scholarly journals Effect of an adequate-protein diet after a low-protein diet on protein catabolism in growing rats

1973 ◽  
Vol 29 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Yoshimitsu Horie ◽  
Kiyoshi Ashida

1. Metabolic alterations related to protein catabolism were studied in rats in transitional states induced by changing from a low-protein (LP) (50 g casein/kg) diet to a high-protein (HP) (250 g casein/kg) diet.2. Twenty-four hours after the diet was changed, the rats showed a more rapid increase in live-weight gain than controls that had been fed on the HP diet throughout. On the 5th day after the diet change, their increase in body-weight had returned almost to the control rate. Food and therefore nitrogen intakes on the 1st and 5th days after the change in diet were the same as those of the controls. It seems likely therefore that the initial high rate of live-weight gain is an indication of a metabolic adaptation which occurred on the LP diet and which did not fully return to normal until the 5th day after the change of diet.3. N balance was higher 24 h after the change in diet than in the controls, owing to a reduction in total urinary N and in urea excretion, but when measured on the 5th day it was similar in both groups.4. Carcass N determination showed that, after 7 d on the LP diet total-, trichloroacetic acid (TCA)-soluble- and TCA-insoluble-N contents (in terms of mg/g rat) were all slightly lower than control values but they had almost returned to normal 5 d after the diet change. There was a significant increase in the TCA-soluble-N content after 24 h on the HP diet to a value greater than the control value.5. Proteolysis was measured in vitro by incubation of liver slices and diaphragms under anaerobic conditions. With liver slices it was significantly lower 24 h after the diet change than in control rats. On the 5th day it was significantly higher than 24 h after the diet change but had not quite reached the control level. In the diaphragm, proteolysis was also lower 1 d after the diet change, and had not increased at all by the 5th day.6. Ureogenesis in the liver was reduced significantly 24 h after the diet change and it had almost returned to the control level on the 5th day. On the other hand, arginase (L-arginine amidinohydrolase; EC 3·5·3·1) activity was significantly lower 24 h after the diet change and did return completely to the control level on the 5th day.7. These results show that the initial increased N balance and reduced N excretion were due to enzymic adaptation to the LP diet, the reduced N excretion being attributable to reduction in hepatic urea production.

1967 ◽  
Vol 9 (1) ◽  
pp. 23-33 ◽  
Author(s):  
I. J. F. Stobo ◽  
J. H. B. Roy ◽  
Helen J. Gaston

1. Eighty-four Friesian heifer calves were used in two experiments (Experiments 4 and 5) to study the protein requirement of the ruminant calf to 12 weeks of age. The calves were weaned at 5 weeks of age and given a concentrate containing one of several protein levels, together with hay and water.2. In Experiment 4, the effect of changing the protein content of the concentrates at 8 weeks of age under ad libitum feeding conditions was studied. A concentrate containing 20·6% crude protein (air-dry basis) tended to promote more rapid weight gains in calves to 8 weeks than a similar concentrate with 12·1% crude protein. Following the change in diet at 8 weeks, both groups of calves given the low-protein diet gained weight at similar rates in the period 8–12 weeks, irrespective of the protein level to 8 weeks. During the period 8–12 weeks calves given the high-protein diet, after receiving a low-protein diet to 8 weeks, tended to gain weight at a faster rate than those given the high-protein concentrate throughout. After adjustment for differences between treatment groups in mean concentrate consumption and mean live-weight at 8 weeks, the live-weight gain from 8 to 12 weeks was significantly greater in calves given the high-protein diet after 8 weeks.3. In Experiment 5, a significantly lower growth rate was obtained when concentrate intake was restricted to a maximum of 2 kg./day than when given ad libitum. Calves given the concentrates containing 15·9% or 20·6% crude protein gained weight significantly faster than those given the concentrate containing 12·1% crude protein, at both levels of feeding, after live-weight gain was adjusted for differences between treatment groups in mean food consumption and live-weight at 1 week.4. It is concluded that no advantage is obtained by giving a concentrate containing more than 15·9% protein to Friesian heifer calves weaned at 5 weeks of age. The results indicate clearly the importance of an adequate supply of energy in the diet of the ruminant calf if maximum live-weight gain is to be achieved.


1970 ◽  
Vol 24 (1) ◽  
pp. 23-28 ◽  
Author(s):  
O. Faruque ◽  
D. M. Walker

1. Thirty-four cross-bred newborn lambs were used. A high-protein diet (25% protein calories) was supplemented daily with retinyl palmitate (range, 13.75–440 μg/kg live weight 24 h), or with β-carotene (range, 68.5–2200 μg/kg live weight 24 h) for 21 days.2. Live-weight gain was not increased by supplementing the basal diet with either retinyl palmitate or β-carotene.3. The relative weights of β-carotene and retinyl palmitate (expressed as retinol) that were required to produce equivalent concentrations of retinol in the serum varied from 5:1 to 25:1, and for the liver (retinal + retinyl esters, expressed as retinol) the ratio varied from 3:1 to 9:1.


1991 ◽  
Vol 52 (2) ◽  
pp. 395-399 ◽  
Author(s):  
P. V. Tan ◽  
M. J. Bryant

ABSTRACTLive-weight gain responses were investigated using 36 individually penned lambs (mean live weight 35·2 kg) given three sodium hydroxide treated straw-based diets: low-protein, low-rapeseed meal (control) diet; high protein, high-rapeseed meal (HR) diet; or high-protein, fish meal (FM) diet. The diets were formulated to provide 3 or 9 g undegradable nitrogen per kg dry matter (DM) respectively for the diets without or with fish meal. Diets were offered once a day in a 50: 50 forage-to-concentrate ratio in amounts calculated to support maintenance plus 150 g gain and were adjusted weekly according to live weight. Live-weight gain, measured for 7 weeks, was improved by the FM diet only (P < 0·05).The three diets were given also to rumen-fistulated sheep. The FM diet maintained higher rumen ammonia concentrations during most of the day. The FM and HR diets reduced rumen solid particle outflow rate (P < 0·05) and increased the effective degradability of DM and acid-detergent fibre.


1967 ◽  
Vol 21 (2) ◽  
pp. 237-256 ◽  
Author(s):  
D. M. Walker ◽  
L. J. Cook

1. Sixteen male cross-bred lambs were given four diets, which differed in the ratio of protein to energy. The protein contents of the diets (on a dry-matter basis) were: 6.1% (diet A), 11.9% (diet B), 17.5% (diet C) and 22.9% (diet D).2. The experimental period of 7 weeks was divided into two 2-week periods (periods 1 and 2), and one 3-week period. The diets given to the lambs were changed between period 1 and period 2. In period 3 all the lambs were given the same dietary treatment as in period 2.3. The daily feed intake of the lambs was regulated according to live weight. Adjustments were made at the beginning of period 1 and of period 2. The level of feeding was 121 kcal/kg live weight 24 h. In period 3 the intake was the same as in period 2.4. Diet digestibility, live-weight gain, and nitrogen and sulphur balances were calculated for each lamb on each diet in all the periods. Wool growth on sample areas was measured over a 2-week and a 4-week period. These wool growth periods corresponded to treatment period 1, and treatment periods 2 and 3, respectively. At the end of the experiment the lambs were slaughtered and the composition of carcass and organs was determined.5. The mean digestibilities of energy, N, ether extractives and dry matter increased significantly as the protein content of the diet increased.6. The live-weight gain increased with increasing protein content of the diets, but only the difference between the means for diet A and all other diets was significant.7. The N and S balances increased with increasing intake of apparently digested N and S, and all differences between the means for individual diets were highly significant.8. There was a significant correlation between N balance and live-weight gain for each diet. However, when compared at the same late of gain, N balance increased as the protein content or the diet increased.9. Wool growth on the sample areas increased with an increase in the protein content of the diet and all differences between the means for individual diets were highly significant. There were no significant differences between the dietary treatments in their effect on the N and S contents of the wool. The mean values were 15.7% N and 2.87% S.10. The retention of N in the wool grown did not account for the increased N retention on the diets of higher protein content. The lambs given diet A, retained more N and S in wool than was supplied by the diet.11. The percentage of fat in the carcass decreased, and the percentage of protein increased as the protein content of the diet increased. The percentages of moisture and ash were not significantly affected by the dietary treatments.12. The percentages of moisture in the liver, pancreas and muscle decreased and the percentages of protein in the liver and muscle increased as the protein content of the diet increased. The ratio of N in the organs (with the exception of the spleen and pancreas) to N in the carcass was highest for lambs given the diet with least protein (diet A).


1967 ◽  
Vol 9 (4) ◽  
pp. 535-545 ◽  
Author(s):  
J. H. D. Prescott ◽  
G. E. Lamming

1. A factorial split-plot experiment was conducted to investigate the growth of entire and castrate male pigs on conventional diets and diets containing higher levels of protein. Thirty-two Large White pigs were fed ad libitum from 50 lb to slaughter at 260 lb live weight. The carcasses were dissected.2. The live-weight gain of entire males was the same as that of castrates on the conventional diet, but they grew non-significantly faster than castrates on the higher protein diet.3. The entire males had a lower dressing percentage and less fat in the carcass than the castrates, but more lean, bone and rind, and a similar lean: bone ratio. The leanness of the entire males was increased on the higher level of dietary protein whereas the leanness of the castrates was unaffected except in the leg. The interactions were not significant.4. The carcasses of the entire males were proportionately heavier in the head and shoulders and lighter in the middle than those of the castrates.5. The majority of the entire males had flesh with a slightly tainted flavour.


1990 ◽  
Vol 64 (3) ◽  
pp. 743-753 ◽  
Author(s):  
J. Huisman ◽  
A. F. B. Van Der Poel ◽  
P. Van Leeuwen ◽  
M. W. A. Verstegen

The effects of lectins in the diet have been mainly studied in rats. An important question is whether results obtained in rats can be extrapolated to larger animals like the pig. Phaseolus vulgaris beans are rich in toxic lectins. Therefore a study was carried out to compare the effects of diets containing 200 g Phaseolus vulgaris beans (raw or toasted)/kg in rats and piglets. Live-weight gain, nitrogen digestibility and N balance were much lower in piglets than in rats fed on diets containing raw beans. Live-weight gain and N balance were slightly negative in the piglets. When toasted beans were given, live-weight gain and N balance values were reduced in piglets but hardly at all in rats. Giving raw beans caused hypertrophy of the pancreas in the rats but in piglets the weight of the pancreas was reduced. Spleen weight was depressed in the piglets but not in the rats. Weight of liver was not affected in either animal species. When toasted beans were given no effects on the weights of pancreas, spleen or liver were found in piglets or rats. It was concluded that the piglet is much more sensitive to antinutritional factors in the Phaseolus vulgaris bean than the rat.


Reproduction ◽  
2006 ◽  
Vol 131 (4) ◽  
pp. 783-794 ◽  
Author(s):  
S Freret ◽  
B Grimard ◽  
A A Ponter ◽  
C Joly ◽  
C Ponsart ◽  
...  

The aim of our study was to test whether a reduction in dietary intake could improve in vitro embryo production in superovulated overfed dairy heifers. Cumulus–oocyte complexes of 16 Prim’ Holstein heifers (14 ± 1 months old) were collected by ovum pick-up (OPU), every 2 weeks following superovulation treatment with 250 μg FSH, before being matured and fertilized in vitro. Embryos were cultured in Synthetic Oviduct Fluid medium for 7 days. Heifers were fed with hay, soybean meal, barley, minerals and vitamins. From OPU 1 to 4 (period 1), all heifers received individually for 8 weeks a diet formulated for a 1000 g/day live-weight gain. From OPU 5 to 8 (period 2), the heifers were allocated to one of two diets (1000 or 600 g/day) for 8 weeks. Heifers’ growth rates were monitored and plasma concentrations of metabolites, metabolic and reproductive hormones were measured each week. Mean live-weight gain observed during period 1 was 950 ± 80 g/day (n = 16). In period 2 it was 730 ± 70 (n = 8) and 1300 ± 70 g/day (n = 8) for restricted and overfed groups respectively. When comparing period 1 and period 2 within groups, significant differences were found. In the restricted group, a higher blastocyst rate, greater proportions of grade 1–3 and grade 1 embryos, associated with higher estradiol at OPU and lower glucose and β-hydroxybutyrate, were observed in period 2 compared with period 1. Moreover, after 6 weeks of dietary restriction (OPU 7), numbers of day 7 total embryos, blastocysts and grade 1–3 embryos had significantly increased. On the contrary, in the overfed group, we observed more <8 mm follicles 2 days before superovulation treatment, higher insulin and IGF-I and lower nonesterified fatty acids in period 2 compared with period 1 (no significant difference between periods for embryo production). After 6 weeks of 1300 g/day live-weight gain (OPU 7), embryo production began to decrease. Whatever the group, oocyte collection did not differ between period 1 and 2. These data suggest that following a period of overfeeding, a short-term dietary intake restriction (6 weeks in our study) may improve blastocyst production and embryo quality when they are low. However, nutritional recommendations aiming to optimize both follicular growth and embryonic development may be different.


1985 ◽  
Vol 104 (1) ◽  
pp. 85-94 ◽  
Author(s):  
R. V. Large ◽  
J. M. Cobby ◽  
R. D. Baker

SummaryTwo experiments were conducted to provide information on the precision of herbage sampling, the degree of replication and the logistics of managing rotational and continuous grazing experiments. In a third experiment the possibility of estimating herbage growth, during the rotational grazing of paddocks for 4 days, by linear extrapolation of measured growth estimates made during the interval between grazings was investigated. A fourth experiment was then conducted to investigate animal and herbage production responses to nitrogen applied at five levels over the range 80–900 kg N/ha with three replicates per treatment.Results from Expts 1 and 2 showed that similar precision could be obtained under both rotational and continuous systems of grazing with the same number of replicates and samples of herbage. There was little advantage in having more than three replicates and four samples per paddock or two replicates and eight samples per paddock. Under continuous grazing a 3-weekly sampling and movement of exclosure cages was indicated. It was also found, from Expt 3 that, under rotational grazing, linear extrapolation of growth from 0–24 days did not reflect growth to 28 days in a consistent manner. Six animals per treatment, permanently in the paddocks, proved adequate for the estimation of live-weight gain.Experiment 4 confirmed that response curves could be fitted with an acceptable degree of precision if there was one low, one very high, and two intermediate levels of nitrogen. Adjustment of the number of animals to maintain sward height at between 5 and 7 cm ensured similar sward conditions and rates of live-weight gain across all treatments.The problems associated with the measurement of herbage production under grazing are discussed.


1983 ◽  
Vol 100 (3) ◽  
pp. 717-722
Author(s):  
J. B. Moran

SUMMARYIndonesian Ongole and swamp buffalo bulls that had previously been given 0, 1·2, 2·4, 3·6 or 4·8 kg/head/day rice bran plus ad libitum elephant grass were slaughtered after 161 days feeding. Abdominal depot fat, full and empty reticulo-rumen and cold carcass weights were recorded. Various carcass variables were measured and the 9–10–11 rib joints were dissected into bone, muscle and fat. Carcass gross energy was calculated from rib-fat content using previously determined regression equations. Feed efficiency was expressed in terms of the ratios of live-weight gain or carcass-energy accretion to metabolizable energy available for growth.Increasing supplementation with rice bran resulted in larger abdominal fat depots, higher dressing percentages, increased carcass fatness (and hence carcass gross energy) and improved rib muscle to bone ratios. Carcass conformation was unaffected by dietary treatment. When feed efficiency was expressed per unit live-weight gain, there was a decrease with increasing rice-bran feeding. Feed efficiency, expressed per unit of carcass energy accretion, improved with rice-bran supplementation and was generally higher in buffalo than in Ongole bulls. Dietary and species differences in feed efficiency could be primarily explained by the differential energy cost of deposition of, and the availability of energy from, carcass protein and lipid.


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