Digestible Content Research Articles

Blend of essential oils can reduce diarrheal disorders and improve liver antioxidant status in weaning piglets.

This study was to assess the effects of different doses of an essential oil blend (EOB) on growth performance, diarrhea occurrence (DO), hematological and blood biochemical profile, intestinal morphometry, morphology and microbiology, relative weight and length of organs, digestive content pH, and liver antioxidant status in weaning piglets. A total of 135 barrows (7.09±0.29 kg body weight) were allotted randomly in a randomized complete block design based on body weight with nine replications and three animals per pen. Dietary treatments were a negative control (NC): basal diet; positive control (PC): NC plus 125 mg performance-enhancing antibiotic (enramycin 8%)/kg diet; NC plus 100 mg EOB/kg diet (EO100); NC plus 200 mg EOB/kg diet (EO200); and NC plus 400 mg EOB/kg diet (EO400). Diarrhea occurrence was monitored daily, and performance at the end of each phase. Gain to feed ratio was greater (p<0.05) in starter II pigs fed EO400 and EO200 than in those fed EO100. Pigs fed EO400 had lower (p<0.05) DO than those fed NC and EO100 in the total period. Pre-starter II pigs fed NC had (p<0.05) lower serum total protein and plasma protein than pigs fed PC. Pigs fed EO100 showed smaller (p<0.05) mean corpuscular volume (MCV) than pigs fed EO400. Starter II pigs fed EO400 had (p<0.05) greater MCV and lower mean corpuscular hemoglobin and erythrocytes than those fed EO100. There was a greater concentration (p<0.05) of band cells for PC, similar to EO400 and EO200. Performance-enhancing antibiotic and EOB to diets increased (p<0.05) liver superoxide dismutase activity. Adding 200 and 400 mg EOB/kg diet decreased DO and was advantageous to hematological and blood biochemical profile and liver antioxidant status without being detrimental to growth performance and gastrointestinal health in nursery pigs.

The first reported case of accidental intestinal myiasis in a domestic dog by the flesh fly, Sarcophaga africa (Wiedeman, 1824)

Myiasis occurs when fly larvae, or maggots, feed on the tissue, secretions or digestive content of a live vertebrate. Here, a rare case of accidental intestinal or enteric myiasis is reported in a domestic dog. The species of fly is molecularly identified as Sarcophaga africa (Wiedeman, 1824) using the barcoding region of cytochrome oxidase I (COI). A brief critique on the usage of the term “pseudomyiasis” is provided and the complex taxonomy of S. africa is briefly summarised in order to shed light on the erroneous use of S. cruenata and S. haemorrhoidalis with obvious downstream effects. Finally, a comparative assessment to the limited cases in the literature is provided. These few cases are however highly fragmented and our understanding of accidental intestinal myiasis and the clinical manifestations thereof remain incomplete.

Structure-digestibility relationships in the effect of fucoidan on A- and B-wheat starch

Fucoidans (FC) have a variety of biological activities, and it can also affect the functionality and nutritional characteristics of starch-based food products. However, there are few studies on the structural and digestive properties of starch - fucoidans blends. The effect of FC at different concentrations (0, 0.6 %, 0.8 %, 1.0 %, w/v) on the structural properties and digestibility properties of A-type wheat starch (AS) and B-type wheat starch (BS) subjected to autoclave treatment were investigated. The results show that compared with native wheat starch, AS with FC displayed higher crystallinity as well as the structural ordering, but the crystallinity and degree of order of BS with FC decreased, which was proposed due to AS interact with FC in crystalline region but BS reacts with FC in the amorphous region. With the interaction of FC with AS and BS, granules compactness of AS and BS were enhanced. The addition of FC delayed digestion in vitro of AS and BS, the rapidly digestible starch content was obviously lower than native one, and the proportion of slowly digestible starch raise markedly. This study might broaden the recognition of wheat starch with different proportion of AS and BS, and provide a theoretical basis for the potential utilization of FC in carbohydrate based food industry.

Osteogenic activities of four calcium-chelating microalgae peptides.

Adequate calcium intake is necessary to prevent osteoporosis, which poses significant public health challenges. The natural bioactive peptide calcium chelates have been regarded as superior calcium supplements. Microalgae peptides are regarded as potential candidates for protection from bone loss in osteoporosis. This study aimed to prepare microalgae calcium-chelating peptides from four microalgae proteins and assess their osteogenic activities in osteoporosis-like zebrafish. After in vitro gastrointestinal digestion, 4.42% Chlorella pyrenoidosa protein, 2.74% Nannochloropsis oceanica protein, 6.07% Arthospira platensis protein and 10.47% Dunaliella salina protein were retained. The calcium-chelating capacities of four microalgae protein hydrolysates (MPHs) ranged from 14.10 ± 7.16%to 34.11 ± 9.34%. CaCl2 addition increased the maximum absorption peaks, absorption intensities and particle sizes of MPHs. Calcium-chelating MPHs showed stronger osteogenic activities than MPHs in the osteoporosis-like zebrafish model, with significantly increased mineralized tissue area and integrated optical density. Microalgae proteins have favorable digestibilities. Among the four MPHs, Nannochloropsis oceanica protein hydrolysates showed the highest calcium-chelating capacity, which might be due to its high degree of hydrolysis after in vitro digestion and high content of Ser, Tyr, Thr, Asp and Glu. The absorption intensities and particle sizes of MPHs both increased after calcium addition. MPH treatment could reverse dexamethasone-induced osteoporosis of zebrafish, and MPHs-Ca chelates showed higher osteogenic activities in osteoporosis-like phenotype zebrafish. © 2022 Society of Chemical Industry.

Effects of maltogenic α-amylase treatment on the proportion of slowly digestible starch and the structural properties of pea starch

In this study, pea starch was modified with maltogenic α-amylase and then its physicochemical properties, chain length distribution, and in vitro digestibility were examined. An analysis of the starch products resulting from the maltogenic α-amylase treatment revealed a decrease in the molecular weight, an increase in the proportion of short chains [degree of polymerization (DP) <13], a decrease in the proportion of long chains (DP > 13), and a decrease in viscosity, resulting in slower digestion. The results indicated that maltogenic α-amylase can selectively hydrolyze α-1,4- and α-1,6-glycosides to some extent. Cleaving the α-1,4 linkage of starch facilitated the transfer of the non-reducing D-glucosyl residues of maltose, thereby generating an α-1,6 branch linkage. The reaction between maltogenic α-amylase and pea starch was affected by the reaction time and enzyme concentration. The maximum slowly digestible starch content (38.5%) was obtained by digesting samples with 60.0 ppm maltogenic α-amylase for 4.0 h. These findings demonstrate that modifying pea starch using maltogenic α-amylase can generate starch products with new branching structures conducive to slow digestion.

The Effects of Making Silage at Different Ratios of Sunflower and Sugar Beet on Silage Quality, In-Vitro Digestibility and Energy Content

Bu çalışma, ayçiçeği hasılı ve şeker pancarı bitkisinden kaliteli bir silaj elde etmek için, en uygun karışım oranlarının belirlenmesi amacıyla gerçekleştirilmiştir. Araştırmada hamur olum döneminde biçilen silajlık ayçiçek hasılı (tam bitki) ve şeker pancarı (yapraklar ve baş dahil tam bitki) silaj materyali olarak kullanılmıştır. Ayçiçek hasılı (A) ve şeker pancarı (ŞP) bitkileri ağırlık esasına göre %100A ve %0ŞP, %85A ve %15ŞP, %55A ve %45ŞP olacak şekilde doğranıp karıştırılarak bir litrelik cam kavanozlarda 5’er tekerrür olacak şekilde silolanmıştır. Kavanozlar 70 günlük inkubasyon süresi sonrasında analizlerin yapılması için açılmıştır. %100A ve %0ŞP, %85A ve %15ŞP, %55A ve %45ŞP gruplarında silaj kuru madde (KM, %) değerleri 24.97, 26.29 ve 28.72; silaj pH değerleri 4.39, 4.34 ve 4.41; amonyak azotu (NH3-N, mg.dl-1) değerleri 5.59, 3.65 ve 4.34; laktik asit (LA, %) değerleri 2.41, 1.91 ve 2.16; Fleig puanı nitelik değerleri iyi, pekiyi ve pekiyi; organik madde sindirilebilirliği (OMS, %) değerleri 54.60, 51.34 ve 49.42; metabolik enerji (ME, Mcal.kg-1) değerleri 1.97, 1.87 ve 1.79; net enerji laktasyon (NEL, Mcal.kg-1) değerleri ise, 1.22, 1.14 ve 1.09 olarak bulunmuştur. Çalışmada hazırlanan silajların ham besin madde kompozisyonu, fermantasyon kalite parametreleri ve in-vitro sindirilebilirlik değerleri ile enerji içerikleri dikkate alındığında, gerek saf ayçiçek hasılı, gerekse ayçiçek hasılı ve şeker pancarı karışımından, her hangi bir katkıya ihtiyaç duyulmaksızın, kaliteli silajlar elde edilebileceği; ancak %45 düzeyinde şeker pancarı bitkisi katkılı grupta OMS ve enerji içeriklerinde düşüş gözlendiği sonucuna varılmıştır.

Making a meal out of bugs

Making a meal out of bugs

Digestible and metabolizable energy prediction models in guinea pig feedstuffs

ABSTRACT In the formulation of rations for guinea pigs, the energy value of the food and the requirements should be expressed as digestible energy (DE) or metabolizable energy (ME); the chemical composition tables do not report values for this species. The conventional determination of DE and ME of the feedstuffs requires animal experimentation, personnel, and specialized high-cost equipment. Study objective was developed mathematical models to estimate DE and ME using chemical composition and digestibility data from 26 forages, 8 dry agro-industrial wastes and 23 concentrated feeds, generated in previous studies using 5 male guinea pigs aged 5–6 months at 600–700 g of weight in each trial. Multiple hierarchical linear regression in SPSS 23 was used to generate the prediction models. Equations based on total digestible nutrient content served as standard equations for comparison with models generated based on . The best fitted equations for predicting ME content were those using DE ( = 0.966), and dry matter, crude protein, crude fiber, organic matter, and organic matter digestibility ( = 0.910). Other equations were generated to predict DE and ME of guinea pig feeds, using other proximal components and digestibility coefficients, with greater than 0.9.

Human-edible protein contribution of tropical beef cattle production systems at different levels of intensification

Sustainable intensification of tropical grasslands has been identified by researchers and stakeholders as a solution to decrease greenhouse gas emissions and deforestation. However, there are concerns about food security and the role of livestock in feed-food competition between animals and humans involving land and other resources. We aimed to determine the net protein contribution (NPC), a feed-food competitiveness index, of tropical beef cattle raised on extensive systems or finished in pastures or conventional feedlots, under different levels of intensification. We modelled five scenarios, from cow-calf to slaughter, based on common beef cattle practices in Brazil, whose main production system is grazing. Scenario 1 represented the lowest level of intensification and the most extensive system. Scenario 2 represented a moderately extensive system. Scenarios 3, 4, and 5 represented different degrees and practices of intensification, with animals in cow-calf and stocker phases raised solely on well-managed permanent pastures. In Scenario 3, the animals were finished in a feedlot. In Scenarios 4 and 5, all animals in the stocker phase received a protein-energy supplement, but in Scenario 4, animals were finished in a permanent pasture with high-concentrate intake. In Scenario 5, animals were finished in a feedlot. The human-edible protein (heP) conversion efficiency (hePCE) was calculated as the ratio of heP produced (meat) to heP consumed as feed, and the NPC was the product of hePCE using the protein quality ratio, accounting for the digestible indispensable amino acid score content. An hePCE > 1 indicated that meat production did not compete with humans for food, and an NPC > 1 indicated that it contributed positively to meet human requirements. Meat production and heP intake consistently increased with intensification. The greatest hePCE values were from Scenarios 1 (9.2), 2 (2.2), and 3 (1.2), which were essentially pasture-fed systems, compared to Scenarios 4 and 5 (average of 1.0). The NPC varied from 24.1 (Scenario 1) to 2.6 (Scenario 5). The area required to produce 1 kg of carcass decreased from 147 to 45 m2, and the slaughter age decreased from 36 to 21 months from the most extensive to intensive systems. Brazilian beef cattle production contributes positively to the protein requirements of humans without limiting human food supplies. The intensification of tropical grazing beef systems is a key strategy to save land and produce more meat without limiting food for humans, playing an important role in the food security agenda.

Effects of ultra-high pressure combined with cold plasma on structural, physicochemical, and digestive properties of proso millet starch

In this study, proso millet starch was isolated and subjected to treatment with ultra-high pressure (UHP), cold plasma (CP), or their combination to modify its functional properties. The changes in structural, physicochemical, and digestive properties of proso millet starch after these treatments were investigated. The proso millet native starch granules showed irregular and polygonal shapes with a smooth surface. Treatments with CP or UHP at low pressures did not change the morphological properties or crystalline structure type of proso millet starch granules, while the treatment with UHP at 600 MPa and CP resulted in a complete gelatinization of starch. Also, UHP treatment at high pressure, followed by CP treatment, destroyed the partial crystalline region and reduced the short-range order of proso millet starch. Besides, a combination of UHP and CP treatment promoted the depolymerization of long chains in proso millet starch. Moreover, the combined treatments could enhance the resistance to high temperature and shearing and improve the pasting stability of starch. Furthermore, the combined treatment could increase the slowly digestible starch content. Therefore, the combination of UHP and CP treatment can be suggested for modifying the functional properties of proso millet starch and promoting its industrial applications.

How to synchronously slow down starch digestion and retrogradation: A structural analysis study

Digestibility and retrogradation properties of starch are important for the nutrition and quality of starch-based foods. In this study, a new idea on the synchronous delay the starch digestion and retrogradation was proposed, and the regulation mechanism was explored from perspectives of structural evolution using 13C NMR, XRD and SAXS techniques as well as the molecular dynamics simulations. Results showed that the chestnut starch treated with hot extrusion and 8% catechins (HE-8% CA)## could reach highest anti-retrogradation rate (AR 76.63%) and lowest rapidly digestible starch content (RDS 64.55%) at day 24. The starch digestion was slowed down by increasing single/double helix, V-type crystallinity and compactness of aggregates, while retrogradation process was suppressed by inhibiting the packing of short-range ordered structure into long-range ordered structure. The hydrogen bonding and van der Waals forces were the main driving force for the interactions between flavonoid polyphenols and starch molecules. Overall, this study is instructive for further investigations on the synchronous modulation of functional properties of starch.

Kithul (Caryota urens) treacle: A healthy natural sweetener?

Incidence of non communicable diseases such as diabetes, cardiovascular disease (CVD), several forms of cancer, hypertension, obesity etc is increasing in our country. It is suggested that these diseases can be moderated, in part, by consuming foods that produce a low blood sugar response. It is presumed that kithul treacle is comparable to simple sugars for sweetness, although currently the beneficial effects are not widely known. To assess the chemical composition and glycaemic indices (GI) of kithul treacle and confectionary (aluwa) made using table sugar and kithul treacle. Chemical composition was analysed with standard AOAC methods. FAO/WHO guidelines were used to determine the glycaemic responses with glucose as the standard. The moisture, crude protein, crude fat, total carbohydrate, starch & glucose and total dietary fibre contents of treacle were 28%, 0.3%, 7.9%, 81%, 28% and 2.20% (DM) with negligible ash content. Similarly both aluwa had negligible ash contents. Total carbohydrate (88-89%), fat (2.9%), protein (3.7-4.2%) and total dietary fibre (7.78-8.32%) contents of both aluwa were not significantly different. However, the digestible carbohydrate contents of treacle (67%) and sugar aluwa (59%) were significantly different (p<0.05). The GI of kithul treacle, aluwa made with treacle and sugar were 35, 55 and 63 respectively. Kithul treacle was categorized as a low GI food whereas both aluwa were categorized as medium GI foods. In comparison to aluwa made with table sugar, the glycaemic response of aluwa made with treacle was lower proving that replacing sugar with treacle leads to lower glycaemic response.

Effects of Dietary Babassu Oil or Buriti Oil on Nutrient Intake and Total Tract Digestibility, and Abomasal Digesta Fatty Acid Profile of Lambs.

Simple SummaryThis research tested the effects of adding babassu oil (450 g/kg C12:0 of total fatty acids—FA) or buriti oil (750 g/kg C18:f total FA) to the diet of lambs on intake, nutrient digestibility, FA profile of abomasal digesta content and biohydrogenation patterns in digestive content. Both are widely available in the Northeast of Brazil and Amazon region. Our results provide evidence that the babassu supplemented diet promotes greater stress to the ruminal bacteria (due to the high concentration of C12:0), changing the normal biohydrogenation of polyunsaturated FA (PUFA) in the rumen, and the FA concentration that flows to the abomasum, compared to the buriti oil supplemented diet, which provided similar results to the non-supplemented diet.Our current understanding of the effect of medium-chain FA (MCFA) rich vegetable oils on ruminant nutrition is limited. We assessed the effects of babassu or buriti oil addition to the diet of lambs on intake, nutrient digestibility, FA profile of abomasal digesta content and biohydrogenation (BH) patterns in digestion. The experimental diets were defined by the addition of babassu oil or buriti oil to the diet, as follows: (1) non-supplemented diet (CON); (2) 40 g/kg of babassu oil (BAO, rich in C12:0); and (3) 40 g/kg of buriti oil (BUO, rich in c9 18:1), on a dry matter (DM) basis. During the last five days of the feedlot, samples of orts and feces were individually collected to determine the nutrient and FA digestibility. At the end of the experiment, animals were slaughtered, and the abomasal digesta was collected, freeze-dried and used for FA determinations conducted by gas chromatography. The BAO diet decreased the DM (p = 0.014) and nutrient intake. The lambs fed BUO had the greatest FA intake, followed by the BAO and CON diets. However, BAO increased total FA digestibility, compared with CON, but did not differ from BUO. The BAO diet extensively changed the FA composition of abomasal digesta when compared with both the CON and BUO diets. The BAO diet also increased C12:0 and C14:0, the sum of PUFA and the BH intermediates FA, including the t-10-18:1 but decreased the C18:0 in abomasal digesta. The BUO addition had the greatest total-FA and C18:0 and the lowest biohydrogenation intermediate content in abomasal digesta. The BH was less complete with the BAO diet and a large increase in t10-18:1 and of t10-/t11-18:1 ratio was observed, which indicates the occurrence of t10 possibly shifted rumen BH pathways, probably as a response to bacterial membrane stress induced by the greater C12:0 concentration in the rumen.

Cross sectional epidemiological study of the severity of buccal ulceration and sharp enamel points in ridden and unridden horses

ABSTRACT The process of domestication of the horse introduced changes limiting accessibility to graze land and roughage while increasing highly digestible carbohydrates content of meal-fed rations. We have tested whether the effect of a higher degree of human contact impacts horses’ welfare by assessing the development of sharp enamel points (SEP) and buccal ulcerations (BU) in ridden and unridden horses. We were able to fit logistic regression models significantly differentiating the impact of these two conditions in both groups of horses (p < 0.001 for SEP and p < 0.01 for BU). The impact is higher in ridden horses for both conditions. These two conditions were found to correlate positively (ρ = 0.63, p < 0.001). We argued that human contact may impact on horses’ welfare. Further studies may help to clarify this impact with more detail. Dentistry may be helpful to provide improved welfare conditions; however, without regular access to grazed land, the stabled horses’ welfare may be at stake.

The effect of the dietary inclusion of pea seeds of colored-flowered and white-flowered varieties on gastrointestinal function in turkeys.

This study investigated the effects of dietary replacement of soybean meal (SBM) with graded levels of pea seeds (PS) on the gastrointestinal function of turkeys. Seeds of 2 pea varieties, a colored-flowered variety and a white-flowered variety (CFP and WFP, respectively) were fed to 56-d-old birds for 8 wk. A total of 539 female Hybrid turkeys were allocated to 7 groups, each group consisted of 7 pens with 11 birds per pen. The experiment had a 2-factorial design, with 3 dietary inclusion levels of PS (100, 200 and 300 g/kg) and 2 pea varieties (CFP and WFP). The control group (diets without PS) was compared with CFP and WFP treatments by simple contrast analysis. In comparison with CFP seeds, WFP seeds contained 7-fold less tannins (0.67 vs. 4.66 g/kg) and less non-starch polysaccharides (NSP, 117.8 vs. 132.7 g/kg), but more trypsin inhibitors (1.34 vs. 0.98 g/kg) and starch (489 vs. 455 g/kg). A rise in the PS content of diets from 100 to 200 and 300 g/kg increased the weight of the small intestine (P = 0.031) and the dry matter (DM) content of intestinal digesta (P = 0.001), but it had no effect on the pH of digesta. Only the highest PS content differentiated the concentrations of short-chain fatty acids (SCFAs) in the small intestinal digesta (WFP > CFP, P = 0.008), whereas PS did not cause any changes in the morphological parameters of the small intestinal mucosa. The dietary inclusion of PS had no influence on the levels of acetate, butyrate, putrefactive SCFAs or total SCFAs in the cecal contents. Apart from increasing the activities of β-glucosidase (P = 0.017) and β-galactosidase (P = 0.025), pea varieties did not affect the activities of the analyzed cecal microbial enzymes. However, CFP seeds decreased the DM content (P = 0.041) and increased the pH of cecal digesta, compared with WFP seeds (P = 0.013). The results of this study, pointing to a few differences in the functional parameters of the small intestine and cecum, indicate that tannins are not a factor differentiating the suitability of CFP and WFP seeds in the nutrition of finisher turkeys. The inclusion of PS at 200 and 300 g/kg of the diet reduces the content of SBM and wheat in turkey diets, which has a positive effect on gastrointestinal function.

Effects of oral glutamine supplementation on jejunal morphology, development, and amino acid profiles in male low birth weight suckling piglets.

BackgroundIt has been shown that small intestine development in low birth weight (LBW) piglets is impaired. Glutamine (Gln) has been reported to improve piglet health and intestinal function in weaned piglets, but data is scarce in suckling piglets. This study was conducted to investigate the effects of oral Gln supplementation compared to Alanine (Ala) on jejunal development and function in 5 and 12 d old male LBW and normal birth weight (NBW) suckling piglets.ResultsGln had no effect on the jejunal morphology, development, tissue and digesta amino acid profiles and mRNA abundance of genes involved in amino acid transport, metabolism, glutathione synthesis in LBW piglets when compared to Ala supplementation and birth weight controls at 5 and 12 d. Only the concentration of Gln in jejunal tissue was higher in NBW piglets supplemented with Gln compared to Ala at 5 d (P < 0.05). A comparison of the birth weight groups showed no differences between LBW and NBW piglets at 5 and 12 d in any parameter. Jejunal crypt depth, villus height / width, tunica muscularis thickness, number of goblet and IgA positive cells, the ratio of jejunal RNA to DNA and the concentration of DNA, protein and RNA changed (P < 0.05) from 5 compared to 12 d. The concentrations of several free, and protein bound amino acids as well as amino metabolites differed between age groups in jejunal tissue but the digesta concentrations were affected to a lesser extent.ConclusionsOral Gln supplementation to suckling male piglets over the first 12 d of life was not associated with changes in jejunal parameters measured in this study. The absence of effects may indicate that Gln is absorbed as well as metabolized in the upper intestinal tract and thus could benefit intestinal development at a more proximal location.

Potential benefits of Moringa peregrina defatted seed: Effect of processing on nutritional and anti-nutritional properties, antioxidant capacity, in vitro digestibility of protein and starch, and inhibition of α-glucosidase and α-amylase enzymes

This study aimed to eliminate the bitter taste of Moringa peregrina press cake (MPC) as a byproduct of oil extraction (by employing safe and conventional methods) and evaluating its potential for formulating value-added food products. The characteristics (nutritional and anti-nutritional properties, monosaccharide composition, in vitro starch and protein digestibility, antioxidant capacity, and in vitro α-glucosidase, and α-amylase inhibitory activity) of raw, debittered (soaked in distilled water and boiled), and roasted (after debitterization) MPC flours were determined. Debitterization significantly increased total protein, fiber, arabinose, xylose, antioxidant activity, in vitro protein digestibility, and α-amylase inhibitory activity, whereas it decreased total starch, resistant starch, starch digestibility, ash, glucose, phytic acid, tannin, and oxalate contents. Fiber content, protein digestibility, α-amylase inhibitory activity, and antioxidant activity were further increased as the result of roasting. MPC and its products could inhibit α-amylase activity, with the highest inhibition belonging to roasted debittered samples. The current study is the first to report on the comprehensive nutritional and bio- and physicochemical aspects of Moringa peregrina press cake and the effect of treatments on improving its sensorial, nutritional, and health-promoting properties. Therefore, these results indicate the potential of treated MPC as a novel natural functional ingredient for various food formulations.

Moderate adiposity levels counteract protein metabolism modifications associated with aging in rats

Physiological parameters such as adiposity and age are likely to influence protein digestion and utilization. The aim of this study was to evaluate the combined effects of age and adiposity on casein protein and amino acid true digestibility and its postprandial utilization in rats. Four groups were included (n = 7/8): 2months/normal adiposity, 2months/high adiposity, 11months/normal adiposity and 11months/high adiposity. Rats were given a calibrated meal containing 15N-labeled casein (Ingredia, Arras, France) and were euthanized 6h later. Digestive contents were collected to assess protein and amino acid digestibilities. 15N enrichments were measured in plasma and urine to determine total body deamination. Fractional protein synthesis rate (FSR) was determined in different organs using a flooding dose of 13C valine. Nitrogen and amino acid true digestibility of casein was around 95-96% depending on the group and was increased by 1% in high adiposity rats (P = 0.04). Higher adiposity levels counteracted the increase in total body deamination (P = 0.03) that was associated with older age. Significant effects of age (P = 0.006) and adiposity (P = 0.002) were observed in the muscle FSR, with age decreasing it and adiposity increasing it. This study revealed that a higher level of adiposity resulted in a slight increase in protein and individual amino acid true digestibility values and seemed to compensate for the metabolic postprandial protein alterations observed at older age.

Differential Effects of Natural Grazing and Feedlot Feeding on Yak Fecal Microbiota.

Variation in food and diet shapes the diversity of the gut microbiota of ruminants. The present study investigated the microbial diversity in the fecal microbiota of yaks reared under natural grazing and feedlot system. A total of 48 domestic yaks with an average age of 7.5 years were selected from two different grazing habitats: one group grazed on natural pasture (grazing yaks—GY) while the other group was fed fodder and concentrate (feedlot yaks—FY). Crude protein, non-fiber carbohydrate, hemicelluloses, and digestible dry matter contents of natural pastures were higher than those in the feedlot. The lower insoluble fiber contents were found in grazing land. The 16S rRNA gene sequencing revealed 675 and 348 unique operational taxonomic units (OTUs) in the GY and FY, respectively, in addition to 1,778 common OTUs. Overall, a total of 9,891 OTUs were identified as a whole, of which 6,160 OTUs were from GY and 3,731 were from FY. Shannon index analysis revealed a higher bacterial diversity in GY than FY. At the phylum level, Firmicutes were dominant bacterial taxa in both groups. The relative abundance of Firmicutes in GY (56% ± 0.05) was higher than in FY (41% ± 0.08). At the family level, GY had a significantly higher abundance of Ruminococcaceae (p < 0.001) and Rikenellaceae (p < 0.001) than FY, but FY had a significantly higher abundance of Prevotellaceae than GY (p < 0.001). At the genus level, abundances of Faecalibacterium, Alloprevotella, and Succinivibrio were higher in FY than in GY. This study presents novel information on fecal bacterial composition and diversity in yaks reared under two different production systems.

Varying apparent metabolizable energy concentrations and protease supplementation affected broiler performance and jejunal and ileal nutrient digestibility from 1 to 35 d of age

An experiment was conducted to evaluate the effects of varying AME concentrations and protease supplementation on broiler performance and jejunal and ileal nutrient digestibility from 1 to 35 d of age. Ross × Ross 308 male broilers (n = 1,008) were equally distributed into 48 floor pens and offered 1 of 6 dietary treatments (8 replicate pens/treatment). Dietary treatments consisted of a factorial arrangement with AME concentration (low-, moderate-, or high-AME) and supplemental protease (without or with) as the main factors. Birds and feed were weighed on 1, 15, 29, and 35 d of age to determine body BW, BW gain (BWG), feed intake (FI) and feed conversion ratio (FCR). At 15 and 29 d of age, jejunal and ileal digesta contents were collected to determine nutrient digestibility. From 1 to 15 d of age, broilers offered moderate-AME diets (P < 0.05) had 6.7, 7.1, 4.8% higher BW, BWG, FI, respectively, and a 2.1% lower FCR compared with those offered low-AME diets. Likewise, protease increased (P < 0.05) BW and BWG by 4.3 and 4.7%, respectively, and decreased (P < 0.05) FCR by 3.4%, compared with those offered the diets without protease. From 1 to 29 d of age, broilers offered high-AME diets had 2.9% lower (P < 0.05) FCR compared with those offered low-AME diets. Protease increased (P < 0.05) BW, BWG, and FI by 3.1, 3.2, and 4.2%, respectively, compared with the unsupplemented diets. From 1 to 35 d of age, broilers receiving high-AME diets had 2.9% lower (P < 0.05) FCR compared with those offered low-AME diets. Protease increased (P < 0.05) FCR by 1.0% compared with those offered unsupplemented diets. Jejunal (15 and 29 d of age) and ileal (29 d of age) starch digestibility and jejunal nitrogen digestibility (29 d of age) were lower (P < 0.05) in broilers offered high-AME diets compared with those offered low-AME diets. Both AME concentration and supplemental protease independently affected broiler performance, with responses being most apparent during early growth phases whereas digestibility measures were mainly influenced by AME concentration.