Impact of fermentation by Saccharomyces Cerevisiae on the macronutrient and in vitro digestion characteristics of Chinese noodles.

This study examined the impact of live bread yeast (Saccharomyces cerevisiae) on the nutritional characteristics of Asian dried noodles. Micronutrient analysis of fermented noodles revealed a 6.9% increase in the overall amino acid content, a 37.1% increase in the vitamin B content and a 63.0% decrease in the phytic acid level. Molecular weight analysis of starch and protein contents revealed moderate decrease in the fermented noodles. The in vitro digestion of fermented noodles showed a slightly faster initial acidification, four-fold decrease in the initial shear viscosity (from 8.85 to 1.94 Pa·s). The initial large food particle count (>2 mm diameter) was 19.5% lower in the fermented noodles. The fermented noodles contained slightly higher free sugar content (73.5 mg g-1 noodle) during the gastric digestion phase. The overall nutrition and digestion results indicate nutritional improvement and digestion-easing attributes in the fermented noodles.

Effects of chickpea grain feeding on the growth and carcass features of growing lambs.

An investigation was conducted to find out how diet formulation of chickpea grains (CHPE) rather than soybean meal and barely grain affected the performance, blood metabolites, carcass, and meat quality features of Awassi lambs. Thirty lambs, with an average age of 73 ± 0.85 days and an initial body weight of 21.0 ± 1.29 kg, were randomly assigned into one of three diets, with 10 lambs per treatment diet. The diets were designed to replace a portion of the barley grain and soybean meal and included no CHPE (CON), 7.5% CHPE (CHPE7.5), and 15% CHPE (CHPE15). Lambs were individually housed, fed every day, and weighed every two weeks to measure performance characteristics over the 60-day study period. Four lambs per treatment were chosen at random on day 42 to participate in an N balance study and assess diet digestibility. All lambs were slaughtered at the termination of the trial period to measure the features of the carcass characteristics and meat quality. As the amount of CHPE included in the diets increased, the cost of diets reduced. As the amount of CHPE in the diets increased, so did the intake of ether extract (EE). The CON group's cost per kilogram of increase was higher (P = 0.017) than that of the CHPE7.5 and CHEP15 groups. The digestibility of EE was higher (P = 0.024) in the CHPE15 diet as opposed to the CHPE7.5 and CON diets. The various treatments did not impact blood metabolites, carcass features, or meat quality. Therefore, the present study suggested that chickpeas might be added to the diets of finishing lambs up to 15% of dry matter.

True digestibility of tryptophan in plant and animal protein.

BACKGROUND: Protein quality, evaluated using Digestible Indispensable Amino Acid Score (DIAAS) requires ileal digestibility values of individual indispensable amino acids (IAA) in each protein. However, true tryptophan (Trp) digestibility has rarely been quantified in humans. OBJECTIVE: To measure the true Trp digestibility and DIAAS of 2H-intrinsically labelled plant and animal protein sources in humans, using the dual isotope tracer technique. METHODS: The true Trp digestibility of 2H intrinsically labelled plant proteins such as whole mung bean (n=6) and dehulled mung bean (n=6), chickpea (n=5), and yellow pea (n=5), and protein from animal source foods such as egg white (n=6), whole egg (n=6), chicken meat (n=6) and goat milk (n=7) was determined against the known digestibility of U-13C spirulina whole cell protein as reference, except for goat milk protein which was measured against free crystalline 13C-Trp as reference. Banked samples from earlier studies conducted to determine true IAA digestibility of different protein sources were used for the analysis. DIAAS was calculated for each test protein using digestibility corrected IAA scores (mg IAA/g of protein) in comparison to the IAA requirement score for adults. RESULTS: The true Trp digestibility of whole mung bean, dehulled mung bean, chickpea, yellow pea, egg white, whole egg, chicken meat, and goat milk were 67.6±3.7%, 74.5±4.4%, 72.6±2.3%, 72.5±2.2%, 89.7±2.5%, 91.4±2.6%, 95.9±2.2%, and 92.8±2.9% respectively. The true Trp digestibility of plant protein sources was significantly lower than that of animal protein sources (p<0.05). Trp was not a limiting IAA in all the tested proteins. CONCLUSION: The true Trp digestibility determined in the present study ranged from 67.6±3.7% to 95.9 ± 2.2% for whole mung bean and chicken meat respectively, and adds to the database of individual true IAA digestibility of different protein sources. This study was registered in Clinical Trials Registry of India (CTRI) with registration number: CTRI/2017/11/010468, CTRI/2020/04/024512, CTRI/2018/03/012265.

Unveiling the nutritional spectrum: A comprehensive analysis of protein quality and antinutritional factors in three varieties of quinoa (Chenopodium quinoa Wild).

Quinoa (Chenopodium quinoa) is renowned for its high protein content and balanced amino acid profile. Despite promising protein characteristics, plant-based sources usually possess antinutritional factors (ANFs). This study aimed to analyze the nutritional and ANFs composition of three quinoa varieties (Black, Yellow, and Red), and assessed the protein quality. Among these varieties, Black quinoa showed the highest protein content (20.90 g/100 g) and total dietary fiber (TDF) (22.97 g/100 g). In contrast, Red quinoa exhibited the highest concentration of phenolic compounds (338.9 mg/100 g). The predominant ANFs identified included oxalates (ranging from 396.9 to 715.2 mg/100 g), saponins (83.27-96.82 g/100 g), and trypsin inhibitors (0.35-0.46 TUI/100 g). All three varieties showed similar in vitro protein digestibility (IVPD) (> 76.9 %), while Black quinoa exhibited the highest protein quality. In conclusion to ensure reduction of ANFs, processing methods are necessary in order to fully benefit from the high protein and nutritional value of quinoa.

The evolution of granular surface structure and functional properties in rice starch during grain filling.

The developmental changes in the granular surface structure and functional properties of starch during the entire grain filling period of rice (around 40 days) were investigated. The specific surface area of rice starch significantly decreased firstly then stabilized during growth due to increasing granular size. The pore volume decreased from 5.40 cm3/g at 6th day after anthesis (DAA-6) to 3.02 cm3/g (DAA-46). More starch granule-associated proteins (SGAPs) accumulated on the surface and in channels. Swelling power decreased by 46 %, whereas the flow behavior index (n) decreased by 32 % in upward curve during starch development from DAA-6 to DAA-30. Tan δ first dropped then remained steady at DAA 22-34 and lightly rebounded at the final stage, indicating that starch in the middle stage tended to have greater viscoelastic gel behavior at all sweeps. Mature starch showed lower in vitro hydrolysis rate and exhibited stronger enzymatic resistance. The results showed that granular surface features of rice starch may be an essential factor in determining rheological behavior and resistance to hydrolysis.

The Influence of High-Concentrate Diet Supplemented with Tannin on Growth Performance, Rumen Fermentation, and Antioxidant Ability of Fattening Lambs.

This experiment aimed to study the effects of tannin supplementation on growth performance, rumen fermentation characteristics, apparent digestibility and serum biochemistry, and antioxidant and immune indexes in fattening lambs. A total of 36 male Hu sheep lambs (body weight = 15.83 ± 0.48 kg and days of age = 55 ± 2 d) were fed a high-concentrate diet and randomly divided into one of three groups of 12 animals each: control with no tannin (CON) and tannin treatments (TA1, 3 g/d per lamb; TA2, 6 g/d per lamb). The feeding experiment lasted for 60 d. The results showed that the average daily gain and ruminal propionate content of lambs in the TA1 group were higher (p < 0.05) than those in the CON group. Lambs fed tannin had significantly increased (p < 0.05) microbial protein and decreased (p < 0.05) ammonia nitrogen concentrations in the rumen. In addition, the crude protein and neutral detergent fiber digestibility of the TA2 group were significantly decreased (p < 0.05) as compared with the TA1 and CON groups, respectively. The serum concentrations of triglyceride, immunoglobulin A, and catalase and the total antioxidant capacity were higher (p < 0.05) in the TA1 group that those in the CON group, whereas an opposite trend of urea nitrogen, interleukin-1ß, and malondialdehyde was found between the two groups. Also, tannin supplementation increased (p < 0.05) Lactobacillus and decreased (p < 0.05) Salmonella counts in the feces of lambs. Taken together, tannin supplementation can improve the growth performance, immunity, and antioxidant ability of fattening lambs fed a high-concentrate diet.

Effects of Different Defatting Methods of Black Soldier Fly (Hermetia illucens) Larvae Meal on the Metabolic Energy and Nutrient Digestibility in Young Laying Hens.

This study aimed to investigate the effects of different defatting methods of black soldier fly (Hermetia illucens) larvae meal (BSFM) on the metabolic energy and nutrient digestibility in laying hens. Sixty young laying hens (Hy-Line W-36) aged 63 days were randomly divided into two groups (G1 and G2), each with five replicates of six hens housed in individual cages. Group G1 was fed 25% pressed black soldier fly meal (BSFMp) and 75% basal diet, and Group G2 was fed 25% extracted black soldier fly meal (BSFMe) and a 75% basal diet. Both diets included 5 g/kg chromium oxide as an external marker. A 7-day preliminary trial was followed by a 4-day experimental period. The results indicate that pressing and extracting significantly affected the digestibility of crude fat and total energy in BSFM, with BSFMp showing significantly higher crude fat digestibility than BSFMe. Similarly, total energy digestibility was also significantly higher in BSFMp. However, there were no significant differences in dry matter, organic matter, and crude protein digestibility between the two processing methods. The apparent metabolic energy values of BSFMp and BSFMe were 16.34 and 12.41 MJ/kg, respectively, showing a significant difference. The nitrogen-corrected metabolic energy values were 15.89 MJ/kg in BSFMp and 11.93 MJ/kg in BSFMe, indicating a highly significant difference. The digestibility of arginine and leucine in BSFMp was significantly higher than in BSFMe, while differences in lysine, cystine, threonine, tryptophan, and isoleucine were not significant. In conclusion, both defatting methods of BSFM had no adverse effects on the metabolic energy and nutrient digestibility in young laying hens, but BSFMp demonstrated better effects on the digestibility of metabolic energy and nutrients in the feed for young laying hens.

Standardized Ileal Digestibility of Calcium and Phosphorus in Feed Ingredients for 21-Day-Old Broilers.

This study aimed to determine the standardized ileal digestibility (SID) of calcium (Ca) and phosphorus (P) in various feed ingredients using the direct method. This study comprised eight experimental diets: a Ca-P-free diet and seven experimental diets, each containing monocalcium phosphate (MCP), dicalcium phosphate (DCP), monosodium phosphate (MSP) + limestone, corn, and soybean meal (SBM) as the sole sources of Ca and/or P. These diets provided 4.21 g/kg of non-phytate P from MCP, DCP, or MSP, and the MSP + limestone diet included 7.50 g/kg of Ca. The corn and SBM diets formulated to determine P digestibility maintained a dietary Ca/total P ratio of 1.4 through the addition of limestone. Chromic oxide was added to the diets as an indigestible index. On day 18, 256 male and 256 female broilers were individually weighed and randomly assigned to eight treatments, each with four replicates for each sex (eight birds per cage). This allocation followed a randomized complete block design based on body weight. On day 21, the birds were euthanized using carbon dioxide, and ileal digesta samples were collected from the distal two-thirds section of the ileum. No significant interactions between the experimental diets and sex regarding the SID of Ca or P were detected, and no effect of sex on the SID was observed. The standardized ileal Ca digestibility of MCP, DCP, limestone, corn, and SBM was found to be 84.7%, 70.1%, 52.6%, 88.6%, and 81.6%, respectively. The standardized ileal P digestibility of MCP, DCP, MSP, corn, and SBM was determined to be 91.8%, 76.8%, 94.4%, 73.1, and 88.4%, respectively. Given the variable digestibility of Ca and P across different feed ingredients, the consideration of the specific type of ingredients used in diet formulation is crucial.

Different Physiochemical Properties of Novel Fibre Sources in the Diet of Weaned Pigs Influence Animal Performance, Nutrient Digestibility, and Caecal Fermentation.

The effect of including micronised fibre sources (FS) differing in fermentability and hydration capacity (HC) on growth performance, faecal digestibility, and caecal fermentation was investigated in piglets. There were four dietary treatments: a control diet (CON) and three treatments differing in the HC and fermentability of FS added at 1.5% to prestarter (28-42 d) and starter (42-61 d) diets. These were: LHC (low-HC by-product-based insoluble fibre (IF) with a prebiotic fraction (PF) from chicory root); MHC (medium-HC by-product-based IF with a PF); and HHC (high-HC non-fermentable wood-based IF with no PF). There were eight replicates per treatment. Over the entire period, LHC and MHC piglets showed a 10% increase in daily growth and feed intake (p ≤ 0.019) and tended to have a reduced feed conversion ratio (p = 0.087) compared to HHC piglets. At 42 d, faecal protein digestibility increased by 5% in the LHC and MHC groups compared with the HHC group (p = 0.035) and did not differ from the CON group. Both LHC and MHC fibres were more fermented in vitro with caecal inocula from 61 d old piglets than HHC fibre (p ≤ 0.003). These results suggest that balanced soluble and insoluble fibre concentrates can improve piglet performance.

Influences of Weizmannia coagulans PR06 Fermentation on Texture, Cooking Quality and Starch Digestibility of Oolong Tea-Fortified Rice Noodles.

Weizmannia coagulans is increasingly employed in food processing owing to its health benefits. Our previous research developed Oolong tea-fortified rice noodles with unique flavor and potent antioxidant activity; however, their texture still requires improvement. In this study, Oolong tea-fortified rice noodles were fermented using W. coagulans PR06 at inoculation amounts of 1%, 3%, and 5% (v/v), and assessed for cooking quality, texture, and starch digestibility. The results indicated that fermentation with 3% and 5% W. coagulans PR06 altered the amylopectin length distribution in the rice noodles and increased the degree of starch short-range order. Furthermore, the fermentation process increased the storage modulus (G') and loss modulus (G″) values, decreased the tan δ value, and strengthened the interactions among tea polyphenols, proteins, and starch in the rice flour gel. Consequently, this process increased the hardness and chewiness of the rice noodles, decreased their broken strip rate and cooking loss, and significantly reduced their in vitro starch digestibility. Overall, fermentation with W. coagulans PR06 markedly improved the texture and cooking quality of Oolong tea-fortified rice noodles while effectively delaying starch digestion. This study highlights the potential application of W. coagulans PR06 in developing diverse and functional rice noodle products.

Optimization of Heat-Moisture Treatment Conditions for High-Amylose Starch and Its Application in High-Resistant Starch Triticale Noodles.

Heat-moisture treatment (HMT) is a widely used method for modifying starch properties with the potential to reduce the digestibility of high-amylose starch (HAS). This study aimed to optimize the HMT conditions for HAS and apply the resulting HMT-HAS to triticale noodles to develop low-glycemic-index products. HMT significantly increased the resistant starch (RS) content and decreased the rapidly digestible starch (RDS) content of HAS. The treatment conditions-temperature, heating time, and moisture content-were found to significantly influence the starch composition. Optimal HMT conditions were determined using response surface methodology: a temperature of 108 °C, a heating time of 5.8 h, and a moisture content of 25.50%. Under these conditions, the RS content of HMT-HAS was 60.23%, nearly double that of the untreated sample. Increasing the level of HMT-HAS in triticale noodles led to significant decreases in short-range order, relative crystallinity, and viscosities, while the RS content increased from 12.08% to 34.41%. These findings suggest that incorporating HMT-HAS into triticale noodles effectively enhances starch digestive resistance, supporting the development of functional, low-glycemic-index triticale-based foods.

Recent Advances in Physical Processing Techniques to Enhance the Resistant Starch Content in Foods: A Review.

The physical modification of starch to produce resistant starch (RS) is a viable strategy for the glycemic index (GI) lowering of foods and functionality improvement in starchy food products. RS cannot be digested in the small intestine but can be fermented in the colon to produce short-chain fatty acids rather than being broken down by human digestive enzymes into glucose. This provides major health advantages, like better blood sugar regulation, weight control, and a lower chance of chronic illnesses. This article provides a concise review of the recent developments in physical starch modification techniques, including annealing, extrusion, high-pressure processing, radiation, and heat-moisture treatment. Specifically, the focus of this paper is on the alteration of the crystalline structure of starch caused by the heat-moisture treatment and annealing and its impact on the resistance of starch to enzymatic hydrolysis, as well as the granular structure and molecular arrangement of starch caused by extrusion and high-pressure processing, and the depolymerization and crosslinking that results from radiation. The impacts of these alterations on starch's textural qualities, stability, and shelf life are also examined. This review demonstrates how physically modified resistant starch can be used as a flexible food ingredient with both functional and health benefits. These methods are economically and ecologically sustainable since they successfully raise the RS content and improve its functional characteristics without the need for chemical reagents. The thorough analysis of these methods and how they affect the structural characteristics and health advantages of RS emphasizes the material's potential as an essential component in the creation of functional foods that satisfy contemporary dietary and health requirements.

Effect of microwave treatment and water-bath heating treatment on the performance of glutenin from Tiger nut seed meal: Insights into changes in structural characteristics, functional properties, and in vitro gastrointestinal digestibility.

In this study, the structural characteristics, functional properties, and in vitro gastrointestinal digestibility of glutenin from Tiger nut seed meal (TNSMG) treated by microwave (140-700 W, 20-60 s) and water-bath heating (40-100 °C, 10-30 min) were investigated. Analysis of the surface hydrophobicity, intrinsic fluorescence spectroscopy and Fourier transform infrared spectroscopy indicated that both microwave and water-bath heating treatments caused structure changes of TNSMG. The results showed an increase in the exposure of sulfhydryl groups and the content of ß-sheet, coupled with a decrease in the content of α-helix and ß-turn. These structural changes contributed to the improved solubility, foamability, emulsification properties, and digestibility of TNSMG under proper thermal treatment conditions. TNSMG exhibited the best solubility (68.48%) and foamability (85.56%) after water-bath heating treatment for 20 min at 80 °C. Furthermore, TNSMG showed the best emulsification property (9.61 m2/g) and digestibility (78.58%) when treated by microwave treatment at 560 W for 40 s.

Structure and digestibility changes of Indica and japonica waxy rice starch during in vitro pre-digestion.

The digestion of starch have been of great interest, yet little is known about the structure changes and structure-digestibility relationships of waxy rice starch during digestion. In this study, waxy rice starch from Indica and Japonica cultivars were in vitro pre-digested for different times, and the changes in their structure and properties were investigated, including granule morphology, chain length distribution, short-range ordered structure, crystallinity, thermal properties, and digestibility. Pre-digested Indica and Japonica waxy rice starch had the characteristics of porous starch, showing similar surface erosion and pores. With the prolongation of pre-digestion time, the amylose content decreased by 0.74 %-2.69 %, the proportion of amylopectin short A chain (DP6-12) and B1 chain (DP13-24) decreased, and the proportion of long B2 (DP25-36) and B3 chain (DP ≥ 37) increased, especially in pre-digested Indica waxy rice starch. The short- and long-range ordered structure of pre-digested starch increased, manifested by an increase in the absorbance ratio at 1047/1022 cm-1, a decrease at 1022/995 cm-1, and an increase in relative crystallinity, leading to higher gelatinization temperature and enthalpy. Pre-digested waxy rice starch had a reduced rapidly digestible starch of 18.27 %-33.93 % and an increased resistant starch of 29.51 %-41.32 %, which will be applied in functional starch and healthy starchy foods.

Potential impact of climate change on dietary grain protein content and its bioavailability-a mini review.

The changing global climate brings a gradual yet constant and adverse shift in crop production. Grain crop plants, particularly cereals and legumes, respond varyingly to adverse climate, including reduction in grain yield and changes to their nutrient densities. An understanding of specific changes to crop systems under differing climatic conditions can help in planning diets to meet human nutrient sufficiency. Grain protein content is also affected by adverse environmental factors. Deficits in protein yield, linked to changes in grain or seed protein and antinutrient concentrations, have been reported in major food crops when exposed to elevated carbon dioxide, high temperature, drought, and humidity. These changes, in addition to affecting the quantity of indispensable or essential amino acids (IAA), also impact their bioavailability. Therefore, it is important to assess consequences of climate change on grain protein quality. An important tool to measure grain protein quality, is measuring its digestibility at the level of the ileum and its IAA concentration, linked to a metric called the Digestible IAA Score (DIAAS). A minimally invasive technique called the dual isotope tracer technique, which measures IAA digestibility after simultaneous administration of two different intrinsically labelled protein sources, one a test protein (2H/15N) and one a reference protein (13C) of predetermined digestibility, has been used in evaluation of grain protein IAA digestibility, and promises more in the evaluation of changes based on climate. This review discusses climate induced changes to grain protein quality through the prism of IAA digestibility, using the dual isotope tracer technique.

Starch in Emulsion-Type Sausage Reduced the Gastric Digestibility of Meat Protein by Reducing the Stability and Increasing the Viscoelasticity of Gastric Digests.

The effect of the addition of native starch (S) and modified starches (distarch phosphate (SP), acetylated distarch phosphate (AP), and starch acetate (SA)) in emulsion-type sausage on the digestion process of meat protein was studied in this work. The addition of native and modified starches reduced the release of -NH2 during the simulated gastric digestion stage, whereas the addition of SA increased the total release of -NH2 after the whole digestion. Peptidomic analysis revealed that the presence of starch decreased the release of peptides in the gastric digestion. The presence of starch reduced the stability of the digests but increased the viscosity of the gastric digestive fluid, which should largely be responsible for the decreased gastric digestibility of meat protein. These results highlighted the physical properties of digests as a key factor affecting the gastric digestion process of meat protein and provided guidance for the application of starches in meat products.

Copper nanoparticles effectively reduce Salmonella Enteritidis in broiler chicken diet and water.

ABSTRACTThe use of copper nanoparticles (CuNP) in the diet of broiler chickens has been studied as a potential alternative to antibiotic growth promoters. This study aimed to analyze the antimicrobial properties of CuNP in the feed and water of broiler chickens against Salmonella Enteritidis and to assess the intestinal integrity and toxicity of CuNP supplementation in their diet. The antimicrobial activity of CuNP against S. Enteritidis was tested in microplates to evaluate three water samples with different mineral compositions and in an in vitro digestibility model that simulated the three primary intestinal compartments of birds to assess feed samples. To evaluate in vivo intestinal integrity and toxicity, the birds were divided into four groups (30 birds per group): (1) basal diet (control); (2) basal diet + CuNP (100 ppm); (3) basal diet + enramycin (10 ppm); and (4) basal diet + CuNP (100 ppm) + enramycin (10 ppm). Intestinal samples were collected for histomorphometric evaluation and lactic acid bacteria count, while chest muscle and whole blood samples were collected to determine copper content. A significant reduction in the S. Enteritidis count was observed in both in vitro treatments (water and feed) with CuNP inclusion, compared to the control group. No significant differences histomorphometric measurements, weight gain, or total lactic acid bacterial counts were found compared to those in the control. These results demonstrate the effectiveness of CuNP in reducing the occurrence of S. Enteritidis and their non-interference with the intestinal integrity of broiler chickens, highlighting the potential of CuNP as an alternative antimicrobial agent in the poultry production chain.

The ileal, total tract and postileal digestibility of compound feeds either rich in wheat or rye in an ileo-caecal fistulated minipig model.

Environmental issues and concerns about animal welfare display current challenges in animal husbandry and feeding. Rye, a cereal that has scarcely been used in animal feed in recent decades, could help address some of the challenges in pig feeding as a climate friendly and health promoting feed ingredient. Distinct constituents of rye - especially its non-starch-polysaccharides (NSP) - are fermented in the large intestine while short chain fatty acids (SCFA) are produced in that process. This can promote gut health and the feeling of satiety in pigs. To examine the site of the digestion of rye within the digestive tract in comparison to wheat as a widely used ingredient in pig diets, two diets with high shares of either wheat or rye (each 69.0%) were fed to ileo-caecally fistulated, adult minipigs. Ileal digesta and faeces were collected and ileal, total tract and postileal digestibility rates were calculated. In the apparent ileal digestibility (AID), significant differences were only found for organic matter (OM) and Nitrogen-free extract (NfE) with lower values for the rye-rich diets (77.2 ± 2.00 vs. 73.8 ± 2.01% and 79.8 ± 2.56 vs. 75.3 ± 2.61%, respectively). These differences could not be recovered for the total tract digestibility (ATTD - 90.2 ± 2.16 vs. 89.8 ± 1.94% and 93.0 ± 1.69 vs. 92.8 ± 1.37%, respectively), resulting in an elevated postileal digestibility which was significant for NfE (13.2 ± 2.42 vs. 17.5 ± 2.77%). Therefore, rye can be used to promote hindgut fill and fermentation in pig feeding, especially in restrictively fed animals such as pregnant sows.

Duckweed protein as an alternative plant-based protein source for dog and cat dry diets.

Duckweed has attracted increasing attention as a high-quality and sustainable novel plant-based protein source. However, little research has been conducted in dogs and cats. We evaluated the effects of inclusion of duckweed protein (Lemna; MCSelect; Parabel; Vero Beach, FL) primarily in replacement of pea protein in dog diets at 0%, 5%, and 10% and cat diets at %, 10%, and 15% on stool quality, nutrient digestibility, and palatability. We hypothesized that duckweed protein would be a viable protein source in both dog and cat diets by showing no detriment to nutritional outcomes. All feeding tests were conducted at an independent research facility (Susquehanna, PA). A standard 2-bowl palatability test over a 2-d period was conducted with adult animals (n = 30 each) to determine intake ratio between test diets (duckweed-containing diets) and control diets (0% duckweed protein). Apparent total tract nutrient digestibility was conducted with 18 adult dogs and 21 adult cats (n = 6 to 7 per diet) with 5 d of diet acclimation followed by 5 d of total fecal collection. Stool quality was evaluated on a 1 to 5 scale where 1 = non-formed or diarrhea and 5 = hard, formed. Palatability data were analyzed using paired t-test (daily consumption) and chi-square test (first choice). All other data were analyzed by ANOVA and contrast (SAS version 9.4). For cats, 10% duckweed had greater (P < 0.05) palatability than control, while no difference was observed between 15% duckweed protein and control. For dogs, 5% and 10% duckweed protein had (P < 0.05) lower palatability, demonstrating a preference to control. Both cats and dogs fed duckweed diets had acceptable stool quality (Mean = 3.4 and 3.3, respectively). No detriments in nutrient digestibility were observed in dogs fed 5% and 10% duckweed protein; however, cats fed 10% and 15% duckweed protein had (P < 0.05) lower dry matter, protein, and energy digestibility vs. control. In conclusion, the data collected indicate that duckweed can be a viable replacement for other plant-based proteins in dog diets at inclusion levels up to 10%; more development is needed for duckweed protein inclusion into cat diets.

Duckweed, an aquatic plant rich in protein, holds promise as a sustainable plant-based protein for companion animals. However, the potential of duckweed protein in dog and cat diets has been relatively unexplored. In our study, we assessed the viability of incorporating duckweed protein into dog and cat diets by examining nutrient digestibility, stool consistency, and diet palatability. Our findings indicate that including duckweed protein in dog diets maintains acceptable nutrient digestibility and improves stool quality, although it may impact diet palatability. For cats, duckweed protein inclusion led to reduced nutrient digestibility, looser stool, and lower diet palatability. While duckweed protein shows potential as a suitable plant-based protein source for dogs, further development is necessary before considering it for cat diets.

Determination of calcium digestibility and bioavailability in 5 limestone sources using commercial broiler and crossbred chickens.

Three experiments were conducted to determine effect of feeding 5 commercial limestones varying in solubility (88-97%), mean particle size (500-700 microns), and geographical origin on Ca bioavailability and digestibility in commercial broiler and crossbred chickens. In Experiment 1, both crossbred and commercial chickens were used to measure the effect of dietary Ca level on tibia bone ash to develop a slope-ratio Ca bioavailability assay. Chickens were fed diets that contained Ca levels ranging from 0.20% to 0.95% from 9 to 22 d-of-age. Regressions of bone ash (mg/tibia and %) on supplemental Ca intake yielded large linear responses in both types of chickens in Experiment 1. In Experiment 2, relative bioavailability of Ca in 5 limestones using bone ash as primary response criterion was determined. Thirteen diets were fed to commercial Ross 308 male broilers which were either a Ca-deficient diet (0.30% Ca) or that diet supplemented 0.15 or 0.30% Ca from either reagent grade calcium carbonate (RCaCO3) or 1 of the 5 commercial limestones from 9 to 22 d-of-age. Bioavailability of Ca in limestones relative to RCaCO3 was determined using multiple linear regression of bone ash (mg/tibia and %) on supplemental Ca intake, which yielded slope-ratio relative Ca bioavailability values ranging from 90% to 106% in Experiment 2. In Experiment 3, apparent ileal digestibility (AID) and apparent total tract retention (TTR) of Ca in broiler chickens was measured for the 5 limestones using corn-based diets. The AID and TTR of Ca at 21 d-of-age were low and variable with a range of 20 to 34% for AID of Ca and 12 to 31% for TTR of Ca. Results from these studies indicate that a slope-ratio bone ash assay with either crossbred or modern commercial chickens can be used to measure relative bioavailability of Ca in limestones and there were few consistent differences in relative Ca bioavailability, AID of Ca, and TTR of Ca among 5 commercial limestones evaluated herein.