The Effect of Feeding Thyroprotein on Egg Shell Quality and Hatchability

Thyroprotein and Fat in Laying Diets

“…Under the conditions of these experiments, thyroprotein did not possess any nutritional significance in laying diets from the standpoint of egg production. Our results confirm the findings of Hutt and Gowe (1948), Hoffmann and Wheeler (1948), Godfrey (1949) and Berg and Bearse (1951). The effectiveness of dietary fat in maintaining body weight and improving feed efficiency was demonstrated.…”

Effect of Iodinated Casein and Thiouracil on the Performance of Laying Birds

“…The birds which under apparently normal environmental and nutritional conditions were unable to produce shells as thick as other birds of the same population (trial 1) responded to the addition of iodinated casein to the feed by producing thicker shells, whereas the birds which normally produced relatively thick shells (trial 2) did not respond to the drug in a like manner. These results would substantiate the contention of Godfrey (1949) who hypothesized that birds which normally produce poor egg shells, as expressed by 14-day incubation weight loss, have a low level of thyroid activity and thus may respond to the feeding of thyroprotein, whereas birds which produce thicker shells do not respond because of greater thyroid activity.…”

“…The fact that significant improvement in shell thickness was obtained with two of the groups of birds but not with the other two, and the fact that the results obtained by Hutt and Gowe (1948) failed to show the improvement in shell quality recorded by co-workers (1946, 1947), Hoffman and Wheeler (1948), and of Godfrey (1949) indicate that the shell-secreting glands of different groups of birds may be affected differently by the feeding of thyroprotein. A comparison of the data secured in trials 1 and 2 would tend to support this hypothesis.…”

“…These results are in agreement with those of Hutt and Gowe (1948) who found that feeding iodinated casein at the rate of 10 grams per 100 pounds of feed caused a decrease in rate of lay during the first eight weeks of the feeding period. Likewise, the data of Godfrey (1949) indicate that a level of 10 grams of the drug caused a more rapid than normal decline in summer egg production. The results of the present investigation and of the aforementioned two investigators are in disagreement with the finding of Turner andco-workers (1945a, 1945b) whose data indicate improvement in rate of lay as a result of feeding iodinated casein.…”

The Supplementation of Thyroprotein (Iodinated Casein) In The Diet of Second and Third-Year Layers

“…al ( , 1947 found that thyroprotein feeding to laying hens resulted in increased egg production. On the other hand, other workers for example, Hutt and Gowe (1948), Godfrey (1949), Berg and Bearse (1951) and Oloufa (1952) reported that dietary thyroprotein depressed egg production. Reports on the effect of thyroprotein on body weight increment, egg shell thickness, egg weight and other economic characteristics of the domestic fowl have likewise been inconsistent (Gutteridge and Pratt (1946), Gutteridge and Novikoff (1947), Hutt and Gowe (1947), Wheeler et al (1947) and Oloufa (1955).…”