Serum growth hormone in and semen characteristics of proven AI dairy sires after administration of growth hormone-releasing factor

1992 ◽  
Vol 72 (4) ◽  
pp. 959-963 ◽  
Author(s):  
G. W. Kazmer ◽  
S. A. Zinn ◽  
H. Rycroft ◽  
R. M. Campbell
Keyword(s):  
Growth Hormone ◽  
Key Words ◽  
Response Curve ◽  
Sperm Concentration ◽  
Production Traits ◽  
Serum Growth Hormone ◽  
Growth Hormone Releasing Factor ◽  
Genetic Groups ◽  
Semen Characteristics ◽  
Dairy Bulls

A growth hormone-releasing factor (GRF) analog was administered at 11, 22 and 33 μg 100 kg−1 to proven dairy sires of varying genetic merit for production traits. Administration of GRF increased mean GH concentrations, but the area under the response curve was not different among the three dosages, nor were there differences between genetic groups overall. However, the maximum GH concentration following the administration of 11 μg 100 kg−1 was greater among superior sires. None of semen motility, sperm concentration or total sperm were affected through an entire spermatogonic cycle. Key words: GRF, growth hormone, semen, dairy bulls

Serum somatotropin concentrations in Holstein heifers administered growth hormone-releasing factor and somatostatin

1998 ◽  
Vol 66 (3) ◽  
pp. 551-556 ◽  
Author(s):  
G. W. Kazmer ◽  
S. A. Zinn
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Early Identification ◽  
Response Curve ◽  
Dairy Calves ◽  
Production Traits ◽  
Individual Animal ◽  
Milk Production Traits ◽  
Serum Growth Hormone ◽  
Blood Samples

AbstractDose-response experiments were designed to determine the dosage of somatostatin (SRIF) necessary to alter serum growth hormone (GH) response to administration of GH-releasing factor (1·44; GRF) in cattle. The objective of this experimentation was to develop a GRF/SRIF challenge model that might be useful in early identification of animals which are genetically superior for milk production traits. In experiment 1, calves received either 0, 5 or 10 /JLg GRF per 100 kg body weight (BW) or GRF 1·29 at 1 ug per 100 kg BW. Both the 5 and 10 ug GRF per 100 kg BW dosages increased GH concentrations (P < 0·05). In experiment 2, animals received 3 ug GRF per 100 kg BW concurrent with administration of 0, 0·5, 1 or 2 ug SRIF per 100 kg BW at 0 min, with second dosage of GRF at +120 min. Administration of SRIF in those dosages did not alter GH response to GRF. In experiment 3, animals received 5 ug SRIF per 100 kg BW at -2, -1, 0 or +1 min relative to 3 ug GRF per 100 kg BW, with a second GRF injection at +120 min. No differences (P < 0·05) were found in response due to timing of SRIF administration. In experiment 4, animals were administered 0, 5, 10 or 20 Xg SRIF per 100 kg BW concurrent with 3 ug GRF per 100 kg BW. SRIF delayed (P < 0·05) the occurrence of maximum GH concentrations but did not affect the maximum concentration nor the area under the GH response curve (AUC) following either the first or second GRF injection. Utilizing data from experiment 4, individual animal response to GRF was reasonably consistent, as repeatabilities of AUCs for 1 h following first and second GRF injections were 0·80 and 0·65, respectively. Furthermore, sufficient among-animal variation existed so that animals could be distinguished from each other. Thus we conclude the method described herein might be useful in identifying superior dairy calves but accuracy would potentially be enhanced by collecting blood samples more frequently during the 20 min immediately after GRF injection.

The influence of dietary monensin and salinomycin on growth and endocrine status of gilts

1992 ◽  
Vol 72 (2) ◽  
pp. 427-429 ◽  
Author(s):  
T. A. Van Lunen ◽  
R. N. Kirkwood ◽  
P. A. Thacker
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Key Words ◽  
Crude Protein ◽  
Protein Diet ◽  
Serum Growth Hormone ◽  
Endocrine Status ◽  
Effect Of Treatment

Seventy-two gilts were fed a 16% crude protein diet supplemented with monensin, salinomycin or not supplemented. There was no effect of treatment on gilt growth between 30 and 100 kg body weight. Monensin-fed gilts tended to have increased, while salinomycin-fed gilts had decreased (P < 0.01), serum growth hormone concentrations. Salinomycin-fed gilts were older and heavier at puberty (P < 0.05). Key words: Monensin, salinomycin, gilts, growth, reproduction

Food intake alters the serum growth hormone response to bovine growth hormone-releasing factor in meal-fed Holstein steers

1988 ◽  
Vol 117 (2) ◽  
pp. 253-259 ◽  
Author(s):  
W. M. Moseley ◽  
G. R. Alaniz ◽  
W. H. Claflin ◽  
L. F. Krabill
Keyword(s):  
Growth Hormone ◽  
Response Curve ◽  
Hormone Response ◽  
Serum Growth Hormone ◽  
Sham Feeding ◽  
Nutritional Factors ◽  
Factors Associated ◽  
Daily Food ◽  
Time Of Feeding ◽  
Serum Gh

ABSTRACT The hypothesis that endocrine or nutritional factors related to feeding may affect pituitary responsiveness to an acute challenge with bovine GH-releasing factor (1–44)-NH2 (GRF) was examined in steers. In these experiments, either steers were trained to consume their total daily food allotment in a 2-h period (meal-fed) or food was withheld at the normal time of feeding (sham-fed). In the first of three experiments, the serum GH pattern was determined around the time of feeding in meal-fed and sham-fed steers. The temporal GH rhythm in both groups appeared to be synchronized to the time of feeding, with limited pulsatile GH activity occurring 2–3 h after feeding. Baseline secretion of GH and total area under the GH response curve were lower (P<0·01) in meal-fed compared with sham-fed steers. In the second experiment, 50 μg GRF was injected i.v. in meal-fed steers at −4, −2, 0, + 2, +4, +6 and + 8 h relative to the time of feeding. The number of steers responding to GRF (53%), the amplitude of the GH peak (15·8 μg/l) and the area under the GH response curve (0·6 arbitrary units) were lower (P< 0·001) after than before feeding (90 ± 6 (s.e.m.)%, 61·3 ± 3·2 μg/l and 2·0 ± 0·3 units respectively). Of those steers responding to GRF, the GH response was significantly reduced following feeding compared with before feeding. In the third experiment, 50 μg GRF was injected i.v. in sham-fed steers at −4, −2, 0, +4 and +6 h relative to the time of sham-feeding. The amplitude of the GRF-induced GH peak (55·4 ± 9·3 μg/l), time to the GH peak (12 ± 2 min) and area under the GH response curve (0·8 ± 4 units) were not significantly different (P>0·1) among the different times of injection of GRF before or after sham-feeding. Apparently factors associated with the ingestion of feed can modulate the release of GH from the pituitary as evidenced by (a) the synchronization of the GH pattern to the time of feeding, and (b) the reduction of the serum GH response to i.v. injection of GRF following feeding. J. Endocr. (1988) 117, 253–259

scholarly journals Response of growth hormone to various doses of growth hormone releasing factor and thyrotropin releasing hormone administered separately and in combination to dairy calves

1991 ◽  
Vol 71 (4) ◽  
pp. 1045-1052 ◽  
Author(s):  
Peter Løvendahl ◽  
John A. Woolliams ◽  
Patrick A. Sinnett-Smith
Keyword(s):  
Growth Hormone ◽  
Area Under The Curve ◽  
Multiplicative Model ◽  
Thyrotropin Releasing Hormone ◽  
Dairy Calves ◽  
Serum Growth Hormone ◽  
Growth Hormone Releasing Factor ◽  
Releasing Hormone ◽  
The Mean ◽  
Multiplicative Effects

Doses of growth hormone releasing factor (GRF) and thyrotropin releasing hormone (TRH) and combinations of these were administered by intravenous injection to six calves aged 155 ± 3 days and weighing 136 ± 16 kg. Injections were at 09:00, 12:00 and 15:00 h on 4 days, and doses were 0, 15, 30 and 60 pmol GRF kg−1 and 0, 275, 550 and 1100 pmol TRH kg−1, with GRF plus TRH at all combinations of these doses. Response of serum growth hormone (GH) was measured as the mean at 5, 10, 15 and 20 min following injection (PEAK) and the area under the curve during 0–60 min (AUC). The correlation between PEAK and AUC was 0.98. The variation in PEAK was related to GH prior to injection and to PEAK 3 h earlier. Separate multiplicative effects for each secretagogue were fitted, with the effects related to the logarithm of dose. Doubling the dose increased PEAK by 1.46-fold following GRF (P < 0.05) and 1.25-fold following TRH (P < 0.05). There was no evidence that the results for either secretagogue were affected by the presence or absence of the other. This multiplicative model provides a description of the synergy between these secretagogues. Key words: GH-release, GRF, TRH, calves, dose response

The effects of intranasal insufflation of growth hormone releasing factor analogie GRF1 – 29 NH2 on growth hormone secretion in children with short stature

1986 ◽  
Vol 113 (4_Suppl) ◽  
pp. S135-S138 ◽  
Author(s):  
M. BORKENSTEIN
Keyword(s):  
Growth Hormone ◽  
Short Stature ◽  
Gh Deficiency ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Normal Children ◽  
Serum Growth Hormone ◽  
Growth Hormone Releasing Factor ◽  
Serum Gh ◽  
Synthetic Growth

ABSTRACT The effects of intranasal insufflation of the synthetic growth hormone releasing factor GRF 1-29-NH2 on serum growth hormone (GH) were investigated in five healthy prepubertal children with short stature. 100 μg/kg/body weight of synthetic GRF 1-29-NH2, 500 μg in 100 μl water, were insufflated intranasally after careful cleaning of the nose. GRF 1-29-NH2 induced a prompt rise of serum GH levels with peak values at 15 minutes in all children investigated. Peak serum GH values were 28.3 ± 12.0 ng/ml (x̄ ± SD), range 17.1 - 47.6 ng/ml; Δ was 27.0 ± 12.2 ng/ml (x̄ ± SD). Serum GH levels were still significantly raised 120 minutes after the insufflation of GRF 1-29-NH2 (p < 0.05). No side effects, except for burning of the nasal mucosa in one patient, were observed. The results of this study demonstrate that intranasal insufflation of synthetic GRF 1-29-NH2 induces a prompt release of GH in otherwise normal children with short stature. Pulsatile intranasal insufflation of GRF 1-29-NH2 probably could be used for the treatment of some children with GH deficiency due to a defect at a suprapituitary level.

Mammary gland development of sows injected with growth hormone-releasing factor during gestation and(or) lactation

1997 ◽  
Vol 77 (2) ◽  
pp. 335-338 ◽  
Author(s):  
C. Farmer ◽  
G. Pelletier ◽  
P. Brazeau ◽  
D. Petitclerc
Keyword(s):  
Growth Hormone ◽  
Mammary Gland ◽  
Key Words ◽  
Mammary Gland Development ◽  
Mammary Glands ◽  
Late Gestation ◽  
Chemical Analyses ◽  
Growth Hormone Releasing Factor ◽  
Mammary Cell ◽  
Gland Development

Twenty-four gilts received s.c. injections of saline or growth hormone-releasing factor (GRF) in late gestation and(or) lactation. Sows were sacrificed on day 30 of lactation and functional mammary glands were excised for chemical analyses. Weight of parenchymal (P = 0.004) and extra-parenchymal tissues (P = 0.002) were decreased with GRF injections during lactation. Parenchymal mass per milligram of DNA also decreased (P = 0.025) with GRF in lactation while parenchymal DNA concentration increased (P = 0.03). Exogenous GRF given to sows during lactation therefore decreased total parenchymal mass, increased cell density and decreased mammary cell size. Key words: Sow, mammary gland, growth hormone-releasing factor

Sign in / Sign up

Export Citation Format

Share Document