Lactating mice (Mus musculus) exhibit compensatory flexibility in gut morphology in response to reduced dietary protein

2013 ◽  
Vol 91 (4) ◽  
pp. 245-251 ◽  
Author(s):  
E.M. Derrickson

Protein affects key life-history traits, and deficiencies in this nutrient may have selected for the ability to invoke physiological or morphological mechanisms to aid nutrient assimilation. I examined the effect of dietary protein on gut characters in lactating mice (Mus musculus L., 1758) and predicted that mice, to improve assimilation efficiency, would increase the mass of the stomach and small intestine and (or) increase food retention in these organs. Mice were maintained on isocaloric diets differing in protein and carbohydrate content (P:C) during the reproductive period. The hypothesis that food would be preferentially retained was not supported. However, both the stomach and the small intestine responded to low P:C with increased mass, and the small intestine exhibited increased diameter. This study demonstrates that mammalian gut morphology of lactating mice can respond to nutrient availability under conditions of constant energy intake. Further study is needed to determine if gut flexibility in response to decreasing P:C levels results in improved nitrogen assimilation efficiency and if this response is a general strategy of mammals or is limited to those with particular breeding strategies.

1976 ◽  
Vol 56 (3) ◽  
pp. 451-456 ◽  
Author(s):  
M. IVAN ◽  
J. P. BOWLAND

Four castrated pigs, each fitted with a re-entrant cannula in the terminal ileum, were used to study digestion in the small intestine. A nitrogen-free diet was used for the estimation of metabolic nitrogen and amino acids. Faba beans, as the sole source of dietary protein, were used raw or after autoclaving for 30 or 60 min. The four diets were fed to the pigs in a 4 × 4 latin square experiment. The pigs were fed each diet for 6 days prior to a 24-hr collection of total ileal contents. Autoclaving of faba beans had no significant effect on digestibility of dry matter, gross energy, nitrogen and individual amino acids except arginine, which was significantly increased. The intestinal uptake of arginine was the highest and of cystine the lowest in all faba bean diets. It was concluded that autoclaving faba beans had no beneficial effect on the digestion of nutrients in the small intestine of the pig.


2016 ◽  
Vol 94 (suppl_2) ◽  
pp. 90-90
Author(s):  
V. V. Almeida ◽  
A. J. C. NuÒez ◽  
P. V. A. Alvarenga ◽  
F. R. Castelini ◽  
Y. V. Silva-Guillen ◽  
...  

1982 ◽  
Vol 48 (3) ◽  
pp. 527-541 ◽  
Author(s):  
B. R. Cottrill ◽  
D. E. Beever ◽  
A. R. Austin ◽  
D. F. Osbourn

1. A total of six diets based on maize silage were formulated to examine the effect of protein- and non-protein-nitrogen, and energy supplementation on the flow of amino acids to the small intestine and the synthesis of microbial amino acids in the rumen of growing cattle. All diets contained 24 g totai nitrogen (N)/kg dry matter (DM), of which 550 g N/kg total N was supplied by either urea or fish meal. Four diets contained low levels of barley (estimated total dietary metabolizable energy content of 10·4 M J/kgDM) and urea-N and fish meal-N were supplied in the ratios 3:1, 1·4:1, 0·6:1 and 0·3:1. The other two diets contained between 300 and 400 g barley/kg total diet (11·3 MJ metabolizable energy/kg DM) and the urea-N to fish meal-N ratios were 3:1 and 0·3:1.2. On the four low-energy diets, fish meal inclusion tended to reduce the extent of organic matter (OM) digestion in the rumen but significantly increased duodenal amino acid supply (P< 0·05) in a quadratic manner. Microbial-N synthesis was increased by the two intermediate levels of fish meal supplementation but declined at the highest level of inclusion. With increasing levels of fish meal inclusion, a greater proportion of the dietary protein was found to escape rumen degradation and the apparent degradabilities of fish meal and maize-silage protein of all four diets were estimated to be 0·22 and 0·73 respectively.3. The substitution of barley for part of the maize silage enhanced duodenal supply of amino acids, irrespective of the form of the N supplement, and stimulated microbial amino acid synthesis. For all diets efficiency of microbial-N synthesis was found to vary between 22·5 and 46 g N/kg rumen-digested OM. Contrary to what was found for low-energy diets, the inclusion of fish meal tended to reduce the flow of dietary protein to the small intestine, but these differences were not statistically significant.4. The results appertaining to microbial synthesis, dietary protein degradabilities and duodenal amino acid flow for all diets are discussed in relation to the Agricultural Research Council (1980) proposals for the protein requirements of ruminants, and the production responses observed when similar diets were fed to growing cattle.


1999 ◽  
Vol 77 (11) ◽  
pp. 1822-1828 ◽  
Author(s):  
Andrew G McAdam ◽  
John S Millar

Growth and female maturation appear to be limited by the availability of dietary protein in natural populations of deer mice (Peromyscus maniculatus borealis) in the Kananaskis Valley, Alberta. We examined the effects of dietary protein content on nestling growth rates and sexual maturation of female deer mice in two laboratory experiments. In the first, mice whose mothers were fed a low-protein mixture of sunflower seeds and oats (14% protein) exhibited slow growth prior to weaning and those fed high-protein cat food (30% protein) postweaning showed compensatory growth. Preweaning but not postweaning diet quality affected the proportion of females who were sexually mature at 42 days of age. Therefore, while deficient nestling growth can be compensated for, the effects of a low-quality maternal diet during lactation may have lasting effects on the maturation of female offspring. In the second experiment, mice raised on isocaloric diets of 14, 20, and 30% protein did not differ in growth as nestlings or juveniles. Differences among the three diets in the proportion of mature females at 42 days did not correspond to dietary protein levels as predicted. Dietary protein content from 14 to 30% appear to be sufficient for juvenile mice raised in captivity.


1963 ◽  
Vol 41 (1) ◽  
pp. 149-160 ◽  
Author(s):  
John R. Beaton ◽  
T. Orme ◽  
A. Turner ◽  
J. Laufer

Male albino rats were fed isocaloric diets (5%, 20%, and 40% protein and 10% corn oil by weight) in restricted amounts (6 g/rat per day) at environmental temperatures of 22 °C and 2 °C. Measurements were made of urinary excretion of nitrogen, potassium, sodium, phosphorus, and creatinine, of blood levels of glucose, urea, amino nitrogen, packed cell volume, and serum total proteins and of body contents of protein, moisture, and total crude fatty acids. Metabolic effects of food restriction were readily apparent at 22 °C and the diet appeared to play a role in modifying some of these effects in approximate proportion to the dietary protein level. With superimposition of cold exposure, metabolic differences among groups were decreased in degree with some suggestive evidence of a beneficial effect of increased dietary protein level and of a deleterious effect of decreased dietary protein (high carbohydrate) under these conditions.


1998 ◽  
Vol 38 (2) ◽  
pp. 188-189
Author(s):  
M. A. Arnal ◽  
M. C. Valluy ◽  
P. Capitan ◽  
G. Bayle ◽  
P. Patureau Mirand

2007 ◽  
Vol 108 (1-3) ◽  
pp. 68-71
Author(s):  
E. Święch ◽  
M. Ceregrzyn ◽  
M. Taciak ◽  
W. Korczyński ◽  
L. Buraczewska

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