Serum thyroid hormones and reproductive characteristics of Rambouillet ewe lambs treated with propylthiouracil before puberty

Wells, Natalie; Hallford, D. M.; Hernández, Jennifer

doi:10.1016/s0093-691x(02)01184-6

Cited by 25 publications

(9 citation statements)

References 8 publications

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“…Plasma T 3 concentrations remained elevated despite a decrease in total T 4 levels from 2 h after birth in lambs [38] . Wells et al [39] determined that T 4 concentrations were 61.6 ng/ml on day 0, 78.5 ng/ml on day 7 and 55.0 ng/ml on day 66. Bekeova et al [40] reported that the blood T 4 values of lambs showed troughs on days 4 and 21 after parturition then a gradual increase from day 25, and the T 3 values tended to decrease to day 21 and then to increase.…”

Section: Discussionmentioning

confidence: 99%

Comparisons of Serum Somatotropin, 3,5,3′-Triiodothyronine, Thyroxine, Total Protein and Free Fatty Acid Levels in Newborn Sakiz Lambs Separated from or Suckling Their Dams

et al. 2005

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Objective: To determine the effects on serum somatotropin, 3,5,3′-triiodothyronine (T₃), thyroxine (T₄), free fatty acids (FFAs) and total protein levels of different feedings and age in Sakiz sheep that have a high twin-bearing rate supported by estrous synchronization. Methods: 20 newborn lambs were used in the study. Lambs were divided into 2 equal groups. The lambs in 1 group were separated from their dams following parturition, and those in other group were kept together with their dams. Separated lambs were fed commercial cow’s milk for 2.5 weeks. After that, they were fed a milk substitute, hay and concentrated supplement for 2 months, and from the end of the 2 months they were fed hay and concentrated supplement. The lambs in other group were kept together with their dams only during the day and in addition were fed hay and concentrated supplement. After 2 months, they were maintained feeding only on hay and concentrated supplement. Blood samples were taken from vena jugularis of lambs at 12 and 24–48 h, and 14, 28, 42 and 56–90 days after parturition. Serum samples were analyzed for somatotropin by enzyme immunoassay, for T₃ and T₄ by radioimmunoassay, and for total protein and FFA by a spectrophotometric method. Results: Serum somatotropin levels were insignificantly different between the lambs with and without their dams. Serum T₃ levels were generally lower in the separated lambs than those in other group. Serum T₄ levels were significantly lower in the separated lambs 48 h and 90 days after parturition than those in other group. Serum FFAs were insignificantly different between 2 groups. Serum total protein concentrations were lower in the separated lambs than lambs kept together with their dams (significantly at 12 and 48 h and 14 days). Conclusion: Ingestion of colostrum and dam milk markedly affected serum total protein levels, but body weight and serum somatotropin levels were insignificantly affected. Also serum T₃ and T₄ levels markedly decreased with advancing age. Serum FFA levels were not affected by the trial.

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Section: Discussionmentioning

confidence: 99%

Comparisons of Serum Somatotropin, 3,5,3′-Triiodothyronine, Thyroxine, Total Protein and Free Fatty Acid Levels in Newborn Sakiz Lambs Separated from or Suckling Their Dams

et al. 2005

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“…Serum IGF-I was quantified by RIA according to procedures of Berrie et al (1995). Thyroxine and T 3 concentrations were determined by RIA utilizing components of commercial kits (Diagnostic Products Corp., Los Angeles, CA), with modifications described by Richards et al (1999) for T 4 and Wells et al (2003) for T 3 . Serum IGF-I was determined in assays with intra-and interassay CV of 12.6 and 4.1%.…”

Section: Serum Analysismentioning

confidence: 99%

Effects of selenium supply and dietary restriction on maternal and fetal metabolic hormones in pregnant ewe lambs1

Ward

Neville

Reed

et al. 2008

Journal of Animal Science

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The objective of these studies was to evaluate the effects of dietary restriction and Se on maternal and fetal metabolic hormones. In Exp. 1, pregnant ewe lambs (n = 32; BW = 45.6 +/- 2.3 kg) were allotted randomly to 1 of 4 treatments. Diets contained (DM basis) either no added Se (control), or supranutritional Se added as high-Se wheat at 3.0 mg/kg (Se-wheat), or sodium selenate at 3 (Se3) and 15 (Se15) mg/kg of Se. Diets (DM basis) were similar in CP (15.5%) and ME (2.68 Mcal/kg). Treatments were initiated at 50 +/- 5 d of gestation. The control, Se-wheat, Se3, and Se15 treatments provided 2.5, 75, 75, and 375 microg/kg of BW of Se, respectively. Ewe jugular blood samples were collected at 50, 64, 78, 92, 106, 120, and 134 d of gestation. Fetal serum samples were collected at necropsy on d 134. In Exp. 2, pregnant ewe lambs (n = 36; BW 53.8 +/- 1.3 kg) were allotted randomly to treatments in a 2 x 2 factorial arrangement. Factors were nutrition (control, 100% of requirements vs. restricted nutrition, 60% of control) and dietary Se (adequate Se, 6 microg/kg of BW vs. high Se, 80 microg/kg of BW). Selenium treatments were initiated 21 d before breeding, and nutritional treatments were initiated on d 64 of gestation. Diets were 16% CP and 2.12 Mcal/kg of ME (DM basis). Blood samples were collected from the ewes at 62, 76, 90, 104, 118, 132, and 135 d of gestation. Fetal blood was collected at necropsy on d 135. In Exp.1, dietary Se source and concentration had no effect (P > 0.17) on maternal and fetal serum IGF-I, triiodothyronine (T(3)), or thyroxine (T(4)) concentrations. Selenium supplementation increased (P = 0.06) the T(4):T(3) ratio vs. controls. In Exp. 2, dietary Se had no impact (P > 0.33) on main effect means for maternal and fetal serum IGF-I, T(3), or T(4) concentrations from d 62 to 132; however, at d 135, high-Se ewes had lower (P = 0.01) serum T(4) concentrations than adequate-Se ewes. A nutrition by Se interaction (P = 0.06) was detected for the T(4):T(3) ratios; ewes fed restricted and adequate-Se diets had greater (P = 0.10) T(4):T(3) ratios compared with the other treatments. Nutrient-restricted ewes had lower (P < 0.05) serum IGF-I, T(3), and T(4) concentrations. Fetal serum IGF-I concentrations were lower (P = 0.01) in restricted-vs. control-fed ewes; however, fetal T(3) and T(4) concentrations were unaffected (P > 0.13) by dietary Se or maternal plane of nutrition. These data indicate that dietary Se may alter maternal T(4):T(3) ratios. In addition, nutrient restriction during gestation reduces maternal IGF-I, T(3), and T(4) and fetal IGF-I concentrations.

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“…In addition, they play a role in a series of biochemical processes, triggering responses throughout the organism, including reproductive responses. Studies on the thyroid hormone dynamics in ovines have shown variations according to the sex, breed, age and physiologic state of the animals (Canola, 1982;Patel et al, 1992;Wells et al, 2003;Georgiev and Nikolov, 2004). The amount of iodine ingested and the daily food intake controls both T 3 and T 4 synthesis and secretion as well (Andrewartha et al, 1980;Rae et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

Serum concentration of thyroid hormones in crioula lanada serrana ewes in gestation and lactation

Colodel

Martins

et al. 2010

Arch. zootec.

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SUMMARYThe effects of gestation and lactation on the dynamics of the thyroid hormones, triiodothyronine (T 3 ) and thyroxine (T 4 ) were evaluated in Crioula Lanada Serrana ewes from the plateau region in Santa Catarina -Brazil. To evaluate the effects of gestation, twenty four ewes were randomly divided into groups I and II. Group I was composed of 12 pregnant ewes and the control group (II) was composed of 12 non-pregnant ewes. The effects of lactation were evaluated in the same ewes of group I after parturition (LE) and in the control group (NL). Blood samples were taken in the first, second and third periods of gestation, at parturition, and at 30, 60 and 90 days of lactation. T 3 and T 4 concentrations were determined by radioimmunoassay (RIA). Pregnant ewes showed lower serum concentrations of T 3 and T 4 than those of non-pregnant ewes. At parturition, there was no significant difference in T 3 concentrations between groups I and II (p>0.05). During lactation, serum T 3 concentrations were lower (p≤0.05) in LE than in NL ewes. Serum T 3 concentrations were greater (p≤0.05) at lambing than during the lactation periods. Serum T 4 concentrations in LE at parturition did not differ (p>0.05) from those of NL ewes. During lactation, T 4 concentrations of LE were lower (p≤0.05) than those of the NL ewes. The results of this study have shown that gestation causes a variation in the T 3 and T 4 serum concentrations, and that lactation results in a decrease of serum concentrations of T 3 and T 4 in Crioula Lanada Serrana ewes. RESUMOOs efeitos da gestação e lactação sobre a dinâmica dos hormônios tireoidianos triiodotironina (T 3 ) e tiroxina (T 4 ) foram avaliados em ovelhas Crioula Lanada Serrana na região do Planalto Serrano Catarinense. Para avaliar os efeitos da gestação, foram utilizadas vinte e quatro ovelhas distribuídas aleatoriamente em dois grupos. O grupo I foi formado por 12 ovelhas gestantes e o grupo controle por 12 ovelhas não gestantes (grupo II). Os efeitos da lactação foram avaliados nas mesmas ovelhas do grupo I após a parição (LE) e no grupo controle (NL). Foram colhidas amostras sanguíneas no primeiro, segundo e terceiro terço da gestação, ao parto e aos 30, 60 e 90 dias de lactação. As concentrações de T 3 e T 4 foram determinadas por radioimunoensaio (RIA). As ovelhas gestantes apresentaram concentrações séricas de T 3 e T 4 inferiores àquelas não gestantes. Ao parto não houve diferença significativa nas concentrações de T 3 entre os grupos I e II (p>0,05). Durante a lactação as concentrações Archivos de zootecnia vol. 59, núm. 228, p. 510

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Serum thyroid hormones and reproductive characteristics of Rambouillet ewe lambs treated with propylthiouracil before puberty

Cited by 25 publications

References 8 publications

Comparisons of Serum Somatotropin, 3,5,3′-Triiodothyronine, Thyroxine, Total Protein and Free Fatty Acid Levels in Newborn Sakiz Lambs Separated from or Suckling Their Dams

Comparisons of Serum Somatotropin, 3,5,3′-Triiodothyronine, Thyroxine, Total Protein and Free Fatty Acid Levels in Newborn Sakiz Lambs Separated from or Suckling Their Dams

Effects of selenium supply and dietary restriction on maternal and fetal metabolic hormones in pregnant ewe lambs1

Serum concentration of thyroid hormones in crioula lanada serrana ewes in gestation and lactation

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