| Abstrakt: |
Additional physiological measurements were studied to aid in understanding the unique observation that marginally vitamin A-deficient cockerels had increased testes size. One-day-old Single Comb White Leghorn cockerels were fed either a vitamin A-deficient or -adequate (6600 USP units/kg) ration. Hematocrits were greater from vitamin A-deficient birds at 6, 9, 10 and 11 weeks of age. Combs, testes, bursae and adrenals were removed and weighed, and the latter 3 organs corrected for body weight. Bursae weights from vitamin A-supplemented birds were larger from 6 through 11 weeks of age. Vitamin A-deficient birds had heavier testes and heavier combs at 8 and 10 weeks of age. Histological examination of the testes from 11-week-old vitamin A-deficient birds showed mature sperm. No sperm were observed in the testes of control birds at this age. Corrected adrenal weights were heavier in the deficient birds at 9, 10 and 11 weeks of age. No differences in oxygen consumption were found between treatments measured at 3, 5 and 11 weeks of age. Increased testis weight, adrenal weight, comb size, red blood cell volume and decreased bursa weight suggested higher androgen secretion by vitamin A-deficient birds. |
