Thyroid hormones are required for the expression of seasonal changes in red deer (Cervus elaphus) stags

1994 ◽  
Vol 6 (2) ◽  
pp. 187 ◽  
Author(s):  
ZD Shi ◽  
GK Barrell
Keyword(s):  
Thyroid Hormones ◽  
Cervus Elaphus ◽  
Seasonal Changes ◽  
Red Deer ◽  
Plasma Concentrations ◽  
Live Weight ◽  
Early Summer ◽  
Plasma Testosterone ◽  
Testicular Regression ◽  
Mixed Age

Experiment 1, from 6 July 1990 (winter) to 8 November 1990 (spring), examined the effect of an early elevation of plasma thyroid hormone concentrations on the expression of seasonal changes in 20-month-old stags. Four stags were injected subcutaneously with 1 mg thyroxine (T4) daily, and four with vehicle only. Plasma T4 concentration was elevated by injection of T4; the mean concentration 24 h after injection was 192 +/- 31 nmol L-1 compared with 58 +/- 5 nmol L-1 in controls on 21 September. However, live weight, testicular diameter, plasma testosterone concentration and moulting underwent similar changes in both groups of animals. Experiment 2 tested the hypothesis that thyroid hormones are required for the expression of changes that occur during spring and early summer in red deer stags. Thyroidectomized (THX) stags (n = 4) of mixed age (> 22 months old) were given a replacement dosage of T4 or vehicle only (controls) during spring (from 7 September). T4-treated THX stags underwent testicular regression, antler regeneration and spring moult during spring and early summer (October-December), whereas control THX stags did not display these changes. During spring and summer, T4-treated stags gained more live weight (P < 0.05) than control stags. These results show that, in stags, thyroid hormones are required for the expression of seasonal changes and that these changes are not caused by the seasonal elevation of plasma concentrations of thyroid hormones.

Seasonal changes in weight gain, growth hormone, and thyroid hormones in male red deer (Cervus elaphus atlanticus)

1982 ◽  
Vol 60 (11) ◽  
pp. 2577-2581 ◽  
Author(s):  
Morten Ryg ◽  
Rolf Langvatn
Keyword(s):  
Growth Hormone ◽  
Weight Gain ◽  
Food Intake ◽  
Thyroid Hormones ◽  
Cervus Elaphus ◽  
Seasonal Changes ◽  
Red Deer ◽  
Antler Growth ◽  
Gain Peak

To elucidate possible endocrine mechanisms in the control of the weight cycle of red deer, we recorded seasonal changes in the concentrations of growth hormone (GH), thyroxine (T4), and triiodothyronine (T3) in serum. T3 and T4 were analyzed with specific radioimmunoassays, GH was analyzed with a hetereologous radioimmunoassay. Changes in the levels of these hormones were compared with changes in weight gain. T3 levels were high in summer and low in winter, corresponding to changes in weight gain. Peak values (1.75–4.82 nmol/L) were found in May or June, nadirs occurred in April (0.22–1.78 nmol/L) or October–November (0–1.19 nmol/L). GH levels increased to peak values, 20–53 ng/mL, in April to June, but were low during most of the period of fast weight gain. There were no consistent changes in T4 levels corresponding to the weight cycle. We conclude that the GH peaks following the casting of old antlers may be related to the onset of antler growth. Seasonal changes in T3 levels may be secondary to changes in food intake.

Growth and reproductive development of red deer calves (Cervus elaphus) born out-of-season

1992 ◽  
Vol 55 (2) ◽  
pp. 265-270 ◽  
Author(s):  
C. L. Adam ◽  
C. E. Kyle ◽  
P. Young
Keyword(s):  
Food Intake ◽  
Cervus Elaphus ◽  
Dry Matter ◽  
Red Deer ◽  
Plasma Concentrations ◽  
Live Weight ◽  
Reproductive Development ◽  
Normal Birth ◽  
Melatonin Administration ◽  
Voluntary Food Intake

AbstractSince the productivity of farmed red deer is constrained by their inherent seasonal biology, the potential advantages of breeding out-of-season following melatonin administration were investigated. Calves born in February (F; no. = 8) were heavier at weaning in September of the same year than calves born with normal birth dates in June (}; no. = 8) (73·2 v. 441 (s.e.d. 3·59) kg; P < 0·001) and at the end of April of the next year (88·0 v. 67·6 (s.e.d. 6·44) kg; P < 0·02) although their suckled live-weight gain to 100 days of age was lower (304 v. 361 (s.e.d. 21·4) g/day; P < 0·05). After weaning, F calves had higher voluntary food intake than / calves (g dry matter per head per day) from September to November (1643 v. 2224 (s.e.d. 92·6); P < 0·002), November to February (1435 v. 926 (s.e.d. 67·9); P < 0·002), and February to April (1487 v. 2059 (s.e.d. 115·5); P < 0·02).Unlike J calves, F calves showed puberty in their first autumn. F male calves (no. = 3) grew antlers which hardened in November, whereas J males (no. = 3) did not, and F males, aged 8 months, had significantly higher mean plasma concentrations of testosterone than J males, aged 4 months (1·35 v. 0·28 (s.e.d. 0·154) fj.g/1, P < 0·001). Oestrous cyclicity was observed in 3/5 group F females, aged 9 months, but in 0/5 group ] females, aged 5 months. Although the dams of F and ] calves had similar live weights at mating, birth and 100 days pos t partum, F dams were heavier (P < 0·05) at weaning. Following parturition, F dams had a mean voluntary food intake of 2700 (s.e. 110) g dry matter per head per day from February to April.

Effect of nutritional growth restriction on timing of reproductive development and plasma concentrations of insulin-like growth factor-1 and growth hormone in male red deer (Cervus elaphus) reared in constant photoperiod

1995 ◽  
Vol 61 (1) ◽  
pp. 155-160 ◽  
Author(s):  
C. L. Adam ◽  
C. E. Kyle ◽  
P. Young ◽  
T. Atkinson
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Red Deer ◽  
Plasma Concentrations ◽  
Live Weight ◽  
Reproductive Development ◽  
Growth Restriction ◽  
Plasma Testosterone ◽  
Insulin Like Growth Factor ◽  
Ad Libitum

AbstractThe effect of nutritional growth restriction on reproductive development in red deer stags reared in constant photoperiod was investigated and the correlation between reproductive status and circulating concentrations of growth hormone (GH) and insulin-like growth factor-1 (IGF-1) examined.Stags were reared from birth in constant photoperiod (12 h light: 12 h dark). They were offered a ‘complete diet’ ad libitum until they reached 52-5 kg live weight (LW) and were then maintained at this LWby restricting daily food dry-matter intake (DMI)for either a long (LR, 26 to 51 weeks of age, no. = 5) or short (SR, 21 to 33 weeks, no. = 6) period before being returned to ad libitum feeding.Relative to SR stags, antlers hardened later in LR stags (72·0 v. 57·5 weeks of age, P < 0·001); sustained elevations in plasma testosterone also began later (55·2 v. 38·5 weeks, P < 0·001) but at lower LW (54·0 v. 60·6 kg, P < 0·05). In both groups, the testosterone rise followed the return to ad libitum food by 4 to 5 weeks. Plasma IGF-1 was closely correlated with DMI (LR, r = 0·84, P < 0·001; SR, r = 0-93, P < 0·001) and with plasma testosterone (LR, r = 0·42, P < 0·001; SR, r = 0·38, P < 0·01). Also the increase in plasma IGF-1 preceded that of testosterone (by 2·8 (s.e. 0·94) weeks) and was associated with a transient plasma GH peak (P < 0·05) and elevated LH concentrations (SR, P < 0·01; LR, P < 0·05).The timing of reproductive development in growth-restricted male red deer in constant photoperiod may therefore be more sensitive to DMI than LW, and changes in plasma IGF-1 concentrations are consistent with a putative permissive role in relaying this information.

Effects of immunization against GnRH upon body growth, voluntary food intake and plasma hormone concentration in yearling red deer stags (Cervus elaphus)

1993 ◽  
Vol 121 (3) ◽  
pp. 381-388 ◽  
Author(s):  
D. O. Freudenberger ◽  
P. R. Wilson ◽  
T. N. Barry ◽  
Y. X. Sun ◽  
R. W. Purchas ◽  
...  
Keyword(s):  
Cervus Elaphus ◽  
Red Deer ◽  
Plasma Concentrations ◽  
Late Summer ◽  
Early Summer ◽  
Body Growth ◽  
Scrotal Circumference ◽  
Voluntary Feed Intake ◽  
Antler Growth ◽  
Velvet Antler

SUMMARYRed deer stags in New Zealand were given a series of immunizations against GnRH at 9–12 months of age (spring/early summer) in 1989 and 1990 and the effects upon plasma concentrations of luteinizing hormone (LH) and testosterone during the rut (15–17 months; autumn) and upon body growth to slaughter at 22 months (spring) were studied in two experiments. Control animals showed a sharp peak in plasma LH and testosterone concentration during late summer/early autumn, just preceding the rut, with scrotal circumference increasing to a maximum during the rut; body growth stopped during the rut in Expt 1 but not in Expt 2. Immunization caused the development of significant antibodies against GnRH during late spring and summer, and reduced but did not eliminate the increase in plasma LH and testosterone and scrotal enlargement leading up to the rut. Immunization did not affect body growth or voluntary feed intake during the rut in either experiment, but in Expt 1 early immunization significantly increased growth during both the pre-rut and post-rut periods. Immunization did not effect dressing out percentage, slightly increased carcass fatness in Expt 1 but not Expt 2, and reduced velvet antler growth by 12 months of age.

scholarly journals Seasonal changes in mineral intake and first antler growth in Iberian red deer (Cervus elaphus hispanicus)

2007 ◽  
Vol 6 (sup1) ◽  
pp. 851-851
Author(s):  
L. Estévez ◽  
F. Ceacero ◽  
Landete Castillejos ◽  
A. J. García ◽  
D. Carrión ◽  
...  
Keyword(s):  
Cervus Elaphus ◽  
Seasonal Changes ◽  
Red Deer ◽  
Cervus Elaphus Hispanicus ◽  
Iberian Red Deer ◽  
Antler Growth

scholarly journals Plasma concentrations of LH, prolactin, oestradiol and progesterone in female red deer (Cervus elaphus) during pregnancy

Reproduction ◽  
1982 ◽  
Vol 64 (2) ◽  
pp. 475-483 ◽  
Author(s):  
R. W. Kelly ◽  
K. P. McNatty ◽  
G. H. Moore ◽  
D. Ross ◽  
M. Gibb
Keyword(s):  
Cervus Elaphus ◽  
Red Deer ◽  
Plasma Concentrations

The effect of post-capture management strategy on the welfare and productivity of wild red deer (Cervus elaphus) hinds introduced to farming systems

1996 ◽  
Vol 63 (2) ◽  
pp. 315-327 ◽  
Author(s):  
P. J. Goddard ◽  
I. J. Gordon ◽  
W. J. Hamilton
Keyword(s):  
Cervus Elaphus ◽  
Plasma Cortisol ◽  
Red Deer ◽  
Live Weight ◽  
Significant Rise ◽  
Remote Site ◽  
Acth Stimulation ◽  
Mean Values ◽  
Capture Site ◽  
The Mean

AbstractWild red deer (Cervus elaphus) hinds were subjected to one of five post-capture management strategies during the period from capture in late pregnancy in March, until weaning in September. The treatments were: remained enclosed at the capture site; relocated to a remote site; relocated to a conventional deer farm on improved pasture; relocated to a conventional deer farm and grazed with farmed hinds; housed prior to calving on a conventional deer farm site. For a further year, all hinds were managed under conventional deer farm conditions. There was considerable evidence, based on mortality and behaviour, to suggest that initial housing of the hinds following capture compromised their welfare. Deaths of hinds (seven out of 20) occurred in this group, associated with bullying during the housed period. Hinds on this treatment also showed a higher frequency of aggressive interactions compared with the groups directly moved to the deer farm (11% v. 2% respectively of scans conducted at 10-min intervals over 6h; P < 0·001) and a reduced level of lying behaviour (15% v. 34 to 47% of scans; P < 0·001) during the gestation period. Similarly, during the calving period, this group lay the least (27% v. 43 to 72% of scans; P < 0·001) and the mean number of interactions between hinds reached 11·7 compared with 1·5 to 4·9 (F < 0·001) in the other groups over a continuous 6-h recording period. The two groups of hinds relocated directly onto sown swards were generally similar to one another in terms of behaviour and performance. However, the group mixed with farmed hinds suffered from considerable calf losses in year 1 due to disease (four out of 12). Losses of hinds over winter in year 1 (nine out of 90) occurred principally amongst those animals which had not become habituated to human presence or supplementary feeding in the summer, i.e. groups remaining enclosed at the capture site or relocated to a remote site. When all hinds were treated similarly in year 2 the hinds from these same two groups, together with those initially housed indoors, showed more hind-hind interactions overall than the two groups located directly onto the deer farm (7·2 v. 3·1 interactions per hind over a 4-h period; P < 0·02) and it is suggested that these hinds had not yet adapted to their new environment. An ACTH stimulation test conducted during year 2 supported the view that the two groups of hinds most recently introduced into the managed system were subject to a chronic stressor at the time of testing, since administration of ACTH did not elicit a significant increase in plasma cortisol concentrations (mean values pre- and post-ACTH 188 and 217 nmol/l respectively). In contrast, the mean plasma cortisol concentrations of the two groups managed under extensive farm conditions from the outset, showed a significant rise (pre- and post-ACTH, 261 and 376 nmol/l respectively; P < 0·01). From this it is concluded that their adaptation to the farm environment had already occurred. The live-weight gains of the wild hinds calves (229 g/day) on the improved pastures in the 1st year of the study were below that for farmed hinds calves (282 g/day; P < 0·05), suggesting that they were not habituated to the management system. However, by the end of year 2 animal performance was comparable with that of farmed hinds and calf growth rates reached 276 g/day. Thus while housing wild red deer immediately after capture is associated with poor welfare, analysis of behaviour, adrenal response and animal production over a longer period suggests that by the end of the study few important differences remained between the groups.

Relationship between rank and plasma testosterone and cortisol in red deer males (Cervus elaphus)

2010 ◽  
Vol 101 (5) ◽  
pp. 628-634 ◽  
Author(s):  
Luděk Bartoš ◽  
Dieter Schams ◽  
George A. Bubenik ◽  
Radim Kotrba ◽  
Milan Tománek
Keyword(s):  
Cervus Elaphus ◽  
Red Deer ◽  
Plasma Testosterone

scholarly journals Effects of subcutaneous melatonin implants during long daylength on voluntary feed intake, rumen capacity and heart rate of red deer (Cervus elaphus) fed on a forage diet

1992 ◽  
Vol 68 (1) ◽  
pp. 77-88 ◽  
Author(s):  
B. M. Françoise Domingue ◽  
P. R. Wilson ◽  
D. W. Dellow ◽  
T. N. Barry
Keyword(s):  
Heart Rate ◽  
Cervus Elaphus ◽  
Feed Intake ◽  
Red Deer ◽  
Live Weight ◽  
Pool Size ◽  
Plasma Prolactin ◽  
Voluntary Feed Intake ◽  
Melatonin Administration ◽  
Autumn And Winter

Subcutaneous melatonin implants were administered to castrated hand-reared male red deer (Cervus elaphus) during a 63 d period in spring, after which effects on voluntary feed intake (VFI), rumen pool size, rumen capacity (i.e. volume) and heart rate were measured on four occasions, evenly spread over a 12-month period, with the deer individually fed indoors on a diet of lucerne (Medicago sativa) chaff. Blood samples for hormone determinations were taken at intervals throughout the study. Day-time plasma melatonin concentration was approximately 5 pg/ml in control animals, whereas during melatonin administration it increased to 60–150 pg/ml and declined to 30 pg/ml by 142 d after the last implantation. Melatonin administration markedly depressed plasma prolactin concentration during the period of implantation, but thereafter plasma prolactin concentration rose in the treated animals during autumn and winter, whilst it declined in control animals over this period. VFI, rumen pool size and heart rate in control animals attained highest values in summer and lowest values in winter, showing a pronounced seasonal cycle. Melatonin administration depressed all these values in late spring and summer and increased all the values in autumn and winter, relative to control animals, and appeared to move the cycles by approximately 6 months. Melatonin-treated animals showed maximum values for all these measurements during winter. The castrated male deer showed little seasonal change in live weight, which was not affected by melatonin administration. The findings support the view that melatonin probably mediates the effect of daylength on digestive function in red deer. Rumen capacity remained relatively constant throughout the year, but rumen pool size as a proportion of rumen capacity increased with increasing VFI.

Temporal changes in LH and testosterone and their relationship with the first antler in red deer (Cervus elaphus) stags from 3 to 15 months of age

1991 ◽  
Vol 131 (3) ◽  
pp. 467-474 ◽  
Author(s):  
J. M. Suttie ◽  
P. F. Fennessy ◽  
S. F. Crosbie ◽  
I. D. Corson ◽  
F. J. Laas ◽  
...  
Keyword(s):  
Body Weight ◽  
Cervus Elaphus ◽  
Red Deer ◽  
Plasma Concentrations ◽  
Pulse Frequency ◽  
Growth Stages ◽  
Second Phase ◽  
Pulsatile Secretion ◽  
Antler Growth ◽  
Velvet Antler

ABSTRACT Blood samples were taken from six tame red deer stags at 3–15 months of age once a month from a jugular catheter every 30 min for 24 h to investigate hormonal secretion during puberty and during growth of the pedicle and first antler. All plasma samples were analysed for LH and testosterone concentrations and the resultant data were analysed using the PULSAR pulse detection routine. In addition each stag was injected with gonadotrophin-releasing hormone (GnRH; 20 ng/kg body weight) after the above samples had been taken and the bleeding regimen was continued for a further 2 h. Body weight, antler size and status (i.e. whether the stags had a pedicle or antler) were also recorded. The pulsatile secretion of LH could be considered to have occurred in three phases. The first of these was one of development, with the LH pulse frequency increasing to 8 pulses/24 h, the second a phase of regression, with a decrease in LH pulse frequency to 2 pulses/24 h, and finally a second phase of development characterized by increased LH pulse frequency to 12 pulses/24 h. Testosterone secretion generally followed the same pattern. During the period before the permanent bony pedicles grew, there were less than five LH pulses/24 h. When the pedicles were growing, LH and testosterone pulsatile secretion increased but the pulse frequency of both hormones fell during velvet antler growth. However, the overall mean testosterone level did not significantly decrease between the growth stages (2·74 and 2·29 nmol/l respectively) although mean testosterone plasma rose during pedicle growth and fell during velvet antler growth. Both hormone plasma concentrations increased dramatically, and testosterone was particularly high (11·82 nmol/l), at the time of antler cleaning. All stags responded to exogenous GnRH by secreting LH and testosterone in all sampling periods. The LH response to GnRH increased during pedicle growth and fell during antler growth before rising again in autumn as the breeding season approached. Testosterone responses largely paralleled those of LH except that they remained high in early antler development. The results are consistent with the following hypotheses. (1) Pedicle initiation is caused by increased plasma level of testosterone stimulated by increasing LH pulse frequency and (2) testosterone is stimulatory for pedicle growth but not necessarily so for velvet antler growth. Journal of Endocrinology (1991) 131, 467–474

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