Feeding Thyroprotein to Cocks During Summer

INTRODUCTION LOW fertility in eggs is a characteristic phenomenon commonly observed in summer hatches of fowl eggs in subtropic countries like Egypt (Hafez and Kamar, 1955). This may be due to a lot of factors, of which the most important one may be the male side when represented by semen production. This work was done in a trial to improve the characteristics of semen produced by the cocks by administering thyroprotein as a replacement for the decreased thyroidal activity that was observed to occur during hot weather (Winchester, 1940; and Reineke and Turner, 1945). This hot weather normally occurs during the summer in Egypt. Hyperthyroidism induced by feeding thyroprotein (0.02%) for a 16 week period to two year old Barred Rock males, did not affect semen volume or sperm concentration. However, there was some deterioration in methylene blue test, motility of spermatozoa and survival time at 4°C. and hence lowered …