scholarly journals Selection for growth on normal and reduced protein diets in mice: I. Direct and correlated responses for growth

1987 ◽  
Vol 50 (1) ◽  
pp. 7-15 ◽  
Author(s):  
B. Vivi Hunnicke Nielsen ◽  
Søren Andersen
Keyword(s):  
Protein Level ◽  
Protein Diet ◽  
Correlated Response ◽  
Family Selection ◽  
Direct Response ◽  
Protein Levels ◽  
Selection Environment ◽  
Normal Protein Diet ◽  
Selection For ◽  
Protein Diets

SummaryMice were selected for growth from 3 to 9 weeks of age on a normal protein diet (N) containing 19·3% protein and a reduced protein diet (R) containing 5·1% protein. On each diet there were 3 high (H), 3 low (L) and 3 unselected control (C) lines. After 6 generations of selection, half of the mice in each line were tested on each diet. Responses were obtained when selecting for both increased and decreased growth on both diets. The realized heritabilities from within-family selection were 33 and 26% for the divergences on the normal and reduced protein diets, respectively. Consistent genotype-environment interactions were found when all lines were tested on both diets in generation 7. Performance on each protein level was best improved by selection on that protein level. Further, the correlated response was significantly less than the direct response when selecting on both diets. The estimates of the genetic correlation between growth on the two protein levels were low, rN = 0·16 from selection on the normal protein diet and rR = 0·51 from selection on the reduced protein diet. Selection resulted in a change in environmental sensitivity in the lines, dependent on the diet and direction of selection. The average of the divergences on the two diets was not dependent on the selection environment.

Selection for components of efficient lean growth rate in pigs 2. Selection pressure applied and direct responses in a Landrace herd

1994 ◽  
Vol 59 (2) ◽  
pp. 263-269 ◽  
Author(s):  
N. D. Cameron ◽  
M. K. Curran
Keyword(s):  
Growth Rate ◽  
Genetic Correlations ◽  
Correlated Response ◽  
Selection Line ◽  
Control Line ◽  
Direct Response ◽  
Lean Growth ◽  
Ad Libitum ◽  
Selection For ◽  
Ad Libitum Feeding

AbstractResponses to divergent selection for lean growth rate with ad-libitum feeding (LGA), for lean food conversion (LFC) and for daily food intake (DFI) in Landrace pigs were studied. Selection was practised for four generations with a generation interval ofl year. A total of 2642 pigs were performance tested in the high, low and control lines, with an average of 37 boars and 39 gilts performance tested per selection line in each generation. The average within-line inbreeding coefficient at generation four was equal to 0·04. There was one control line for the DFI and LFC selection groups and another control line for the LGA selection group. Animals were performance tested in individual pens with mean starting and finishing weights of 30 kg and 85 kg respectively with ad-libitum feeding. The selection criteria had phenotypic s.d. of 32, 29 and 274 units, for LGA, LFC and DFI, respectively, and results are presented in phenotypic s.d.Cumulative selection differentials (CSD) were 5·1, 4·5 and 5·5 phenotypic s.d. for LGA, LFC and DFI, respectively. Direct responses to selection were 1·4,1·1 and 0·9 (s.e. 0·20) for LGA, LFC and DFI. In each of the three selection groups, the CSD and direct responses to selection were symmetric about the control lines. The correlated response in LFC (1·1, s.e. 0·19) with selection on LGA was equal to the direct response in LFC. In contrast, the direct response in LGA was greater than the correlated response (0·7, s.e. 0·18) with selection on LFC. There was a negative correlated response in DFI (-0·6, s.e. 0·18) with selection on LFC, but the response with selection on LGA was not significant (0·2, s.e. 0·16).Heritabilities for LGA, LFC and DFI ivere 0·25, 0·25 and 0·18 (s.e. 0·03), when estimated by residual maximum likelihood, with common environmental effects of 0·12 (s.e. 0·02). Genetic correlations for LFC with LGA and DFI were respectively positive (0·87, s.e. 0·02) and negative (-0·36, s.e. 0·09), while the genetic correlation between DFI and LGA was not statistically different from zero, 0·13 (s.e. 0·10). Selection on components of efficient lean growth has identified LGA as an effective selection objective for improving both LGA and LFC, without a reduction in DFI.

The performance of calves given concentrate diets treated with formaldehyde

1973 ◽  
Vol 24 (4) ◽  
pp. 613 ◽  
Author(s):  
GJ Faichney ◽  
HL Davies
Keyword(s):  
Food Consumption ◽  
Protein Level ◽  
Rumen Fluid ◽  
Amino Nitrogen ◽  
Peanut Meal ◽  
Plasma Urea ◽  
Protein Levels ◽  
Low Protein ◽  
Formaldehyde Treatment ◽  
Protein Diets

Five groups of Friesian bull calves were given concentrate diets containing 70 % barley in which low (12 %), medium (15 %), and high (19%) protein levels were obtained by varying the amount of peanut meal included. The effects of protein level and of formaldehyde treatment of the complete diet at the low and medium protein levels were studied in terms of liveweight gain, voluntary food consumption, digestibility of the diet, ammonia nitrogen in rumen fluid, and urea and a-amino nitrogen in blood plasma. Observations were begun when the calves reached 70 kg liveweight and continued until they reached 130 kg liveweight. The calves given the low protein diets grew more slowly than those given the higher protein diets. The calves given the high protein diet grew no better than those given the medium protein diets. Formaldehyde treatment was associated with an increase in the rate of liveweight gain of 9% (P = 0.11) at the low protein level but had practically no effect at the medium protein level. The treatment did not adversely affect voluntary food consumption but was associated with decreases in the digestibility of nitrogen and in rumen ammonia levels and small increases in plasma urea levels.

EFFECTS OF GRADED DIETARY PROTEIN LEVELS ON UREA RECYCLING IN THE PIG

1982 ◽  
Vol 62 (4) ◽  
pp. 1193-1197 ◽  
Author(s):  
P. A. THACKER ◽  
J. P. BOWLAND ◽  
L. P. MILLIGAN ◽  
E. WELTZIEN
Keyword(s):  
Dietary Protein ◽  
Protein Diet ◽  
Nitrogen Excretion ◽  
Entry Rate ◽  
Protein Nitrogen ◽  
Protein Levels ◽  
Low Protein ◽  
Key Words Pig ◽  
Urea Recycling ◽  
Protein Diets

The kinetics of urea recycling were determined in six female crossbred pigs utilizing a radioisotope dilution technique. The experimental animals were fed three times daily 500 g of a corn-soybean meal diet formulated to contain 8.4, 15.8 or 24.7% crude protein. Nitrogen digestibility, urinary nitrogen excretion, total nitrogen excretion and retained nitrogen were highest on the 24.7% protein diet and decreased with decreasing dietary protein. Urea pool size, entry rate and excretion rate were also highest on the 24.7% protein diet and decreased with decreasing protein intake. Expressed as a percentage of the total entry rate, a significantly higher percentage of urea was recycled in pigs fed the low protein diets compared with those fed a higher protein diet. Key words: Pig, urea, recycling, kinetics, protein

scholarly journals Effects of Dietary Protein Levels on Bamei Pig Intestinal Colony Compositional Traits

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Dong Wang ◽  
Guoshun Chen ◽  
Lili Song ◽  
Mingjie Chai ◽  
Yongfeng Wang ◽  
...  
Keyword(s):  
Dietary Protein ◽  
Protein Level ◽  
Crude Protein ◽  
Microbial Flora ◽  
Protein Levels ◽  
Low Protein ◽  
Dietary Crude Protein ◽  
Protein Diets ◽  
Crude Protein Level ◽  
Microbial Diversities

Diets containing different crude protein levels (16%, 14%, and 12%) were created to feed Bamei pigs in order to study the effect of these compositions on intestinal colonies. Therefore, 27 healthy Bamei pigs of similar weight ( 20.99   kg ± 0.16   kg ) were selected and randomly divided into three groups for microbial diversity analysis. The results of this study show that microbial diversities and abundances in Bamei pig jejunum and caecum samples after feeding with different dietary protein levels were significantly different. Dietary crude protein level exerted no significant effect on the Shannon index for cecum microbes in these pigs, while Simpson, ACE, and Chao1 indices for group I were all significantly higher than those of either the control group or group II ( P < 0.05 ). Indeed, data show that microbial diversities and abundances in the 14% protein level group were higher than those in either the 16% or 12% groups. Dominant bacteria present in jejunum and cecum samples given low-protein diets were members of the phyla Firmicutes and Bacteroidetes. Data show that as dietary crude protein level decreases, representatives of the microbial flora genus Lactobacillus in jejunum and cecum samples gradually increases. Values for the KEGG functional prediction of microbial flora at different dietary protein levels also show that genes of jejunum and cecum microorganisms were mainly enriched in the “metabolism” pathway and indicate that low protein diets increase intestinal metabolic activity. Therefore, we recommend that Bamei pig dietary protein levels are reduced 2% from their existing level of 16% crude protein. We also suggest that essential synthetic amino acids (AA) are added to optimize this ideal protein model as this will increase intestinal flora diversity in these pigs and enhance health. These changes will have a positive effect in promoting the healthy growth of Bamei pigs.

Digestion by sheep of concentrate diets containing formaldehyde-treated peanut meal

1972 ◽  
Vol 23 (5) ◽  
pp. 859 ◽  
Author(s):  
GJ Faichney
Keyword(s):  
Organic Matter ◽  
Peanut Meal ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Plasma Urea ◽  
Protein Levels ◽  
Low Protein ◽  
Formaldehyde Treatment ◽  
Protein Diets

The effect of formaldehyde treatment of peanut meal on the digestion of barley-peanut meal diets was studied in fistulated crossbred sheep at two peanut meal and therefore dietary protein levels. There were no differences either between protein levels or due to treatment in the overall digestion of organic matter, but more of this digestion took place in the stomach when the low protein diets were given. Dietary starch was completely digested. There was no effect of protein level or of formaldehyde treatment on the partition of starch digestion between the stomach and the intestines. About 10% of the dietary nitrogen disappeared from the stomach when the high protein diet containing untreated peanut meal was given; treatment resulted in a small net gain of nitrogen in the stomach. There was a net gain of nitrogen in the stomach when the low protein diets were given, the gain tending to be greater when the peanut meal was treated. When the meal was treated, there was a small but not significant increase (c. 2%) for the low protein diet and a substantial increase (c. 31 %) for the high protein diet in the amount of crude protein digested in the intestines per unit of digestible organic matter intake. Changes observed in the composition and flow of digesta and in plasma urea and cc-amino nitrogen levels are discussed in relation to the digestion of organic matter and protein.

Formaldehyde treatment of concentrate diets for sheep. III.* Absorption of amino acids from the small intestine

1979 ◽  
Vol 30 (6) ◽  
pp. 1163 ◽  
Author(s):  
GJ Faichney ◽  
GA White
Keyword(s):  
Amino Acids ◽  
Small Intestine ◽  
Protein Level ◽  
High Protein Diet ◽  
Protein Diet ◽  
Protein Levels ◽  
Formaldehyde Treatment ◽  
Lower Protein ◽  
True Protein ◽  
The Individual

The effects of formaldehyde treatment of barley/soybean meal diets on the flow of amino acids to the small intestine, their release and absorption there, and their levels in jugular plasma were studied at four protein levels in fistulated crossbred sheep. There were substantial losses of amino acids during passage through the stomach at the highest protein level which were prevented by formaldehyde treatment; the net gains of amino acids observed with the lower protein diets were enhanced by treatment. There were no statistically significant effects of treatment on the proportions of the individual amino acids apparently absorbed in the small intestine, but a tendency for the values to decrease for the highest protein diet suggested that this diet was overtreated. This was confirmed by calculation of the true digestibilities in the small intestine: the true digestibility of true protein in the small intestine was 0.74 for the treated high protein diet and 0.81 for all the other diets. Of the individual amino acids, only lysine was adversely affected by treatment; however, despite reduced intakes, the net absorption of lysine was equal to or greater than that achieved with the untreated diets at all but the lowest protein level. Formaldehyde treatment was associated with substantial increases in the concentration of ε-N-methyl-lysine in plasma. As the amount of protein absorbed from the small intestine increased to about 110 g/day, the concentrations in plasma of the amino acids normally present in protein declined to a minimum or remained steady; thereafter, except for lysine, the concentrations increased. ____________________ *Part II, Aust. J. Agric. Res. 28: 1069 (1977).

scholarly journals Responses to divergent selection for plasma concentrations of insulin-like growth factor-1 in mice

1989 ◽  
Vol 53 (3) ◽  
pp. 187-192 ◽  
Author(s):  
H. T. Blair ◽  
S. N. McCutcheon ◽  
D. D. S. Mackenzie ◽  
P. D. Gluckman ◽  
J. E. Ormsby ◽  
...  
Keyword(s):  
Growth Factor ◽  
Plasma Concentrations ◽  
Selection Criterion ◽  
Divergent Selection ◽  
Correlated Response ◽  
Insulin Like Growth Factor ◽  
Family Selection ◽  
Selection For ◽  
High Control ◽  
And Control

SummaryA divergent selection experiment with mice, using plasma concentrations of insulin-like growth factor-1 (IGF-1) at 42 days of age as the selection criterion, was undertaken for 7 generations. Lines were not replicated. To obtain sufficient plasma for the IGF-1 assay, blood from four individuals was volumetrically bulked to obtain a litter mean IGF-1 concentration. This necessitated the use of between family selection. Although inbreeding accumulated in a linear fashion in each of the high, control and low lines, the rates were different for each line (3·6, 1·6 and 5·3% per generation for the high, control and low lines, respectively). As a consequence, the effects of selection and inbreeding are confounded in this experiment. Divergence between the high and low lines in plasma concentrations of IGF-1 continued steadily until generation 5. In generations 6 and 7, there was a reduced degree of divergence and this contributed towards the low realized heritability value of 0.15 ± 0.12. Six-week liveweight showed a steady positive correlated response to selection for or against plasma concentrations of IGF-1 until generation 4 (high-low difference = 1·7 g = 12%). In generation 5, a substantial drop in 6-week liveweight in the low line relative to both the high and control lines occurred (high-low difference, 3·9; g, 25%). This difference was maintained until generation 7.This experiment suggests that genetic variation exists at 6 weeks of age in plasma concentrations of IGF-1 in mice. Furthermore, genetic covariation between plasma IGF-1 concentrations and liveweight at 6 weeks of age is likely to be positive. Further experiments have been initiated to examine these theories.

scholarly journals Low Crude Protein Diet Affects the Intestinal Microbiome and Metabolome Differently in Barrows and Gilts

2021 ◽  
Vol 12 ◽  
Author(s):  
Xin Tao ◽  
Bo Deng ◽  
Qizhi Yuan ◽  
Xiaoming Men ◽  
Jie Wu ◽  
...  
Keyword(s):  
Intestinal Microbiota ◽  
Dietary Protein ◽  
Crude Protein ◽  
High Protein Diet ◽  
Stage I ◽  
Protein Diet ◽  
Stage Ii ◽  
Protein Levels ◽  
Low Protein ◽  
Protein Diets

Low protein diets are commonly used in the growing-finishing pig stage of swine production; however, the effects of low dietary protein on the intestinal microbiota and their metabolites, and their association with pig sex, remain unclear. The present study aimed to assess the impact of a low crude protein (CP) diet on the gut microbiome and metabolome, and to reveal any relationship with sex. Barrows and gilts (both n = 24; initial body = 68.33 ± 0.881 kg) were allocated into two treatments according to sex. The four groups comprised two pairs of gilts and barrows fed with a high protein diet (CP 17% at stage I; CP 13% at stage II) and a low protein diet (CP 15% at stage I; CP 11% at stage II), respectively, for 51 d. Eight pigs in each group were slaughtered and their colon contents were collected. Intestinal microbiota and their metabolites were assessed using 16S rRNA sequencing and tandem mass spectrometry, respectively. The low protein diet increased intestinal microbiota species and richness indices (P &lt; 0.05) in both sexes compared with the high protein diet. The sample Shannon index was different (P &lt; 0.01) between barrows and gilts. At the genus level, unidentified Clostridiales (P &lt; 0.05), Neisseria (P &lt; 0.05), unidentified Prevotellaceae (P &lt; 0.01) and Gracilibacteria (P &lt; 0.05) were affected by dietary protein levels. The relative abundance of unidentified Prevotellaceae was different (P &lt; 0.01) between barrows and gilts. The influence of dietary protein levels on Neisseria (P &lt; 0.05), unidentified Prevotellaceae (P &lt; 0.01) and Gracilibacteria (P &lt; 0.05) were associated with sex. Metabolomic profiling indicated that dietary protein levels mainly affected intestinal metabolites in gilts rather than barrows. A total of 434 differentially abundant metabolites were identified in gilts fed the two protein diets. Correlation analysis identified that six differentially abundant microbiota communities were closely associated with twelve metabolites that were enriched for amino acids, inflammation, immune, and disease-related metabolic pathways. These results suggested that decreasing dietary protein contents changed the intestinal microbiota in growing-finishing pigs, which selectively affected the intestinal metabolite profiles in gilts.

scholarly journals Effect of varying protein levels on growth and digestive enzyme activities of pengba Osteobrama belangeri (Valenciennes, 1844)

2017 ◽  
Vol 64 ◽  
Author(s):  
R. Ramesh ◽  
K. Dube ◽  
A. K. Reddy ◽  
P. V. Rangacharyulu ◽  
G. Venkateshwarlu ◽  
...  
Keyword(s):  
Dietary Protein ◽  
Protein Level ◽  
Enzyme Activities ◽  
Polynomial Regression ◽  
Proteolytic Enzymes ◽  
Digestive Enzyme ◽  
Protein Diet ◽  
Protein Levels ◽  
Significant Difference ◽  
Digestive Enzyme Activities

Pengba, Osteobrama belangeri (Valenciennes, 1844) is considered as one of the candidate species for diversification of aquaculture. However, only scanty information is available on its nutrient requirements. Hence, the present study was conducted on growth and digestive enzyme activities of pengba fry in response to different dietary protein levels. Six semi-purified isocaloric diets were formulated with different levels of protein at 5% increments (25, 30, 35, 40, 45 and 50%) and fed to different groups of pengba fry for a period of 60 days. Survival of fish was significantly influenced by different protein levels (p<0.05). The highest weight gain% and specific growth rate (4.17% day-1) was obtained at 45% protein level which thereafter declined. The best feed conversion ratio (1.46) was observed at 45% protein level and the highest protein efficiency ratio (2.14) was obtained at 25% protein levelwith significant difference (p<0.05). The crude protein content of fish was significantly affected by dietary protein levels (p<0.05) and highest was recorded at 45% protein diet. Moisture, ether extract and ash content did not show significant (p>0.05) variation among dietary treatments. The activity of proteolytic enzymes (proteases, typsin and chymotrypsin) and acid phosphatase were signicantly (p<0.05) enhanced by dietary protein levels up to 45%, which were found to decline thereafter. Amylase activity was significantly decreased as protein levels increased in the diet. Lipase and alkaline phosphatase activities were not influenced by dietary protein levels. In the present study, penbga fry fed with 45% protein diet, showed the best growth performance and highest digestive enzyme activities. The activity of digestive enzymes in the gut clearly demonstrated that the proteolytic enzymes are activated in response to dietary protein utilisation and also revealed that pengba fry may require high protein (45%) diet for better growth and survival. Second order polynomial regression analysis revealed that the maximum protein requirement of pengba fry was 45.1% (r2 = 0.90). The findings of the study is expected to have significant implications for feed development for pengba aquaculture.

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