Age Influenced Variations in Plasma Cholesterol, Testicular Cholesterol and Testicular Ascorbic Acid of Prepubertal Turkeys (meleagris Gallopavo)

Arneja D. V., D. Chand, G. C. Georgie: Age influenced Variations in Plasma Cholesterol, Testicular Cholesterol and Testicular Ascorbic Acid of Prepubertal Turkeys (Meleagris gallopavo). Acta vet. Bmo, 50, 1981: 53-59. The blood plasma and testicular cholesterol and testicular ascorbic acid concentrations were determined in prepubertal male turkeys at different periods between 135 and 235 days of age and were related to testicular maturation. Plasma cholesterol concentration was negatively correlated with testicular weight (r = -0.48, P < 0.01) and showed a decline with age from 8.12 to 3.84 mmol.l-1 during the period. A statistically non-significant decline in testicular cholesterol concentration (101.27 to 40.36 ",mol/g wet weight) Was observed. The testicular ascorbic acid concentration showed a significant (P < 0.01) fall, from 97.7 to 18.5,tmol/g wet weight, between 145 and 175 days of age. During the study period, testicular weight steadily increased from 0.663 to 21.326 g and showed a size asymmetry with the left testicle being almost double in weight than the right. Maturation, testicular mass. The relationship of cholesterol concentrations of testicular tissue to maturation and steroidogenesis (Massa and Aoki 1976; Ikegwuonu and Aire 1977; Chand et. a!. 1978) as well as spermatogenesis (Kanwar et al. 1977) in that tissue have been studied in birds. Attempt has also been made to study the testicular ascorbic acid depletion in phases of increased steroidogenic activity during testicular growth in cockerels (Chand et a!. 1978) because of the key role this phenomenon plays in steroidogenesis (Kitabachi 1967). Though changes in testicular weights at different ages have -been reported for turkeys (Zidkih 1962; Burke 1973), the authors have not come across reports where estimates of testicular cholesterol or ascorbic acid concentrations have been made and related these to testicular maturation in this species. This paper presents the results of the investigation carried out to establish the age influenced changes in testicular cholesterol and ascorbic acid concentration to testicular growth in turkeys (Meleagris gallopavo), and to enquire into the possibility of existence of a relationship between the levels of these tissue constituents to testicular maturation. Simultaneously, estimates of testicular lipid concentrations were also made and the changes in testicular cholesterol concentrations were related to the total lipid chilnges of testes. The circulating plasma cholesterol concentration has been correlated to the changes in testicular weight and its cholesterol content, as there are conflicting reports that plasma cholesterol levels are influenced by gonadal activity in birds (Hoffman 1960; Anisko 1974). Materials and Methods Beginning with the age of 135 days, Broad-Breasted Bronze turkey tcms (Meleagris gaUopavo) were sacrificed by decapitation in batches of 5 at 135, 145, 175, 195 and 215 days age. At 235 days of age only 4 toms were slaughtered. The schedule of slaughter was discontinued when other toms of the same hatch left with females showed successful mounting which resulted in the production of fertile eggs. Before sacrifice, the live weights were recorded and bloed samples were