Dietary Protein Content Research Articles

Use of chia seed on regular and low-fat crackers, their antioxidant properties, and in-vitro bioaccessibility

Although having functional properties, fat is known to be adversely effective in case of high consumption. High fat consumption causes health disorders such as obesity, cardiovascular diseases and high blood pressure, insulin balance disorders and cancer. For this reason, it is important to reduce fat consumption and create food formulations rich in bioactive components. In the scope of this study, CS (Chia seed) was replaced with wheat flour 10%, 20%, and 30% (w/w) and the fat amount was decreased in 25%, 50%, 75% (w/w) ratios for formulating low-fat crackers, and the antioxidative potential of the samples was evaluated. Extractable, hydrolysable, bioaccessible phenolic fractions of samples were analyzed in terms of TEACABTS, TEACCUPRAC, TEACDPPH and Total Phenolic Content (TPC) (Folin Ciocalteu’s method). CS replacement was determined to be more effective than a fat reduction on AC and TPC results of samples. By 25, 50 and 100% fat reduction of extractable, hydrolysable and bioaccessible phenolic fractions, TEACABTS values increased respectively as 5.87%, 9.33% and 12.11%. 75% fat reduced-30% CS supplemented sample was 91.0% higher than 100% fat including-30% CS supplemented sample and 143.4% higher than the control sample in terms of TEACABTS for bioaccessible phenolic fractions. The dietary fiber, protein content and fatty acid composition are thought to be effective in the potential of CS. It is proved that CS could be expressed as a convenient pseudo-cereal for functional food formulations.

Oscillating dietary crude protein concentrations increase N retention of calves by affecting urea-N recycling and nitrogen metabolism of rumen bacteria and epithelium.

The purpose of this study was to investigate the effects of oscillating crude protein (CP) concentration diet on the nitrogen utilization efficiency (NUE) of calves and determine its mechanism. Twelve Holstein calves were assigned randomly into static protein diet (SP, 149 g/kg CP) and oscillating protein diet (OP, 125 and 173 g/kg CP diets oscillated at 2-d intervals) groups. After 60 days of feeding, the weights of total stomach, rumen and omasum tended to increase in calves fed OP. The apparent crude fat digestibility, NUE and energy metabolism also increased. In terms of urea-N kinetics evaluated by urea-15N15N isotope labeling method, the urea-N production and that entry to gastrointestinal tended to increase, and urea-N reused for anabolism increased significantly in calves fed OP during the low protein phase. These data indicate that urea-N recycling contributed to improving NUE when dietary protein concentration was low. In addition, the differentially expressed genes in rumen epithelium and the rumen bacteria involved in protein and energy metabolism promoted the utilization of dietary protein in calves fed OP.

No adverse effect of a maternal high carbohydrate diet on their offspring, in rainbow trout (Oncorhynchus mykiss).

In order to develop a sustainable salmonid aquaculture, it is essential to continue to reduce the use of the protein-rich fishmeal. One promising solution to do so is the use of plant-derived carbohydrates in diet destined to broodstock. However, in mammals, the reduction of protein content (replaced by carbohydrates) in parental diet is known to have strong adverse effects on offspring phenotypes and metabolism. For the first time, the effect of a paternal and a maternal high carbohydrate-low protein diet was assessed on progeny at long term in the rainbow trout. A 30% protein diminution in both males and females broodstock diet during 10 month and 5 months, respectively, did not trigger adverse consequences on their offspring. At the molecular level, offspring transcriptomes were not significantly altered, emphasizing no effect on metabolism. Tenuous differences in the biochemical composition of the liver and the viscera were observed. The recorded effects remained in the normal range of value and accordingly offspring growth were not negatively affected over the long term. Overall, we demonstrated here that a 30% protein diminution during gametogenesis is feasible, confirming the possibility to increase the proportion of plant-derived carbohydrates in female broodstock diets to replace fishmeal proteins.

Quantification of fetal organ sparing in maternal low-protein dietary models

Background: Maternal malnutrition can lead to fetal growth restriction. This is often associated with organ sparing and long-lasting physiological dysfunctions during adulthood, although the underlying mechanisms are not yet well understood. Methods: Low protein (LP) dietary models in C57BL/6J mice were used to investigate the proximal effects of maternal malnutrition on fetal organ weights and organ sparing at embryonic day 18.5 (E18.5). Results: Maternal 8% LP diet induced strikingly different degrees of fetal growth restriction in different animal facilities, but adjustment of dietary protein content allowed similar fetal body masses to be obtained. A maternal LP diet that restricted fetal body mass by 40% did not decrease fetal brain mass to the same extent, reflecting positive growth sparing of this organ. Under these conditions, fetal pancreas and liver mass decreased by 60-70%, indicative of negative organ sparing. A series of dietary swaps between LP and standard diets showed that the liver is capable of efficient catch-up growth from as late as E14.5 whereas, after E10.5, the pancreas is not. Conclusions: This study highlights that the reproducibility of LP fetal growth restriction studies between laboratories can be improved by careful calibration of maternal dietary protein content. LP diets that induce 30-40% restriction of prenatal growth provide a good model for fetal organ sparing. For the liver, recovery of growth following protein restriction is efficient throughout fetal development but, for the pancreas, transient LP exposures spanning the progenitor expansion phase lead to an irreversible fetal growth deficit.

Effects of feeding a diet with reduced dietary cation and anion difference to lactating cows on production, nutrient digestibility, and ammonia emissions from manure

Lowering dietary cation and anion difference (DCAD; Na + K - Cl - S) can reduce urine pH and this may lower manure pH, potentially mitigating ammonia emissions from manure. However, previous studies reported reducing DCAD can negatively affect DMI, production, and fiber digestibility. Therefore, the objective was to examine effects of a diet with reduced DCAD on urine pH and ammonia emitting potential of dairy manure. Also, production and nutrient digestibility were determined. Twenty Holstein cows (mean ± SD; 140 ± 15 days in milk and 40 ± 6 kg/d milk yield) were used in a randomized block design and fed a diet with DCAD of 220, 150, or 75 mEq/kg (n = 6, 7, and 7, respectively). A commercial acidogenic product (SoyChlor®) was included to decrease DCAD by mainly replacing soybean meal. The diets were formulated to be balanced for all nutrients. The experiment was conducted with a 10-d covariate period followed by 5 week for production. Spot fecal and urine samples were collected in week 5 to estimate fecal and urine output for nutrient digestibility and nitrogen excretion. The estimated fecal and urine outputs were used to reconstitute manure for individual cows and the manures were incubated for 5 d to monitor ammonia emissions using a continuous air-flux chamber system. Data were analyzed using the MIXED procedure of SAS. Reducing DCAD lowered (25.3–23.6 kg/d; P = 0.02) dry matter intake (DMI) in a linear manner. Milk yield, milk composition, energy-corrected milk, and feed efficiency were not different among treatments. Total tract apparent digestibility of dry matter and neutral detergent fiber did not differ among treatments. Urine N and urea-N excretion were quadratically affected with 150 DCAD being the lowest, which occurred due to slight differences in dietary crude protein content among diets. Estimated urine volume increased (21.7–24.1 kg/d; P = 0.04) and urine pH decreased (8.25 to 7.86; P < 0.01) in a linear manner with decreasing DCAD. However, this decrease of urine pH failed to lower manure pH significantly and ammonia emissions from manure. In conclusion, lowering DCAD of a lactation diet from 220 to 75 mEq/kg decreased DMI but did not affect milk yield and composition and total tract nutrient digestibility. In addition, reducing DCAD to 75 mEq/kg did not affect ammonia emissions from manure, suggesting that further reducing DCAD below 75 mEq/kg is worth studying.

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

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 < 0.05) in both sexes compared with the high protein diet. The sample Shannon index was different (P < 0.01) between barrows and gilts. At the genus level, unidentified Clostridiales (P < 0.05), Neisseria (P < 0.05), unidentified Prevotellaceae (P < 0.01) and Gracilibacteria (P < 0.05) were affected by dietary protein levels. The relative abundance of unidentified Prevotellaceae was different (P < 0.01) between barrows and gilts. The influence of dietary protein levels on Neisseria (P < 0.05), unidentified Prevotellaceae (P < 0.01) and Gracilibacteria (P < 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.

Exploring the Potential of Andean Crops for the Production of Gluten-Free Muffins

The aim of this study was to determine the potential of Andean Crop Flours (ACF) to develop muffins suitable for people with celiac disease or gluten intolerance, as these flours do not contain gluten in their composition. The physico-chemical, rheological, microbiological and sensory properties of muffins from different blends of the following ACF were evaluated: camote (Ipomea batatas), oca (Oxalis tuberosa), achira (Canna indica) and mashua (Tropaeolum tuberosum), formulated with sucrose or sucralose. Wheat muffins with sucrose were used for control purposes. The effect of 5-day storage on color, texture and microbiology was also studied. The use of ACF sharply increased the amount of total dietary fiber, while fat and protein contents were slightly lower with respect to the control. Regarding color, formulations with ACF resulted in darker products, showing an important decrease in L* and b* values while a* increased in all ACF formulations. According to their rheological properties, all doughs showed an unstructured and viscous behavior, and the mixture of camote, achira and mashua with sugar was very similar to wheat muffin. On textural parameters, there was an increasing (p &lt; 0.0) effect on firmness and chewiness noticeable on day 5 in all samples. The resultant muffins were considered safe products due to low counts of total microorganisms, molds and yeasts and the absence of Enterobacteria and Staphylococcus aureus during storage. Muffins with ACF showed good overall acceptability, especially muffins containing sucralose, which obtained the highest score. This study showed that ACF could be used as an alternative raw material in the preparation of gluten-free muffins with good nutritional quality, thus providing a useful alternative for underused crops.

Contrasting gut microbiota in captive Eurasian otters (Lutra lutra) by age

Understanding the gut microbiota characteristics of endangered species such as the Eurasian otter (Lutra lutra), especially in their early stages of life, could be essential for improving their management and ex situ conservation strategies. Here, we analyzed the gut microbiota diversity, composition, and function of captive Eurasian otters at different ages using high-throughput 16S rRNA gene sequencing. We found that: (1) Clostridiaceae was abundant in all age stages; (2) Lactococcus in cubs is thought to predominate for digesting milk; (3) bacteria associated with amino acid metabolism increase with age, while bacteria associated with carbohydrate metabolism decrease with age, which is likely due to decrease in dietary carbohydrate content (e.g., milk) and increase in dietary protein contents (e.g., fishes) with age; and (4) fish-related bacteria were detected in feces of healthy adults and juveniles. Overall, the gut microbiota of captive Eurasian otters was taxonomically and functionally different by age, which is thought to be attributed to the difference in the diet in their life stages. This study provided baseline information regarding the gut microbiota of Eurasian otters for the first time and contributes to improvement in their management in captivity.

Effects of Dietary Protein and Lipid Levels on Growth, Body Composition, Blood Biochemistry, Antioxidant Capacity and Ammonia Excretion of European Grayling (Thymallus thymallus)

This study evaluated growth, body composition, antioxidant capacity, innate immunity and ammonia excretion of European grayling (Thymallus thymallus) fed diets containing different protein and lipid contents. Six diets were produced to contain 30, 40, or 50% protein and 10 or 20% lipid. Juvenile fish averaging 25.2 ± 0.28 g were stocked into eighteen 450-L circular tanks in a recirculating aquaculture system (RAS) and fed the test diets to satiation twice daily for 12 weeks. Fish weight gain (WG) was enhanced (P &amp;lt; 0.05) as dietary protein increased from 30% (229% WG) to 40% (262% WG) and plateaued thereafter. Enhancing protein and lipid content of diet led to reduced feed intake. Also, feed efficiency was improved by increasing dietary protein (by 40.8%) and lipid (by 16.5%) levels. An interaction of protein and lipid was found on whole-body lipid, and muscle lipid content increased as dietary lipid level increased. Muscle arachidonic acid (ARA), eicosapentaenoic acid (EPA, 20:5n-3) and total n-6 long-chain polyunsaturated fatty acids (LC-PUFA) contents enhanced by increasing dietary protein level. Moreover, increasing fat content of diet led to enhanced muscle linoleic acid, linolenic acid, total monounsaturated fatty acids (MUFA), total n-6, ratio of docosahexaenoic acid (DHA, 22:6n-3) to EPA and n-6/n-3. However, EPA, DHA, total n-6 LC-PUFA, total n-3, total n-3 LC-PUFA, and EPA/ARA ratio decreased at higher dietary lipid level. Serum triglyceride (TG) level and lactate dehydrogenase (LDH) activity decreased as dietary protein level increased. Increasing fat content of diet led to enhanced serum TG, cholesterol and glucose concentrations and reduced alanine aminotransferase, aspartate amino transferase and LDH activities. Serum malondialdehyde concentration was enhanced by increasing both dietary protein and lipid. Furthermore, serum myeloperoxidase activity was enhanced at higher dietary lipid level. Water ammonium nitrogen (NH4+-N) concentration was measured after 5 and 24 h of last feeding, and the results indicated the reduction of ammonia excretion as dietary lipid content increased. These findings suggest that 40% dietary protein can support optimal growth of juvenile European grayling reared in RAS and increasing lipid content from 10 to 20% can improve feed utilization and reduce ammonia excretion to the rearing water.

Differences in Antioxidants, Polyphenols, Protein Digestibility and Nutritional Profile between Ganoderma lingzhi from Industrial Crops in Asia and Ganoderma lucidum from Cultivation and Iberian Origin.

Carpophores of Ganoderma lingzhi (GZ) from industrial crops in China were analysed and compared with carpophores of three Iberian strains of cultivated Ganoderma lucidum (GL) (Aveiro, Madrid, Palencia) previously genetically characterized. The genetic determination of all the fungi in the study coincided with the identification provided by the companies and entities that supplied the samples. Cultivation time ranged between 107 and 141 days. The analysis of total phenol content showed to be 56.8% higher for GL from Palencia than for GZ. Intraspecific variation was a maximum of 56% from GL. The content of antioxidants, both intraspecific and interspecific, was found to be strain-dependent with a maximum variation of 78.5%. The nutritional analysis shows that there are differences in dietary fiber, protein, ash and sodium content between GL and GZ. In fatty acids analysis, only trans fatty acids showed significant differences, being higher in GL. Protein profile and digestibility of GZ and GL-Madrid mushroom proteins were evaluated by digestion with simulated gastric fluid and were different. The two species were perfectly differentiated according to their protein profile. These results should be considered for nutritional and industrial applications.

Chemical and nutritional characteristics of crackers substituted with Cucurbita pepo L. seed flour

The aim of the study was determined the suitability of Cucurbita pepo L. (pumpkin) seed flour (PSF) supplement, which is limited for use in the food industry, to increase some chemical and functional properties of crackers. PSFs were used to replace wheat flour in cracker formulation at the levels of 5, 10, 20 and 30%. Particularly, the total dietary fiber, protein and ash content of crackers with PSF increased. The highest increase in mineral contents of crackers were determined in P&gt; K&gt; Mg&gt; Ca&gt; Zn&gt; Fe&gt; Cu. The predominant organic acid of crackers was tartaric acid and the dominant fatty acid was linoleic acid. Crackers prepared with Nevşehir variety PSF yielded better results than other crackers due to their nutritious properties. As a result, with the addition of PSF, a functional food product with health benefits was obtained and a contribution was made to the product range.

Comparison of Diet Preferences of Laboratory-Reared and Apartment-Collected German Cockroaches.

The German cockroach, Blattella germanica (L.) (Blattodea: Ectobiidae), is a common pest of human-built structures worldwide. German cockroaches are generalist omnivores able to survive on a wide variety of foods. A number of studies have concluded that laboratory-reared B. germanica self-select diets with an approximate 1P:3C (protein-to-carbohydrate) ratio. We predicted that field-collected insects would exhibit more variable dietary preferences, related to the wide-ranging quality, quantity, and patchiness of foods available to them. We compared diet self-selection of B. germanica within apartments and in the laboratory by offering them a choice of two complementary diets with 1P:1C and 1P:11C ratios. We observed high variation in the population-level self-selection of these diets among individual apartment sites as well as among various life stages tested in laboratory-based assays. Significant differences between populations in various apartments as well as between populations maintained in the laboratory suggested that factors beyond temporary food scarcity influence diet choice. Nevertheless, we found significant correlations between the amounts of diets ingested by cockroaches in apartments and cockroaches from the same populations assayed in the laboratory, as well as between males, females, and nymphs from these populations. These findings suggest that females, males, and nymphs within apartments adapt to the local conditions and convergently prefer similar amounts of food of similar dietary protein content.

Dietary protein and lipid concentrations affect the growth, nutritional indices, and whole-body composition of long-whisker catfish, Mystus gulio, fry

Dietary protein and lipid concentrations affect the growth, nutritional indices, and whole-body composition of long-whisker catfish, Mystus gulio, fry

Dietary protein oscillation: Effects on feed intake, lactation performance, and milk nitrogen efficiency in lactating dairy cows

Limited research with growing ruminants indicates that oscillating (OS) dietary crude protein (CP) concentration may improve nitrogen use efficiency (NUE). Our aim was to determine if a total mixed ration (TMR) based on OS CP (48-h phases of 13.4% and 16.5% CP, respectively) would increase NUE of lactating dairy cows compared with a static CP TMR (ST; 14.9% CP). The experiment was a randomized complete block design with 50 cows [150 ± 61 (mean ± SD) d in milk]. Cows were blocked by parity, days in milk, and milk protein yield. On average, diets were equal in composition over the total experiment. Cows were milked twice daily, and 8 milk samples were collected in each 4-d period. Each 48 h of low-CP (LP) and high-CP (HP) TMR offered to OS cows corresponded to milk collected at milkings 1 to 4 and 5 to 8, respectively. Dry matter intake (mean = 25.5 kg/d for both treatment groups); yields of milk (mean = 31.5 kg/d for both treatment groups), protein, fat, lactose, and fat- and protein-corrected milk (mean = 33.6 kg/d for both treatment groups); and milk concentration of protein, fat, and lactose did not differ between treatments. However, milk urea concentration was higher for OS compared with ST (12.2 vs. 11.3 mg/dL). Body weight, body condition score, NUE, and feed efficiency were unaffected by OS. Apparent total-tract digestibility of dry matter (695 vs. 677 g/kg), organic matter (714 vs. 697 g/kg), CP (624 vs. 594 g/kg), neutral detergent fiber (530 vs. 499 g/kg), and starch (976 vs. 973 g/kg) were higher for OS than for ST cows. Cows in OS responded transiently, and regression analysis of differences within block over time revealed changes in yield of milk (-531 g/d), milk protein (-25.6 g/d), and milk lactose (-16.7 g/d) in LP. Opposite effects were observed for yield of milk (+612 g/d), milk protein (+28.8 g/d), and milk lactose (+28.0 g/d) during HP. Changes in concentrations of milk protein (-0.050%/d), lactose (+0.030%/d), and urea (-3.0 mg/dL per day) during LP, and in milk lactose (-0.024%/d) and urea (+4.3 mg/dL per day) during HP, were observed. Milk yield, lactose yield, and protein yield were lower for OS than ST cows at the last milking of LP and at the first milking of HP. Milk urea concentration did not show such a lag and was lower in the last 2 milkings of LP, and higher in the last 3 milkings of HP, in OS compared with ST cows. Overall, performance and NUE were unaffected by OS treatment, but apparent total-tract digestibility and milk urea concentration increased, and transient effects on milk yield and composition occurred in OS cows.

دراسة تأثير الطحين والمركز البروتيني لبذور الترمس على الخصائص الفيزيائية والكيميائية والحسية للبسكويت

The purpose of this study was to determine the effect of lupine flour (L.f) and lupine protein concentrate (L.P.C) incorporation on chemical, nutritional and sensual qualities characteristics of biscuit (L.P.C) was prepared by isoelectric precipitation method. A standard recipe for biscuit preparation by wheat patent flour used as the control. Wheat flour in the control treatment was replaced with (L.f) and (L.P.C) at levels 10, 20 &amp; 30%. Chemical composition of (L.f), (L.P.C) and biscuit treatments were studied. Results showed that protein contents were 35.35 &amp; 75.80% for (L.F) and (L.P.C), respectively. While they amounted to 14.70, 16.16 &amp; 18.61% for (L.f) incorporated biscuits and 15.20, 18.09 &amp; 21.08% for (L.P.C) incorporated biscuits at the substitution levels studied, respectively compared 12.43% control. Results also indicated contents of total dietary fibers and tannins in (L.f),( L.P.C) and biscuits prepared. Sensory evaluation of biscuit treatments revealed that there was significant decrease at substitution level up to 30% of (L.f) except color score, while all scores of sensory properties were improved significantly at all substitution levels of (L.P.C). Spread ratio was affected adversely by incorporation of (L.f) and slightly when (L.P.C) used. Results showed a reduction in biscuit tenderness during storage. Reverse to the above statement with 30% incorporation of (L.f) while increased at (L.P.C) treatments. The study demonstrated that (L.f) and (L.P.C) can be incorporated into biscuits formulation by replacing up to 20, &amp; 30% of wheat flour control 12.43%, respectively to increase dietary fiber and protein contents.

Impact of Dietary Protein Content on Soil Bacterial and Fungal Communities in a Rice-Crab Co-culture System.

Although co-culture of paddy fields with aquatic animals is lucrative, the ecological impacts of high-protein content entering the agricultural soil via animal pellet feed and feces have not been well studied. Moreover, the effects of dietary protein on soils and soil microbes remain unclear. To elucidate this, we examined soil bacterial and fungal community composition and temporal changes in paddy fields subjected to different protein-content diets via 16S/18S rRNA gene amplicon sequencing analysis with a high-throughput next-generation sequencer. MiSeq sequencing revealed that protein content significantly impacted fungal community structure. High-protein diets reduced bacterial community diversity and relative abundance in both July and October. The phylum-level bacterial taxonomic composition was not affected by diet treatment, while in fungi, a major phylum-level shift was evident. Hierarchically clustered analysis showed that high-protein diets significantly reduced the relative abundance of Brevundimonas in both July and October. Saprotrophic macrofungal diversity was negatively related to dietary protein content. Considering microbial community structure and environmental factors, ca. 15% protein content is appropriate for the rice-crab co-culture system that we studied.

Interaction of CP levels in maternal and nursery diets, and its effect on performance, protein digestibility, and serum urea levels in piglets

Reduced protein levels in nursery diets have been associated with a lower risk of postweaning diarrhea, but the interaction with CP levels in maternal diet on the performance of the offspring remains unclear. The objective of this study was to determine the effect of protein content in sow gestation and piglet nursery diets on the performance of the piglets until slaughter. This was studied in a 2 × 2 factorial trial (35 sows, 209 piglets), with higher or lower (H or L) dietary CP in sow diets (168 vs 122 g CP/kg) during late gestation. A standard lactation feed was provided for all sows (160 g CP/kg). For both sow treatments, half of the litters received a higher or lower CP in the piglet nursery diet (210 vs 166 g CP/kg). This resulted in four possible treatment combinations: HH, HL, LH and LL, with sow treatment as first and piglet treatment as second letter. For each phase, all diets were iso-energetic and had a similar level of essential amino acids. Ps*p is the p-value for the interaction effect between sow and piglet treatment. In the nursery phase (3.5–9 weeks of age), a tendency toward interaction between piglet and sow treatments with feed efficiency (Ps*p = 0.08) was observed with HH having the highest gain:feed ratio (G:F) (0.74 ± 0.01), LH the lowest (0.70 ± 0.01) and the other two groups intermediate. In the growing-finishing phase, an interaction was observed between the piglet and sow diets with decreased G:F for LH (Ps*p = 0.04) and a tendency toward interaction with increased daily feed intake for LH (Ps*p = 0.07). The sow diet showed a tendency toward a long-lasting effect on the dressing percentage and meat thickness of the offspring, which was higher for the progeny of H sows (Ps < 0.01 and Ps = 0.02, respectively). At 23 weeks, serum urea concentrations tended to be lower for the HH and LL groups (Ps*p = 0.07). Fecal consistency scores were higher at day 10–day 14 after weaning for piglets from L sows (Ps = 0.03 and Ps < 0.01, respectively). At day 7 after weaning, fecal consistency score was higher for piglets fed the higher protein diet (Pp < 0.01). At 8 weeks of age, the apparent total tract digestibility of CP (ATTDCP) interacted between piglet and sow diet (Ps*p = 0.02), with HH showing the highest digestibility values. In conclusion, the protein levels in sow late-gestation and piglet nursery diets interacted with feed efficiency, ATTDCP and serum urea concentrations in the nursery phase.

Low dietary protein increases vitamin A absorption and deposition into milk in periparturient rats.

Our objective was to study the effect of differing dietary crude protein and vitamin A on retinoid metabolism in a periparturient rat model. Sixty female rats, approximately 21 d before parturition, were fed rations containing either low protein (13%; LP) or high protein (22%; HP) crude protein and either low vitamin A (3IU/g; LA) or high vitamin A (5IU/g; HA), yielding treatments HPHA, HPLA, LPHA, and LPLA. Samples were collected at d -14, d +3, and +10 relative to parturition and analyzed for all-trans retinoid acid (RA), 13-Cis RA, and retinol. At d -14, serum all-trans RA concentrations decreased compared to baseline. At both d +3 and d +10, serum retinol increased and liver 13-Cis RA decreased. In the small intestine, 13-cis RA was higher in HPHA than HPLA pre-partum (0.93±0.12 vs. 0.40±0.12ng/ml, P=0.04). Post-partum, 13-cis RA was lower in high vitamin HPHA and LPHA groups (0.35±0.06 and 0.38±0.06ng/ml) than in low vitamin A HPLA and LPLA treatments (0.50±0.06 and 1.32±0.06ng/ml, P<0.01). In rats fed LA diets, TNF-alpha expression tended to be lower in HPLA than LPLA groups on day +3 (0.69±0.34 vs 1.00±0.52, P=0.08), but not day +10 (0.56±0.25 vs. 1.00±0.49 fold change, P>0.10). Retinoids accumulated during pregnancy and were mobilized during lactation. The sequestration of retinoids was increased when dietary protein content was low. Further studies are needed to investigate how retinoid metabolism could be manipulated to improve vitamin A delivery to milk.

Low Protein Diets and Energy Balance: Mechanisms of Action on Energy Intake and Expenditure.

Low protein diets are associated with increased lifespan and improved cardiometabolic health primarily in rodents, and likely improve human health. There is strong evidence that moderate to severe reduction in dietary protein content markedly influences caloric intake and energy expenditure, which is often followed by a decrease in body weight and adiposity in animal models. While the neuroendocrine signals that trigger hyperphagic responses to protein restriction are better understood, there is accumulating evidence that increased sympathetic flux to brown adipose tissue, fibroblast growth factor-21 and serotonergic signaling are important for the thermogenic effects of low protein diets. This mini-review specifically focuses on the effect of low protein diets with variable carbohydrate and lipid content on energy intake and expenditure, and the underlying mechanisms of actions by these diets. Understanding the mechanisms by which protein restriction influences energy balance may unveil novel approaches for treating metabolic disorders in humans and improve production efficiency in domestic animals.

217 Effects of Dietary Protein Content and Crystalline Amino Acid Supplementation Patterns on Growth Performance of Weaned Pigs Raised Under Different Sanitary Conditions

Abstract The objective of this experiment was to determine the effects of dietary crude protein (CP) content and crystalline amino acids (CAA) supplementation patterns on the growth performance of weaned pigs under clean (CSC) or unclean sanitary conditions (USC). One hundred forty-four piglets (6.35 ± 0.63 kg BW) were housed under CSC or USC for 3 wk and assigned to 1 of 3 diets: a high CP (HCP; 21%) and two low CP (LCP; 18%) diets supplemented with 10 crystalline indispensable amino acids (IAA) to meet all IAA requirements or only 6 IAA (Lys, Met, Thr, Trp, Val, and Ile) to meet IAA requirements except Leu, His, and Phe. Each treatment had 8 replicates (3 pigs per pen) per sanitary condition. The CSC room was cleaned and washed weekly. For the USC room, sow manure was spread and remained unwashed. Data were analyzed using the MIXED procedure of SAS with orthogonal polynomial contrasts. Pigs raised under USC had reduced (P &amp;lt; 0.05) ADG and G:F in wk 2, but overall, no difference was found between sanitary conditions due to contrary results in wk 3. Overall, ADG and ADFI were not affected but G:F tended (P &amp;lt; 0.10) to be lower for USC pigs. Also, G:F did not differ between HCP (0.79) and LCP (0.81) under CSC, however, LCP interactively decreased (P &amp;lt; 0.05) G:F to 0.75 compared to 0.83 in HCP under USC. The CAA supplementation patterns did not influence growth except reduced (P &amp;lt; 0.05) ADFI in wk 3. Pigs fed the HCP diet had higher (P &amp;lt; 0.05) fecal scores throughout the experiment than those fed LCP diets under both sanitary conditions. In conclusion, overall growth performance did not differ between HCP and LCP under CSC, but LCP diets reduced G:F under USC. The fecal score decreased in LCP diets regardless of sanitary conditions.