scholarly journals Mammary sensitivity to protein restriction and re-alimentation

1996 ◽  
Vol 76 (3) ◽  
pp. 423-434 ◽  
Author(s):  
M. G. Goodwill ◽  
N. S. Jessop ◽  
J. D Oldham
Keyword(s):  
Cell Activity ◽  
High Protein Diet ◽  
Experimental Period ◽  
Dry Mass ◽  
High Protein ◽  
Protein Diet ◽  
Synthetase Activity ◽  
Lactation Period ◽  
Sprague Dawley ◽  
Ad Libitum

The present study tested the influence of protein undernutrition and re-alimentation on mammary gland size and secretory cell activity in lactating rats. During gestation, female Sprague-Dawley rats were offered a high-protein diet (215 g crude protein (N x 625; CP)/kg DM; H); litters were standardized to twelve pups at parturition. During lactation, two diets were offered ad libitum, diet H and a low- protein diet (90 g CP/kg DM; L). Lactational dietary treatments were the supply ad libitum of either diet H (HHH) or diet L (LLL) for the first 12 d of lactation, or diet L transferring to diet H on either day 6 (LHH) or 9 (LLH) of lactation. On days 1, 6, 9 and 12 of lactation, rats from each group (n > 6) were used to estimate mammary dry mass, fat, protein, DNA and RNA; the activities of lactose synthetase (EC 2.4.1.22) enzyme and Na+, K+-ATPase (EC 3.6.1.37) were also measured. Rats offered a diet considered protein sufficient (H) from day 1 of lactation showed a decrease in mammary dry mass and fat but an increase in DNA, RNA and protein on day 6, after which there was no further change, except for mammary protein which continued to increase. However, rats offered diet L showed a steady loss in mammary mass and fat throughout the 12 d lactation period and no change in mammary DNA, RNA or protein. Rats previously protein restricted for either the first 6 or 9 d of lactation had their mammary dry mass and mammary fat loss halted and showed a rapid increase in mammary DNA, RNA and protein on re-alimentation. Lactose production in group HHH, as measured by lactose synthetase activity, was similar on days 1 and 6 of lactation, after which a significant increase was seen. Protein- restricted rats showed no change in lactose synthetase activity during the 12 d experimental period. Changing from diet L to diet H led to a significant increase in lactose synthetase activity to levels comparable with those offered diet H from day 1. These results show that rats offered a protein-restricted diet during lactation suffer mammary underdevelopment, but this may be rapidly reversed by re-alimentation with a high-protein diet

Urea-salt block supplementation of adult Merino wethers grazing wheat stubble in Western South Australia

1971 ◽  
Vol 11 (49) ◽  
pp. 153
Author(s):  
JJ Messenger ◽  
IM Donald ◽  
DC Brown
Keyword(s):  
South Australia ◽  
High Protein Diet ◽  
Experimental Period ◽  
High Protein ◽  
Protein Diet ◽  
Wool Production ◽  
Wheat Stubble ◽  
Ad Libitum

Blocks containing 30 and 35 per cent urea were offered to adult Merino wethers grazing wheat stubble during summer and autumn of 1965. Two groups of sheep were supplemented with two different urea-salt blocks while a third group had no supplement. Urea consumption from the two blocks was 5.3 and 7.2 g per sheep per day. Supplemented sheep had a significantly higher (P<0.05) apparent herbage consumption, but showed less selectivity in grazing for a high protein diet. Supplemented sheep had significantly higher (Pt0.05) liveweights, but four months after the experimental period there were no significant liveweight differences. Supplementation had no effect on wool production. Although the sheep had ad libitum access to the blocks no cases of urea toxicity were reported.

Splanchnic sequestration of amino acids in aged rats: in vivo and ex vivo experiments using a model of isolated perfused liver

2008 ◽  
Vol 294 (3) ◽  
pp. R748-R755 ◽  
Author(s):  
M. Jourdan ◽  
L. Cynober ◽  
C. Moinard ◽  
M. C. Blanc ◽  
N. Neveux ◽  
...  
Keyword(s):  
Amino Acids ◽  
Ex Vivo ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Aged Rats ◽  
Sprague Dawley ◽  
Adult Rats ◽  
Urea Production

Splanchnic sequestration of amino acids (SSAA) is a process observed during aging that leads to decreased peripheral amino acid (AA) availability. The mechanisms underlying SSAA remain unknown. The aim of the present study was to determine whether a high-protein diet could increase nitrogen retention in aged rats by saturating SSAA and whether SSAA could be explained by dysregulation of hepatic nitrogen metabolism. Adult and aged male Sprague-Dawley rats were housed in individual metabolic cages and fed a normal-protein (17% protein) or high-protein diet (27%) for 2 wk. Nitrogen balance (NB) was calculated daily. On day 14, livers were isolated and perfused for 90 min to study AA and urea fluxes. NB was lower in aged rats fed a normal-protein diet than in adults, but a high-protein diet restored NB to adult levels. Isolated perfused livers from aged rats showed decreased urea production and arginine uptake, together with a release of alanine (vs. uptake in adult rats) and a hepatic accumulation of alanine. The in vivo data suggest that SSAA is a saturable process that responds to an increase in dietary protein content. The hepatic metabolism of AA in aged rats is greatly modified, and urea production decreases. This result refutes the hypothesis that SSAA is associated with an increase in AA disposal via urea production.

scholarly journals Influence of a high-protein diet on energy balance in obese cats allowed ad libitum access to food

2010 ◽  
Vol 95 (3) ◽  
pp. 359-367 ◽  
Author(s):  
A. Wei ◽  
A. J. Fascetti ◽  
K. J. Liu ◽  
C. Villaverde ◽  
A. S. Green ◽  
...  
Keyword(s):  
Energy Balance ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Ad Libitum ◽  
Access To Food

Evaluation of different feeding strategies for the lactating sow

1990 ◽  
Vol 1990 ◽  
pp. 89-89
Author(s):  
C J M Anderson ◽  
P R English ◽  
S A Edwards ◽  
O McPherson
Keyword(s):  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Feeding Strategies ◽  
Standard Diet ◽  
List Type ◽  
Subsequent Performance ◽  
Fat Reserves ◽  
Ad Libitum ◽  
Lactating Sow

Feeding strategies for the lactating sow must aim to achieve high piglet survival and growth rates and maximise subsequent reproductive performance of the sow. Feeding less frequently and feeding ad libitum may be ways of reducing disturbance and crushing of piglets, enhancing milk yield and maintaining sow body condition to enhance subsequent performance. High protein diets may encourage sows to utilise body fat reserves for milk production without compromising rebreeding. This experiment was designed to investigate these possibilities in commercial practice.100 Camborough hybrid sows were allocated to one of 4 dietary treatments:1)ration fed with the daily allocation divided between two feeds2)ration fed with the total daily allocation given in one feed3)fed ad libitum on the standard diet (CP 150 g/kg)4)fed ad libitum on a high protein diet (CP 180 g/kg).The feeding scale for the ration fed sows, based on commercial farm practice, was as follows: 2.5 kg on days 1-3, 3.5 kg on days 4-5, 5.0 kg on days 6-9 and 7.0 kg/day thereafter.The experimental diets were based on barley and soya, with the higher protein diet obtained by substituting an additional 75 g/kg of barley with soyabean meal.

scholarly journals Nutritional manipulation in goats: Supplementation of high protein concentrate, effect on performance and resilience of internal parasites

2020 ◽  
Vol 46 (2) ◽  
pp. 193-201
Author(s):  
A. O. Yusuf ◽  
T. O. Ajayi ◽  
O. S. Ajayi ◽  
O. A. Yusuf
Keyword(s):  
Growth Performance ◽  
High Protein Diet ◽  
Cost Effective ◽  
Experimental Period ◽  
High Protein ◽  
Protein Diet ◽  
Weight Changes ◽  
Protein Levels ◽  
Low Protein ◽  
Protein Diets

Eighteen West African Dwarf Goats (WAD) were used in 77-days experimental period to test the efficacy of high protein levels on growth performance and parasite loads of WAD goat. The goats were grouped into three treatments of six animals each per group using their FAMACHA scores (C3-E5) in a completely randomized design. Concentrate diets of varying levels of protein were fed at 7.5 % (low protein, LP), 10.5 % (medium protein, MP) and 14.5% (high protein, HP) inclusion level, respectively while Megathyrsus maximums and water was providedad libitum. Data were collect on FAMACHA score, weight changes. oocyst count and egg per gram of the faeces. The result of this study indicated that the supplemented protein decreased the FAMACHA score from the onset of the experiment to the end of the experiment. Animals fed high protein diet displayed highest growth performance, followed by animals fed with medium protein diet while animals fed with low protein diets had a slight increase in their growth performance.Goats fed high proteinous diet (HP) had a reduced oocyst and egg per gram of the faeces compared to their counterparts fed medium and low protein diets. It can be concluded that feeding WAD goats up to 14% crude protein inclusion is quite adequate to cover their protein requirements and increase their growth performance.Feeding high proteinous diets to goats is an economic and cost effective way of controlling gastrointestinal parasite.

scholarly journals Effect of a low-glycaemic index–low-fat–high protein diet on the atherogenic metabolic risk profile of abdominally obese men

2001 ◽  
Vol 86 (5) ◽  
pp. 557-568 ◽  
Author(s):  
Jean G. Dumesnil ◽  
Jacques Turgeon ◽  
Angelo Tremblay ◽  
Paul Poirier ◽  
Marcel Gilbert ◽  
...  
Keyword(s):  
Phase I ◽  
High Protein Diet ◽  
Glycaemic Index ◽  
Risk Profile ◽  
High Protein ◽  
Protein Diet ◽  
Metabolic Risk ◽  
Low Fat ◽  
Cholesterol Ratio ◽  
Ad Libitum

It has been suggested that the current dietary recommendations (low-fat–high-carbohydrate diet) may promote the intake of sugar and highly refined starches which could have adverse effects on the metabolic risk profile. We have investigated the short-term (6-d) nutritional and metabolic effects of anad libitumlow-glycaemic index–low-fat–high-protein diet (prepared according to the Montignac method) compared with the American Heart Association (AHA) phase I diet consumedad libitumas well as with a pair-fed session consisting of the same daily energy intake as the former but with the same macronutrient composition as the AHA phase I diet. Twelve overweight men (BMI 33·0 (SD 3·5) KG/M2) WITHOUT OTHER DISEASES WERE INVOLVED IN THREE EXPERIMENTAL CONDITIONS WITH A MINIMAL WASHOUT PERIOD OF 2 WEEKS SEPARATING EACH INTERVENTION. BY PROTOCOL DESIGN, THE FIRST TWO CONDITIONS WERE ADMINISTERED RANDOMLY WHEREAS THE PAIR-FED SESSION HAD TO BE ADMINISTERED LAST. DURING THEAD LIBITUMVERSION OF THE AHA DIET, SUBJECTS CONSUMED 11695·0 (sd 1163·0) kJ/d and this diet induced a 28 % increase in plasma triacylglycerol levels (1·77 (sd 0·79)v.2·27 (sd 0·92) mmol/l,P<0·05) and a 10 % reduction in plasma HDL-cholesterol concentrations (0·92 (sd 0·16)v.0·83 (sd 0·09) mmol/l,P<0·01) which contributed to a significant increase in cholesterol:HDL-cholesterol ratio (P<0·05), this lipid index being commonly used to assess the risk of coronary heart disease. In contrast, the low-glycaemic index–low-fat–high-protein diet consumedad libitumresulted in a spontaneous 25 % decrease (P<0·001) in total energy intake which averaged 8815·0 (sd 738·0) kJ/d. As opposed to the AHA diet, the low-glycaemic index–low-fat–high-protein diet produced a substantial decrease (-35 %) in plasma triacylglycerol levels (2·00 (sd 0·83)v.1·31 (sd 0·38) mmol/l,P<0·0005), a significant increase (+1·6 %) in LDL peak particle diameter (251 (sd 5)v.255 (sd 5) Å,P<0·02) and marked decreases in plasma insulin levels measured either in the fasting state, over daytime and following a 75 g oral glucose load. During the pair-fed session, in which subjects were exposed to a diet with the same macronutrient composition as the AHA diet but restricted to the same energy intake as during the low-glycaemic index–low-fat–high-protein diet, there was a trend for a decrease in plasma HDL-cholesterol levels which contributed to the significant increase in cholesterol:HDL-cholesterol ratio noted with this condition. Furthermore, a marked increase in hunger (P<0·0002) and a significant decrease in satiety (P<0·007) were also noted with this energy-restricted diet. Finally, favourable changes in the metabolic risk profile noted with thead libitumconsumption of the low-glycaemic index–low-fat–high-protein diet (decreases in triacyglycerols, lack of increase in cholesterol:HDL-cholesterol ratio, increase in LDL particle size) were significantly different from the response of these variables to the AHA phase I diet. Thus, a low-glycaemic index–low-fat–high-protein content diet may have unique beneficial effects compared with the conventional AHA diet for the treatment of the atherogenic metabolic risk profile of abdominally obese patients. However, the present study was a short-term intervention and additional trials are clearly needed to document the long-term efficacy of this dietary approach with regard to compliance and effects on the metabolic risk profile.

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