The effect of nutritional supplements in late pregnancy on ewe colostrum production plasma progesterone and IGF-1 concentrations

1992 ◽  
Vol 43 (2) ◽  
pp. 325 ◽  
Author(s):  
DG Hall ◽  
PJ Holst ◽  
DA Shutt
Keyword(s):  
Growth Factor ◽  
Nutritional Supplements ◽  
Late Pregnancy ◽  
Nutritional Supplementation ◽  
New Method ◽  
Average Weight ◽  
Insulin Like Growth Factor ◽  
Milk Secretion ◽  
Plasma Progesterone ◽  
Blood Samples

Mechanisms by which nutritional supplementation might improve colostrum production and enhance lamb survival were examined in adult Border LeicesterxMerino ewes. Ewes were either unsupplemented or supplemented with 500 g/day of oat grain, lupin grain or a formaldehyde-protected sunflowerseed meal (SFM) from day 130 of gestation until parturition while grazing spring pastures containing about 1000 kg green DM/ha. Blood samples were obtained on day 140, day 145 and immediately after parturition. Colostrum production at parturition and for the next 6 h was determined. A new method to determine concentrations of insulin-like growth factor-1 (IGF-1) is presented. Colostrum production at parturition (P.< 0.01) and IGF-1 concentration on day 140 (P.< 0.01) and at parturition (P.< 0.001) were higher, and progesterone concentrations on days 140, 145 and at parturition were lower (P.< 0.001) for single than twin bearing ewes. The unsupplemented ewes and ewes fed oat grain, lupin grain or SFM had an average weight of colostrum at parturition of 292, 328, 452 and 392 g (P.< 0.01), milk secretion rate to 6 h after parturition of 58, 64, 85 and l00g DM/h (P.< 0.05), IGF-1 concentrations after parturition of 199, 223, 262 and 265 ng/mL (P.< 0.001) and progesterone concentrations on day 140 of 49, 43, 39 and 41 nmol/L (P.< 0.01) respectively. Twin compared to single bearing ewes had about half the amount of colostrum at parturition per kg of lamb birthweight. Progesterone concentrations on day 140 and at parturition (P.< 0.01) were negatively related to estimated pasture intake during pregnancy, which was 17% higher for single than twin bearing ewes (P.< 0.05). Supplementation with lupins and SFM may be expected in similar circumstances to enhance the survival of multiple born lambs, while oat grain would not.

A new method for the purification of bioactive insulin-like growth factor-binding protein-3

2010 ◽  
Vol 71 (2) ◽  
pp. 160-167 ◽  
Author(s):  
Haymo Pircher ◽  
Andrea Matscheski ◽  
Andreas Laich ◽  
Martin Hermann ◽  
Barbara Moser ◽  
...  
Keyword(s):  
Growth Factor ◽  
Binding Protein ◽  
New Method ◽  
Insulin Like Growth Factor ◽  
Factor Binding

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.

Colostrum production and hormone responses of parturient ewes fed varying amounts and types of supplement

2005 ◽  
Vol 45 (10) ◽  
pp. 1231 ◽  
Author(s):  
P. J. Holst ◽  
D. G. Hall ◽  
G. J. Lee
Keyword(s):  
Growth Factor ◽  
Practical Importance ◽  
Late Pregnancy ◽  
Analysis Data ◽  
Insulin Like Growth Factor ◽  
Protein Supplements ◽  
Treatment Groups ◽  
Nitrogen Intake ◽  
Hormone Responses ◽  
Sheep Production

Low perinatal lamb loss and fast lamb growth rates are important measures for efficient sheep production. To understand the role of ewe nutrition in late pregnancy, 100 adult Border Leicester × Merino ewes were joined at a synchronised oestrus. Ewes were nutritionally managed to maintain maternal body condition until day 130 of pregnancy at which time 50 twin-bearing ewes entered single pens. Thirteen ewes were allocated as controls and 14, 11 and 12 ewes for the 3 treatments groups. All were fed a base diet of lucerne hay (17.3% crude protein; 9.4 MJ ME/kg DM). Three of the 4 treatment groups were supplemented with oaten grain, formaldehyde-treated sunflower meal or lupin grain at 1 of 3 nominal feeding levels: 250, 500 or 750 g/ewe.day of supplement. Actual intake was less than amounts offered. Intakes measured in the final 5 days prepartum, were used in the analysis. Data were collected on peripheral progesterone and insulin-like growth factor-1 at 4 days prepartum and 50 min postpartum; peripheral oestrone sulfate at 4 and 3 days prepartum and 50 min postpartum; and colostrum weight and score at 50 min postpartum. Feeding level of supplement, but not type of supplement, significantly increased insulin-like growth factor-1 and decreased progesterone and oestrone sulfate levels. Correlations of energy and nitrogen intake with insulin-like growth factor-1, progesterone and oestrone sulfate levels were positive (P<0.01), as were the correlations of colostrum weight with these traits. An unexpected high correlation between energy and nitrogen intake masked any differential effects on colostrum production and hormone response. Nevertheless, the supply of energy and protein supplements were associated with elevated colostrum weights and scores, and lower progesterone concentration. Lowering progesterone levels is considered necessary for successful parturition. Oaten grain was the least desirable grain supplement. These observations support the practical importance of providing adequate nutrition in late pregnancy and its effect on colostrum yield and presumably lamb survival and growth.

Increase in milk secretion and mammary blood flow by intra-arterial infusion of insulin-like growth factor-I into the mammary gland of the goat

1990 ◽  
Vol 126 (3) ◽  
pp. 437-443 ◽  
Author(s):  
C. G. Prosser ◽  
I. R. Fleet ◽  
A. N. Corps ◽  
E. R. Froesch ◽  
R. B. Heap
Keyword(s):  
Blood Flow ◽  
Mammary Gland ◽  
Growth Factor ◽  
Insulin Like Growth Factor ◽  
Milk Secretion ◽  
Arterial Infusion ◽  
Factor I ◽  
Lactating Goats ◽  
Igf I ◽  
Growth Factor I

ABSTRACT The close-arterial infusion of free insulin-like growth factor-I (IGF-I; 1·1 nmol/min) for 6 h into the pudic artery supplying one mammary gland of lactating goats caused a 25±6% (mean ± s.e.m., n = 6) increase in the rate of milk secretion of that gland. The increase in the rate of milk secretion in the adjacent non-infused gland (14±4%) was not significantly different from that observed during saline infusion (4±5%). Blood flow to the infused gland was increased from 378±26 ml/min 1 h before to 487±56 ml/min approximately 5 h after the start of the infusion of IGF-I, declining to 420±44 ml/min approximately 2 h after the end of the infusion. The total concentration of IGF-I (free and bound) in milk of the infused gland was significantly higher than that of the non-infused gland. The concentrations of IGF-I in carotid arterial plasma samples increased during IGF-I infusion from a mean value of 32±2 nmol/l before to a maximum of 49±3 nmol/l 5 h after the infusion commenced. Circulating concentrations of total IGF-I declined slowly after the infusion with an estimated half-life of 5 h. Infusion of saline alone did not alter mammary blood flow or the concentration of total IGF-I in milk or plasma. The results indicate that the infusion of free IGF-I into the mammary arterial supply enhances milk secretion and mammary blood flow in intact, conscious goats. The more pronounced effect in the infused compared with the non-infused gland suggests that free IGF-I acts directly on the mammary gland. The response in the non-infused gland was attenuated presumably due to association of IGF-I with plasma binding proteins during recirculation. Journal of Endocrinology (1990) 126, 437–443

89 Does progesterone block the nerve growth factor–induced luteinizing hormone surge in llamas?

2021 ◽  
Vol 33 (2) ◽  
pp. 152
Author(s):  
R. A. Carrasco ◽  
S. Pezo ◽  
G. P. Adams
Keyword(s):  
Nerve Growth Factor ◽  
Growth Factor ◽  
Seminal Plasma ◽  
Treatment Time ◽  
Suppressive Effect ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Time Interaction ◽  
Site Of Action ◽  
Lh Release

The central inhibitory effects of progesterone on gonadotrophin secretion have been well documented in several species, including camelids. Nerve growth factor (NGF) in seminal plasma triggers ovulation in camelids and is thought to act at the level of the hypothalamus. The objective of the study was to determine the effect of progesterone on NGF-induced LH release in llamas. In Experiment 1, llamas were assigned to a low, medium, or high progesterone group (n=4 per group). The low progesterone group consisted of non-mated (non-ovulatory) llamas, the medium progesterone group consisted of mated llamas (luteal phase; 3–4 weeks pregnant), and the high progesterone group consisted of non-mated llamas given a single intramuscular (IM) dose of progesterone (300mg IM, Progesterone BioRelease LA). A jugular catheter was placed, and the following day llamas were given an intravenous dose of 1mg of NGF isolated from seminal plasma. Blood samples were taken every 30min from 1h before to 5.5h after NGF treatment. In Experiment 2, the pituitary LH response to gonadotrophin-releasing hormone (GnRH) was compared between llamas treated with either Progesterone BioRelease LA or saline (n=4 per group). Sixteen hours later, llamas in both groups were given 50µg of gonadorelin (GnRH) IV, and blood samples were collected by jugular puncture at 0.5h before and 0, 1, 2, and 4h after GnRH. Blood samples were centrifuged, and plasma was stored frozen until radioimmunoassay for LH and progesterone. Data are presented as mean±s.e.m. Data were analysed by one-way ANOVA for single-point and repeated-measures, and independent or paired t-tests. In Experiment 1, plasma progesterone concentrations in the low, medium, and high progesterone groups were 0.6±0.3, 8.2±0.4, and 14.9±1.2ng mL−1, respectively, at the time of NGF treatment (P&lt;0.05). Circulating concentrations of LH did not differ among progesterone groups (treatment, P=0.49; time, P&lt;0.01; treatment×time interaction, P=0.65). In all groups, LH concentrations were elevated within 30min of NGF administration, reached a peak by 2h, and remained elevated beyond the sampling period. Comparison of samples collected during the pretreatment period (i.e. −60, −30, and 0min), however, revealed that plasma LH concentrations in the high progesterone group were half that of the low and medium progesterone groups (P&lt;0.03). In Experiment 2, plasma progesterone concentrations in the progesterone- and saline-treated groups were 12.7±2.2 and 1.3±0.3ngmL−1, respectively (P&lt;0.01). Despite the difference in circulating progesterone concentrations, the LH response to GnRH treatment was not different between groups (treatment group, P=0.43; time, P&lt;0.01; treatment×time interaction, P=0.84). Results demonstrate a suppressive effect of progesterone on basal LH release in llamas, but no suppressive effect on NGF- or GnRH-induced surge release from the pituitary gland. Results are consistent with the hypothesis that the site of action of NGF is downstream of the hypothalamic site of action of progesterone. This research was supported by NSERC Canada.

Late pregnancy increases hepatic expression of insulin-like growth factor-I in well nourished guinea pigs

2005 ◽  
Vol 15 (2) ◽  
pp. 165-171 ◽  
Author(s):  
P.A. Grant ◽  
K.L. Kind ◽  
C.T. Roberts ◽  
A. Sohlstrom ◽  
P.C. Owens ◽  
...  
Keyword(s):  
Growth Factor ◽  
Guinea Pigs ◽  
Late Pregnancy ◽  
Insulin Like Growth Factor ◽  
Hepatic Expression ◽  
Factor I ◽  
Growth Factor I
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