Production performance and nitrogen metabolism in dairy cows fed supplemental blends of rumen undegradable protein and rumen-protected amino acids in low- compared with high-protein diets containing corn distillers grains

2021 ◽  
Author(s):  
A.V. Stevens ◽  
K. Karges ◽  
P. Rezamand ◽  
A.H. Laarman ◽  
G.E. Chibisa
Keyword(s):  
Amino Acids ◽  
Dairy Cows ◽  
Nitrogen Metabolism ◽  
High Protein ◽  
Production Performance ◽  
Distillers Grains ◽  
Rumen Undegradable Protein ◽  
Corn Distillers ◽  
High Protein Diets ◽  
Protein Diets

Dietary protein paradox: decrease of amino acid availability induced by high-protein diets

1993 ◽  
Vol 264 (6) ◽  
pp. G1057-G1065 ◽  
Author(s):  
C. Moundras ◽  
C. Remesy ◽  
C. Demigne
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Dietary Protein ◽  
High Protein ◽  
Glutamine Metabolism ◽  
Metabolic Adaptation ◽  
Casein Diet ◽  
Serine Dehydratase ◽  
High Protein Diets ◽  
Protein Diets

The aim of the present study was to evaluate the effect of changes in dietary protein level on overall availability of amino acids for tissues. For this purpose, rats were adapted to diets containing various concentrations of casein (7.5, 15, 30, and 60%) and were sampled either during the postprandial or postabsorptive period. In rats fed the protein-deficient diet, glucogenic amino acids (except threonine) tended to accumulate in plasma, liver, and muscles. In rats fed high-protein diets, the hepatic balance of glucogenic amino acids was markedly enhanced and their liver concentrations were consistently depressed. This response was the result of a marked induction of amino acid catabolism (a 45-fold increase of liver threonine-serine dehydratase activity was observed with the 60% casein diet). The muscle concentrations of threonine, serine, and glycine underwent changes parallel to plasma and liver concentrations, and a significant reduction of glutamine was observed. During the postabsorptive period, adaptation to high-protein diets resulted in a sustained catabolism of most glucogenic amino acids, which accentuated the drop in their concentrations (especially threonine) in all the compartments studied. The time course of metabolic adaptation from a 60 to a 15% casein diet has also been investigated. Adaptation of alanine and glutamine metabolism was rapid, whereas that of threonine, serine, and glycine was delayed and required 7-11 days. This was paralleled by a relatively slow decay of liver threonine-serine dehydratase (T-SDH) activity in contrast to the rapid adaptation of pyruvate kinase activity after refeeding a high-carbohydrate diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Rats fed prolonged high protein diets show an increase in nitrogen metabolism and liver megamitochondria

1987 ◽  
Vol 258 (2) ◽  
pp. 426-435 ◽  
Author(s):  
Remedios Zaragozá ◽  
Jaime Renau-Piqueras ◽  
Manuel Portolés ◽  
José Hernández-Yago ◽  
Antonio Jordá ◽  
...  
Keyword(s):  
Nitrogen Metabolism ◽  
High Protein ◽  
High Protein Diets ◽  
Protein Diets

scholarly journals Stimulation of amino acid transport into liver cells from rats adapted to a high-protein diet

1982 ◽  
Vol 206 (1) ◽  
pp. 13-18 ◽  
Author(s):  
P Fafournoux ◽  
C Rémésy ◽  
C Demigné
Keyword(s):  
Amino Acids ◽  
Decisive Role ◽  
High Protein Diet ◽  
Isolated Hepatocytes ◽  
Hepatic Uptake ◽  
High Protein ◽  
Protein Diet ◽  
High Protein Diets ◽  
Protein Diets

After adaptation of rats to a 90%-casein diet, hepatic uptake of alanine is strikingly increased in vivo, with concomitant appearance of a concentration of favourable for uptake. With a high-protein diet, uptake of 2-aminoisobutyrate by isolated hepatocytes in the presence of various concentrations of substrates suggested induction of the A system (high-affinity system), whose emergence has been reported during starvation or after glucagon treatment. The other system (ASC, L) were characterized: induction processes only affected the A system. Dibutyryl cyclic AMP addition resulted in an increase in 2-aminoisobutyrate transport at low substrate concentration, the response being greater after adaptation to a high-protein diet. Evidence is presented suggesting that the increased uptake of amino acids by the liver of rats fed on high-protein diets is obtained by developing favourable gradients and enhancing transport capacities. These adaptations allow sufficient amounts of amino acids to enter the liver, where accelerated metabolism plays a decisive role.

Effect of protein level and grain source on milk production, nutrient digestibility and ruminal fermentation in primiparous Holstein cows

2021 ◽  
pp. 1-7
Author(s):  
H. Mirzaei-Alamouti ◽  
A. Mohammad ◽  
M. Vazirigohar ◽  
P. Rezamand ◽  
M. Mansouryar
Keyword(s):  
Milk Production ◽  
Protein Level ◽  
Nutrient Digestibility ◽  
High Protein ◽  
Production Performance ◽  
Holstein Cows ◽  
Ruminal Fermentation ◽  
Low Protein ◽  
High Protein Diets ◽  
Protein Diets

Abstract This study investigated whether the interaction of protein level and grain type can affect milk production, nutrient digestibility and rumen fermentation in primiparous Holstein cows. Four dietary treatments were used: high-protein with barley as the only grain source, HP-B; (2) high-protein with an equal mix of barley and maize, HP-BM; (3) low-protein with barley as the only grain source, LP-B and (4) low-protein with equal proportions of barley and maize, LP-BM. High-protein diets showed no improvement in milk or protein yield compared with low-protein, but barley and maize mix diets increased energy-corrected milk yield and fat yield compared with barley-only diets. The highest total apparent digestibility of dry matter, organic matter and neutral detergent fibre was observed for LP-BM whereas HP-BM showed the greatest crude protein digestibility. Treatment had no effect on total volatile fatty acid concentrations, molar proportion of acetate and propionate and acetate to propionate ratio. The lowest ruminal pH was observed for LP-B. High-protein diets resulted in greater concentrations of ammonia nitrogen (N), urinary N, blood and milk urea nitrogen compared with low-protein diets, whereas low-protein diets showed better nitrogen utilization efficiency. This study showed that primiparous lactating cows do not benefit from high-protein diets with different fermentation rates of grain sources, but barley and maize diets may improve milk production performance, ruminal fermentation and pH under the present dietary conditions. The current results on milk production performance should be interpreted with caution due to the small number of cows used (eight in each treatment).

A study of nitrogen metabolism in sheep on high protein diets.

1930 ◽  
Vol 20 (1) ◽  
pp. 1-17
Author(s):  
James Stewart
Keyword(s):  
Nitrogen Metabolism ◽  
High Protein ◽  
High Protein Diets ◽  
Protein Diets

In the course of an investigation into the pathological effects of excessive protein diets on sheep (1) experiments were designed to show the changes in metabolism as recorded by nitrogen balances and weight curves. The animals were placed in metabolism cages similar to those described by Wood and Woodman (2) in their digestibility trials, and a harness of the Halnan type used.

Familial Hypoglycemia Precipitated by Amino Acids

PEDIATRICS ◽  
1956 ◽  
Vol 18 (2) ◽  
pp. 192-192
Keyword(s):  
Amino Acids ◽  
Isovaleric Acid ◽  
High Protein ◽  
Dramatic Effect ◽  
Low Protein ◽  
Normal Individuals ◽  
True Blood ◽  
Protein Feeding ◽  
High Protein Diets ◽  
Protein Diets

This paper reports three cases of hypoglycemia in one family and an unrelated case in which profound hypoglycemia and convulsions were produced by the administration of proteins or amino acids. The patients described are similar to the group which have been reported in the literature as infantile idiopathic hypoglycemosis. Casein, leucine, and isovaleric acid fed to the patients caused a marked fall in the fasting concentration of true blood sugar. High protein feeding led to more convulsions and lower concentrations of sugar in the blood than did a low protein diet. Leucine had the most dramatic effect. Casein and leucine did not produce a fall in the sugar in the blood in normal individuals. The literature on metabolic interrelations between amino acids and carbohydrates and the concentration of sugar in the blood is reviewed. The mode of action of amino acids in depressing the concentration of sugar in the blood in infants with spontaneous hypoglycemia is considered and several hypotheses proposed. This paper is of unusual interest and of great importance for the treatment of infants with spontaneous idiopathic hypoglycemia. It is suggested that in this particular type of hypoglycemia high protein diets should be avoided. Small amounts of carbohydrate may be given 30 to 40 minutes after the ingestion of a meal containing protein to offset the effect of protein in lowering the concentration of sugar in the blood.

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