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