Dynamics of Thyroid Hormones in Growth and Development of South Indian Sheep (Bannur (original) (raw)

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.

Serum Profile of Thyroid Hormones from Birth to Puberty in Buffalo Calves and Heifers

Journal of Buffalo Science, 2012

Growth is outcome of interactions among several factors, where thyroid hormones play a key role in coordination of these factors and the information of thyroid hormones in relation to growth in buffalo calves and heifers is not adequate. Thus the study was conducted on Murrah female buffalo calves and heifers, varying in age from newborn to 30 months. The study investigated the serum thyroid patterns in female Murrah buffalo calves and heifers from birth to puberty. The thyroid stimulating hormone concentration did not differ and remained almost the same from birth to 4-6 months. The thyroid stimulating hormone then gradually increased and reached a highest value at 24-30 months. The concentration recorded at 21-24 months and 24-30 month i.e. at the age of attaining the puberty, was about 3-4 times higher than recorded at birth. The T3 concentration recorded at 0-7 days of age was significantly higher than recorded for other age groups, except at 18-21 months, 21-24 months and 24-30 months. The T3 concentration did not exhibit specific trend during the ages 16 days-1 month to 15-18 months. The highest T4 concentration was recorded in 0-7 days old buffalo calves. The concentration decreased to lower value at 1-2 months. The T4 concentration from 2-4 months of age increased significantly and the values remained almost similar with minor fluctuations upto 24-30 months. The T4: T3 ratio recorded at different ages did not exhibit specific trend.

A Study of Thyroid Hormone Levels in Beetal Goats During Different Development Stages

International Journal of Bio-resource and Stress Management

Thyroid hormones are the key regulators of mammalian physiological functions. These hormones have been shown to be crucial for growth, development, energy metabolism and reproduction (Eiler, 2005). These hormones are known to be important modulators of developmental processes and general metabolism in mammals (Kaneko et al., 2008). They also play an important role in defense against infection through the modulation of innate immune cell function (Spek et al., 2017). Changes in the concentrations of serum thyroxine (T 4) and tri-iodothyronine (T 3) of sheep in seasonal heat and cold stress have already been investigated (Dhanda et al., 2001). Circadian variation in thyroid hormones levels have also been reported in domestic animals (Nazifi et al., 2008).

Effects of Seasonal and Physiological Variations on the Serum Chemistry, Vitamins and Thyroid Hormone Concentrations in Sheep

Journal of Veterinary Medicine Series A, 2006

The aim of this study was to investigate the possible effects of the reproductive status and seasonal variations on the serum chemistry and vitamin status and their relationships with the thyroid hormones in Sakiz-Awassi crossbreed sheep. The sheep (n ¼ 34) were divided into two groups. The first group (n ¼ 22) was mated; the second group (n ¼ 12) was not mated. Their serum samples were collected four times a year at the each season and under reproductive status. The periods are 1, early pregnancy (October); 2, late pregnancy (January); 3, lactation (April); and 4, dry season (July). The results of this study indicated that (1) total protein (TP), globulin, cholesterol, creatinine, uric acid and T4/T3 vary with reproductive status but not seasonal variations; (2) alanine aminotransferase, T4, fT4 concentrations in serum vary only with reproductive status; (3) the urea, creatine kinase, lactate dehydrogenase, alkaline phosphatase, aspartate aminotransferase, amylase, albumin, triglyceride, VLDL, Vit A-E, T3 and fT3 concentration could vary with both reproductive status and seasonal variations; (4) the glucose, c-glutamyl transpeptidase, folate concentrations were altered neither season of the year nor the reproductive status; (5) a single reference interval for folate, c-glutamyl transpeptidase (GGT), glucose, TP, globulin, cholesterol, creatinine, uric acid and T4/T3 can be used for both mated and non-mated sheep because of no differences were found due to the reproductive status. Taking the results together suggests that reproductive status and seasonal variations have to be taken into consideration for a correct interpretation of the serum chemistry values of sheep. Nutritional supplements are required for sheep during certain periods to avoid a decline of their performance, which would then represent consequent economic, loses.

Thyroid hormones in the cerebrospinal fluid of the third ventricle of adult female sheep during different periods of reproductive activity

Polish Journal of Veterinary Sciences, 2010

Thyroid hormones (THs) are obligatory for transition from breeding season to anestrus in sheep. In this process, THs act during a very limited time of the year and primarily within the brain. In ewes chronically equipped for sampling cerebrospinal fluid (CSF) from the third ventricle, we have characterized the concentrations of total and free thyroxine (T4), triiodothyronine (T3), and total reverse T3 (rT3) in the CSF during breeding season, anestrus and during a critical period required for transition to anestrus (December-March). The total T4, T3, rT3 and free T3 average concentrations (± SEM) in CSF were 1.5 ± 0.07 ng/ml, 14.5 ± 1.2 pg/ml, 43 ± 7.4 pg/ml, and 0.6 ± 0.05 pg/ml, respectively, and all were significantly lower (p < 0.001) than in blood plasma except free T4 (12.6 ± 1.1 pg/ml), which was similar to that in plasma. There was a seasonal trend (p < 0.05) in the concentration of total T3 (highest in December) and free T4 (highest in November) in the CSF that does not follow that in blood plasma. During the period of transition to anestrus the CSF total T3/TT4 molar ratio and free T3/ T4 ratio were significantly lower (p < 0.05 and p < 0.01, respectively) than in blood plasma, while the total rT3/T4 ratio was significantly higher (p < 0.01) at the end of this period (March). Additionally, the CSF total rT3 concentrations were also significantly correlated with the CSF total T4 levels (r = 0.57; p < 0.05). In conclusion, the CSF in sheep may serve as a considerable source of thyroid hormones for neuroendocrine events. The lack of significant changes in THs concentrations in the CSF during the period of transition to anestrus indicate that neither seasonal changes of THs circulating in the blood plasma nor THs circulating in the CSF actively drive the transition to anestrus.

Circadian Variations of Thyroid Hormone Levels of Nonpregnant Uniparous Fat-tailed Iranian Ewes in Summer

Turkish Journal of Veterinary & Animal Sciences, 2008

Circadian variations in serum triiodothyronine (T3), thyroxine (T4), free triiodothyronine (fT3), and free thyroxine (fT4) levels were investigated in Iranian ewes. For that purpose, blood samples were collected from the jugular veins of 15 adult clinically healthy Iranian nonpregnant uniparous ewes every 6 h (0600, 1200, 1800, and 0000) during 6 days in summer with a mean ambient temperature of 40 °C. Serum T3, T4, fT3, and fT4 were measured by radioimmunoassay. There were statistically significant differences in thyroid hormone concentrations (T3, T4, fT3, and fT4) at different hours of the day. The results revealed that serum T3, T4, fT3, and fT4 levels were highest at 1800 (P < 0.05). Significant 24 h periodicity in the serum levels of T3, T4, fT4 and fT3 was observed in nonpregnant uniparous Iranian ewes. It is concluded that circadian rhythm was observed in serum thyroid hormones.

Changes in Thyroid Hormones Levels and Metabolism in Dairy Cows around Calving

Acta Veterinaria, 2017

The hormonal activity of the thyroid gland has an important role in ruminants for the modulation of metabolic variables. In this study changes in thyroid hormones and biochemical parameters in dairy cows around calving were evaluated and the critical thyroid hormones thresholds for predicting the risk of ketosis were estimated. Blood samples were collected from 82 dairy cows at 5±3 days pre-partum and 5±3 days postpartum. Serum values of triiodothyronine (T3), thyroxine (T4), thyroid-stimulating hormone (TSH), non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHB), insulin, glucose, Ca, Cl, Mg, P, K, Na, aspartate transaminase (AST), alanine transaminase (ALT) and urea were evaluated. Signifi cant decrease in the levels of T3, T4 and TSH was found in the postpartum period. The values of T3 and T4 were negatively correlated with NEFA and BHB levels, and TSH values were negatively correlated with NEFA. A critical T3 threshold was found by means of ROC analysis for predicting the r...

Clinical endocrinology of thyroid gland function in ruminants

Veterinární medicína, 2012

After briefly introducing the basec steps in production and metabolism of thyroid hormones, the author gives an overview of nutritional, metabolic and disease related factors and endocrine interactions influencing thyroid gland function in ruminants, particularly in the postpartum dairy cow. Involvement of thyroid hormonal regulation of seasonal patterns of reproduction as well as ovarian endocrine function are discussed.