Peripheral plasma testosterone levels in hypothyroid-induced male goats (original) (raw)
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CHANGES OF THYROID HORMONES IN DIFFERENT PHYSIOLOGICAL PERIODS IN WHITE GOATS
Journal of Animal and Plant Sciences
The levels of thyroid hormones are important indicator of metabolic activity. The knowledge of the metabolic activity in different physiological periods, animals readjusted dietary regimen. Therefore, in this study, changes of triiodotironine (T3) and thyroxine (T4) hormones in the blood serum of female (n=14) and male (n=9) white goats were studied for a duration of one year through different physiological periods [breeding (September-October), gestation (November to March), postpartum-sucking (April-May) and milking (June to August)]. Results show that the differences in T3 and T4 hormone levels between sexes are statistically unimportant in breeding, gestation, postpartum-sucking and milking periods, while the changes for each sex between the physiological periods are important (p<0.05). Also, it has been found out that the thyroid hormone levels in different physiological periods are under the influence of the environmental temperature changes.
Annual Change of the Testosterone Hormone in Male White Goats
Agricultural Sciences in China, 2011
In this research, changes of testosterone hormone in the blood serum of 9 male (3 of age 2 and 6 of age 4) White goats have been studied for a duration of one year. Analyses performed show that the general monthly averages of the testosterone hormone of the male White goats in the period of 12 months starting in January were (2.mL -1 , respectively (P<0.05). The effect of the age factor on the testosterone production in White goats (age 2 and 4) was generally significant (P <0.05) for differences among months in each age group, but not significant for differences between age groups in each month. The testosterone hormone levels of male White goats encountered significant changes (P<0.05) with respect to the season.
Pathological and biochemical studies of experimental hypothyroidism in sheep
The objective of this experiment was to determine pathological and biochemical changes in hypothyroid sheep. Experiments were carried out using 12 Iranian crossbred sheep aged between 3-3.5 years old and weighing 45-65 kg. The animals were divided into two groups, 4 sheep as control and 8 as the experimental group. Hypothyroidism was induced in experimental animals by giving thiourea 50 mg/kg body mass daily for 4 weeks. Blood samples were taken weekly for T3 and T4 measurements. There was a highly significant decrease (P<0.01) in values of T3 and T4 in experimental animals as compared to the control group. At the end of the experiment all the animals of control and experimental groups were sacrificed and necropsied. Tissue samples were collected from the thyroid, kidney, liver, skin and spleen and stained by hematoxylin and eosin and sudan 3 and 4. In the experimental group the following changes were observed: the thyroid gland was moderately enlarged and firm in texture and dar...
Pathological and Biochemical Studies on Experimental Hypothyroidism in Growing Lambs
Journal of Veterinary Medicine, Series B, 2000
Secondary iodine deficiency was experimentally produced in growing male lambs by oral administration of 50 mg/kg bodyweight of Thiourea daily for 3.5 months. At the end of the experiment the animals became weak, emaciated, anaemic, significantly reduced in body weight with facial oedema and alopecia at thigh, legs and abdomen. The clinical analysis showed significant reduction in erythrocyte and leucocyte numbers and in levels of triiodothyronine and testosterone at the end of the experiment. The histopathological picture of the thyroid gland revealed hyperplasia of the follicle-lining epithelial cells which project into the lumen. The lumens of the follicles are devoid of colloid. The testes showed illdeveloped small, empty seminiferous tubules. In the liver, the hepatocytes showed degeneration and vacuolation with proliferation of Kupffer cells, which contain haemosiderin pigment. The kidney showed glomerular lipidosis with accumulation of haemosiderin pigment in the cytoplasm of the renal tubules. Hyperkeratosis of the epidermis associated with excessive keratin formation within the hair follicles was detected. In conclusion, deficiency of iodine causes hypothyroidism which leads to retardation of growth, reduced wool production and interferes with sexual maturity of growing male lambs.
2018
The present study attempted to: (1) simplify the existing enzyme immunoassay (EIA) for the measurement of insulin-like peptide 3 (INSL3) concentrations in goats (2) to measure circulating INSL3 and testosterone in pre-pubertal Jamnapari X local crossbred goats (3) to examine the relationships among INSL3 concentration, testosterone concentration, scrotal circumference and body weight during the pre-pubertal age. Serial blood samples were collected from normal pre-pubertal male Jamnapari X local crossbred goats (n = 6) at the ages of 19 to 28 weeks. Serum INSL3 was measured using a recently reported EIA with modifications to the original procedure. The detection ranges of the INSL3 and testosterone assays were 0.08 to 80 ng/mL and 0.01 to 40 ng/mL, respectively. The intra-assay coefficient of variations were 3.79% for INSL3 (n = 6) and 3.72% (n = 6) for testosterone. Serum INSL3 concentrations ranged from 13.62 ± 3.25 to 22.45 ± 6.09 ng/mL (mean ± SEM) in pre-pubertal goats. Those concentrations increased (p < 0.05) from 20 (13.62 ± 3.25 ng/mL) to 22 (22.45 ± 6.09 ng/mL) weeks of age. Testosterone concentrations ranged from 0.30 ± 0.07 to 1.22 ± 0.43 ng/mL in pre-pubertal goats. A significant drop was observed in testosterone concentrations at 23 weeks of age. INSL3 was correlated (r = 0.58; p < 0.05) with scrotal circumference while no significant correlation was observed among other tested parameters. A rapid, sensitive EIA system was simplified to quantify INSL3 in goats, by simplifying the existing procedure. Different serum INSL3 and testosterone dynamics were found from 19 to 28 weeks of age of the goats. Compared with testosterone, INSL3 dynamics seemed to be more consistent with the age of pre-pubertal goats and showed a relationship with the testicular growth.
Testosterone and LH concentrations in the male Angora goat during puberty
Animal Reproduction Science, 1990
Fifteen Angora male kids were used in order to investigate long-term reproductive endocrine changes associated with testis size, liveweight and season in a study of puberty and duration of the first breeding season. Blood samples were collected at weekly intervals; testis size and liveweight were recorded at 2-week intervals from post-weaning through puberty. With respect to the testosterone and LH concentrations and testis and body growth rates, that is, onset of puberty, two different groups of kids were distinguished (groups A and B). Testosterone and LH levels were significantly higher (P< 0.01) in group A than in group B during the breeding season, as were testis size and body weight, reflecting that group A animals reached puberty earlier (~ 178 + 12 days of age). The high levels of testosterone (4.09_+ 1.78 ng/ml) found in autumn were evidently a result of increased testicular steroidogenic activity (testicular responsiveness to LH). The elevation in testosterone and LH levels was accompanied by decreasing daylength and temperature, and increasing humidity. It thus appears that in male kids the onset of puberty and sexual maturation are individually variable.
Small Ruminant Research, 2015
The possible effect of testosterone administration and the male-to-female ratio regarding the male sexual behavior during the resting season and the out-of-season reproductive performance of anestrous goats exposed to the male effect under subtropical conditions (26 • N) was evaluated. In the experiment-1 two treatments were considered (1) Testosterone-treated bucks (TTB; n = 4; 25 mg, i.m., testosterone, every 3-days × 3-week), and (2) Non-testosterone treated bucks (NTTB; n = 4; i.m. saline every 3-days × 3week). Thereafter, both experimental groups were exposed to adult goats over two days (1 h × 2days) and two sexual behavior tests were performed: appetitive sexual behavior (ASB) and consummatory sexual behavior (CSB). In the experiment-2, multiparous lactating and anoestrous crossbred goats (n = 60) were randomly assigned to one of four treatments with different male-to-female ratios (MFR): (1) High MFR goats [HMFR; n = 20, 1:10 ratio], (2) Low MFR [LMFR; n = 10, 1:5 ratio] each group exposed to two NTTB, (3) High MFR goats [HMFR + T; n = 20, 1:10 ratio], and (4) Low MFR [LMFR + T; n = 10, 1:5 ratio] each group exposed to two TTB. While the TTB displayed higher ASB (p < 0.01; 91.9% vs 8.1 %), the NTTB did not express neither CSB (p > 0.05; 100% vs 0%) nor sexual behavior irrespectively of the male-to-female load. The HMFR + T depicted a higher ASB (p < 0.01; 65% vs 35%) than the LMFR + T, without differences in CSB between HMFR + T and LMFR + T. Also, TTB induced estrus response (86.6%) and pregnancy rate (83.3%) while NTTB did not. Neither estrus response (85 vs 90%) nor pregnancy rate (85 vs 80%) differed between the HMFR + T and LMFR + T groups. Exposing of anestrous goats to testosterone-treated bucks, irrespective of mating load, was able to successfully invoke neurophysiological pathways to activate ovarian function and to promote a uterine milieu prone to the establishment of pregnancy during the anoestrus season.