Glucagon, insulin, and growth hormone responses to glucose infusion in lactating dairy cows

1985 ◽  
Vol 248 (1) ◽  
pp. E108-E114 ◽  
Author(s):  
J. L. Sartin ◽  
K. A. Cummins ◽  
R. J. Kemppainen ◽  
D. N. Marple ◽  
C. H. Rahe ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Dairy Cow ◽  
Glucose Infusion ◽  
Early Lactation ◽  
Adaptive Responses ◽  
Exogenous Glucose ◽  
Lactating Dairy Cows ◽  
Nutrient Partitioning ◽  
Hormone Responses ◽  
G Ratio

Early lactation in the dairy cow is associated with an increased demand for energy that can only be met by hormone-mediated partitioning of nutrients. The purpose of this study was to determine adaptive responses of basal and glucose-stimulated glucagon (IRG), insulin (IRI), and growth hormone (GH) concentrations to early lactation. Blood was collected via jugular cannulas from nonpregnant nonlactating (NPNL) cows and cows 14 days antepartum (AP) and 5 and 30 days postpartum (PP). Basal concentrations of IRI decreased with lactation, IRG was essentially unchanged, and GH was increased with lactation. The molar IRI/IRG (I/G) ratio was decreased from 4.6 at day 14 AP to 1.3 at day 30 PP. The effects of exogenous glucose (0.56 mM/kg body wt) on IRI were greatest during pregnancy and declined with lactation. IRG responses to glucose were similar except in NPNL cows, which had a minimal but prolonged IRG inhibition, GH responses to glucose infusion were absent in NPNL cows and were most significant at 5 days PP. The decreased I/G and elevated GH concentrations suggests that both IRG and GH play a role in nutrient partitioning during early lactation.

Effect of propionate infusion on plasma glucagon, insulin and growth hormone concentrations in lactating dairy cows

1985 ◽  
Vol 109 (3) ◽  
pp. 348-354 ◽  
Author(s):  
J. L. Sartin ◽  
K. A. Cummins ◽  
R.J. Kemppainen ◽  
R. Carnes ◽  
D. G. McClary ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Dairy Cows ◽  
Plasma Concentrations ◽  
Energy Partitioning ◽  
Early Lactation ◽  
Plasma Glucagon ◽  
Metabolic Hormones ◽  
Lactating Dairy Cows ◽  
Nutrient Partitioning ◽  
Insulin Responses

Abstract. Altered concentrations of metabolic hormones have been suggested as important mediators of energy partitioning during early lactation. This study was initiated to determine the effects of propionate (1.0 mmol/kg body weight) infusion on plasma concentrations of glucagon, insulin, growth hormone, propionate and glucose at 14 days ante-partum (AP) and days 5 and 30 postpartum (PP). No differences were seen in propionate concentrations between sampling days. Glucose concentrations were elevated following propionate infusion in pregnant cows but were not elevated in the PP cows. Insulin responses to propionate infusion did not differ between days while the glucagon response was blunted at day 5 PP. Basal glucagon concentrations were elevated between days 5 and 30 PP, insulin concentrations were unchanged between days, while the molar insulin/glucagon ratio was decreased during early lactation. Basal growth hormone (GH) concentrations were elevated between day 14 AP and day 30 PP. GH responsiveness to declining propionate concentrations was greatest at day 5 PP. These data further suggest a role for glucagon as well as GH in nutrient partitioning during early lactation.

The effect of asynchronous diets on the function of the rumen in the lactating dairy cow

1998 ◽  
Vol 1998 ◽  
pp. 19-19
Author(s):  
A.R. Henderson ◽  
P.C. Garnsworthy ◽  
J.R. Newbold ◽  
P.J. Buttery
Keyword(s):  
Protein Synthesis ◽  
Dairy Cows ◽  
Dairy Cow ◽  
Production Performance ◽  
Early Lactation ◽  
Microbial Protein ◽  
Nutrient Flows ◽  
Lactating Dairy Cows ◽  
Overall Efficiency ◽  
Fermentation Parameters

Sinclair et al. (1993) found that a diet formulated to be synchronous with regard to hourly release of nitrogen and energy increased microbial protein synthesis by 14% in sheep. Dairy cows in early lactation experience a shortfall of energy and protein, with available protein determining the overall efficiency of metabolism (MacRae and Lobley, 1986) and subsequent milk production. It is therefore necessary to maximise microbial protein yield during this period. In this study diets were designed for lactating dairy cows to contain the same feed ingredients, but to release nitrogen and energy in the rumen at different times. Rumen fermentation parameters, nutrient flows to the small intestine and production performance were investigated.

Differential growth hormone responses to glucose and growth hormone releasing hormone in lactating dairy cows

1989 ◽  
Vol 120 (3) ◽  
pp. 319-325 ◽  
Author(s):  
J. L. Sartin ◽  
A. C. Pierce ◽  
R.J. Kemppainen ◽  
F. F. Bartol ◽  
K. A. Cummins ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Dairy Cows ◽  
Plasma Glucose ◽  
Post Partum ◽  
Regulatory System ◽  
Glucose Infusion ◽  
Differential Growth ◽  
Plasma Ffa ◽  
Hormone Responses ◽  
As Effects

Abstract. Dairy cows in early lactation were reported to secrete growth hormone in response to declining glucose concentrations at day 5 but not day 30 post-partum, whereas GH responses to TRH were reported to be enhanced after day 30 post partum. The present study examined GH response following glucose infusion and the effect of GHRH as well as effects of SRIH on GHRH-stimulated GH release. Declining plasma glucose concentrations after glucose infusion stimulated GH release at day 5 post partum but not in nonpregnant, nonlactating cows or in cows at days 30 and 90 post partum. GHRH stimulated GH release on all days tested, but the response was highest at day 30 post partum when compared to other days. Somatostatin infusion inhibited GHRH effects on GH concentrations only at day 30 post partum and in nonpregnant, nonlactating cows. Thus, a differential response of the GH regulatory system could be demonstrated between days 5 and 30 post partum utilizing different stimuli. Evaluation of plasma glucose and free fatty acid concentrations on days 5, 10, 20, and 30 post partum revealed a progressive decrease in FFA but not glucose as lactation progressed. Decreased plasma FFA concentrations were paralleled by a decrease in basal GH, somatomedin-C and epinephrine. Thus, a decline in FFA may be responsible for the disparity between effects of GHRH and glucose on GH release between days 5 and 30 post partum.

scholarly journals 1049 The effect of exogenous glucose infusion on early embryonic development in lactating dairy cows

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 502-503
Author(s):  
S. Leane ◽  
M. M. Herlihy ◽  
N. Forde ◽  
M. C. Lucy ◽  
P. Lonergan ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Dairy Cows ◽  
Glucose Infusion ◽  
Early Embryonic Development ◽  
Exogenous Glucose ◽  
Lactating Dairy Cows

The effect of asynchronous diets on the function of the rumen in the lactating dairy cow

1998 ◽  
Vol 1998 ◽  
pp. 19-19 ◽  
Author(s):  
A.R. Henderson ◽  
P.C. Garnsworthy ◽  
J.R. Newbold ◽  
P.J. Buttery
Keyword(s):  
Protein Synthesis ◽  
Dairy Cows ◽  
Dairy Cow ◽  
Production Performance ◽  
Early Lactation ◽  
Microbial Protein ◽  
Nutrient Flows ◽  
Lactating Dairy Cows ◽  
Overall Efficiency ◽  
Fermentation Parameters

Sinclair et al. (1993) found that a diet formulated to be synchronous with regard to hourly release of nitrogen and energy increased microbial protein synthesis by 14% in sheep. Dairy cows in early lactation experience a shortfall of energy and protein, with available protein determining the overall efficiency of metabolism (MacRae and Lobley, 1986) and subsequent milk production. It is therefore necessary to maximise microbial protein yield during this period. In this study diets were designed for lactating dairy cows to contain the same feed ingredients, but to release nitrogen and energy in the rumen at different times. Rumen fermentation parameters, nutrient flows to the small intestine and production performance were investigated.

scholarly journals The effect of exogenous glucose infusion on early embryonic development in lactating dairy cows

2018 ◽  
Vol 101 (12) ◽  
pp. 11285-11296 ◽  
Author(s):  
S. Leane ◽  
M.M. Herlihy ◽  
F. Curran ◽  
J. Kenneally ◽  
N. Forde ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Dairy Cows ◽  
Glucose Infusion ◽  
Early Embryonic Development ◽  
Exogenous Glucose ◽  
Lactating Dairy Cows

GROWTH HORMONE RESPONSES TO FRUCTOSE IN DIABETES MELLITUS

1974 ◽  
Vol 75 (3) ◽  
pp. 497-502
Author(s):  
Mayer B. Davidson ◽  
Roger M. Steele
Keyword(s):  
Diabetes Mellitus ◽  
Growth Hormone ◽  
Fasting Glucose ◽  
Area Under The Curve ◽  
Oral Glucose ◽  
Gh Secretion ◽  
Significant Difference ◽  
Duration Of Disease ◽  
Hormone Responses

ABSTRACT Since fructose is normally metabolized in diabetics and has recently been shown to stimulate GH secretion, it was used to assess GH responses in diabetics. Fourteen diabetics (9 on insulin) and 8 controls matched for weight were studied. Fructose, infused over 10 min, was compared to arginine, infused over 30 min, both at 0.5 g/kg. Samples were collected at 0, 30, 60, 90 and 120 min and GH responses assessed as area under the curve minus the fasting area. There was no significant difference between the GH responses in diabetics and controls to either agent. Responses to arginine and fructose were significantly correlated (r = 0.60, P < 0.01) in all subjects, but not related to therapy, duration of disease or fasting glucose (75–287 mg/100 ml) in the diabetics. Oral glucose blunted the GH response to fructose in 2 controls. It is concluded that 1) fructose can stimulate GH secretion in male diabetics; 2) however, fructose-stimulated GH responses are not increased in diabetes mellitus.

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