The effects of dietary nitrogen level on the collagen of rat skin

1978 ◽  
Vol 39 (1) ◽  
pp. 181-192 ◽  
Author(s):  
R. Dawson ◽  
G. Milne
Keyword(s):  
Crude Protein ◽  
Collagen Content ◽  
Male Rats ◽  
Control Group ◽  
Protein Nitrogen ◽  
Total N ◽  
Dietary Nitrogen ◽  
Low Protein ◽  
Skin Collagen ◽  
Commercial Stock

1. Male rats of approximately 120 g body-weight were maintained on a commercial stock diet containing 204 g crude protein (nitrogen × 6.25)/kg, a hydroxyproline-free high-protein (HP) diet containing 200 g casein/kg as the only protein source, or a low-protein (LP) diet containing 40 g casein/kg. After 6 weeks on these diets half of each group was transferred to a non-protein (NP) diet and the experiment was continued for a further 6 weeks. Animals from each group were killed at 4 d, 3 weeks and 6 weeks after the transfer to the NP diet.2. Throughout the experiment the urinary excretion of N, hydroxyproline and creatinine, and the content and solubility of the skin collagen were determined.3. When compared with a control group killed at the beginning of the experiment the rats maintained on the LP diet showed an increase of 25% in total N content of the skin but collagen content increased by 100%. Rats transferred from the HP to the NP diet lost both N and collagen from the skin, but those transferred from the LP to the NP diet lost N but increased the collagen content by 42%.4. Protein deprivation brought about marked changes in the solubility of the skin collagen, suggesting an increase in the rate of maturation of skin collagen.

UREA IN CORN SILAGE AS A SUPPLEMENTAL NITROGEN SOURCE FOR LACTATING COWS

1979 ◽  
Vol 59 (2) ◽  
pp. 403-410 ◽  
Author(s):  
F. D. SAUER ◽  
J. D. ERFLE ◽  
S. MAHADEVAN ◽  
J. R. LESSARD
Keyword(s):  
Crude Protein ◽  
Protein A ◽  
Daily Intake ◽  
Negative Control Group ◽  
Ammonia Nitrogen ◽  
Negative Control ◽  
Corn Silage ◽  
Feed Consumption ◽  
Control Group ◽  
Protein Nitrogen

Thirty-two Holstein cows in second or later lactation were randomly allocated to four treatment groups within 7 to 10 wk postpartum. Treatment rations were fed ad libitum as a complete feed and consisted of a negative control group which was fed a corn-oats-barley concentrate-corn silage mixture (40:60) with 9.4% crude protein, a urea silage group fed the same grain concentrate mixed with corn silage that contained 0.6% urea (on a fresh weight basis) to give 12.5% total ration crude protein, a group fed a soybean meal concentrate mixed with corn silage (12.7% crude protein), and a group fed a 3% urea corn-oats-barley concentrate mixed with corn silage to give a 12.8% total ration crude protein. The three groups supplemented with protein or non-protein nitrogen had greater weight gains, feed consumption, milk yields, milk persistencies, rumen ammonia nitrogen concentrations and greater rumen microbial cell populations than the negative control group. The results indicate that urea supports milk production when fed as part of a complete feed. Previous work showed that the same daily intake of urea when fed twice daily as part of the concentrate was ineffective.

scholarly journals Protein and energy relations in the broiler chicken

1990 ◽  
Vol 64 (2) ◽  
pp. 515-523 ◽  
Author(s):  
R. W. Rosebrough ◽  
A. D. Mitchell ◽  
M. F. Von Vleck ◽  
N. C. Steele
Keyword(s):  
Enzyme Activities ◽  
Crude Protein ◽  
Broiler Chicken ◽  
Glucose Production ◽  
Intact Protein ◽  
Hepatic Enzyme ◽  
Protein Nitrogen ◽  
Low Protein ◽  
Energy Relations

Chickens were fed on diets containing either 12.8 MJ, 150 g crude protein (nitrogen x 6.25)/kg or 12.8 MJ, 200 g crude protein/kg to determine differences in metabolism. The diet containing 12.8 MJ, 150 g crude protein/kg contained either 8 or 12 g lysine/kg. Treatment variables examined in vitro were lipogenesis, glucose production and hepatic enzyme activities to compare metabolism in chicks fed on a low-protein, lysine-supplemented diet and a diet formulated to contain the required amount of lysine from intact protein. Growth was similar in chicks fed on diets containing either 12.8 MJ, 154 g crude protein with 12 g lysine/kg or 12.8 MJ, 200 g crude protein/kg. Net glucose production was greater (p < 0.05) in liver explants from chickens fed on diets containing either 12.8 MJ, 154 g crude protein with 12 g lysine/kg or 12.8 MJ, 200 g crude protein/kg than in explants from chickens fed on 12.8 MJ, 150 g crude protein with 8 g lysine/kg. Pyruvate use for glucose production was greater (p < 0.05) in chickens fed on a diet containing 12.8 MJ, 150 g crude protein with 8 g lysine/kg. The findings from the present study suggest that crystalline and ‘natural’ lysine additions to chick diets may influence metabolism differently.

Studies on the growth and carcass composition in Daldale wether lambs. 2. The effect of dietary protein/energy ratio

1987 ◽  
Vol 38 (2) ◽  
pp. 417 ◽  
Author(s):  
o Soeparn ◽  
HL Davies
Keyword(s):  
Crude Protein ◽  
High Energy ◽  
Conversion Ratio ◽  
Carcass Composition ◽  
Feed Conversion Ratio ◽  
Energy Ratio ◽  
Feed Conversion ◽  
Total N ◽  
Low Protein ◽  
Protein Energy

Two experiments on the effect of dietary protein/energy ration on growth and carcass composition in Daldale wether lambs were carried out.In experiment 1, two groups of eight lambs in each group were fed in pens at a restricted intake (30 g air-dry feed per kg liveweight) either on a high protein/high energy diet (HP/HER) (20.7% crude protein) or on a low protein/high energy diet (LP/HER) (10.3% crude protein). The lambs were grown from 24.8 kg liveweight until slaughter at 37.5 kg. In experiment 2, two groups of eight lambs in each group were fed in pens a pelleted diet ad libitum, either on a high protein/high energy ration (HP/HEA) or on a low protein/high energy ratio (LP/HEA). The lambs were grown from 22.0 � 0.8 kg liveweight until slaughter at 37.5 kg. Those lambs on the HP/HE diets grew significantly faster than their counterparts on the LP/HE diets. Accordingly, animals given the HP/HE diets showed a superior feed conversion ratio than animals given the LP/HE diets. Despite these differences, there was no overall differences between treatments either at restricted or at ad libitum intake in the weight of carcass, the dressing percentage, and in the chemical composition of the carcass. In general, the carcasses produced contained a similar amount of fat (30.6%-32.9% of carcass). It was concluded that varying protein to energy ratio in diets affected liveweight gain and feed conversion ratio, but did not affect carcass composition.An experiment was conducted on the diets to investigate some aspects of digestion in the stomach and intestines at the two levels of crude protein.Dietary crude protein level had little effect upon the apparent digestibility of organic matter (OM) and neutral detergent fibre in the whole tract, the proportion of NDF digested in the stomach, the total volatile fatty acid concentration (VFA) in the rumen and the proportions of individual VFA.The flow of rates of digesta from the rumen and abomasum were also similar for the two diets. However, the proportion of the total digestion of OM occurring in the stomach decreased, while the flow of total N and crude protein (CP) (total N minus ammonia N x 6.25) to the intestines and the amounts of N and CP digested therein was higher on the HP diet.The data from the digestion experiment showed that the amount of digestible CP in the intestines per unit of digestible OM intake did not affect carcass composition.

Preparation and Evaluation of the Curative Effect of Blue Shark (Prionace glauca) Skin Collagen Composite Gel in a Rat Oral Ulcers Model

2021 ◽  
Vol 11 (10) ◽  
pp. 1924-1931
Author(s):  
Meineng Huang ◽  
Sheng Jiang ◽  
Tong Chen ◽  
Xu Han ◽  
Xinyu Yang ◽  
...  
Keyword(s):  
Male Rats ◽  
Control Group ◽  
High Dose ◽  
Dependent Manner ◽  
Curative Effect ◽  
Blue Shark ◽  
Shark Skin ◽  
Oral Ulcers ◽  
Composite Gel ◽  
Skin Collagen

Objective: To evaluate the curative effect of blue shark skin collagen composite gel on oral mucosal ulcer using the rat oral ulcers model stimulated by glacial acetic acid. Methods: Collagen from blue shark skin was isolated and physiochemically characterized by FTIR, SDS-PAGE and scanning electron microscopy (SEM). Seventy standard male rats were divided into seven groups. The surface and the area of the ulcer were observed and calculated daily. After 12 days of administration, rats in the model group and the control group were killed and the ulcer and surrounding tissues were cut to pieces about one mm3 size. The specimens were stained with 10% formalin solution, paraffinembedded sections, HE staining and light microscope were used to observe the histopathological changes in ulcer tissues. Results: The high-dose group had the fastest ulcer healing effects after 12 days of treatment with blue shark skin collagen composite gel. The composite gel was found to significantly accelerate the healing of oral ulcers in a dose-dependent manner. Conclusion: The blue shark skin collagen composite gel in this study may be a good biomedical material candidate for the treatment of oral ulcers in the near future. Potential of other marine fish skin collagen comples on healing oral ulcers should be also considered.

Effect of 75% replacement of dietary N by urea and ammonium sulphate on the composition and properties of sheep's milk

1973 ◽  
Vol 40 (3) ◽  
pp. 323-328
Author(s):  
G. Tanev
Keyword(s):  
Amino Acids ◽  
Ammonium Sulphate ◽  
Milk Yield ◽  
Statistical Significance ◽  
Essential Amino Acids ◽  
Control Group ◽  
Protein Nitrogen ◽  
Milk Clotting ◽  
Dietary Nitrogen ◽  
Control Milk

SummaryA 23-week trial was conducted using 4 groups each of 6 ewes to study the effects on milk yield and composition of substituting non-protein nitrogen (NPN) for 75 % of the dietary nitrogen. The control group received a winter ration which included silage followed by a summer ration containing lucerne. The test groups received substitutes of urea, ammonium sulphate, or urea+(NH4)2SO4. The milk yield of the test groups was lower (P< 0·01) than that of the control group. Depression of the fat content of the milk reached statistical significance (P< 0·01) in the groups receiving (NH4)2SO4and urea+(NH4)2SO4. In comparison with the control group, the protein content of the milk was greater in the group receiving urea and smaller in the other 2 test groups. The milks of the test groups had lower amounts of essential amino acids in the free state and higher amounts of non-essential amino acids than did the control milk. Milk-clotting time was increased in the test groups; the increase was greatest (P< 0·01) for the group receiving (NH4)2SO4and least (P< 0·05) for that receiving urea.

scholarly journals Artificial rearing of pigs

1980 ◽  
Vol 44 (2) ◽  
pp. 171-178 ◽  
Author(s):  
M. J. Newport
Keyword(s):  
Small Intestine ◽  
Crude Protein ◽  
Skim Milk ◽  
Live Weight ◽  
Proximal Region ◽  
Soya Bean ◽  
Protein Digestion ◽  
Protein Nitrogen ◽  
Total N ◽  
Bean Protein

1. Pigs (twenty-one/diet) were weaned at 2 d of age and given liquid diets (200 g dry matter/l) at hourly intervals during a 26 d experiment. The pigs were fed on a scale based on live weight. The diets contained (g/kg DM): dried skim-milk 730 (diet A), dried whey 508·5, isolated soya-bean protein 218, DL-methionine 3·5 (diet S), and soya-bean oil 270 (diets A and S). Diet T contained equal proportions of diets A and S. Soya-bean supplied 0, 370 and 740 g crude protein (nitrogen × 6·25)/kg total crude protein in diets A, T and S respectively.2. Performance was similar for both diets A and T (P > 0·05). Pigs given diet S scoured severely, and fourteen died. The survivors grew very poorly. Nitrogen retention (g/d per kg live weight) was greater for diet A compared with diet T (P < 0·0r), and decreased with age (P < 0·01).3. Protein digestion was examined in the pigs killed at 28 d of age. The amount of soya-bean protein in the diet did not affect the amount of digesta in the stomach, but soya-bean protein decreased the pH, DM and total N content of the digesta (P < 0.01), and increased, though not significantly (P < 0·05), pepsin activity in the digesta and stomach tissue. Acid secretion into the stomach appeared to be enhanced in pigs given a diet containing soya-bean protein.4. Amounts of trypsin, chymotrypsin, total N and proportion of non-protein-N in the digesta from the small intestine were similar for both diets A and T. The amounts for both diets were greater in the distal compared with the proximal region of the small intestine (P < 0·05). Chymotrypsin activity in the pancreas was reduced (P < 0·05) in pigs given diet T, although this reduction did not seem to impair digestion in 28-d-old pigs. Trypsin activity in the pancreas was similar for both diets A and T.5. It seems likely that the neonatal pig does not have the digestive capacity to tolerate the large daily intakes of soya-bean protein when dried skim-milk was totally replaced in the diet (diet S). When half the dried skim-milk was replaced, protein digestion was not impaired in 28-d-old pigs.

scholarly journals The efficacy of protein supplementation in overcoming urea toxicity in sheep

1976 ◽  
Vol 35 (1) ◽  
pp. 47-54 ◽  
Author(s):  
E. Payne ◽  
L. Laws
Keyword(s):  
Crude Protein ◽  
Protein Supplementation ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Synthetase Activity ◽  
Argininosuccinate Synthetase ◽  
Argininosuccinate Lyase ◽  
Short Term ◽  
Protein Nitrogen ◽  
Low Protein

1. In the first experiment sheep taken from pasture were given a low-protein diet for 6 weeks in individual pens. Then, for 1 week, groups were given a supplement of lucerne chaff, safflower meal or lucerne chaff plus safflower meal. In the second experiment eighteen sheep maintained on lucerne chaff rather than pasture were then depleted of protein to a greater extent by feeding on a restricted low-protein diet. Six of the sheep received a supplement of molasses throughout the period of protein depletion while six of the sheep on the basal ration received a supplement of safflower meal after 6 weeks on the low-protein diet.2. The urea tolerance of the sheep, as indicated by blood ammonia levels after oral dosing with aqueous solutions of urea, was determined after the period of supplementation. ‘Arginine synthetase’ activity (combined activities of argininosuccinate synthetase (EC 6.3.4.5) and argininosuccinate lyase (EC 4.3.2.1)) was determined in liver samples obtained by biopsy at various intervals during the experiment.3. Supplementation for 7 d with 73 g crude protein (nitrogen × 6.25)/d increased the tolerance to urea, as indicated by reduced blood NH3 levels, and also increased ‘arginine synthetase’ activity.4. Giving supplements of molasses delayed the onset of urea toxicity but not the extent of toxicity.5. It is suggested that short-term feeding of protein concentrates to sheep before giving urea supplements can increase their tolerance to urea.

The effects of dietary urea and ammonium sulphate on the yield and composition of sheep milk

1971 ◽  
Vol 38 (3) ◽  
pp. 309-314 ◽  
Author(s):  
G. Tanev
Keyword(s):  
Ammonium Sulphate ◽  
Milk Fat ◽  
Milk Protein ◽  
Control Group ◽  
Fat Percentage ◽  
Control Groups ◽  
Protein Nitrogen ◽  
Dietary Nitrogen ◽  
Sheep Milk ◽  
Urea Group

SummaryAn experiment lasting 4 years has been carried out with 4 groups (3 test and a control) of 10 sheep. Non-protein nitrogen (NPN) (as urea, ammonium sulphate or a mixture of the two) replaced 25% of the dietary nitrogen in the first 2 years and 50% in the second 2 years. The yields of milk, protein and fat were generally depressed in the test groups but not all of the differences reached significance. In the group receiving ammonium sulphate, the milk fat percentage was higher than in the control group in all years and the protein percentage was higher in the last 2 years. Contrary to results elsewhere, the yield of lactose was depressed in all test groups. In the urea group, the content of minerals and of calcium in the milk was significantly less than in the control groups. The total amount of NPN and its components (ammonia, urea and creatine) in milk were not affected by the substitution of NPN in the rations.

scholarly journals Effects of Feeding Low Protein Diets on Serum and Faeces Parameters in Weaned Piglets

2019 ◽  
Vol 63 (2) ◽  
pp. 37-44 ◽  
Author(s):  
Ľ. Bindas ◽  
L. Bujňák ◽  
I. Maskaľová ◽  
T. Mihok ◽  
P. Timkovičová Lacková ◽  
...  
Keyword(s):  
Body Weight ◽  
Biochemical Parameters ◽  
Crude Protein ◽  
Process Analysis ◽  
Average Concentration ◽  
Nitrogen Excretion ◽  
Control Group ◽  
Experimental Diet ◽  
Low Protein ◽  
Experimental Group

Abstract This study was conducted to determine the effects of a low-protein diet supplemented with synthetic amino acids on the biochemical parameters in the blood serum, the indicators of fermentation processes, and nitrogen excretion in 12 crossbred piglets. The piglets (weaned at 28 days of age) were divided into two groups with 6 piglets each. The control group had an initial average body weight of 8.8 ± 0.6 kg and the experimental group with an average initial body weight of 8.6 ± 0.7 kg. The control diet contained 210.8 g.kg−1 crude protein and the experimental diet contained 186.4 g.kg−1. The experimental diet was supplemented with lysine, methionine and threonine to achieve a more ideal amino acid pattern. The blood collections from the sinus ophthalmicus for the determination of the biochemical parameters were performed 4 times at weekly intervals in the control and experimental groups 4—5 hours after feeding. The faeces were taken from the rectum at the end of the study period. The decrease in the dietary crude protein content of the experimental group was manifested by a significant decrease of the blood urea level (2.61 mmol.l−1 average concentration) compared to the control groups (4.21 mmol.l−1 average concentration) (P < 0.001). The other serum component concentrations (total protein, albumin, glucose, cholesterol, total lipids and selected enzymes) showed no significant statistical changes between the control and experimental groups. The results of the fermentation process analysis indicated that the butyrate concentration decreased (P = 0.0017) and the pH increased (P = 0.0180) in the experimental group compared to the control group. The levels of crude protein and ammonia in the faeces of experimental animals were significantly lower (P < 0.001) in comparison with those in the control animals.

Effects of various low protein diets on the distribution of ruminal nitrogen and on the nitrogen required for maintenance of African sheep

1964 ◽  
Vol 6 (3) ◽  
pp. 345-355 ◽  
Author(s):  
R. C. Elliott ◽  
J. H. Topps
Keyword(s):  
Nitrogen Balance ◽  
Crude Protein ◽  
Diurnal Changes ◽  
Protein Requirement ◽  
N Content ◽  
Total N ◽  
Protein Levels ◽  
Low Protein ◽  
Voluntary Intake ◽  
Protein Diets

1. Four groups of diets made up with differing proportions of roughage and concentrates were each given ad lib. to 4 Blackhead Persian wether sheep. The four diets in each group contained approximately 4, 6, 8 and 10% crude protein. The distribution of nitrogen in the rumen at various times after feeding and the nitrogen balance of the sheep were measured.2. Total N and ammoniacal N content of the rumen liquor were both closely related to the N content of the diet. Diurnal changes in the concentrations of these components were most marked with the diets which had the highest concentration of protein, and consisted of rapid increases after feeding followed by declines later in the day. Each group of diets produced characteristic patterns of change and these changes appeared to be related to the proportion of concentrates in the diet.3. With sheep given poorly digested veldt grass, very low in protein, levels of ammonia in the rumen were unusually high. This effect was thought t o be due to the recycling of urea and its conversion to ammonia in the rumen.4. The amounts of digestible N required by the sheep for N equilibrium differed between groups of diets. High apparent requirements of digestible N were associated with relatively high ruminal ammonia levels, but the latter were not considered to be the cause of high requirements.5. On all groups of diets, sheep were in N equilibrium only when their intakes of total digestible nutrients (TDN) were adequate for maintenance. This indicates that the protein requirement for maintenance was a function of protein content and TDN content of the diet and the effect of these factors on voluntary intake of TDN.

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