Protein Control Diet Research Articles

Progression of renal function in patients with chronic kidney disease on a low-protein diet supplemented with aminoacids and ketoanalogues

chronic kidney disease (CKD) is a public health problem. Low-protein diets supplemented with ketoacids and essential aminoacids have proved effective at different CKD stages. to assess the progression of renal failure in adult patients with CKD stages 3b and 4 receiving a protein-controlled diet supplemented with aminoacids and ketoanalogues. retrospective, descriptive intervention study. The nutritional intervention consisted of a protein/calorie intake of 0.4-0.6 g/kg/day and 30-35 kcal/kg/day plus a tablet of ketoanalogues (Ketosteril®)/5 kg weight. We assessed nutritional condition, glomerular filtration (GF) and creatinine, urea and albumin levels at 0, 3, 6, 9 and 12 months. SPSS version 18 was used for data statistical analysis. thirty-three patients were studied (67% male; mean age 59.7 years, r: 24-87). Protein/calorie intake was 0.55 ± 0.20 g/kg/day and 34 ± 4.51 kcal/kg/day. Ketosteril® intake was 11.87 tablets/day (r: 9-14). Initial GF was 24.97 ± 6.64 ml/min/1.73 m2, showing a significant increase between three and 12 months (25.51 ± 8.57 and 29.26 ± 10.33 ml/min/1.73 m2; p = 0.006). Urea nitrogen decreased significantly at six months compared with the initial level (p < 0.005). Body mass index did not change significantly (initial, 26. 63 ± 4.08 kg/m2; after a year, 26.78 ± 3.98 kg/m2). Initial and final albumin levels were 3.53 ± 0.64 g/l and 4.00 ± 0.53 g/l, respectively (p = 0.79). a low-protein diet supplemented with ketoanalogues administered to patients with CKD stages 3b and 4 preserved nutritional condition and mineral balance, improved GF significantly and decreased urea levels.

Whey Protein Components - Lactalbumin and Lactoferrin - Improve Energy Balance and Metabolism

Whey protein promotes weight loss and improves diabetic control, however, less is known of its bioactive components that produce such benefits. We compared the effects of normal protein (control) diet with high protein diets containing whey, or its fractions lactalbumin and lactoferrin, on energy balance and metabolism. Diet-induced obese rats were randomized to isocaloric diets: Control, Whey, Lactalbumin, Lactoferrin, or pair-fed to lactoferrin. Whey and lactalbumin produced transient hypophagia, whereas lactoferrin caused prolonged hypophagia; the hypophagia was likely due to decreased preference. Lactalbumin decreased weight and fat gain. Notably, lactoferrin produced sustained weight and fat loss, and attenuated the reduction in energy expenditure associated with calorie restriction. Lactalbumin and lactoferrin decreased plasma leptin and insulin, and lactalbumin increased peptide YY. Whey, lactalbumin and lactoferrin improved glucose clearance partly through differential upregulation of glucoregulatory transcripts in the liver and skeletal muscle. Interestingly, lactalbumin and lactoferrin decreased hepatic lipidosis partly through downregulation of lipogenic and/or upregulation of β-oxidation transcripts, and differentially modulated cecal bacterial populations. Our findings demonstrate that protein quantity and quality are important for improving energy balance. Dietary lactalbumin and lactoferrin improved energy balance and metabolism, and decreased adiposity, with the effects of lactoferrin being partly independent of caloric intake.

Sex Differences in the Hormonal and Metabolic Response to Dietary Protein Dilution.

Consumption of a low-protein, high-carbohydrate diet induces a striking increase in circulating fibroblast growth factor-21 (FGF21), which is associated with improved cardiometabolic health and increased longevity. Increased lifespan during this dietary protein "dilution" has been explained by resource-mediated trade-offs between reproduction and survival, such that fecundity is optimized at a greater relative intake of proteins/carbohydrates. The magnitude of this trade-off is thought to be sex-dependent. In this study, we tested the hypothesis that metabolic responses to dietary protein dilution are likewise dependent on sex. We maintained age-matched adult male and female C57BL/6J mice on isocaloric diets containing 22% fat and differing in the ratio of protein/carbohydrate. The normal protein (NP) control diet contained 18% protein and 60% carbohydrate by kcal. The protein diluted (PD) diet contained 4% protein and 74% carbohydrate. Consistent with previous reports, PD males gained less weight and less fat than did normal protein controls and exhibited both improved glucose tolerance and decreased plasma lipids. In contrast, these metabolic benefits were absent among age-matched females maintained on the same diets. Likewise, whereas circulating FGF21 was increased up to 66-fold among PD male mice, this was substantially blunted among female counterparts. Sex differences in energy balance, glucose control, and plasma FGF21 were reversed upon ovariectomy. Collectively, our findings support that female mice are relatively less sensitive to the metabolic improvements observed following dietary protein dilution. This is accompanied by blunted circulating levels of FGF21 and requires an intact female reproductive system.

Reduced protein diets increase intramuscular fat of psoas major, a red muscle, in lean and fatty pig genotypes

The present study aims to assess the effects of pig’s genotype (lean v. fatty) and dietary protein level (control v. reduced) on intramuscular fat (IMF) content, fatty acid composition and fibre profile of psoas major, a representative red muscle in pig’s carcass scarcely studied relative to white longissimus lumborum. The experiment was conducted on 40 intact male pigs (20 Alentejana purebred and 20 Large White×Landrace×Pietrain crossbred) from 60 to 93 kg of live weight. Pigs were divided and allocated to four dietary groups: control protein diet equilibrated for lysine (17.5% of CP and 0.7% of lysine) and reduced protein diet (RPD) not equilibrated for lysine (13.1% of crude protein and 0.4% of lysine) within a 2×2 factorial arrangement (two genotypes and two diets). Alentejana purebred had higher IMF content (15.7%) and monounsaturated fatty acids (MUFA) (8.9%), whereas crossbred pigs had higher PM weight (46.3%) and polyunsaturated fatty acids (PUFA) (20.1%). The genotype also affected colour with higher lightness (15.1%) and yellowness (33.8%) and lower redness (9.9%) scores in crossbred pigs. In line with this, fatty pigs displayed more oxidative fibres (29.5%), whilst lean pigs had more glycolytic (54.4%). Relative to fatty acids, RPD increased MUFA (5.2%) and SFA (3.2%) but decreased PUFA (14.8%). Ultimately, RPD increased IMF content (15.7%) in the red muscle under study, with no impact on glycolytic to oxidative fibre type transformation.

Efficacy of Crystalline Lysine in Alternative Diets for Pond‐raised Hybrid Catfish, ♀ Ictalurus punctatus × ♂ Ictalurus furcatus

AbstractA study was conducted to examine the efficacy of crystalline lysine in alternative diets for pond‐raised hybrid catfish, ♀ Ictalurus punctatus × ♂ Ictalurus furcatus. Two 28% protein alternative diets supplemented with l‐lysine HCl at the required level based on 62% (previously published value) or 100% lysine availability were compared with a traditional 28% protein control diet. Hybrid catfish fingerlings (mean initial weight = 43 g/fish) were stocked into 15 earthen ponds (0.04 ha) at a density of 14,826 fish/ha with five ponds per treatment. Fish were fed once daily to apparent satiation for a 173‐d growing season. There were no significant differences in total diet fed, net yield, weight gain, and survival among dietary treatments. There were also no significant differences in carcass yield, fillet yield, and fillet proximate composition and fillet lysine concentration among treatments. Fish fed the traditional control diet had slightly, but significantly, lower feed conversion ratio than fish fed alternative diets, which is likely related to higher dietary fiber levels in the alternative diets. Results from this study show that crystalline lysine can be considered 100% available when used to supplement lysine‐deficient diets for pond‐raised hybrid catfish.

Effect of obesity and type 2 diabetes on protein anabolic response to insulin in elderly women

Obesity and type 2 diabetes have been shown to alter the insulin sensitivity of glucose and protein metabolism in middle-aged women. We aimed to determine whether these findings translate to the elderly who are at increased risk of muscle loss. We assessed whole-body protein (1-13C-leucine) and glucose (3-3H-glucose) kinetics in 10 healthy (age: 71.6±1.8years; BMI: 23.2±0.8kg/m2), 8 obese (age: 72.9±1.3; BMI: 33.1±1.0) and 8 obese well-controlled type 2 diabetic (age: 69.8±1.6; BMI: 34.4±1.5) elderly women in the postabsorptive state and during a hyperinsulinemic, euglycemic, isoaminoacidemic clamp. All subjects followed an isoenergetic, protein-controlled diet for 6days preceding the clamp. The net protein anabolic response to hyperinsulinemia was similarly blunted in obese (0.08±0.06) and obese type 2 diabetic women (0.06±0.04) compared to healthy women (0.24±0.05μmol·kg fat free mass−1·min−1; ANOVA p=0.018). In contrast, the insulin-mediated glucose disposal (healthy: 9.72±0.67) was decreased with obesity (6.96±0.86) and further with diabetes (5.23±0.27mg·kg fat free mass−1·min−1; ANOVA p<0.001). Endogenous glucose production was not completely suppressed during the clamp only in diabetic women. Thus, the glucose infusion rate was the lowest in this group. Obese elderly women with and without type 2 diabetes have a similar degree of insulin resistance of protein anabolism, despite worse glucose metabolism in type 2 diabetes. Similar to previous findings in middle-aged women, obesity exerted a blunting effect on protein anabolism, which may contribute to the development of sarcopenic obesity. Our results suggest that the presence of type 2 diabetes at an advancing age does not further aggravate this effect.

Evaluation of Low‐protein Alternative Diets for Pond‐raised Hybrid Catfish, Ictalurus punctatus × Ictalurus furcatus

AbstractA study was conducted to evaluate low‐protein traditional or alternative diets for pond‐raised hybrid catfish, Ictalurus punctatus × Ictalurus furcatus. Three 24% protein diets containing decreasing levels of soybean meal (30, 20, and 15%) and increasing levels of cottonseed meal and corn germ meal were compared with a 28% protein control diet. Hybrid catfish fingerlings (mean initial weight = 71 g/fish) were stocked into 20 earthen ponds (0.04 ha) at a density of 14,826 fish/ha with five ponds per dietary treatment. Fish were fed once daily to apparent satiation for a 191‐d growing season. There were no significant differences in total diet fed, net yield, weight gain, feed conversion ratio (FCR), survival, or fillet proximate nutrient composition among dietary treatments (P ≥ 0.10). However, regression analysis showed for fish fed 24% protein diets there was a linear increase in FCR as soybean meal levels decreased (P = 0.06). Compared with fish fed the 28% protein control diet, fish fed 24% protein diets had lower carcass and fillet yield. Results demonstrate a 24% protein alternative diet containing 20% soybean meal may be substituted for 28% protein diets for hybrid catfish during food fish production.

Nutrition for the prevention and treatment of chronic kidney disease in diabetes.

The prevention and treatment of chronic kidney disease (CKD) in diabetes through diet and lifestyle have been a topic of much interest over the years. Consideration of the type and amount of carbohydrate, protein and fat is required for optimal blood glucose control, for clinical outcomes related to renal function and for consideration of risk reduction for cardiovascular disease. Controversy has existed regarding the clinical significance of a protein-controlled diet, not to mention the ideal recommended intake in view of the benefits and risks. Furthermore, the level of CKD with which to implement dietary changes should also be considered. This review seeks to provide guidance and clarity concerning the nutritional management of CKD in diabetes.

Dietary chromium polynicotinate enhanced growth performance, feed utilization, and resistance to Cryptocaryon irritans in juvenile large yellow croaker (Larmichthys crocea)

Abstract A feeding trial was conducted to determine the effects of dietary chromium polynicotinate (Cr-Nic) on growth, feed utilization, and resistance to Cryptocaryon irritans in juvenile large yellow croaker ( Larimichthys crocea ). Six diets containing 42% crude protein and graded levels of Cr-Nic (0, 5, 10, 20, 40 and 80 mg kg − 1 diet) were fed to croaker juveniles initially averaging 8.74 ± 0.48 g for 10 weeks. Another diet containing 45% crude protein without Cr-Nic supplementation was also fed and served as a control. Wheat starch was used as the carbohydrate source for all of the experimental diets. Fish fed the diet supplemented with 5 mg kg − 1 Cr-Nic had significantly higher rates of survival, specific growth rate (SGR), feed efficiency (FE), and protein efficiency ratio (PER), but lower feed intake than fish fed diets with 0 and 80 mg kg − 1 Cr-Nic. Fish fed the diet containing 5 mg kg − 1 Cr-Nic had significantly higher SGR and PER than fish fed the 45% crude protein control diet. Analysis of SGR, FE, and PER by second-order regression indicated that the optimal dietary level of Cr-Nic for juvenile large yellow croaker was estimated to be 6.70–7.10 mg kg − 1 of diet. The 3-week cumulative mortality rate following natural infection of the parasite C. irritans was lowest in fish fed the diet containing 5 mg kg − 1 Cr-Nic, which was significantly lower than in fish fed the diet without Cr-Nic addition. It is suggested that Cr-Nic supplementation protects against C. irritans infection prior to parasitic outbreak to alleviate mortality.

Comparative Study on Growth, Feed Consumption and Survival of Spiral Babylon Babylonia spirata Linnaeus, 1758 (Mollusca: Gastropoda) Fed with Formulated Diets

A growth trial was conducted to determine the effects of the dietary protein level on growth, feed utilization and survival of Babylonia spirata . The triplicate groups of 50 animals (with an initial average weight of 49.24 +0.8 g) were stocked in 50-l tanks and fed to apparent satiation twice daily for three months with two experimental diets of 30% and 40% protein content and control diet of fresh meat clam. The growth of snails that were fed with natural food was not significantly (P 0.05) in growth and FCR between snails that were fed with experimental diets. The result of the present study indicates that a diet containing 30% and 40% of protein content may be recommended for the growth of B. spirata .

The potential for enhancement of immunity in cats by dietary supplementation

This study was conducted to examine the potential benefits of dietary supplementation on the feline immune system. Forty three cats (8 or 9 per group) were fed a low protein control diet (22.7% DM basis), the same diet supplemented with yeast-derived nucleotides, salmon oil or l-arginine or a commercial moist high protein diet (53.0% DM basis) for a period of five weeks. The low protein diets were formulated using a commercial moist diet base with added fat and starch and fed ad libitum, along with water. Specific immune assays showed that supplementation with arginine caused a significant enhancement of lymphocyte proliferative responses to the T-cell mitogen PHA after 35 days (P=0.018), while supplementation with either nucleotides or salmon oil resulted in significant enhancement after both 14 (P=0.0048, P<0.0001 respectively) and 35 days (both P<0.0001). Dietary supplementation with arginine, nucleotides or salmon oil each led to significant increases in blood leucocyte phagocytic activity after both 14 (P=0.0003, P=0.0077, P<0.0001 respectively) and 35 days (P<0.0001). This indicates that a number of dietary ingredients have the ability to modulate the immune system of healthy cats possibly resulting in a greater ability to fight infection and disease.

Marine ash-products influence growth and feed utilization when Atlantic cod Gadus morhua L. are fed plant-based diets

Atlantic cod Gadus morhua L. were fed high plant protein diets added to either shrimp-shell meal or crab-shell meal. The aims were to investigate if diluting dietary energy would reduce the liver index (HSI) and if marine ash would add value to plant protein-based diets. Two control diets were used: a high plant protein control diet (PP) with no marine ash addition, and a fishmeal-based diet (FM) with no marine ash addition. All diets were evaluated in small cod (initial weight 79 ± 15g) and in market-size cod (initial weight 1579 ± 20 g). Addition of crab-shell meal up to 20% and shrimp-shell meal up to 10% did not influence liver size in either small or market-size cod. An addition of up to 20% crab-shell meal and 10% shrimp-shell meal improved growth compared to the PP control diet, and stimulated increased feed intake. However, 10% shrimp-shell meal and 20% crab-shell meal diets resulted in a similar intake of energy and protein as the control groups. Increasing shrimp-shell meal to 20% resulted in reductions in feed intake, fat digestibility and growth, and in altered gut histology. All diets, except the 20% shrimp added diet, resulted in normal ranges of plasma nutrients and blood hematological values, showing good fish health with or without the marine ash addition.

Developmental programming of aging of isolated pancreatic islet glucose-stimulated insulin secretion in female offspring of mothers fed low-protein diets in pregnancy and/or lactation.

Diabetes predisposition is determined by pancreatic islet insulin secretion and insulin resistance. We studied female rat offspring exposed to low-protein maternal diet (50% control protein diet) in pregnancy and/or lactation at postnatal days 36, 110 and 450. Rats were fed either control 20% casein diet (C) or restricted diet (R - 10% casein) during pregnancy. After delivery, mothers received either C or R diet until weaning to provide four offspring groups: CC, RR, CR and RC (first letter denoting maternal pregnancy diet and the second lactation diet). Serum glucose, insulin and homeostatic model assessment (HOMA) were measured. Pancreatic islets were isolated and in vitro insulin secretion quantified in low glucose (5 mM) and high glucose (11 mM). Serum glucose, insulin and HOMA were similar in all groups at 36 and 110 postnatal days. HOMA was only higher in RR at 450 postnatal days. Only CC demonstrated differences in glucose sensitivity of β-cells to high and low doses at the three ages studied. At 36 days, RR, CR and RC and at 450 days RR and RC groups did not show glucose-stimulated insulin secretion differences between low and high glucose. Aging-associated glucose-stimulated insulin secretion loss was affected by maternal dietary history, indicating that developmental programming must be considered a major factor in aging-related development of predisposition to later-life dysfunctional insulin metabolism. Female offspring islets' insulin secretion was higher than previously reported in males.

Effects of carnosine supplementation to an all-plant protein diet for rainbow trout (Oncorhynchus mykiss)

Fish meal may contain “unknown growth factors” that have yet to be identified for their physiological role. Carnosine is a histidine-β-alanine dipeptide found in muscle and nervous system tissue which has been demonstrated to have biological activity, but its physiological role is not well defined. A 9-week feeding study was conducted comparing diet FM, a 100% fish meal protein control diet, to fish fed three plant protein diets: diet SPI, 100% of the fish meal replaced with soy protein isolate; diet SPI+AA, diet SPI supplemented with methionine, lysine, threonine and glycine to diet FM levels; and diet CSN, diet SPI+AA supplemented with carnosine. Feeding diet SPI resulted in significant differences in feed conversion ratios (FCR), percent gain and protein retention efficiencies relative to fish fed diet FM. Feeding diets SPI+AA and CSN resulted in FCRs, percent gains and protein retention efficiencies that were not significantly different from fish fed diet FM. Fish fed diets SPI, SPI+AA and CSN resulted in reduced muscle ratio (MR) and feeding diets SPI+AA and CSN resulted in increased intraperitoneal fat ratio (IPFR) relative to fish fed diet FM. Supplementing carnosine to an all-plant protein diet resulted in elevated plasma carnosine and increased muscle free pool anserine. Feeding diets SPI, SPI+AA and CSN resulted in reduced muscle development and increased calpain induced proteolysis. In conclusion, carnosine supplementation did not significantly improve the 100% plant protein diets in regard to the measured growth characteristics above the amino acid supplemented treatments and other unidentified factors may be limiting in the diet causing the reductions in MR and elevated IPFR.

Enhanced Behavioral Response to Serotonin-Related Agonists in Postweaning Protein Malnourished Mice

We investigated whether postweaning protein malnutrition (PM) affects serotonergic systems. Mice were fed a PM diet or normal protein (control) diet from weaning (21 d of age). Twenty days later, we tested for behavioral effects of the selective serotonin (5-HT)(1A) receptor agonist 8-hydroxy-N,N-dipropyl-2-aminoteralin (8-OH-DPAT) and the 5-HT releaser d-fenfluramine. The number of head weaving responses induced by 8-OH-DPAT or d-fenfluramine in the PM mice was significantly increased compared with the control diet group. The effects of 8-OH-DPAT and d-fenfluramine were blocked by pretreatment with the selective 5-HT(1A) receptor antagonist WAY-100635 (0.01 mg/kg). However, postpubertal (56 d of age) mice fed with the PM diet did not show an enhancement of the 8-OH-DPAT-induced head weaving response. These results indicate the occurence of a supersensitivity of postsynaptic 5-HT(1A) receptor in the postweaning PM group. Moreover, they highlight the postweaning stage as a vulnerable period to malnutrition-induced alterations in central serotonergic systems.

Chronic Maternal Protein Deprivation in Mice Is Associated with Overexpression of the Cohesin-Mediator Complex in Liver of Their Offspring

Epigenetic mechanisms may play an important role in the developmental programming of adult-onset chronic metabolic diseases resulting from suboptimal fetal nutrition, but the exact molecular mechanisms are incompletely understood. Given the central role of the liver in metabolic regulation, we investigated whether chronic maternal dietary protein restriction has long-term effects on liver gene expression in the offspring. We fed adult C57BL/6J dams ad libitum an 8% maternal low-protein (MLP) or 20% protein control diet (C) from 4 wk prior to mating until the end of lactation. Male pups were weaned to standard nonpurified diet and singly housed at 21 d of age (d 21). Body weights were followed to 1 y of age (1 y). At d 21 and 1 y, organs were quantitatively dissected and analyzed. MLP offspring had significantly lower body weights at all ages and significantly lower serum activity of alanine aminotransferase and lactate dehydrogenase at 1 y. Gene expression profiling of liver at 1 y showed 521 overexpressed and 236 underexpressed genes in MLP compared to C offspring. The most important novel finding was the overexpression of genes found in liver that participate in organization and maintenance of higher order chromatin architecture and regulation of transcriptional activation. These included members of the cohesin-mediator complex, which regulate gene expression by forming DNA loops between promoters and enhancers in a cell type-specific fashion. Thus, our findings of increased expression of these factors in liver of MLP offspring implicate a possible novel epigenetic mechanism in developmental programming.

Effects of Branched-Chain Amino Acids Supplementation in Patients With Cirrhosis and a Previous Episode of Hepatic Encephalopathy: A Randomized Study

Protein intake impacts on nutritional status and may determine the recurrence of hepatic encephalopathy (HE). A low-protein diet has been considered the standard treatment after an episode of HE, while branched-chain amino acids (BCAA) have been shown to improve minimal HE. We performed a study to investigate the long-term effects of supplementing a protein-controlled diet with BCAA. A randomized, double-blind, multicenter study that included 116 patients with cirrhosis and a previous episode of HE was conducted in four tertiary care hospitals. All patients received a standard diet of 35 kcal/kg per day and 0.7 g of proteins/kg per day and a supplement of 30 g of BCAA (BCAA group) or maltodextrin (MDX group) during 56 weeks. The actuarial risk of remaining free of HE did not differ between groups (BCAA=47%, MDX=34%, P=0.274), but patients in the BCAA group exhibited a better outcome on two neuropsychological tests and an increase in the mid-arm muscle circumference. Recurrence was associated with low plasma albumin at baseline and a decrease in sodium and an increase in creatinine during follow-up. Patients with recurrence of HE exhibited a lack of improvement in global cognitive function. Diet supplementation with BCAA after an episode of HE does not decrease recurrence of HE. However, supplementation with BCAA improves minimal HE and muscle mass. Identification of risk factors for recurrence of HE may allow the development of new preventive therapies that could decrease the neuropsychological sequelae of repeated episodes of HE.

Dietary Medium-Chain Triglycerides Attenuate Hepatic Lipid Deposition in Growing Rats with Protein Malnutrition

The objective of this study was to investigate the effects of dietary medium-chain triglycerides (MCT) on hepatic lipid accumulation in growing rats with protein malnutrition. Weaning rats were fed either a low-protein diet (3%, LP) or control protein diet (20%, CP), in combination with or without MCT. The four groups were as follows: CP-MCT, CP+MCT, LP-MCT, and LP+MCT. Rats in the CP-MCT, CP+MCT and LP+MCT groups were pair-fed their respective diets based on the amount of diet consumed by the LP-MCT group. Rats were fed each experimental diet for 30 d. Four weeks later, the respiratory quotient was higher in the LP-MCT group than those in the other groups during the fasting period. Hepatic triglyceride content increased in the LP groups compared with the CP groups. Hepatic triglyceride content in the LP+MCT group, however, was significantly decreased compared with that in the LP-MCT group. Levels of carnitine palmitoyltransferase (CPT) 1a mRNA and CPT2 mRNA were significantly decreased in the livers of the LP-MCT group, as compared with corresponding mRNA levels of the other groups. These results suggest that ingestion of a low-protein diet caused fatty liver in growing rats. However, when rats were fed the low-protein diet with MCT, hepatic triglyceride deposition was attenuated, and mRNA levels encoding CPT1a and CPT2 were preserved at the levels of rats fed control protein diets.

Impact of goat milk powdered formulations on mineral absorption, peak bone mass and bone loss due to ovariectomy in rats

AbstractBACKGROUND: Goat milk is recognised as nutritious, with benefits to growth and skeletal development. The initial aim of this study was to investigate the effect of three different goat milk formulae—a whole milk, a skim milk and a goat milk growing‐up formula fortified with pre‐ and probiotics (Formula 1)—on mineral absorption and retention in rats. The effect of long‐term intake of the fortified formula diet on peak bone mass and post‐ovariectomy bone loss in rats was then investigated in a follow‐up study and was assessed by bone density dual‐energy X‐ray absorptiometry and biomechanical testing of bone ex vivo.RESULTS: Goat whole milk and fortified milk formulations improved calcium and phosphorus absorption and retention. Body composition analysis showed that rats fed the fortified diet had higher body calcium and phosphorus content. The fortified diet was then tested in a long‐term feeding trial. Rats fed the fortified diet from weaning had a higher peak bone mass than rats fed a soy protein control diet. Bone mineral content (BMC) and density (BMD) of the lumbar spine were higher in rats fed the fortified diet. After ovariectomy, all rats lost bone mass, but rats fed the fortified diet maintained significantly higher BMD and BMC values throughout the trial, though still lower than those of non‐ovariectomised control rats. The fortified diet increased bone strength.CONCLUSION: Goat milk specific nutrients supported by pre‐ and probiotics in Formula 1 may improve mineral status during growth and support attainment of peak bone mass. Copyright © 2008 Society of Chemical Industry

The Influence of an Exogenous Microbial Enzyme Supplement on Feed Consumption, Body Growth and Follicular Development of Pre-Lay Pullets on Maize-Soy Diets

2 Abstract: An experiment was conducted to examine the benefits of supplementing maize-soy diets with a composite microbial enzyme, Allzyme SSF, for laying hens at the pullet stage. Seven hundred and twenty 12- week old Isa Brown pullets were used in the different level of protein content diets. Feed intake from 12 to 16 weeks of age was unaffected by the enzyme supplement, except at the lowest protein content (P<0.05). Feed intake was, however, affected by the enzyme supplement between 16 and 20 weeks (P<0.001) and over the entire trial period (P<0.05). Body weight at 16 weeks of age was reduced (P<0.05) on the control low- protein diet. Feed conversion ratio was not affected by dietary protein content or through supplementation with the microbial enzyme. The relative weight of the ovary was reduced (P<0.01) on the low protein control diet, but the weight of visceral organs associated with digestion was not affected. The pullets in all groups failed to come into lay at 17 weeks of age, mainly due to very severe winter, as the experiment was conducted in a house that was not completely temperature-controlled. Onset of lay occurred from about 23 weeks of age, after the hens were already on a commercial diet but effects of previous dietary treatments on early egg production were noticeable.