Low protein

About: Low protein is a research topic. Over the lifetime, 8139 publications have been published within this topic receiving 213225 citations.

Low-protein amino acid-supplemented diets in broiler-chickens: effects on performance, carcass characteristics, whole-body composition and efficiencies of nutrient utilisation

Abstract: Two concurrent trials were conducted to investigate the influence of low-protein amino acid-supplemented diets on the performance, carcass characteristics, whole-body composition and efficiencies of nutrient utilisation by the male broiler chicken from age 3 to 6 weeks. The first trial comprised five isoenergetic (13.0 MJ kg−1) diets containing 225 (control), 210, 190, 172 or 153 g kg−1 crude protein (CP) supplemented with essential amino acids (EAAs) to meet the minimum National Research Council recommendations. In the second trial a composite mixture of non-essential amino acids (NEAAs) was added to the lower-CP diets (ie 210–153 g kg−1) such that they became isoproteinous (N × 6.25) with the 225 g kg−1 control. Neither the lowering of dietary CP nor NEAA supplementation had any significant influence on weight gain or the relative weights of the various carcass cuts. However, chicks fed the lowest-CP diets consumed more feed (P ≤ 0.05) and had poorer (P ≤ 0.05) feed conversion efficiency (FCE). NEAA supplementation enhanced FCE to the control levels. Whole-body compositional analysis showed that lowering dietary CP increased (P ≤ 0.01) total body fat in a linear fashion (P ≤ 0.001; r = −0.72). Equalising dietary CP with the control (ie maintaining identical energy/protein ratio) by NEAA supplementation did not correct for the fat deposition. Total body protein (g kg−1) was identical with the control with or without NEAA supplementation. Dietary energy, protein retention efficiency (PRE) and protein efficiency ratio (PER) were more efficient (P ≤ 0.01) in the lower-protein diets, while NEAA supplementation significantly (P ≤ 0.01) decreased the efficiency of N utilisation. Reducing dietary CP from 225 to 153 g kg−1 decreased N excretion in a highly significant linear fashion (P ≤ 0.001; r = 0.73). The nutritional and environmental implications of the increased body fat deposition on the one hand and the decreased N excretion on the other in the low-protein-fed chickens are discussed and the need to harmonise these apparently conflicting interests is emphasised. © 2000 Society of Chemical Industry

Maternal Protein Restriction Influences the Programming of the Rat Hypothalamic-Pituitary-Adrenal Axis

Abstract: The role of glucocorticoids in the intrauterine programming of hypertension was assessed in the progeny of rats fed either 18 g casein/100 g diet (control diet) or 9 g casein/100 g diet (low protein diet), before conception and throughout pregnancy. Rats exposed to the low protein diet had significantly (P < 0.05) higher systolic blood pressures than control animals, when weaned. These rats had elevated brain and liver activities of specific glucocorticoid-inducible marker enzymes, relative to controls. Glycerol 3-phosphate dehydrogenase activity was also higher (377%) in whole brains of newborn rats exposed to low protein diet in utero, but no similar effect of corticosteroids was noted in brains of d 20 fetuses. Weanling rats of the low protein group exhibited a blunted diurnal pattern of adrenocorticotrophin (ACTH) concentrations in plasma. Plasma corticosterone concentrations were unaltered by prenatal dietary experience and exhibited a normal pattern of diurnal variation. Brain regional 11beta-hydroxysteroid dehydrogenase activities were unaltered by prenatal dietary experience, as was binding of 3H-corticosterone to type I glucocorticoid receptors in hippocampus, hypothalamus and liver. Type II glucocorticoid receptor binding capacity and receptor numbers in male rats were apparently elevated in hippocampus of low protein-exposed rats and were significantly lower in liver (P < 0.05), relative to control rats. Programming of the hypothalamic-pituitary-adrenal axis is inferred, and the observation that binding of steroid to type II receptor sites in vascular tissue is increased in low protein exposed rats may provide a direct mechanism for modulation of blood pressure by glucocorticoids in this model.

The frequency of type I heterozygous protein S and protein C deficiency in 141 unrelated young patients with venous thrombosis.

Abstract: The frequency of heterozygous protein C and protein S deficiency, detected by measuring total plasma antigen, in a group (n = 141) of young unrelated patients (less than 45 years old) with venous thrombotic disease was studied and compared to that of antithrombin III, fibrinogen, and plasminogen deficiencies. Among 91 patients not receiving oral anticoagulants, six had low protein S antigen levels and one had a low protein C antigen level. Among 50 patients receiving oral anticoagulant therapy, abnormally low ratios of protein S or C to other vitamin K-dependent factors were presented by one patient for protein S and five for protein C. Thus, heterozygous Type I protein S deficiency appeared in seven of 141 patients (5%) and heterozygous Type I protein C deficiency in six of 141 patients (4%). Eleven of thirteen deficient patients had recurrent venous thrombosis. In this group of 141 patients, 1% had an identifiable fibrinogen abnormality, 2% a plasminogen abnormality, and 3% an antithrombin III deficiency. Thus, among the known plasma protein deficiencies associated with venous thrombosis, protein S and protein C deficiencies (9%) emerge as the leading identifiable associated abnormalities.