Lupins and energy-yielding nutrients in ewes. 1. Glucose and acetate biokinetics and metabolic hormones in sheep fed a supplement of lupin grain

1989 ◽  
Vol 40 (4) ◽  
pp. 913 ◽  
Author(s):  
E Teleni ◽  
WR King ◽  
JB Rowe ◽  
GH McDowell

Measurements were made of metabolism of glucose and acetate and changes in plasma hormones in sheep fed a basal ration to meet maintenance requirements for metabolizable energy (ME) or fed the same level of basal ration and given either a supplement of 750 g day-1 lupin grain (Experiment I) or intravenous glucose infusions over periods of 17 h (Experiment 2).In ewes given supplementary lupins, concentrations of volatile fatty acids (VFAs) in rumen liquor increased but molar proportions of VFAs were unchanged. Plasma concentrations of glucose, acetate and propionate increased; entry rates of glucose, acetate and CO2 increased and glucose oxidation (but not acetate oxidation) increased during supplementation with lupins. Other changes measured during lupin supplementation included increased plasma urea, a transient and marked increase in plasma insulin and a concomitant decrease in plasma growth hormone during the first three days, and an increase in plasma tri-iodothyronine (T3) with no changes in plasma thyroxine (T4).When glucose was infused intravenously at rates ranging from 0 to 46.8 mmoles h-1 (cf. 31 mmoles h-1 due to lupins) endogenous entry rate of glucose only increased at the highest infusion rate. There was a negative linear relationship between infusion rate of glucosc and plasma urea, whereas positive linear relationships were found between glucose infusion rate and both plasma insulin and T3.It was concluded that ewes on a maintenance basal diet and fed a supplement of 750 g day-1 lupin grain would rapidly switch to the anabolic mode concomitant with increases in glucose entry rate by more than 100% and acetate entry rate by more than 50%. Long-term intravenous infusion of the amount of glucose equivalent to that promoted by the lupin grain supplement would probably not suppress endogenous glucose production.

1972 ◽  
Vol 23 (3) ◽  
pp. 483 ◽  
Author(s):  
DJ Farrell ◽  
RA Leng ◽  
JL Corbett

Studies were made on three initially similar groups of adult Merino sheep at pasture; each group comprised eight animals of which four each had a rumen cannula. Group A was kept at about the initial mean liveweight of 35 kg; groups B and C were reduced in weight over 14 weeks by restriction of grazing and then held at about 26 and 23 kg respectively for 9 months. Measurements were made at intervals of 4-6 weeks of ruminal concentrations of volatile fatty acids (VFA) and ammonia, rumen volume and flow rate of digesta, tritiated water (TOH) space, and blood composition. Haemoglobin concentrations and haematocrit values decreased in the undernourished sheep, but there were no marked changes in blood β-hydroxybutyrate, or lactate, or plasma urea nitrogen. Estimates of body composition from TOH space indicated that sheep in groups B and C lost 51 and 58 Mcal respectively during the first 14 weeks; estimated fat contents were thereafter about 9 and 7% of liveweight. Metabolizable energy requirements for maintenance were calculated from estimated VFA production rates and changes in body energy content. During a 9 month period commencing shortly after shearing and extending into winter, requirements per unit liveweight were about 45% greater for the undernourished groups B and C than for group A.


1992 ◽  
Vol 43 (8) ◽  
pp. 1795 ◽  
Author(s):  
JC O'Kelly ◽  
WG Spiers

Brahman (B) and Hereford (H) cattle were used to study protozoal population density of ruminal fluid (RF) in relation to some aspects of rumen and body metabolism. Steers were fed restricted intakes of lucerne hay (HQ) or low-quality hay (LQ) in each of eight experiments. In the 8 h period following the once-daily feeding of HQ the number of entodiniomorphs declined by 50%, while the number of holotrichs increased by 60% before reducing to pre-feeding levels. There were no significant rises and falls in the numbers of protozoa of steers fed LQ once daily nor in those fed either HQ or LQ at hourly intervals. The numbers of entodiniomorphs, dasytrichs, total protozoa, pH and bacterial content of RF were higher and rumen temperature lower in B than in H. Urinary allantoin excretion used as an index of the total microbial population in the rumen distinguished between diets but not between breeds. The concentrations of propionic, butyric, isobutyric and isovaleric acids in RF and of glucose in plasma were higher in B than in H. The concentrations of all classes of long-chain fatty acids contained in the protozoa and bacteria of RF and of cholesterol and essential fatty acids in plasma were higher in B than in H. The amount of dry matter disappearing from nylon bags in the rumen of steers fed HQ did not differ between breeds, but was higher in B than in H fed LQ. Elevation of pH to peak values in RF with an accompanying disappearance of protozoa and volatile fatty acids during fasting from either HQ or LQ occurred more rapidly in B than in H. The plasma concentrations of non-esterified fatty acids were higher in B than in H during fasting. It is proposed that at the same level of intake of either HQ or LQ: (1) the higher protozoal population density in RF of B contributes to quantitative breed differences in the end products of digestion, (2) that B achieve and maintain a higher body weight because more metabolizable energy and essential nutrients are supplied from the rumen to their body tissues, and (3) after the same period of feed deprivation B have fasted for a longer period of time because the residual feed in their rumens is fermented at a more rapid rate.


1988 ◽  
Vol 39 (3) ◽  
pp. 505 ◽  
Author(s):  
HA Abdul-Razzaq ◽  
R Bickerstaffe ◽  
GP Savage

Changes in the body composition, blood metabolites and rumen volatile fatty acids were measured in growing 12-week-old lambs fed whole-loose barley or ground barley pelleted with minerals for 10 weeks. Feeding whole-loose barley produced a propionic type of rumen fermentation and ground barley pelleted with minerals, an acetic acid type.The propionic type of fermentation was associated with a significant increase in the plasma concentrations of glucose and insulin, a reduction in the concentrations of plasma urea, and a reduction in almost all of the plasma amino acids, particularly alanine, methionine, valine, isoleucine and leucine. There was also a significant increase in the amount of body fat and dry matter, a higher level of protein per kg fat free empty body weight, and a more efficient utilization of dietary energy in the animals with a propionic acid type of fermentation.The elevation in the concentration of rumen propionic acid produced two important changes. It increased the supply of the main glucogenic precursor propionate, which probably reduces the body's requirement for alternative gluconeogenic precursors, and it stimulated directly and/or indirectly the pancreatic secretion of insulin. The latter is most likely responsible for the efficient peripheral utilization of glucose and other nutrients in lambs with a propionic acid type of rumen fermentation.Thus, a propionic type of fermentation is associated with an increase in the plasma levels of glucose and insulin, an increase in fat deposition and an increase in the efficiency of ME retention; all of these factors contribute to the improved performance of this group of lambs compared to those with an acetic acid type of fermentation.


1976 ◽  
Vol 36 (3) ◽  
pp. 353-368 ◽  
Author(s):  
Sarah A. Allen ◽  
E. L. Miller

1. Plasma urea entry rate, urinary urea excretion and, by difference, urea recycling in the body, together with the flow of non-ammonia N through the abomasum and digestion of dry matter (dm) before the abomasum were determined in both wethers and lambs receiving cereal-starch diets supplemented with urea to give 60–120 g crude protein (N × 6.25)/kgdm.2. Lambs excreted less urea in urine than wethers given the same diet.3. Relationships between plasma urea entry rate or urine urea excretion rate and plasma urea concentration were different for lambs compared to wethers suggesting greater conser vation of body N by renal control in lambs.4. Recycling of urea was not related to plasma urea concentration in wethers but was related exponentially in lambs, suggesting recycling is controlled rather than the result of simple diffusion from the blood to the gastro-intestinal tract.5. Abomasal non-ammonia-N flow was similar for wethers and lambs and increased linearly with urea supplementation.6.dmdigestion prior to the abomasum was not significantly altered, although there was a tendency for decreased digestion of the basal diet given to lambs.7. Maximum microbial N flow to the abomasum was estimated as 30 g N/kg organic matter (OM) fermented in the rumen.8. This work and the literature reviewed suggested maximum net microbial production can be obtained when the diet supplies an amount of fermentable N equal to the microbial N output. It is calculated the diet should supply approximately 26 g fermentable N/kg digestible OM or 1.8 g fermentable N/MJ metabolizable energy. This corresponds to a fermentable crude protein supply varying from 65 to 130 g/kg DM as digestible OM content increases from 400 to 800 g/kg DM.


1969 ◽  
Vol 23 (3) ◽  
pp. 443-453 ◽  
Author(s):  
E. R. Ørskov ◽  
W. P. Flatt ◽  
P. W. Moe ◽  
A. W. Munson ◽  
R. W. Hemken ◽  
...  

1. In an experiment of 3 x 3 latin square design, four lactating Holstein cows were given a basal ration designed to induce low percentages of milk fat. The treatments were (I) basal ration, a pelleted mixture of lucerne hay (20%) and concentrates (80%), with 40 l. of water infused intraruminally, (2) basal ration with acetic acid substituted for 15.4% of the metabolizable energy (ME) and (3) propionic acid substituted for 15.4% of the ME. In the last 3 weeks of the 6-week experimental period respiration trials were carried out in an open-circuit indirect calorimeter. The levels of feeding offered in the three periods were 325, 275 and 225 kcal ME/kg body-weight 0.75 in periods 1, 2 and 3 respectively.2. No differences were detected in the utilization of the energy of acetic and propionic acids, but there were differences in the partition of energy into milk or body tissues; with acetic acid infusion more energy was secreted as milk and with propionic acid infusion more was deposited in body tissue.3. There was an increase in milk fat percentage with acetic acid infusion, but not complete recovery to normal. The milk fat percentages were 1.96, 2.58 and 1.92 for treatments 1, 2 and 3 respectively. Acetic acid infusion caused increases in the C12, C14 and C16 fatty acids of milk fat and decreased the proportion of C18:1 fatty acids.4. It is suggested that the low percentages of milk fat found when cows are given concen- trates could result from a decreased extent of fermentation in the rumen, allowing a greater proportion of the starch consumed to be absorbed as glucose in the small intestine.


1990 ◽  
Vol 30 (5) ◽  
pp. 585 ◽  
Author(s):  
JC O'Kelly ◽  
WG Spiers

Supplements of safflower oil (300 mL/day) were given to groups of steers fed 4 different diets. Hereford steers were fed 6 kg/day lucerne hay (LH) or LH + 33 mg/kg monensin (LHM). Brahman steers were fed 4 kg/day low quality hay (DA) or DA + 1 kg sucrose + 60 g urea + 2.7 g sulfur (DAS). Metabolic measurements were made when the animals were fed an equal portion of the daily ration at hourly intervals. On all diets, safflower oil had no affect on rumen temperature, pH or the concentrations of volatile fatty acids in ruminal fluid. Safflower oil increased concentrations (mg/L) of microbial lipid in ruminal fluid (LH, 160.4 v. 317.1; LHM, 266 v. 541.7; DA, 194.6 v. 321.8; DAS, 172.8 v. 440.5) and increased plasma concentrations (�g/mL) of non-esterified fatty acids (LH, 117.2 v. 180.1; LHM, 101.1 v. 189.5; DA, 218.2 v 325.4; DAS, 197.4 v 311.4), especially 18:1 trans- 11 and polyunsaturated acids. In steers fed DA and DAS, safflower oil reduced protozoal numbers and increased the bacterial mass in ruminal fluid, and increased water intake and the daily amounts of urinary allantoin excreted. The addition of safflower oil to all diets depressed plasma urea concentrations (mg/L) (LH, 233 v. 203; LHM, 236 v. 191; DA, 74.6 v. 47.6; DAS, 96.6 v. 54). The excretion of daily amounts (mg/kg liveweight) of urinary urea increased in animals fed DA (3.5 v. 10.0) and DAS (6.2 v. 13.6) but decreased in those fed LH (208.8 v. 187.9) and LHM (188.8 v. 158.1). Safflower oil supplementation conserved body protein, accelerated liveweight gains in animals fed LH and LHM diets and retarded liveweight loss in those fed DA and DAS diets.


1989 ◽  
Vol 62 (1) ◽  
pp. 35-49 ◽  
Author(s):  
M. E. Symonds ◽  
M. J. Bryant ◽  
M. A. Lomax

The aim of the present study was to determine how the long-term metabolic adaptations to winter shearing of the pregnant ewe result in significant changes in the rates of lipid mobilization and utilization of non-esterified fatty acids (NEFA) in comparison with unshorn controls. Continuous infusions of [1-14C]palmitic acid, [2-3H]glycerol and NaH14CO3 were used to measure whole-body lipid metabolism in fed (estimated metabolizable energy (ME) intake 9.54 MJ/d) and under-fed (estimated ME intake of 3 MJ/d), shorn and unshorn sheep over the final 4 weeks of pregnancy. Whole-body carbon dioxide, estimated heat production, total NEFA entry and oxidation rates were all significantly higher in fed shorn ewes compared with unshorn controls, even though there was no difference in the arterial plasma NEFA concentration. These differences may be mediated via an increase in the plasma concentrations of thyroid hormones in shorn animals. As a result of under-feeding any significant differences in lipid metabolism between shorn and unshorn groups were removed. In all sheep the mean total NEFA entry rate as measured using [1-14C]palmitic acid was 3.4 times the value obtained using [2-3H]glycerol. It is concluded that when sheep are fed on a diet from which no more than half the required ME for late pregnancy is obtained, then lipolysis of body fat depots occurs via the incomplete breakdown of adipose tissue triglycerides. This effect is significantly greater in the fed shorn pregnant ewe which exhibits higher entry and oxidation rates of NEFA.


1978 ◽  
Vol 45 (1) ◽  
pp. 128-131 ◽  
Author(s):  
G. Holm ◽  
P. Bjorntorp ◽  
R. Jagenburg

To elucidate early metabolic adaptations of physical training obese and nonobese subjects were studied before and at different intervals after 1 h of bicycle exercise at 70% of maximal working capacity. Four h after exercise intravenous glucose tolerance (IVGT) and plasma level of alanine were decreased. Compared to the diurnal variation plasma concentration of cortisol was increased. Twenty-four hours after exercise plasma concentrations of cortisol and trihlycerides were decreased. Furthermore, plasma insulin during IVGT test was decreased and blood glycerol increased in the obese subjects. There were no changes in basal insulin, IVGT, or plasma levels of amino acids which were elevated in the obese subjects (valine, isoleucine, leucine, tyrosine, phenylalanine). Forty-eight hours after exercise plasma insulin during IVGT test and plasma triglycerides remained decreased in the obese subjects. Low cortisol levels 24 h after exercise might result in increased insulin effect leading to low plasma insulin levels seen in physically trained subjects. Elevated glycerol levels in the obese subjects might be the first sign of diminishing fat stores secondary to increased lipolysis.


1966 ◽  
Vol 20 (3) ◽  
pp. 509-517 ◽  
Author(s):  
E. R. Ørskov ◽  
D. M. Allen

1. The effect, on the concentration of volatile fatty acids (VFA) in the rumen, of increasing the frequency of feeding from twice daily to four or six times daily was investigated in sheep given isocaloric rations containing VFA salts. In a second experiment isocaloric rations containing acetate and propionate were given to groups of lambs in two or six equal feeds daily. The efficiency with which the lambs utilized the VFA salts was measured as gain in live weight, empty body weight and carcass weight and was compared to that of lambs receiving only the basal ration. The composition of the carcasses was estimated from that of the loin. 2. Increasing the frequency of feeding from twice daily to four or six times daily significantly reduced the marked changes in rumen VFA composition associated with giving rations containing VFA salts twice daily. In lambs receiving acetate and propionate, final live weight, empty body weight and carcass weight were significantly greater than in lambs receiving only the basal ration (P < 0.001). The combustible energy from added VFA was apparently utilized more efficiently than the calculated metabolizable energy of the basal rations given above maintenance level, and there was no difference between the utilization of acetate and propionate. 3. There were no differences approaching significance between feeding twice daily and six times daily either between groups of lambs receiving only the basal diet or between those given the diets supplemented with VFA salts. Nor were there any interactions between VFA and frequency of feeding. 4. It is postulated that in ruminants the effect of frequency of feeding depends on the environment and level of feeding.


2004 ◽  
Vol 142 (6) ◽  
pp. 697-704 ◽  
Author(s):  
A. S. JUÁREZ-REYES ◽  
M. A. CERRILLO-SOTO ◽  
C. A. MEZA-HERRERA ◽  
G. NEVÁREZ-CARRASCO

The objective of the study was to determine the chemical composition of the diet, intake and plasma concentrations of glucose, urea and non-esterified fatty acids (NEFA) during pregnancy in goats grazing a thorn scrubland of the semi-arid region of North Mexico. Additionally, monthly changes during pregnancy of plasma concentrations of luteinizing hormone (LH), growth hormone (GH), insulin (INS) and progesterone (P4) were also measured. A herd of 250 goats was bred in August and blood samples were collected from 12 goats at monthly intervals up to December to evaluate plasma glucose, urea, NEFA, LH, GH, INS and P4. Three goats fitted with oesophageal cannulae (38±1·7 kg BW) were used to obtain diet samples during pregnancy. Response variables were analysed by split-plot ANOVA for repeated measures on animals across time. When significant differences were observed among pregnancy months, multiple comparisons were performed using the PROC GLM-PDIFF option of SAS. The response variables organic matter (OM), crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF), lignin, hemicellulose and cellulose differed across pregnancy. Mean values for the whole period were (g/kg DM) 866 (OM), 149 (CP), 524 (NDF), 364 (ADF), 131 (lignin), 160 (hemicellulose), and 233 (cellulose). Mean values for dry matter intake (DMI, kg/day), metabolizable energy intake (MEI, MJ/day) and metabolizable protein intake (MPI, g/day) were 1·2, 8·9 and 74·0, respectively and were different among periods of sampling (P<0·05). Mean plasma glucose concentration was 41±4·3 mg/dl with no significant differences (P>0·05) across pregnancy. Plasma NEFA concentrations increased (P<0·05) at the end of pregnancy (August, 0·396 v. November, 1·27 mM/l). Plasma urea concentrations were higher (P<0·05) in August (26·3 mg/dl) and November (26·2 mg/dl). Serum urea concentrations were related to MPI (r=0·82, P=0·10) and to the undegraded protein absorbed from the duodenum (r=0·79; P=0·07), but not with the rumen NH3-N concentration (r=−0·25; P=0·68). Hormone plasma concentrations differed (P<0·05) across pregnancy. While the largest serum LH concentration (P<0·05) was observed in mid pregnancy (October, 7·8 ng/ml), the lowest value was depicted at the end of gestation (4·8 ng/ml). A similar pattern was observed in plasma P4, with monthly increases from August to November, and a reduction during the last month of gestation (August, 5·6 v. December 2·5 ng/ml). With respect to the metabolic hormones, a negative correlation (−0·23, P=0·05) was observed between GH and INS, with the largest plasma INS levels in mid pregnancy (October 1·9 ng/ml), the lowest INS levels in December, 0·8 ng/ml and the largest serum GH concentration in December, 20·2 ng/ml. Results from the study indicate that DMI, MEI and MPI in grazing goats are useful indicators of the nutritive value of the forage consumed by goats which allowed them to keep an important steroidogenic luteal activity during gestation (P4=5·7±0·82 ng/ml, litter size=1·44 kids). Nonetheless, the observed plasma levels of glucose, urea, NEFA, INS and GH indicate that a schedule of energy supplementation may be outlined to ensure an adequate nutritional status of goats during late pregnancy and early lactation.


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