Improved Protein Digestibility Research Articles

Pulsed electric field: Effect on in-vitro simulated gastrointestinal protein digestion of deer Longissimus dorsi

The effect of pulsed electric field (PEF) on in-vitro simulated gastrointestinal protein digestion of cold-boned deer Longissimus dorsi was elucidated. PEF treated samples viz. T1 (2.5 kV, 50 Hz) and T2 (10 kV, 90 Hz) along with a control were subjected to in-vitro simulated gastrointestinal protein digestion. Samples were collected after 0, 30, and 60 min of gastric digestion and 120 and 180 min of intestinal digestion. A significant (P < 0.05) increase was observed in the protein digestibility and soluble protein (%) of PEF treated samples, highlighting a positive influence of PEF processing on the digestion process. Higher concentrations of almost all the free amino acids were observed for the PEF treated samples. No significant effect of PEF was observed on the release of various minerals. PEF may be utilized for the development of novel muscle foods with improved protein digestibility.

Meeting Global Feed Protein Demand: Challenge, Opportunity, and Strategy.

Feed protein supplements are one of the most expensive and limiting feed ingredients. This review offers a comprehensive analysis of how the expected expansion of animal production, driven by the rising world population and living standards for more animal-sourced foods, is creating a global shortage of feed protein supply. Because ruminants, chickens, and pigs contribute to 96% of the global supply of animal protein and aquaculture is growing fast, means of meeting the feed protein requirements of these species are elaborated. Geographic variation and interdependence among China, Europe, and North America in the demand and supply of feed protein are compared. The potential and current state of exploration into alternative feed proteins, including microalgae, insects, single-cell proteins, and coproducts, are highlighted. Strategic innovations are proposed to upgrade feed protein processing and assessment, improve protein digestion by exogenous enzymes, and genetically select feed-efficient livestock breeds. An overall successful and sustainable solution in meeting global feed protein demands will lead to a substantial net gain of human-edible animal protein with a minimal environmental footprint.

Genetic Basis of Protein Digestibility in Grain Sorghum

Sorghum [Sorghum bicolor (L.) Moench] plays a key role in food and nutritional security for over half‐a‐billion people in Africa and Asia. In industrialized nations, sorghum is mainly cultivated as animal feed and more recently as a feedstock for biofuel production. Despite its comparable nutritional profile with other cereals, which is even better in health promoting phytochemicals, sorghum is viewed as a low‐value crop primarily due to the low digestibility of its proteins. Decades of research to improve the trait has not yet produced high‐protein‐digestible sorghum cultivar with acceptable agronomic characteristics. The efforts were frustrated by strong association between the high lysine and high protein digestibility traits and floury endosperm phenotype. Recently, several biotechnological strategies have been pursued to address the problem. Perturbation of sorghum protein bodies by downregulating α‐kafirin and suppression of kafirin cross‐linking by silencing γ‐kafirin synthesis have produced transgenic sorghum lines with substantially improved protein digestibility, but these too were, in most cases, associated with floury endosperm phenotype. However, there is an indication that careful tweaking of the expression of γ‐kafirin has potential to produce cultivars with high protein digestibility and vitreous endosperm texture. Moreover, natural variation for protein digestibility exists among sorghum germplasm and can be used in improving the traits through breeding. The objective of this article is to compile and document previous endeavors in improving sorghum nutritional quality through research targeted at increasing protein digestibility, to highlight recent developments, and to share perspectives on future research to address the challenge.

The effect of traditional malting technology practiced by an ethnic community in northern Uganda on in-vitro nutrient bioavailability and consumer sensory preference for locally formulated complementary food formulae.

The occurrence of anti‐nutritional constituents in plants is an important factor that negatively affects bioavailability of nutrients and effectiveness of plant‐based foods in complementary feeding in rural areas in developing countries. However, proven methods that improve bioavailability of nutrients and tailored for application in processing complementary foods among rural communities are largely lacking. This study examined the efficacy of a traditional malting technology practiced by the Acholi ethnic community of northern Uganda to improve protein digestibility and bioavailability of iron and zinc from millet–sesame–soy composite containing 200, 300, and 550 kcal meant for complementary feeding of children aged 6–8, 9–12, and 13–23 years old, respectively. The technology involves washing and soaking of ingredients for 12 hr; malting ingredients individually for 48 hr with water changed after every 6 hr; and sun‐drying malted ingredients for 72 hr. Results showed that the level of anti‐nutritional factors significantly reduced (p ≤ 0.05) in all the composite formulae except the content of total phenolics in 200, tannins in 300 and 550 kcal, composite formula, respectively. In vitro protein digestibility significantly improved (p ≤ 0.05) in all the composite formulae except in the 200 kcal formula. Iron bioavailability significantly increased (p ≤ 0.05) in all the composite formulae except in the 550 kcal energy category. Improvement in zinc bioavailability was only observed in the 300 kcal formula. However, there were significant reductions (p ≤ 0.05) in the level of caregiver preferences for sensory properties and overall acceptability of the composites. These results demonstrate that the traditional malting technology has potential to improve nutrient bioavailability in plant‐based foods but requires improvement in order to increase its efficacy and mitigate negative effects on sensory appeal.

High hydrostatic pressure-assisted enzymatic hydrolysis improved protein digestion of flaxseed protein isolate and generation of peptides with antioxidant activity

Exploration of innovative high hydrostatic pressure (HHP)-assisted enzymatic hydrolysis of plant based food proteins may help improve peptide yield and bioactivity of hydrolysates. In this study, we performed enzymatic hydrolysis of flaxseed proteins using trypsin under HHP (100 and 300 MPa for 5 and 10 min) to evaluate the effect of presurization on protein denaturation, degree of hydrolysis (DH), and peptide profile and bioactivity of hydrolysate. Spectrofluorimetric analyses showed that 300 MPa induced the maximum destablization of flaxseed protein structures. The same pressure level drastically improved the DH by 1.7 times as compared to that of control. Applying HHP did not modify the peptide profiles of flaxseed protein hydrolysates but their concentrations increased with severity of treatment. Similarly, peptide molecular weight distributions were affected by pressurization parameters, increasing mainly the relative abundance of 500–1500 Da peptides. Finally, pressurization at 300 MPa for 5 and 10 min improved the antioxidant activity of flaxseed protein hydrolysates by 39 and 55%, respectively, compared to the control.

Evaluation of Feed for Thin-Tailed Sheep Fattening with Supplemented Protected and Unprotected Aldehide

The purpose of this study was to determine the effect of the use of soybean protection supplements in sheep ration in vivo in terms of consumption, digestibility, nutrient value index, and the digestible nutrients in the ration. Livestock used in this study were 15 heads of thintailed sheep male with an average body weight of 20.81 ± 1.40kg. The rations used in this study consisted of elephant grass, basal concentrate, soybean groats protected and without protected. The comparison between elephant grass and basalt concentrate is 30:70. Feed treatment in the form of supplementary concentrate from soybean groats ingredients without protection and protection. Protection of soybeans using 37% formaldehyde. The treatment given is P0 = 30% Elephant grass + 70% Basal concentrate, P1 = 30% Elephant grass + 60% Basal Concentrate + 10% soybeans groats without formaldehyde protection, and P2 = 30% Elephant grass + 60% Basal Concentrate + 10% soybeans groats formaldehyde protection. Supplementation of 10% soybean protected feeding in male thin tail sheep fattening ration had significant effect (P <0.05) on crude protein digestibility, nutrient value index and digested crude protein. The use of 10% of soybean protected 37% formaldehyde protected soy by 1% of the dry weight of the concentrate in thin tail fattening rations could improve protein digestibility, nutrient value index and abrasive proteins that can be ingested in vivo.

Effect of Dietary Supplementation of Fish Oil on Nutrient Utilization, Haematology and Serum Metabolites of Captive Indian Leopards (Panthera pardus fusca)

This experiment was conducted to asses the effect of fish oil supplementation on nutrient utilization, haematology and serum metabolites of captive Indian leopards fed solely on buffalo meat on bone (BMB). Nine adult leopards (age 3–18 yrs; average BW 42.5 kg) were randomly distributed into 3 equal groups, in a replicated Latin square design. All the animals were fed normal zoo diet of BMB at 2.5 kg/d/animal for 6-d a week. The basal diets of the animals in three groups were supplemented with either 13 g of tallow (T1), 6.5 g of tallow and 6.5 g of fish oil (T2), or 13 g of fish oil (T3). Intake of nutrients was similar (P>0.05) among the groups. Digestibility of OM, CP and gross energy was higher (P<0.01) in groups T2 and T3. Serum concentrations of urea (P<0.001), total protein and globulins were higher and ratio of albumin: globulin was lower (P<0.05) in T2 and T3 as compared T1. However, serum total cholesterol was lower (P<0.05) in T3, only. Thus, it is concluded that supplementation of fish oil in captive Indian leopards would improve protein digestion and reduce serum cholesterol without affecting diet palatability, nutrient utilization and haematology.

Potential non-dairy probiotic products – A healthy approach

Abstract The consumer demand has changed from energy providing diet to the diet with balanced nutrient profile along with metabolic, physiological, health and functional benefits. Probiotics, neutraceutical and functional foods belong to such diet category. Probiotics are selective viable micro-organisms administered in adequate amount to confer health benefits beyond inherent general nutrition. These microorganisms have various health promoting functions like prevents intestinal tract infections, improves lactose metabolism, reduces serum cholesterol level, enhance immunity, stimulates calcium absorption, improves protein digestibility, synthesis of vitamins (vitamin B, nicotinic acid and folic acid), and counteracts the effects of food-borne pathogens. For wider distribution and acceptability, probiotic must be low cost, convenient and viable during the processing, storage and consumption. Consumer health consideration from the perspective of cholesterol in probiotic dairy products for the developed countries and economic reasons for the developing countries has diverted research towards non-dairy based probiotics. This has led to development of rapidly emerging cereals, legumes, fruits and vegetables based non-dairy probiotics. These alternative sources are cheaper in cost, possess more phytochemicals and can reduce the risk of cholesterol problems in lactose intolerance people.

Effects of dietary fermented spent coffee ground on nutrient digestibility and nitrogen utilization in sheep.

ObjectiveThe objective of the study was to determine the effect of fermented spent coffee ground (FSCG) on nutrient digestibility and nitrogen utilization in sheep.MethodsFermentation of spent coffee ground (SCG) was conducted using Lactobacillus plantrum. Fermentation was performed at moisture content of 70% and temperature of 39°C with anaerobic air tension for 48 h. Four adult rams (initial body weight = 56.8±0.4 kg) were housed in a respiration-metabolism chamber and the treatments were: i) control (Basal diet; 0% SCG or FSCG), ii) 10% level of SCG, iii) 10% level of FSCG, and iv) 20% level of FSCG in 4×4 Latin square design. Each dietary experiment period lasted for 18-d with a 14-d of adaptation period and a 4-d of sample collection period.ResultsIn SCG fermentation experimental result, acid detergent insoluble nitrogen (ADIN) concentration of FSCG (64.5% of total N) was lower than that of non-fermented SCG (78.8% of total N). Digestibility of dry matter and organic matter was similar among treatment groups. Although crude protein (CP) digestibility of the control was greater than FSCG groups (p< 0.05), the 10% FSCG group showed greater CP digestibility and nitrogen retention than non-fermented 10% SCG group (p<0.05). Body weight gain and average daily gain were linearly decreased with increasing FSCG feeding level (p<0.05). When the feeding level of FSCG was increased, water intake was linearly increased (p<0.05). With an increasing FSCG level, dry matter intake did not differ among groups, although the gain to feed ratio tended to decrease with increasing level of FSCG (p<0.10).ConclusionMicrobial fermentation of SCG can improve protein digestibility, thereby increasing CP digestibility and nitrogen utilization in sheep. Fermentation using microorganisms in feed ingredients with low digestibility could have a positive effect on improving the quality of raw feed.

Impacts of energy feeds and supplemental protease on growth performance, nutrient digestibility, and gut health of pigs from 18 to 45kg body weight.

A total of 144 pigs with 18.4 ± 2.3 kg initial body weight (BW) at 6 wk of age were used in a 40-d trial to evaluate effects of protease (300,000 U/kg feed, BioResource International Inc., Durham, NC, USA) on growth performance, apparent ileal digestibility (AID) of nutrients, and gut health of pigs fed diets with sorghum. Pigs were randomly allotted to 4 treatments (12 pens per treatment, 3 pigs per pen) in a 2 × 2 factorial arrangement (corn or sorghum basal diets, and 0 or 0.05% protease as 2 factors) with sex and initial BW as blocks. Experimental period had phase 1 (d 1 to 21) and phase 2 (d 22 to 40). About 65% (phase 1) and 72% (phase 2) of cereal grains were used in corn or sorghum based diets. Both grains were ground to 400 μm. Body weight and feed intake were recorded weekly. On d 35, serum was collected to quantify tumor necrosis factor-α (TNF-α) and malondialdehyde (MDA). Titanium dioxide (0.3%) was added as an indigestible marker for an additional 4 d feeding. On d 40, 32 pigs (8 pigs per treatment) were euthanized to collect digesta from jejunum and ileum (for viscosity and AID), tissues (for morphology) and mucosa samples (for TNF-α and MDA) from duodenum, jejunum, and ileum. Replacing corn with sorghum in the diet increased (P < 0.05) overall average daily gain (from 756 to 787 g/day) and average daily feed intake (from 1,374 to 1,473 g/day), reduced (P < 0.05) overall gain:feed ratio (from 0.553 to 0.537), and did not affect AID. Pigs fed diets with sorghum had lower (P < 0.05) MDA content in serum (from 14.61 to 6.48 μmol/L) and jejunum (from 1.42 to 0.91 μmol/g protein), and reduced (P < 0.05) villus height (from 492 to 396 μm) and crypt depth (from 310 to 257 μm) in jejunum. Dietary protease improved (P < 0.05) AID of crude protein (from 81.8% to 86.0%), decreased MDA level (from 1.20 to 0.98 μmol/g protein) in duodenum, and increased (P < 0.05) the ratio of villus height to crypt depth (from 1.08 to 1.21) in duodenum. Overall, use of sorghum fully replacing corn in diets could benefit pigs with enhanced growth and feed intake potentially by reducing oxidative stress, whereas feed efficiency was compromised. Supplementation of protease improved protein digestion and maintained gut health, irrespective of sorghum or corn based diets.

English

Improving protein digestibility in nutrient poor fish feeds through incorporation of dietary enzymes is expected to be achieved with protease. Understanding the role of other dietary enzymes was therefore evaluated to guide appropriate use for optimal fish growth. Protein digestibility of 30, 35, 50 and 55% crude protein (CP) diets was determined with catfish gut enzyme extract, sprouted sorghum, protease and phytase both singly and in a mixture of 500 units of protease and phytase using the pH drop method in vitro. Significant (p&lt;0.05) digestibilities were recorded in 30 and 35% CP diets incorporated with phytase and in 50 and 55% CP diets incorporated with protease singly. These results showed that protein digestibility was more efficient with protease enzyme in high protein diets while phytase was efficient in low protein diets. This implied that the use of protease was more beneficial in catfish starter feeds and phytase in grower/finisher diets and provided a basis for enzyme selection for production of cost-effective catfish diets. Key words: In-vitro protein digestion, catfish gut enzyme extract, phytase, protease, sprouted sorghum.

Lignocellulose Improves Protein and Amino Acid Digestibility in Roosters and Egg Hatchability in Broiler Breeders.

The present work assessed the effect of supplementation of 0.8% dietary Arbocel® RC Fine, a readily available commercial lignocellulose, to poultry feed. In a complete randomized design using 36 individually caged mature dubbed Hy-Line roosters (aged 55 weeks) grouped in 4 treatments with 9 birds per treatment, a digestibility trial was performed to determine apparent and true metabolizable energy values along with digestibility coefficients of protein and amino acid in Arbocel® containing diets. Results showed that 0.8% Arbocel® supplemented diets improved protein digestibility by 6% (P<0.05). Additionally, Arbocel® caused an increase in apparent and true amino acid digestibility in roosters when compared to control diets and controls with 0.8% wheat bran (WB) supplementation. In a second experiment, 26,000 layers and 2,600 roosters aged 33 weeks (Ross 308 broiler breeder strain) were maintained in 6 poultry houses at a commercial breeding farm, with an average of 4330 layers and 433 roosters per house. Performance, egg grade, and hatchability rate were assessed over a post peak period of 6 months. Compared to the control group fed the 0.8% WB diet, the 0.8% lignocellulose dietary supplementation resulted in a decrease (P<0.05) in percent infertility leading to an average increase of 4.07% (P<0.05) in egg hatchability. The Arbocel® fed group had 3.8 more eggs per housed hen compared to control birds. Overall, Arbocel® supplementation at 0.8% resulted in the production of 5.7 more saleable chicks per housed hen during the 6 months trial, a sizeable profit to the farmer.

Effects of dietary phytase supplementation on growth performance and apparent digestibility coefficients of Pacific White ShrimpLitopenaeus vannamei

A growth trial and a digestibility trial were conducted to evaluate the efficacy of phytase supplemented to practical shrimp feeds. The 5 weeks growth trial evaluated the effects of phytase supplementation in replete phosphorus (P) diets on the performances and compositions of juvenile Pacific white shrimp, Litopenaeus vannamei. No significant differences were observed in final biomass, final mean weight, weight gain, feed conversion ratio (FCR), protein retention and survival across all the treatments. Shrimp reared on the P deficient diet had significantly higher P retention and lower whole body P levels as compared to shrimp fed the other diets. Copper content in the whole shrimp body was significantly increased in the treatment supplemented with 1,000 IU kg−1 feed phytase. The digestibility trial was conducted to study the combined effects of phytase supplementation levels and diet type (plant-based versus fishmeal-based) on apparent digestibility coefficients of Pacific white shrimp, Litopenaeus vannamei. There were no effects of diet type so the data was combined. Phytase incorporation at both 500 and 2,000 IU kg−1 significantly improved protein digestibility, whereas P digestibility was enhanced when 2,000 IU kg−1 phytase was supplemented to the diet. Apparent digestibility coefficients of alanine, arginine, aspartic acid, cysteine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, ornithine, phenylalanine, proline, serine, threonine, tyrosine and valine were significantly increased when fed diets contained 500 and 2,000 IU kg−1 phytase supplementation. Results of this work demonstrate that under the conditions of the study growth was not enhanced by phytase supplementation in P replete diets. However, nutrient retention for Cu and digestibility of P, protein and a number of amino acids were enhanced.

Fermented Infant Formula Increases Ileal Protein Digestibility and Reduces Ileal Proteolytic Activity Compared with Standard and Hydrolyzed Infant Formulas in Piglets1–3

Background: An infant formula that contained milk fermented by the bacteria Bifidobacterium breve and Streptococcus thermophilus (Lactofidus) was reported to alleviate functional digestive symptoms in infants. It was hypothesized that improved protein digestibility of the fermented infant formula could contribute to this effect.Objective: The aim of this study was to evaluate the protein digestibility of a specific fermented (FF), a standard (SF), and an extensively hydrolyzed protein (HF) formula.Methods: Four-week-old piglets (n = 7) were fitted with a T-cannula at the terminal ileum and received each formula in a Latin square design. FF, SF, and HF contained 11.7%, 9.3%, and 11.9% (w/w) crude protein; 1.5%, 5.4%, and 5.6% (w/w) fiber; and had a casein/whey ratio of 60:40, 50:50, and 0:100 per kilogram of powder, respectively. Ileal digesta were collected and analyzed for amino acids and proteolytic activity.Results: FF had a significantly higher apparent ileal crude protein digestibility (92.1% ± 1.0%) than SF and HF (84.4% ± 1.0% and 83.9% ± 0.9%, respectively). FF also had a significantly higher dry matter digestibility than SF and HF. The ileal crude protein flow of FF was significantly lower than that of SF and HF. The ileal flow of FF total proteolytic activity was significantly lower than that of SF but not significantly different from that of HF (412 ± 163 kU/8 h vs. 1530 ± 163 and 703 ± 156 kU/8 h, respectively).Conclusions: The FF in piglets had a significantly higher apparent ileal crude protein digestibility than the SF and HF and displayed lower ileal proteolytic activity than the SF. Both effects may contribute to the alleviation of functional gastrointestinal symptoms reported in infants fed fermented infant milk formula.

Preparation and characterisation of soya milk enriched with isoflavone aglycone fermented by lactic acid bacteria combined with hydrothermal cooking pretreatment

SummaryA fermented soya milk (FSM) enriched with isoflavone aglycone (FSM‐SPIA) was prepared from heated soya protein isolate (SPI)‐isoflavone complex. After 48 h of fermentation, FSM‐SPIA contained higher contents of living bacteria, free amino acids and aglycone compared with the FSM of SPI (FSM‐SPI) and the FSM of SPI‐isoflavone complex (FSM‐Mix). In the in‐vitro digestion experiment, FSM‐SPIA showed higher antioxidant capacity and isoflavones (ISO) bioavailability than FSM‐SPI and FSM‐Mix. This was likely due to the soya milk containing a higher level of amino acid, peptides and the presence of soya bean isoflavone. The improved protein digestibility, the interaction and binding ability between proteins and ISO may affect the properties of the protein and the fermented products. The FSM enriched with isoflavone aglycone can be used as a functional fermented drink, as well as an auxiliary food for menopausal women during a specific pathological period.

Co-suppression of synthesis of major α-kafirin sub-class together with γ-kafirin-1 and γ-kafirin-2 required for substantially improved protein digestibility in transgenic sorghum

Co-suppressing major kafirin sub-classes is fundamental to improved protein digestibility and nutritional value of sorghum. The improvement is linked to an irregularly invaginated phenotype of protein bodies. The combined suppression of only two genes, γ kafirin-1 (25 kDa) and γ-kafirin-2 (50 kDa), significantly increases sorghum kafirin in vitro digestibility. Co-suppression of a third gene, α-kafirin A1 (25 kDa), in addition to the two genes increases the digestibility further. The high-digestibility trait has previously only been obtained either through the co-suppression of six kafirin genes (α-A1, 25 kDa; α-B1, 19 kDa; α-B2, 22 kDa; γ-kaf1, 27 kDa; γ-kaf 2, 50 kDa; and δ-kaf 2, 18 kDa) or through random chemical-induced mutations (for example, the high protein digestibility mutant). We present further evidence that suppressing just three of these genes alters kafirin protein cross-linking and protein body microstructure to an irregularly invaginated phenotype. The irregular invaginations are consistent with high pepsin enzyme accessibility and hence high digestibility. The approach we adopted towards increasing sorghum protein digestibility appears to be an effective tool in improving the status of sorghum as a principal supplier of energy and protein in poor communities residing in marginal agro-ecological zones of Africa.

The Influence of an Acidifier Feed Additive on Biochemical Parameters and Immune Response of Broilers

Aims: Dietary acidifiers appear to be a possible alternative to feed antibiotics in order to improve performance of broilers. It is generally known that dietary acidifiers lower gastric pH, resulting in increased activity of proteolytic enzymes, improved protein digestibility and inhibiting the proliferation of pathogenic bacteria in GI tract. The present paper assesses the different dosage of an acidifier on commercial broilers. Study Design: Two hundred and Forty day-old chicks were randomly distributed in a completely randomized experimental design with four treatments and three replications of twenty chicks each. Diets prepared without additive as Control (CON) (group1); 0.025% Acidifier Agent (AA1) (group2); 0.05% Acidifier Agent (AA2) (group3) and 0.1% Acidifier Agent (AA3) (group4). Place and Duration of Study: Department of Animal Science, Malayer University, Malayer, Iran, between May 2013 and September 2013. Methodology: At the end of the trials, six birds from each replicate were sacrificed by cutting the jugular vein and blood samples were individually collected in 10-mL heparinized tubes and stored on ice for hematological analysis. Serum was separated after 8 to 10 hours and was stored at –20oC for subsequent analysis. The individual serum samples were analyzed for antibody titers against Newcastle disease (ND), Infectious Bursal Original Research Article Annual Research & Review in Biology, 4(10): 1637-1645, 2014 1638 Disease (IBD) and Avian Influenza (AI) by ELISA technique and using an automatic analyzer. Treatment-wise means of titers were computed. The collected blood samples were analyzed for total proteins, serum albumin, uric acid and the activities of gamma glutamyltransferase (GGT) and alanine amino transferase (ALT). Results: Results showed that there was no significant difference among the dietary treatments for all antibody titers again Newcastle Disease (ND), Infectious Bursal Disease (IBD) and Avian Influenza (AI). The results of total protein, serum albumin and serum globulin showed no significant difference among the dietary treatments for these parameters. Activities of serum gamma glutamyltransferase (GGT), alanine amino transferase (ALT) and Alkaline phosphatase (ALP) also remained non-significant. Conclusion: It can be concluded that dietary acidifier agent did not have a clear positive effect on immune response and serum biochemical levels; however, there was a slight positive effect on 0.1 % level of inclusion in the diet.

Evaluation of soybean meal source and particle size on broiler performance, nutrient digestibility, and gizzard development

Although there have been several reports concerning the effects of particle size of cereal grains on productive performance of poultry, there is limited information about the effects of soybean meal (SBM) particle size on broiler performance. The objective of the present experiments was to evaluate the effects of SBM source and particle size on broiler performance, gizzard weight, and nutrient digestibility. The first experiment was a 2 × 2 factorial arrangement of 2 SBM sources: expeller-extracted (ESBM) and solvent-extracted (SSBM), and 2 particle sizes: coarse grind, 971 µm, and fine grind, 465 µm. The second experiment was a 2 × 2 factorial arrangement of 2 ESBM particle sizes: coarse grind, 1,290 µm, and fine grind, 470 µm, and 2 corn particle sizes: coarse grind, 1,330 µm, and fine grind, 520 µm. In the first experiment, there was an interaction (P < 0.05) between SBM source and particle size on BW at 49 d of age. No differences in BW were observed when birds were fed coarse SSBM or ESBM, whereas birds fed diets containing fine ESBM exhibited lower BW than birds fed diets containing fine SSBM. In the second experiment, fine-grind ESBM (P < 0.05) and corn (P < 0.01) produced greater 19-d BW than did coarse grind. A significant interaction (P < 0.01) between ingredient type and particle size revealed that chicks fed coarse particles of corn or ESBM exhibited higher protein digestibility compared with chicks fed only fine particles. Corn particle size had a greater effect on gizzard weight than ESBM particle size. Birds fed diets that contained coarse corn had larger gizzards than birds fed fine corn (P < 0.01), but differences in gizzard weight were not observed when birds were fed coarse or fine ESBM. Particles greater than 1,300 µm depressed BW but improved protein digestibility.

Storage Stability of Food Protein Hydrolysates—A Review

In recent years, mainly due to the specific health benefits associated with (1) the discovery of bioactive peptides in protein hydrolysates, (2) the reduction of protein allergenicity by protein hydrolysis, and (3) the improved protein digestibility and absorption of protein hydrolysates, the utilization of protein hydrolysates in functional foods and beverages has significantly increased. Although the specific health benefits from different hydrolysates are somewhat proven, the delivery and/or stability of these benefits is debatable during distribution, storage, and consumption. In this review, we discuss (1) the quality changes in different food protein hydrolysates during storage; (2) the resulting changes in the structure and texture of three food matrices, i.e., low moisture foods (LMF, aw < 0.6), intermediate moisture foods (IMF, 0.6 ≤ aw < 0.85), and high moisture foods (HMF, aw ≥ 0.85); and (3) the potential solutions to improve storage stability of food protein hydrolysates. In addition, we note there is a great need for evaluation of biofunction availability of bioactive peptides in food protein hydrolysates during storage.

Effects of different levels of metabolite combination produced by Lactobacillus plantarum on growth performance, diarrhoea, gut environment and digestibility of postweaning piglets

A study was conducted to investigate the effects of different levels of metabolite combinations produced by Lactobacillus plantarum on growth performance, diarrhoea incidence, gut environment and nutrient digestibility in postweaning piglets. A total of 40 piglets were assigned into one of five treatments: (1) negative control (free antibiotic); (2) positive control (0.03% antibiotic of chlortetracycline); (3) Met 1 (0.1% metabolite combination of TL1, RG14 and RS5 strains); (4) Met 3 (0.3% metabolite combination of TL1, RG14 and RS5 strains); and (5) Met 5 (0.5% metabolite combination of TL1, RG14 and RS5 strains). After 5 weeks of the trial, the average daily gain (ADG) and daily feed intake (DFI) was significantly (P < 0.05) improved in Met 5 group compared to the negative control and Met 1 group. The diarrhoea incidence was significantly (P<0.05) reduced when were piglets fed with positive control and Met 5 dietary treatment. The pH value and Enterobacteriaceae (ENT) in the gut were reduced in Met 5 treatment as compared to negative control and Met 1 group. However, lactic acid bacteria (LAB) counts and short chain fatty acids (SCFA) in the gut were significantly higher (P<0.05) when piglets were fed with Met 5 dietary treatment. In contrast, feeding of metabolite combination to piglets did not improve energy utilisation. In addition, piglets fed with Met 5 dietary treatment improved protein digestibility compared to the negative control and Met 1 group. The results obtained in this study showed that feeding of 0.5% metabolite combinations could improve growth performance, gut health environment and protein digestibility in postweaning piglets.