Milk Producer - March 2009 - (Page 38)

RESEARCH By Lindsay Brown Connecting the dots Researchers investigate role genetics play in calf health and long-term survival P roducers and veterinarians are well aware that diarrhea and respiratory diseases are the leading cause of illness and death in young dairy calves. It’s long been thought these diseases resulted from poor management practices. However, early results from evaluating a large heifer calf population in New York State have shown survival rates may also be attributed to a calf’s genetics. In light of this finding, University of Guelph animal scientists are looking into what role genetics play in calf health and survival. Lynsay Henderson, a graduate student in the department of population medicine, is studying the association between genetics, calf health and survival. She’s using a standardized calf health scoring system to monitor disease occurrence while documenting the calves’ survival rates until weaning, and comparing these results to parental genetics. “Currently in Canada, calf survival is only routinely recorded for the first 24 hours of life, and used to genetically evaluate the calf survival trait,” says Henderson. “However, we would like to determine the influence of genetic merit on survival and disease occurrences beyond the first 24 hours, through the neonatal period, and up until weaning.” The research project has two distinct components. The first is being carried out on 16 Holstein farms across southwestern Ontario to record calf health and survival between birth and weaning. The farms range in size from a small, 40cow tie-stall herd to a large 800-cow free-stall operation. Henderson is recording all diarrhea, respiratory disease and death occurrences. She is also measuring immunity transfer, height and weight to assess growth and development until weaning. Preliminary research found some sires produce offspring with low survival rates, while other sires’ calves live until weaning. Since producers on these farms had completed a birth record for every heifer calf, the researchers were informed of any difficulties the calves may have experienced during calving. Farm workers were required to record treatments the dam received before calving, as well as those given to the calf after birth up until weaning. The researchers also completed herd level surveys to account for any herd management differences. The second part of this research project involves a DairyCOMP database from New York State. It is used to link calf health with documented pedigree information dating back to calves born in 1998. The database contains information on about 15,000 calves reared on a large heifer-raising facility in upstate New York. The calves in this study were evaluated on immunity transfer, growth parameters, disease occurrences and survival from birth to weaning. Henderson is using this data to help draw conclusions for her Ontario research to determine if there’s a genetic effect on calf survival and disease incidence. So far, her initial database analysis confirmed that wide and meaningful survival rates can be due to a sire’s genetics. Some sires produce offspring with low survival rates, while other sires’ calves are able to live until weaning. These variations are considerably higher and lower than the average survival rate. Henderson hopes her ongoing research will eventually reveal a great deal about how parental genetics determines calf survival. She hopes this research will lead to incorporating this information into future genetic evaluation programs. Lindsay Brown is a student writer with the University of Guelph’s office of research. Additional collaboration on this research was provided by University of Guelph professors Ken Leslie and Dave Kelton, department of population medicine, Andy Robinson, department of animal and poultry science and Dr. Filippo Miglior, Canadian Dairy Network and Agriculture and Agri-Food Canada. Funding for this research was provided by the DairyGEN Council of the Canadian Dairy Network and by the Natural Sciences and Engineering Research Council. 38 | March 2009 | MilkPRODUCER

Table of Contents for the Digital Edition of Milk Producer - March 2009

Milk Producer - March 2009
Contents
Editor's Notes
DFO Chair's Message
Dairy Update
DFC Promotion
Farm Finance
P5Pool Update
Issues Update
Weathering the Storm
Research
Applied Science
Ruminations
Markets
New 'N' Noted
Back Forty

Milk Producer - March 2009