Young Cockerels Research Articles

Avian Medullary Bone

SINCE the report by Kyes and Potter1 that the marrow cavities of the tibia and femora of female pigeons become filled with endosteal bone during the laying cycle, this phenomenon has been the subject of intensive study in the sparrow2, duck3 and domestic fowl4,5, as well as in the pigeon6,7. This highly labile medullary bone appears to serve as a readily available store of calcium for the calcification of the egg shell. It has been studied almost exclusively in the long bones of the legs, though Zondek8 found it also in the vertebral column of young cockerels after treatment with œstrogen.

Hypertrophy of the testis induced by sulphadimidine and other pyrimidine derivatives.

The administration of sulphonamido derivatives of pyrimidine (e. g. sulphadimidine) to young cockerels induces testicular hypertrophy. Of thirty-five compounds tested for the effect, only phenylsulphonamide derivatives of pyrimidine and quinoxaline have been found to be active. The effect of testicular hypertrophy appears to be independent of bacteriostatic action as it is produced by 2-phenysulphonylamido-4:6-dimethylpyrimidine, and the effect of sulphadimidine is not neutralized by administration of p -aminobenzoic acid or of folic acid. Sulphadimidine reversed the inhibitory effect of stilboestrol on the testes of young rats. Testicular hypertrophy could not be induced regularly in normal young rats or mice by sulphadimidine. The synthesis of some new pyrimidine derivatives is described.

The Use of Thiouracil and Diethylstilbestrol in Finishing Turkeys for Market

TURKEYS are normally marketed as soon as they are “finished.” This condition is determined by fleshing and freedom from pin feathers. According to Hixson and Thompson (1951) growth, finish, and feathering depend upon the amount and quality of the feed consumed. They state further that hot weather is generally considered to be a cause of reduced feed consumption. From these statements, it can be inferred that turkeys of top quality cannot be produced under hot weather conditions.Lorenz (1944) reported that diethylstilbestrol gave a slight improvement in fleshing and freedom from pin feathers in turkeys. Other estrogen compounds have been tried with varying degrees of success (Davis and Thayer, 1948). The use of a combination of thiouracil and diethylstilbestrol for improving finish in chickens was reported by Schnetzler et al. (1945). Andrews and Bohren (1947) found that thiouracil and diethylstilbestrol administered, in combination, to young cockerels improved fleshing and marketing .

The Influence of Thiouracil and Stilbestrol on Broiler Quality

FOLLOWING the discovery that a large number of substances related to thiourea inhibit thyroid hormone secretion and decrease basal metabolic rate in the rat (Richter and Clisby, 1942, Astwood and co-workers, 1943, and MacKenzie and MacKenzie, 1943), it was shown that thiouracil would increase fat deposition and improve market quality in the chicken (Kempster and Turner, 1945; Andrews and Schnetzler, 1946; and Andrews and Bohren, 1947).It has likewise been shown that the subcutaneous implantation of stilbestrol pellets or the feeding of certain estrogens, especially 3, 4-dianisylhexene-3, would increase fattening and improve carcass quality in poultry (Lorenz, 1943 and 1945; Jaap and Thayer, 1944; and Thayer et al., 1945).Schnetzler et al. (1945), observed that thiouracil and stilbestrol in combination increased the amount of fat in 18-month old cocks. Andrews and Bohren (1947) found that administration of thiouracil and stilbestrol in combination to young cockerels improved fleshing and market grade .

Residual Estrogens in the Tissues of Fowl Treated with Dienestrol Diacetate

SYNTHETIC estrogens are now being used commercially to feminize male fowl and thereby to increase their market quality. It is desirable to obtain as much information as possible on the quantity of estrogens remaining in the edible tissues of treated birds. Since Lorenz and Bachman (1947) have shown that dienestrol diacetate, when fed at levels of .0033 to .01 percent of the diet, has the ability to increase the fat deposition in young cockerels, it might well be a very good hormone to use commercially if there is no appreciable amount of this estrogen remaining in the edible tissues. Bird et al., (1947) have demonstrated that in birds treated with dienestrol diacetate there is a negligible quantity of that substance left in the abdominal adipose tissue. Although these workers assayed edible tissues of 3 males that had been fed the dimethyl ether of hexestrol, they did not assay any of .

TTHE INHIBITION OF COMB GROWTH IN COCKERELS AND CAPONS BY ESTRONEW123

A NTAGONISTIC as well as augmentative effects of the simultaneous ad'JLX. ministration of male and female sex hormones in mammals have been the subjects of numerous reports in the literature. The antagonistic effect is usually interpreted as an inhibition of the gonadotropic activity of the pituitary as suggested by Moore and Price (i), while the synergistic effects have not as yet been explained In Brown Leghorn capons, Juhn, D'Amour and Womack (2) found neither an ntagonism nor an intensification of effect when purified testis'tissue concentrates (2, capon units per day) and a urinary estrogen preparation (150 R.U. per day) were injected simultaneously for 34 days. Juhn, Gustavson and Gallagher (3) administered urinary estrogenconcentrates (10 R.U. per 25 gm. body weight) to young cockerels of various ages and found no evidence of antagonism except a shrinkage of the comb in a few birds in the group 12weeks of age. Since the testes of these birds were normal histologically.