The effect of reduced protein supply on energy and nitrogen metabolism in early lactation cows

Author(s):  
F. Sutter ◽  
D.E. Beever

After calving, milk secretion in dairy cows increases rapidly, but the slower rate of increase in feed intake by the cow can lead to a substantial negative energy balance in the animal. Consequently, body tissues, comprising principally of adipose tissue are mobilised and this energy contribution is accounted for in calculating the feeding regime of the animal. In contrast, the extent of body protein mobilisation is considered to be much less but the potential contribution of such to the animal's protein requirements for milk synthesis are neither recognised or exploited in most of the feeding systems used in Europe, including the Swiss ‘APD’ system. The objective of this study was to examine the effect of reducing the calculated supply of absorbed protein on the secretion of milk and milk constituents and whole body energy and nitrogen metabolism in order to quantify any possible contribution of body protein to the nutrition of early lactation cows.

1993 ◽  
Vol 265 (3) ◽  
pp. E402-E413 ◽  
Author(s):  
S. Tesseraud ◽  
J. Grizard ◽  
E. Debras ◽  
I. Papet ◽  
Y. Bonnet ◽  
...  

Early lactating goats show insulin resistance with respect to extramammary glucose utilization. However, much less is known about the two major factors, insulin and plasma amino acid concentration, that regulate protein metabolism in lactating goats. To examine this question, the in vivo effect of acute insulin was studied in goats during early lactation (12-31 days postpartum), midlactation (98-143 days postpartum), and the dry period (approximately 1 yr postpartum). Insulin was infused (at 0.36 or 1.79 nmol/min) under euglycemic and eukaliemic clamps. In addition, appropriate amino acid infusion was used to blunt insulin-induced hypoaminoacidemia or to create hyperaminoacidemia and maintain this condition under insulin treatment. Leucine kinetics were assessed using a primed continuous infusion of L-[1-14C]-leucine, which started 2.5 h before insulin. In all animals the insulin treatments failed to stimulate the nonoxidative leucine disposal (an estimate of whole body protein synthesis) under both euaminoacidemic and hyperaminoacidemic conditions. Thus, in goat as well as humans, infusion of insulin fails to stimulate protein synthesis even when combined with a substantially increased provision of amino acids. In contrast, insulin treatments caused a dose-dependent inhibition of the endogenous leucine appearance (an estimate of whole body protein degradation). Under euaminoacidemia the initial slope from the plot of the endogenous leucine appearance as a function of plasma insulin (an insulin sensitivity index) was steeper during early lactation than when compared with the dry period. A similar trend occurred during midlactation but not to any significant degree. These differences were abolished under hyperaminoacidemia. It was concluded that the ability of physiological insulin to inhibit protein degradation was improved during lactation, demonstrating a clear-cut dissociation between the effects of insulin on protein and glucose metabolism. This adaptation no doubt may provide a mechanism to save body protein.


1998 ◽  
Vol 94 (3) ◽  
pp. 321-331 ◽  
Author(s):  
Derek C. MacAllan ◽  
Margaret A. McNurlan ◽  
Anura V. Kurpad ◽  
George De Souza ◽  
Prakash S. Shetty ◽  
...  

1. Differing patterns of protein metabolism are seen in wasting due to undernutrition and wasting due to chronic infection. 2. We investigated whole body energy and protein metabolism in nine subjects with pulmonary tuberculosis, six undernourished subjects (body mass index < 18.5 kg/m2) and seven control subjects from an Indian population. Fasting subjects were infused with l-[1-13C] leucine (2.3 μmol · h−1 · kg−1) for 8 h, 4 h fasted then 4 h fed. Leucine kinetics were derived from 13C-enrichment of leucine and α-ketoisocaproic acid in plasma and CO2 in breath. 3. Undernourished subjects, but not tuberculosis subjects, had higher rates of whole body protein turnover per unit lean body mass than controls [163.1 ± 9.4 and 148.6 ± 14.6 μmol compared with 142.8 ± 14.7 μmol leucine/h per kg, based on α-ketoisocaproic acid enrichment (P = 0.039)]. 4. In response to feeding, protein oxidation increased in all groups. Tuberculosis subjects had the highest fed rates of oxidation (47.0 ± 10.5 compared with 37.1 ± 5.4 μmol · h−1 · kg−1 in controls), resulting in a less positive net protein balance in the fed phase (controls, 39.7 ± 6.2; undernourished subjects, 29.2 ± 10.6; tuberculosis subjects, 24.5 ± 93; P = 0.010). Thus fed-phase tuberculosis subjects oxidized a greater proportion of leucine flux (33.2%) than either of the other groups (controls, 24.0%; undernourished subjects, 24.0%; P = 0.017). 5. Tuberculosis did not increase fasting whole body protein turnover but impaired the anabolic response to feeding compared with control and undernourished subjects. Such ‘anabolic block’ may contribute to wasting in tuberculosis and may represent the mechanism by which some inflammatory states remain refractory to nutrition support.


1980 ◽  
Vol 95 (3) ◽  
pp. 497-514 ◽  
Author(s):  
R. T. Cowan ◽  
J. J. Robinson ◽  
I. McDonald ◽  
R. Smart

SUMMARYThirty-six mature Finnish Landrace × Dorset Horn ewes, each suckling two lambs, were used in a comparative slaughter experiment to measure changes in body tissues during early lactation. Two levels of body fatness at lambing were established by giving ewes a complete diet containing 10 MJ metabolizable energy (ME) and 139 g crude protein (CP)/kg d.m. either close to requirements or ad libitum during the second half of pregnancy. In lactation half the ewes in each group were given a complete diet containing either 90 (diet A) or 60 (diet B) % milled hay ad libitum. These diets contained 7·9 and 9·2 MJ ME and 121 and 132 g CP/kg d.m. respectively.Ewes fed at the two levels in pregnancy contained 8·4 and 19·6 kg chemically determined fat 5 days after lambing but had similar amounts of body protein, ash and water. Over 6 weeks of lactation ewes given diet A lost 60 and 69% of these weights of fat respectively, while ewes given diet B gained 5% and lost 30% respectively. Up to 26 g of body protein was lost daily from ewes given diet A but none from ewes on diet B. During early lactation the weight of the empty digestive tract increased while the weights of most other body components, particularly the carcass, decreased. The ratio of body energy change to live-weight change varied from 24 to 90 MJ/kg. Thus live-weight change did not accurately reflect relative or absolute changes in body energy.Voluntary food intake was greater for ewes given the high-energy diet (B) than for those given diet A and was depressed in the fatter ewes. Differences in intake could be explained by the effects of body fatness and diet on the weight of gut contents. Milk yield was not significantly affected by body fat reserves but was higher on diet B than A. Fat content of milk was higher and protein content lower for ewes with the higher fat reserves at lambing.As the contribution of fat loss to energy available for milk synthesis increased there appeared to be a reduction in the energetic efficiency of milk synthesis. A number of possible reasons for this are discussed.


1989 ◽  
Vol 67 (6) ◽  
pp. 624-628 ◽  
Author(s):  
P. Pencharz ◽  
J. Beesley ◽  
P. Sauer ◽  
J. Van Aerde ◽  
U. Canagarayar ◽  
...  

Protein turnover rates in neonates have been calculated largely by measuring urinary [15N]urea enrichment following administration of [15N]glycine. Although ammonia has been increasingly recognized as an end product of nitrogen metabolism, in neonates it yields a different estimate of protein turnover than does urea. Comparisons of ammonia and urea end products in parenterally fed neonates have not previously been reported. A third and independent way of estimating protein turnover, developed for adults, is to use breath 13CO2 as an end product following administration of [1-3C]leucine. We therefore carried out simultaneous measurements of protein turnover in 10 parenterally fed neonates, using the three end products. The infants were clinically stable, weighed 2.6 ± 0.2 kg, and received 3.1 ± 0.2 g∙kg−1∙d−1 of amino acid, 2.2 ± 0.1 g∙kg−1∙d−1 of lipids, and an energy intake of 90 ± 4 kcal∙kg−1∙d−1 (1 kcal = 4.186 kJ). The turnover estimates derived from the 13CO2 and [15N]urea end products were very similar. The [15N]ammonia end product produced values approximately 66% (p < 0.01) of the other two. We conclude that the ammonia and urea end products probably originate in different precursor pools. The similarity of the urea and breath carbon dioxide results helps validate the use of the urea end product in studying the nitrogen metabolism of parenterally fed neonates. Ideally in future studies two or more end products should be used, since they provide information about different aspects of the nenonates' protein metabolism.Key words: neonates, protein metabolism, nitrogen-15, [1-13C]leucine.


2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 186-187
Author(s):  
Maciej M Misiura ◽  
Joao A N Filipe ◽  
Carrie L Walk ◽  
Ilias Kyriazakis

Abstract Key underlying assumptions of current pig growth models, developed in the context of nutritionally balanced feeds, may be invalid for pigs given inadequate dietary phosphorous (P). To account for pig performance on feeds of different P content, a dynamic, mechanistic growth model was developed where ingested P is allocated to either soft tissue or skeletal tissue. The following issues needed to be addressed: 1) potential impact of different dietary P concentrations on feed intake; 2) estimation of the whole-body protein (Pr):P relationship; 3) allocation of ingested P into different body tissues. Statistical analyses of the published literature data, utilising meta-regression indicated the following answers: 1) there was no compensatory feed consumption in pigs fed P-deficient diets (p > 0.05); 2) the whole-body Pr:P relationship was feed-dependent, i.e., body P was directly proportional to body Pr in pigs fed P-adequate diets but lower in pigs fed P-deficient diets; 3) P retention in the soft tissue was prioritised over P deposition in bone when the dietary P was low (p < 0.001). A growth model incorporating mechanisms based on the above data analyses suggests that pigs given P-limiting feeds attempt to maintain the same level of lean tissue retention attained with a P-balanced diet, but at the expense of reduced skeletal deposition. Specifically, bone P growth was reduced in relation to a balanced-diet for moderately-P-deficient diets, and static for severely-P-deficient diets. The overall average daily gain remained largely unaffected for moderately-P-deficient pigs. The present in-silico framework of P kinetics could be utilised to study the consequences of different P feeding strategies on animal growth and body composition, and to verify whether further reduction in dietary P requirements could be achieved with no loss in animal performance.


2000 ◽  
Vol 70 (3) ◽  
pp. 503-514 ◽  
Author(s):  
F. Sutter ◽  
D. E. Beever

AbstractEnergy and nitrogen metabolism were examined at weekly intervals during lactation weeks 1 to 8 in Holstein-Friesian cows (no. = 9) offered a diet of hay, maize pellets (whole plant) and concentrates, (barley, maize and soya bean; forage : concentrate ratio 65 : 35), with feeding levels close toad libitum.After calving, the cows lost body weight until week 7, with peak milk yield (35 kg/day) recorded during week 3. Dry-matter intakes increased progressively to week 4 then remained relatively constant. Apparent digestibility of dietary energy was unaffected by stage of lactation but the overall value was low (0·653) indicative of the quantity and quality of long hay in the diet. Metabolizable energy intakes ranged between 163 and 202 MJ/day, with little between-week variation after that between weeks 1 and 2 (P< 0·01). Milk energy output was relatively stable during weeks 1 to 4 but then declined progressively for each remaining week, whilst heat energy output was relatively constant throughout. Estimates of body energy retention indicated the cows were in negative energy balance at all times, being greater in week 1 (64 MJ/day,P< 0·01) than weeks 2 to 4 (mean, 35 MJ/day) or weeks 5 to 8 (22 MJ/day). Digestible nitrogen (N) intake was reduced in week 1, whilst apparent N digestibility declined significantly , with little between-week variation after that between weeks 1 and 2 < 0·05) as lactation progressed. The cows were in negative N balance (–19 g/day) during week 1, with zero (week 2) or positive balances noted thereafter.It is concluded that during early lactation, the extent of body tissue mobilization in average yielding cows can be substantial and prolonged, whilst attainment of positive body N status occurred earlier and was not related to the energy status of the cows.


Author(s):  
Alicja Urbaniak ◽  
Anna Skarpańska-Stejnborn

Abstract. The aim of the study was to review recent findings on the use of POM supplements in athletes of various disciplines and physically active participants. Eleven articles published between 2010 and 2018 were included, where the total number of investigated subjects was 176. Male participants constituted the majority of the group (n = 155), as compared to females (n = 21). 45% of research described was conducted on athletes, whereas the remaining studies were based on highly active participants. Randomised, crossover, double-blind study designs constituted the majority of the experimental designs used. POM supplementation varied in terms of form (pills/juice), dosage (50 ml–500 ml) and time of intervention (7 days–2 months) between studies. Among the reviewed articles, POM supplementation had an effect on the improvement of the following: whole body strength; feeling of vitality; acute and delayed muscle fatigue and soreness; increase in vessel diameter; blood flow and serum level of TAC; reduction in the rate of increase for HR, SBP, CK and LDH; support in the recovery of post-training CK, LDH, CRP and ASAT to their baseline levels; reduction of MMP2, MMP9, hsCRP and MDA; and increased activity of antioxidant enzymes (glutathione peroxidase and superoxide dismutase). In the majority of reviewed articles POM supplementation had a positive effect on a variety of parameters studied and the authors recommended it as a supplement for athletes and physically active bodies.


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