Libraries at University of Nebraska-Lincoln


Document Type


Date of this Version



Thesis (M.S.)—University of Nebraska—Lincoln, 1950. Department of Dairy Husbandry.


Copyright 1950, the author. Used by permission.


With more and more attention being focused on the reproductive processes of dairy bulls due to the extensive use of each individual through artificial breeding, it becomes of practical importance to determine the effect of administering thyroidially active substances on their reproductive performance. Studies on the effect of excess of circulating thyroid hormone on reproduction is limited and needs further investigation.

It was the purpose of this study to investigate further the effect of thyroidially active materials on the reproductive ability of dairy bulls.

The animals used in this experiment were males in the University of Nebraska Stud owned by the University of Nebraska and the University of Nebraska Foundation. Six bulls, including 3 Milking Shorthorns, 2 Jerseys, and 1 Guernsey, were fed thyroprotein at the rate of 4 grams per day for a period of one week after which the dosage was increased to 8 grams per day for the remained of the five month’s feeding period.

Advisor: Andrew B. Schultze