cataloging phenotypes for 220 crossbred beef cows at the North Range Research Unit. Phenotype collecBon began in December 2013 and will conclude in November of 2014 so that their hair shedding is tracked for an enBre calendar year from full winter coat through shedding to a full winter coat again. Once phenotypes for 12 months have been gathered, we will analyze the data to determine the months when most shedding occurs. Development of this protocol will enable further studies into how shedding affects performance and well-‐being of beef ca,le.
This will make it easy to see how quickly parBcular cows are shedding, what kind of coats they had to start with, and what kinds of coats they Methods develop in response to seasonal change. Performance data (calf weaning To keep track of each cow’s shedding pa,erns, pictures of a large weights, body condiBon scores, and rebreeding informaBon) will also be number o f c rossbred b eef c ows ( n=220) a re b eing c ollected a nd collected for later analysis to determine whether hair coat shedding cataloged in a database. e ebconomically egan assembling these pictures in affects performance of ca,le W for important traits.
December 2013 and we will track the shedding pa,erns in these animals for one year, ending in November 2014. December was chosen as the start date because most animals should have a full winter coat by mid winter, which provides the opportunity to track performance throughout an enBre year from full winter coat to shedding and through hair coat regrowth the following winter. Pictures are taken once per month and each animal’s picture is tagged with individual animal IDs for later scoring. Each picture will be scored according to a hair shedding scoring system developed at Mississippi State University (Table 1). This will make it easy to see how quickly parBcular cows are shedding, what kind of coats they had to start with, and what kinds of coats they develop in response to seasonal change. Performance data (calf weaning weights, body condiBon scores, and rebreeding informaBon) will also be collected for later analysis to determine whether hair coat shedding affects performance of ca,le for economically important traits.
Hair Shedding Score
DefiniBon
5
Full winter coat, No shedding observed (0%)
4
Coat exhibits iniBal shedding, Approximately 25% shed
3
Coat is halfway shed, Approximately 50% shed
2
Coat is mostly shed, Approximately 75% shed
1
Slick, short summer coat, Completely shed (100%)
Table 1: Hair shedding phenotype scoring system Discussion
Cows that shed quickly in response to warmer weather will likely be more adapted to their environment. The ca,le that shed their winter coat slowly will likely exhibit more heat stress, and their performance (body condiBon score and subsequent rebreeding performance) and their calf’s performance may suffer. Likewise, it’s important for ca,le to regrow winter coats during the colder months of the year so that they can withstand cold winter winds and snowy condiBons. Cold temperatures increase the amount of feed resources animals must consume to keep warm, which increases producBon costs for producers. Therefore, it is important to have ca,le that can adapt to summer weather by shedding and also regrow winter coats. By developing this collecBon protocol, we will develop a criBcal tool needed to collect phenotypes for hair shedding in beef ca,le. This will enable us to study the effect of shedding on ca,le performance by uBlizing addiBonal producBon data on these ca,le. If there are significant effects on performance or animal well-‐being, it may be beneficial to breed ca,le with their shedding pa,erns in mind or to develop management tools to miBgate the effects of ca,le that do not shed properly during the summer.
Acknowledgements and References
I would like to thank Trent Smith from the Animal Science Department at Mississippi State University for sharing their hair shedding phenotype recording system. I would also like to thank Dr. David Lalman and Mr. Adam McGee for working with us and allowing us access to the ca,le at the North Range Research Unit for data collecBon.
Hair Shedding Scoring System Score of 5
Score of 3
Score of 1
Score of 4
Score of 2