scholarly journals Effects of recent sexual experience and melatonin treatment of rams on plasma testosterone concentration, sexual behaviour and ability to induce ovulation in seasonally anoestrous ewes

Reproduction ◽  
2000 ◽  
Vol 120 (1) ◽  
pp. 169-176 ◽  
Author(s):  
H. Rosa ◽  
D. Juniper ◽  
M. Bryant
Keyword(s):  
Sexual Behaviour ◽  
Sexual Experience ◽  
Plasma Testosterone ◽  
Melatonin Treatment ◽  
Testosterone Concentration

The influence of the presence of the female on the sexual behaviour and plasma testosterone levels of the mature male pig

1981 ◽  
Vol 32 (1) ◽  
pp. 61-65 ◽  
Author(s):  
P. H. Hemsworth ◽  
C. G. Winfield ◽  
W. A. Chamley
Keyword(s):  
Treatment Period ◽  
Sexual Behaviour ◽  
Mature Male ◽  
Social Conditions ◽  
Receptive Female ◽  
Plasma Testosterone ◽  
Consistent Difference ◽  
Testosterone Concentration ◽  
The Difference ◽  
The Individual

ABSTRACTTwenty-seven mature boars were housed in individual pens for 9 weeks under one of the following social conditions: isolated from female pigs; near sexually non-receptive female pigs; and near sexually receptive female pigs. The sexual behaviour of the boars during the 9-week treatment period was observed weekly in standard 15- min tests. The sum of the individual courting behaviour activities and the total time spent ejaculating were significantly greater for the boars housed near either sexually receptive or sexually non-receptive females than for those boars isolated from female pigs (P<0·01 and P<0·05, respectively). Although the boars housed near sexually receptive and sexually non-receptive females achieved 43 and 38% more copulations, respectively, than those isolated from females, the difference was significant only for the latter comparison (P<005). There was no consistent difference in testosterone concentration over a 12-h period between boars housed near sexually-receptive females and those isolated from females.

Effects of recent sexual experience and melatonin treatment of rams on plasma testosterone concentration, sexual behaviour and ability to induce ovulation in seasonally anoestrous ewes

Reproduction ◽  
2000 ◽  
pp. 169-176 ◽  
Author(s):  
HJ Rosa ◽  
DT Juniper ◽  
MJ Bryant
Keyword(s):  
Seasonal Changes ◽  
Body Condition Score ◽  
Sexual Experience ◽  
Plasma Testosterone ◽  
Melatonin Treatment ◽  
Plasma Progesterone ◽  
Plasma Melatonin ◽  
Live Body Weight ◽  
Condition Score ◽  
Subcutaneous Implant

The aim of this study was to determine whether advancing the seasonal changes associated with rams by treatment with exogenous melatonin and allowing the rams previous sexual experience would increase the proportion of anoestrous ewes ovulating in early July. North Country Mule ewes (n = 225) were grouped by live body weight and body condition score and allocated randomly to the following treatments: (i) isolated from rams (control; n = 25); (ii) introduced to rams (treatment 2); (iii) introduced to rams that had mated with ewes during the previous 2 days (treatment 3); (iv) introduced to rams implanted with melatonin (treatment 4); and (v) introduced to rams that were implanted with melatonin and had mated with ewes during the previous 2 days (treatment 5). Treatments 2-5 were replicated (2 x 25 ewes) and two rams were introduced to each replicate group. Introductions began on 4 July and were completed by 11 July. The rams were withdrawn from the ewes after 8 days. Melatonin was administered as a subcutaneous implant (Regulin((R))) on 22 May and again on 20 June. Blood samples were taken from all rams to determine plasma melatonin and testosterone concentrations (19 samples in 6 h). The behaviour of the sheep was videotaped continuously during the first 3 h after the ram was introduced. Ovulation was detected by an increase in plasma progesterone concentrations from < 0.5 ng ml(-1) to > 0.5 ng ml(-1). Mean +/- SE plasma melatonin concentrations were 649.7 +/- 281.4 and 18.3 +/- 2.4 pg ml(-1) in rams with and without melatonin implants, respectively (P < 0.001). Melatonin implants also increased plasma testosterone concentrations from 4.30 +/- 1.88 to 10.10 +/- 1.10 ng ml(-1) (P < 0.01), the libido of the rams and the proportion of ewes that ovulated in response to the rams (43 and 56% (treatments 4 and 5) versus 24% (treatments 2 and 3)). In conclusion, implanting rams with melatonin before introducing them to seasonally anoestrous ewes increases the proportion of ewes that ovulate in response to introduction of a ram, but previous sexual experience of rams appears to have little or no effect.

scholarly journals Effect of oral contraceptives on plasma testosterone concentration.

BMJ ◽  
1977 ◽  
Vol 1 (6053) ◽  
pp. 107-107 ◽  
Author(s):  
M C Browning ◽  
J Anderson
Keyword(s):  
Oral Contraceptives ◽  
Plasma Testosterone ◽  
Testosterone Concentration

Peripheral plasma testosterone concentration and sexual behavior in young prenatally stressed boars

1979 ◽  
Vol 12 (5) ◽  
pp. 289-305 ◽  
Author(s):  
H.G. Kattesh ◽  
E.T. Kornegay ◽  
F.C. Gwazdauskas ◽  
J.W. Knight ◽  
H.R. Thomas
Keyword(s):  
Sexual Behavior ◽  
Plasma Testosterone ◽  
Testosterone Concentration ◽  
Peripheral Plasma ◽  
Prenatally Stressed

Plasma steriod hormone concentrations in relation to reproductive cycle of the sweep Scorpis lineolatus (Kyphosidae) caught from the wild

1992 ◽  
Vol 43 (4) ◽  
pp. 753 ◽  
Author(s):  
M Deual ◽  
NW Pankhurst
Keyword(s):  
Steroid Hormones ◽  
Reproductive Cycle ◽  
Gonadosomatic Index ◽  
Plasma Concentrations ◽  
Plasma Testosterone ◽  
Hepatosomatic Index ◽  
Spawning Period ◽  
Testosterone Concentration ◽  
Low Concentrations ◽  
Advanced Stages

Changes in gonadosomatic index (GSI), hepatosomatic index (HSI), oocyte development and plasma levels of steroid hormones were studied during the reproductive cycle of the sweep Scorpis lineolatus. GSI values for both sexes were maximal in March and April. During this period the size distribution of oocytes showed a predominance of advanced stages of vitellogenesis, whereas males were completing spermatogenesis. However, staging data suggest that spawning may not begin until April. HSI was maximal 2 months prior to the beginning of gametogenesis in both sexes. Plasma concentrations of oestradiol-17β in females increased rapidly from February, reached a peak (2.3 ng mL-1) in association with the end of vitellogenesis in March, and returned to low concentrations in May and June. Plasma concentrations of 17α,20α-dihydroxy-4-pregnen-3-one (17,20βP) also peaked in March in females, but 17,20βP was generally not detectable in males. Plasma testosterone concentration peaked along with other steroids in March in females but showed no significant change in males. Plasma ll-ketotestosterone (1 1KT) concentration was maximal in males before spawning (February), but was not elevated during the spawning period itself. Changes in oestradiol-17β and testosterone in association with vitellogenensis in females are consistent with those reported for other teleosts, whereas changes in 17,20βP, testosterone and 11-ketotestosterone in males are different from those previously reported.

PLASMA TESTOSTERONE AND SHELL QUALITY

1989 ◽  
Vol 69 (4) ◽  
pp. 1107-1109
Author(s):  
S. LEESON ◽  
C. D. BENNETT ◽  
L. J. CASTON ◽  
C. E. ANDERSON-LANGMUIR ◽  
R. J. ETCHES
Keyword(s):  
Key Words ◽  
Testosterone Level ◽  
Plasma Testosterone ◽  
Production Cycle ◽  
Testosterone Concentration ◽  
Shell Quality ◽  
Testosterone Levels ◽  
Commercial Strain ◽  
Eggshell Quality ◽  
Key Words Testosterone

Plasma testosterone levels were measured in commercial strain Leghorn pullets from 16 to 80 wk of age. Testosterone level was high just prior to first egg, but subsequently declined and stayed at a constant level through the production cycle. There was no relationship between testosterone concentration and eggshell quality (P > 0.05). Key words: Testosterone, shell quality

Plasma testosterone during treadmill exercise

1980 ◽  
Vol 49 (2) ◽  
pp. 249-253 ◽  
Author(s):  
J. E. Wilkerson ◽  
S. M. Horvath ◽  
B. Gutin
Keyword(s):  
Treadmill Exercise ◽  
Submaximal Exercise ◽  
Whole Body ◽  
Plasma Testosterone ◽  
Total Testosterone ◽  
Work Intensity ◽  
Maximal Aerobic Capacity ◽  
Direct Role ◽  
Testosterone Concentration ◽  
Venous Plasma

Five male volunteers performed 20 min of steady-state submaximal exercise on a motor-driven treadmill at five intensities (30, 45, 60, 75, and 90% VO2 max) as well as several maximal aerobic capacity tests. Peripheral venous plasma testosterone concentrations increased above resting values in proportion to exercise intensity. However, this increase in plasma testosterone concentration was virtually equal in magnitude to the decrease in plasma volume observed consequent to the exercise bouts, resulting in no change in total testosterone contents. There was an unexpected anticipatory elevation in resting preexercise control testosterone concentration and content with increasing work intensity. The possibility that testosterone has a direct role in the organism's response to whole-body exercise is questioned.

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