Leo S. Jensen

Selenium Deficiency and Impaired Reproduction in Japanese Quail

Summary Impaired reproduction was observed in Japanese quail fed a diet low in both selenium and vitamin E from 1 day of age to maturity. Oviposition rate and fertility were not affected by the deficiency but hatchability of fertile eggs was markedly reduced and viability of both the adult females and the newly hatched chicks were reduced. Dietary supplementation with either selenium (1 ppm) or vitamin E (30 IU/kg) prevented the impaired reproduction but ethoxyquin (0.3%) was only partially effective.

Pancreatic Hypertrophy and Chick Growth Inhibition by Soybean Fractions Devoid of Trypsin Inhibitor.

Summary Fractionation studies on raw soybean meal have shown that the major chick growth inhibiting factor resides in the water insoluble residue. This fraction was devoid of anti-trypsin activity. Other fractions which contained high anti-trypsin activity were found to have an innocuous effect on growth of chicks. In all cases, where growth depression occurred, the pancreas was markedly hypertrophied.

Influence of Dietary Vitamin E and Selenium on Distribution of Se75 In the Chick.

Summary Three-week-old chicks fed either a Vit. E deficient or supplemented diet were intraperitoneally injected with Se75, and distribution of the isotope was determined in various tissues at 24, 48, and 168 hours after injection. Similarly, 2-week-old chicks fed a selenium deficient or supplemented diet were given an oral dose of Se75 and the distribution of the isotope in several tissues was determined at 24 and 168 hours after administration. Vitamin E had no effect on distribution of selenium, but selenium itself had a marked effect on the uptake and retention of radioselenium. One-half of the dose was retained by selenium-deficient chicks at 7 days, whereas only 1/5 of the dose was retained by chicks fed 1 ppm selenium from day-of-age. Considerable selenium was deposited and retained in the cerebellum of chicks even though this element cannot prevent encephalomalacia.

Histo-physiological studies on chick pancreas as influenced by feeding raw soybean meal.

Summary Pancreatic hypertrophy in chicks fed raw soybean meal is caused by an accumulation of zymogen material in the acinar cells. Failure of the pancreas to respond in the expected way to pilocarpine injection suggests that the raw soybean meal interferes in some way with the basic mehanism by which zymogen is released from the pancreatic cells. It therefore seems unlikely that the growth depression in chicks fed raw soybean could be due to excessive fecal loss of critical amino acids contained in pancreatic enzymes.

Improvement in nutritional value of peas by cooking.

Summary Growth and feed utilization of chicks and poults fed diets containing high levels of peas (P. sativum) were markedly improved by cooking or autoclaving peas prior to mixing into diets. Greatly increasing caloric content of diets by adding tallow did not give a growth response comparable to that obtained by simply cooking the peas. Alkali-insoluble fractions of peas depressed chick growth but alkali-soluble fractions did not. It is suggested that peas (P. sativum) contain a growth inhibitor for birds that is inactivated by heating treatments employed.

Distribution of Se75 in Serum Proteins of Chicks and Influence of Selenium on Albumin Recovery.

Summary Se75 was orally administered to 3-week-old chicks fed either selenium deficient or supplemented diets. Distribution of Se75 in serum proteins with time and its effect on serum protein pattern were determined electrophoretically. Selenium in the diet had no effect on the distribution of Se75 in the protein fraction, but markedly decreased its retention. After 2 hours the major portion of the dose was found in the beta and gamma fraction and the activity in this fraction increased with time. Marked increases in A/G ratios in depleted chicks were observed within 96 hours after administration of Se75. Albumin was increased and globulin fractions were decreased. Increases in A/G ratios, somewhat smaller in magnitude, were also noted in chicks receiving a diet supplemented with selenium.