I certify that I have read this study and that in my 

 opinion it conforms to acceptable standards of scholarly 

 presentation and is fully adequate, in scope and quality, as 

 a dissertation for the degree of Doctor of Philosophy. 



i.Kfi*0*JK 



L. R. McDowell, Chair 

 Professor of Animal Science 



I certify that I have read this study and that in my 

 opinion it conforms to acceptable standards of scholarly 

 presentation and is fully adequate, in scope and quality, as 

 a dissertation for the degree of Doctor of Philosophy. 



H\f Conrad 

 'Professor of Animal Science 



I certify that I have read this study and that in my 

 opinion it conforms to acceptable standards of scholarly 

 presentation and is fully adequate, in scope and quality, as 

 a dissertation for the degree of Doctor of Philosophy. 



^O £> • t^>&> 



Doug 1 a k B . Ba t e s 

 Associate Professor of 

 Animal Science 



I certify that I have read this study and that in my 

 opinion it conforms to acceptable standards of scholarly 

 presentation and is fully adequate, in scope and quality, as 

 a dissertation for the degree of Doctor of Philosophy. 



Cousins 

 Boston Family Professor of 

 Human Nutrition 



