THE INFLUENCE OF EXOGENOUS GROWTH HORMONE ON OVULATION RATE IN GILTS

1988 ◽  
Vol 68 (4) ◽  
pp. 1097-1103 ◽  
Author(s):  
R. N. KIRKWOOD ◽  
P. A. THACKER ◽  
A. D. GOONERATNE ◽  
B. L. GUEDO ◽  
B. LAARVELD
Keyword(s):  
Growth Hormone ◽  
Crude Protein ◽  
Ovulation Rate ◽  
Daily Injection ◽  
Corpora Lutea ◽  
Blood Samples ◽  
High Incidence ◽  
Exogenous Growth ◽  
Ad Libitum

A total of 32 prepubertal gilts of Yorkshire and Landrace breeding were selected at 138 d and fed ad libitum a 16.2% crude protein diet formulated to provide 13.1 MJ DE kg−1. From selection until the end of second estrus, the gilts were exposed to a boar for 30 min d−1 to facilitate the detection of pubertal and second estrous periods. From 14 d after puberty, the gilts received daily injections of either porcine growth hormone at 90 μg kg−1 body weight (GH; n = 20) or vehicle (CT; n = 12) until 24 h after the onset of second estrus and were then killed 9 d later to determine ovulation rate. Gilts not displaying a second estrus by 24 day after puberty were considered anestrus and the injection regime was halted. Anestrous gilts were killed 30–32 d after puberty and their ovaries examined for the presence of corpora albicantia and the absence of corpora lutea. Blood samples were obtained from all gilts at 14, 17, and 20 d after puberty. There was no treatment effect on the duration of the estrous cycle (20.8 vs. 21.3 d for GH and CT, respectively), but while all CT gilts cycled normally, only 55% of the GH gilts had a second estrus (P < 0.01). In those gilts having a second estrus, the daily injection of growth hormone increased ovulation rate (14.3 vs. 12.4 for GH and CT respectively; P < 0.03). Serum type 1 insulin-like growth factor (IGF-1) concentrations were higher (P < 0.001) in GH than in CT gilts, but there was no difference between cycling and anestrous GH gilts. We suggest that the effect of growth hormone on ovulation rate was mediated by increased secretion of IGF-1. The etiology of the high incidence of anestrus is, however, not known. Key words: Gilts, growth hormone, ovulation rate

Effects of growth hormone-releasing factors and cottonseed meal on hormones and metabolites in plasma from lambs fed lucerne chaff ad libitum

1994 ◽  
Vol 45 (6) ◽  
pp. 1125 ◽  
Author(s):  
RD Sainz ◽  
BJ Hosking ◽  
FJ Hart ◽  
GSG Spencer
Keyword(s):  
Fatty Acids ◽  
Growth Hormone ◽  
Growth Factor ◽  
Cottonseed Meal ◽  
Metabolic Effects ◽  
Insulin Like Growth Factor ◽  
Plasma Urea ◽  
Blood Samples ◽  
Esterified Fatty Acids ◽  
Ad Libitum

This study was part of an experiment on the effects of cottonseed meal (CSM) and growth hormone-releasing factor (GRF) on growth in lambs fed lucerne chaff. Forty-eight crossbred lambs were fed lucerne chaff ad libitum, alone or with a cottonseed meal supplement (CSM; 300 g/day). Eight lambs from each group were injected twice daily with recombinant or synthetic GRF (rGRF and sGRF respectively; 30 8g per kg body weight/day) or excipient only for 28 or 30 days. Jugular blood samples were obtained on days 0, 7, 14, 21 and 28. On day 29, blood samples were taken from selected lambs (n = 2/group) at 0, 20, 40, 60, 80, 100, 120, 160 and 240 min after injection. Supplementation of lucerne chaff with CSM generally increased glucose and urea concentrations in plasma, reflecting improved energy and protein status. However, concentrations of growth hormone, insulin-like growth factor-1 and insulin were unaffected by CSM, as were plasma proteins, triacylglycerols and non-esterified fatty acids. Injection of rGRF and sGRF stimulated secretion of growth hormone (GH), insulin-like growth factor-1 (IGF-1) and insulin. Peak GH concentrations (20 min) following injection of GRF appeared to be higher in lambs fed CSM than in those receiving lucerne chaff alone. In contrast, maximal concentrations of IGF-1 were seen after 14 days of treatment. These changes were accompanied by increased plasma glucose, with no changes in triacylglycerols, non-esterified fatty acids and protein. Plasma urea was reduced by GRF, indicating that amino acids were diverted away from catabolism towards protein synthesis. These two sources of GRF were very similar in their endocrine and metabolic effects. This confirms similar observations regarding their effects on growth performance and carcass composition.

scholarly journals Effect of the GH secretagogue L-163,255 and restricted feeding time on GH pulsatility in the rat

2002 ◽  
pp. 143-148 ◽  
Author(s):  
AN Moulas ◽  
JD Veldhuis ◽  
JC Chan ◽  
Keyword(s):  
Growth Hormone ◽  
Oral Administration ◽  
Feeding Time ◽  
Restricted Feeding ◽  
Growth Hormone Secretagogue ◽  
Deconvolution Analysis ◽  
Blood Samples ◽  
Pulsatile Release ◽  
Before And After ◽  
Ad Libitum

OBJECTIVE: To determine the effect of repeated treatments with the growth hormone secretagogue (GHS) L-163,255 on the pulsatile release of GH when administered in meal-fed rats before and after feeding. DESIGN: The first group of rats (AL, n=6) had food available ad libitum. The second (restricted, R, n=6), third (GHSB, n=6), and fourth (GHSA, n=6) groups were fed from 1100 to 1400 h. Groups GHSB and GHSA were given GHS by gavage, 3.0 mg/kg L-163,255, at 1000 h (before feeding, B) and at 1500 h (after feeding, A) respectively. Three weeks after the initiation of the treatment, blood samples were collected at 10-min intervals over 6 h, and GH levels were determined. RESULTS: In group R, the concentrations of GH were higher before feeding (17.6+/-2.4 ng/ml) than during feeding (11.2+/-1.2 ng/ml), P<0.05. The average concentrations of the peak in response to GHS were higher when GHS was administered before (121.70+/-33.68 ng/ml) than after (49.67+/-17.87 ng/ml) feeding. The mass of GH, as calculated by deconvolution analysis was also higher in the GHSB group than in the GHSA group (251.6+/-64.1 ng/ml per min vs 85.3+/-22.9 ng/ml per min respectively, P<0.05). CONCLUSION: L-163,255 is effective in inducing GH release after repeated oral administration in rats. The effectiveness is greater when GHS is administered before rather than after feeding in meal-fed animals.

scholarly journals Plasmatic Urea Nitrogen in Growing Rabbits with Different Combinations of Dietary Levels of Lysine, Sulphur Amino Acids and Threonine

Animals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 946
Author(s):  
Pablo Jesús Marín-García ◽  
Mari Carmen López-Luján ◽  
Luís Ródenas ◽  
Eugenio Melchor Martínez-Paredes ◽  
Enrique Blas ◽  
...  
Keyword(s):  
Amino Acids ◽  
Crude Protein ◽  
Experimental Diet ◽  
Urea Nitrogen ◽  
Energy Unit ◽  
Blood Samples ◽  
Commercial Diet ◽  
Protein Retention ◽  
Ad Libitum ◽  
Sulphur Amino Acids

A total of 27 experimental diets were formulated starting from the same basal mixture, with a moderate content of crude protein and digestible energy (155 g and 9.86 MJ/kg of digestible matter (DM), respectively, both estimated). The contents of lysine, sulphur amino acids and threonine were variable. The first one, close to the current recommendations (Medium, M; 8.1, 5.8 and 6.9 g/kg DM for lysine, sulphur amino acids and threonine, respectively), and two other levels were on average 15% higher (High, H; 9.4, 6.6 and 7.8 g/kg DM for lysine, sulphur amino acids and threonine, respectively) or lower (Low, L; 6.7, 4.9 and 5.7 g/kg DM for lysine, sulphur amino acids and threonine, respectively). Diets were named with three letters, indicating lysine, sulphur amino acids and threonine levels, respectively. In total, 918 weaned rabbits (28 days old) were used (34 per diet). At weaning, animals were fed ad libitum with a commercial diet until day 46, day 47 each collective cage was randomly switched to one experimental diet. At day 48, blood samples were collected at 08:00h then the animals were subjected to 10 h of fasting and a second blood sample was extracted at 21.00h. At 08:00h, Pasmatic urea nitrogen (PUN) was higher with the L level of lysine (p < 0.001), unaffected by the level of sulphur amino acids and increased with the level of threonine (p < 0.001). At 21:00h, minimum PUN was observed with the MHL diet (14.72 ± 0.661 mg/dL). Taken into account the usual recommendations (established for a diet containing 11.3 MJ DE/kg DM, and then being 0.72, 0.51 and 0.61 g/MJ DE for lysine, sulphur amino acids and threonine, respectively), these results suggest that a diet containing more lysine and sulphur amino acids per energy unit (around 0.82 and 0.67 g/MJ DE) could better fit the growing rabbit requirements, although studies on the effects of such a diet on performance and protein retention are necessary.

EFFECT OF EXOGENOUS GROWTH HORMONE DURING THE FOLLICULAR PHASE ON hCG BINDING BY PORCINE LUTEAL TISSUE

1990 ◽  
Vol 70 (2) ◽  
pp. 719-721 ◽  
Author(s):  
R. N. KIRKWOOD ◽  
P. A. THACKER ◽  
B. L. GUEDO ◽  
B. LAARVELD
Keyword(s):  
Growth Hormone ◽  
Key Words ◽  
Ovarian Function ◽  
Binding Capacity ◽  
Follicular Phase ◽  
Corpora Lutea ◽  
Exogenous Growth ◽  
Luteal Tissue

From 14 d after puberty, 37 Yorkshire Landrace gilts received nine daily injections of porcine growth hormone (GH) or vehicle. Gilts were killed 10 d after the onset of their second estrus and their ovaries recovered. Treatment with GH resulted in an increase (P < 0.05) in the hCG binding capacity of the corpora lutea (0.17 vs. 0.11 nmol L−1 mg−1 protein). These data provide a possible mechanism whereby GH may influence ovarian function. Key words: Gilts, hCG binding, growth hormone

scholarly journals INFLUENCE OF THYROTROPIN-RELEASING HORMONE (TRH) ON PLASMA PROGESTERONE AND PITUITARY HORMONE CONCENTRATIONS IN CATTLE

1975 ◽  
Vol 55 (4) ◽  
pp. 633-640 ◽  
Author(s):  
J. G. MANNS ◽  
H. D. HAFS ◽  
G. E. LAMMING
Keyword(s):  
Growth Hormone ◽  
Corpus Luteum ◽  
Prolactin Secretion ◽  
Thyrotropin Releasing Hormone ◽  
Saline Control ◽  
Pituitary Hormone ◽  
Corpora Lutea ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Releasing Hormone

Four Friesian heifers 14–16 mo of age were injected through jugular catheters six times per day (0600, 0900, 1200, 1500, 1800 and 2100 h) with 100 μg thyrotropin-releasing hormone or saline (control). TRH and saline treatment continued for 14 days beginning 1 day after a luteolytic dose of prostaglandin (PGF2α, 30 mg) which was given during diestrus. Blood samples were collected via the catheters at 0900 and 2100 h each day for progesterone prolactin and LH determinations and before and 10, 20, 30, 40 and 60 min after the 0600 and 2100 h TRH injections on the 1st, 7th and 13th days of treatment for growth hormone (GH) and prolactin analysis. After 14 days, heifers were injected with 10 mg PGF2α and changes in blood progesterone were measured for 24 h. There were two treatment periods; hence, each animal was subjected to both TRH and saline injections. Results support the following conclusions: (1) Prolactin secretion in response to TRH did not diminish with time. (2) Plasma progesterone of TRH-treated animals was lower (P < 0.05) from approximately day 5 of the cycle (estrus = day 0) until corpora lutea were destroyed with PGF2α; this provides no support for a luteotrophic role for prolactin. (3) Corpora lutea of all animals regressed after 10 mg PGF2α, suggesting that TRH had not increased the resistance of the corpus luteum to the luteolytic effects of PGF2α.

Specific depletion of body fat in parabiotic partners of tube-fed obese rats

1984 ◽  
Vol 247 (2) ◽  
pp. R380-R386 ◽  
Author(s):  
R. B. Harris ◽  
R. J. Martin
Keyword(s):  
Fatty Acids ◽  
Growth Hormone ◽  
Food Intake ◽  
Body Fat ◽  
Blood Samples ◽  
Reverse Triiodothyronine ◽  
Obese Rats ◽  
Ad Libitum ◽  
Beta Hydroxybutyrate ◽  
Normal Food

One member in each of 15 parabiosed pairs of rats was fed twice its normal food intake as four tube-fed meals per day. Seven other pairs ate ad libitum. Partners of overfed rats ate approximately 90% of the intake of individual members of ad libitum pairs. After 46 days of overfeeding, blood samples were taken and the rats were killed for carcass analysis. Tube-fed parabiotic rats had gained a considerable amount of fat and some protein. Their partners had a normal lean body mass but very little fat. Serum corticosterone, reverse triiodothyronine, free fatty acids, and beta-hydroxybutyrate were the same in all parabionts. Serum triiodothyronine and insulin were increased and growth hormone was decreased in obese rats. Serum thyroxine and triiodothyronine were increased and glucose was decreased in their parabiotic partners. The results are discussed as evidence for a humoral factor that crossed the parabiotic union and acted as a "lipid-depleting" agent in the partners of overfed rats.

The effects of zeranol on performance and carcass characteristics of young bulls

1986 ◽  
Vol 1986 ◽  
pp. 94-94
Author(s):  
B M Scott ◽  
A V Fisher ◽  
R A Cooper ◽  
J A Kirk
Keyword(s):  
Growth Performance ◽  
Crude Protein ◽  
Dry Matter ◽  
Carcass Characteristics ◽  
Carcass Quality ◽  
Blood Samples ◽  
Chemical Company ◽  
Holstein Bull ◽  
Bull Calves ◽  
Ad Libitum

Kirk and Cooper (1983) reported two experiments in which the growth performance and carcass conformation of intensively fed dairy-bred bulls was improved by sequential implantation with Zeranol®. Two further studies have been conducted in which there has been repeat implantation of Zeranol® and detailed carcass dissection to measure precisely the effects on carcass quality.In trial A, 16 Holstein bull calves were purchased from pedigree breeders and weaned at eight weeks of age, when they were divided into two groups of eight, balanced by weight. From 8 to 12 weeks they were given commercial rearing pellets followed by a. commercial pencil and hay was given ad libitum. From 12 weeks onwards a cereal mix was offered ad libitum, formulated to give 13 MJ/kg dry matter, 160 g/kg crude protein. Hay was withdrawn from 14 weeks of age. At eight weeks of age, half the animals were implanted with 36 mg Zeranol® (Ralgro, Crown Chemical Company, Kent), and re-implanted a further three times every 70 days. Five blood samples were taken from all animals over a 15h period at about 8, 14, 33 and 43 weeks of age.

THE INFLUENCE OF EXOGENOUS GROWTH HORMONE ON ENDOCRINE STATUS AND THE OVULATORY RESPONSE TO PMSG IN PREPUBERTAL GILTS

1990 ◽  
Vol 70 (1) ◽  
pp. 309-312 ◽  
Author(s):  
R. N. KIRKWOOD ◽  
P. A. THACKER ◽  
R. S. KORCHINSKI ◽  
B. LAARVELD
Keyword(s):  
Growth Hormone ◽  
Key Words ◽  
Jugular Vein ◽  
Serum Concentrations ◽  
Blood Samples ◽  
Exogenous Growth ◽  
Endocrine Status ◽  
The Difference ◽  
To Receive ◽  
Surge Height

Twenty-three prepubertal Yorkshire × Landrace gilts were allocated to receive daily injections of either porcine growth hormone (pGH) or vehicle for 6 consecutive days. At the time of first pGH or buffer injection, all gilts received an injection of 500 IU PMSG. Blood samples were taken by jugular vein puncture at 0, 24 and 48 h then every 12 h until 96 h then every 8 h until 144 h. Samples were assayed for triiodothyronine (T3), insulin, glucose and LH. Treatment with pGH elevated (P < 0.01) serum concentrations of T3, insulin and glucose, and was associated with a reduced (P < 0.05) LH surge height. Fewer pGH-treated than vehicle-treated gilts ovulated (4/12 vs. 7/11), but the difference was not significant. Key words: Gilts, growth hormone, gonadotrophins, ovulation

THE INFLUENCE OF EXOGENOUS GROWTH HORMONE ON OVULATION RATE IN GILTS FED DIETS WITH DIFFERENT ENERGY AND PROTEIN CONTENTS

1989 ◽  
Vol 69 (1) ◽  
pp. 265-268 ◽  
Author(s):  
R. N. KIRKWOOD ◽  
P. A. THACKER ◽  
B. LAARVELD
Keyword(s):  
Growth Hormone ◽  
Key Words ◽  
Feed Intake ◽  
Dietary Treatment ◽  
High Energy ◽  
Ovulation Rate ◽  
Induced Ovulation ◽  
Exogenous Growth

Following pregnant mare's serum gonadotrophin (PMSG) induced ovulation, 61 Yorkshire × Landrace gilts were allocated to be fed either a control or a high-energy diet for 30 d. From 14 d, gilts on each dietary treatment received nine daily injections of porcine growth hormone or vehicle. Growth hormone depressed feed intake by 30% (P < 0.001), but did not influence ovulation rate. No influence of diet or growth hormone on the incidence of a subsequent ovulation was apparent. Key words: Gilts, diet, growth hormone, ovulation rate

The effect of condition at service and plane of nutrition in early pregnancy in the sow 1. Uterine and extra-uterine changes

1972 ◽  
Vol 15 (2) ◽  
pp. 147-155 ◽  
Author(s):  
I. H. Pike ◽  
T. G. Boaz
Keyword(s):  
Mortality Rate ◽  
Crude Protein ◽  
Uterine Wall ◽  
Ovulation Rate ◽  
The Other ◽  
Corpora Lutea ◽  
Litter Weight ◽  
Foetal Membranes ◽  
Adverse Pregnancy ◽  
In Pregnancy

SUMMARYTwelve sows (F) were fed 7·3 kg/day and twelve (T) 3·7 kg/day of a 16% crude protein (CP) diet for the last 5 weeks of an 8-week lactation, so that at the subsequent service F sows were heavier (16%) and in better condition.From service to slaughter 70 days later, sows received either 3·7 kg/day (H) or 1·8 kg/day (L) of a 15% CP diet, giving four treatment combinations; FH, FL, TH and TL.In pregnancy H sows gained more weight than L sows and, on the low plane, F sows gained more weight than T sows. Ovulation rate as measured by corpora lutea count at slaughter was higher for TH than TL sows and for FL sows than FH sows. A combination of low ovulation rate and high mortality rate gave fewer foetuses (10·0) in the TL sows than in sows on the other treatments (13·5). Similarly mean foetal weight and thus foetal litter weight was least in TL sows. Foetal membranes, uterine fluids and uterine wall were lighter at slaughter in T sows than F sows and lighter in L sows than H sows, those of TL sows being appreciably the lightest.The results indicate that when the sow is in poor condition at service, body reserves being depleted, the uterus and its contents become more vulnerable to adverse pregnancy nutrition.

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