Apparent Faecal Digestibility Research Articles

Effect of degraded flaxseed meals on the growth performance, nutrient digestibility, and health status of broilers.

The present study evaluated the effect of flaxseed meal degraded by a protease, Lactobacillus plantarum, or both on the growth performance, nutrient digestibility, and health status of broilers. There were four diets containing flaxseed meals in its non-degraded form (control, CON), degraded with 3,000 U/kg of protease (ELM), 1.0×109 CFU/kg of Lactobacillus plantarum (FLM), or both (DLM). Each form of flaxseed meals was added at 15% of diet. A total of 480 yellow-feathered broilers at 22 d of age were distributed into 4 groups with 6 replicates of 20 chickens each. The feeding trial lasted for 42 d. Growth performance, apparent fecal digestibility (dry matter, energy, crude protein, and ash), and serum immunoglobins and antioxidases were determined at 42 and 63 d of age. Results showed that ELM, FLM, and DLM increased (p<0.001) the contents of peptides and decreased (p<0.001) cyanogenic glycosides, compared to CON. The diets with degraded flaxseed meals increased (p<0.05) feed intake and body weight gain throughout the feeding trial, and the digestibility of energy, crude protein, and ash at the end of feeding trial. Furthermore, all degraded groups enhanced (p<0.05) broiler health status by increasing serum immunoglobulins A and G. Additinally, DLM showed more pronounced effects (p<0.05) on these parameters than ELM or FLM. Flaxseed meals degraded by enzymolysis, fermentation, or both had improved nutrition and application in broilers.

Effect of lysophospholipids on the growth performance, nutrient digestibility, lipid metabolism and meat quality of fattening rabbits

ABSTRACT The present study aimed to investigate the effect of emulsifier lysophospholipids (LP), enzymatically modified from soy phospholipids, on the growth performance, nutrient digestibility, lipid metabolism and meat quality of fattening rabbits. The LP was added in control (CON), LP1, LP2 and LP3 at 0, 200, 400 and 600 mg/kg, respectively. A total of 240 rabbits at approximately 52 d of age were divided into 4 groups with 6 replicates of 10 rabbits each. The feeding trial lasted for 42 d. Results showed that compared to CON, LP1, LP2 and LP3 increased (p < 0.05) body weight gain, feed efficiency, the apparent faecal digestibility of gross energy, crude protein and ether extract, the percentages of dissectible fat and ether extract in the longissimus and legs, the serum contents of apolipoprotein B, free fatty acid and total phospholipids in the longissimus, but decreased (p < 0.05) serum total triglyceride and total cholesterol. Meanwhile, LP1, LP2 and LP3 had higher (p < 0.05) carcass weight, longissimus weight and percentages of foreleg and hindleg than the CON; and the three LP diets also increased (p < 0.05) the tenderness, lightness and redness of longissimus. It is concluded that soy LP as an emulsifier can improve the growth, digestibility and meat quality of fattening rabbits.

Effect of a Bacillus-Based Probiotic on Performance and Nutrient Digestibility When Substituting Soybean Meal with Rapeseed Meal in Grower-Finisher Diets.

The objective of the present study was to test the hypothesis of B. subtilis and B. licheniformis supplementation to a negative control diet in comparison to a standard control diet, had the potential to improve the performance and nutrient digestibility of growing-finishing pigs. For this purpose, 384 fattening pigs of 85 d of age were allotted to three treatments: a standard diet, a negative control (NC) diet (5% soybean meal replaced by 5% rapeseed meal), or a NC diet + probiotic. After reaching a body weight of approximately 110 kg, all animals going to the slaughterhouse (87% of total pigs) were selected to measure carcass quality. Moreover, the apparent total tract digestibility of protein was evaluated at the end of the grower period. The results of this study indicate that supplementation of the tested Bacillus-based probiotic significantly improved average daily gain (ADG, +14.6%) and Feed:gain ratio (F:G, -9.9%) during the grower phase compared to the NC diet. The improvement observed during the grower phase was maintained for the whole fattening period (ADG, +3.9%). Probiotic supplementation significantly improved the total apparent faecal digestibility of dry matter and crude protein in pigs at the end of the grower period. The improvements observed with the additive tested could indicate that supplementation of the Bacillus-based probiotic was able to counteract the lower level of crude protein and standardised ileal digestible amino acids in the NC diet by means of improved protein digestibility.

Effect of Increasing the Methionine Level and Reducing the Threonine Level in the Diet of Fast-Growing Rabbits.

The main aim of this work was to evaluate a novel combination of the first limiting amino acids (lysine, methionine, and threonine) in fast-growing rabbits (combination MHL, shown to minimise levels of plasmatic urea nitrogen in previous research, medium level of lysine, high level of methionine, and low level of threonine) and compare it with current recommendations (combination MMM, medium level of all amino acids). A total of 165 weaned rabbits (28 d old) from a paternal line selected for growth rate were used in the growth trial. The effect of the diet on apparent fecal digestibility, as well as the apparent and true ileal digestibility, were studied. Nutrient retention was also determined. Although no differences in digestibility between diets were observed, animals fed with Diet MHL improved the global average daily gain (+2.3 g/d; p = 0.0482) and feed conversion ratio (-0.10; p = 0.0229). Animals fed with Diet MMM reduced the protein-to-energy ratio retained (p = 0.0086). In conclusion, Diet MHL promoted an improvement in growth traits in a paternal line. Consequently, we propose its levels of 6.4, 5.4, and 5.0 g/kg DM of true ileal digestible lysine, methionine, and threonine, respectively.

Dietary fibers with low hydration properties exacerbate diarrhea and impair intestinal health and nutrient digestibility in weaned piglets

BackgroundThis study aimed to investigate the hydration properties of different-source fibrous materials by comparing their water-binding capacity (WBC), water swelling capacity (WSC), viscosity, and in vivo effects of selected samples on growth performance, nutrient digestibility, diarrhea, and intestinal health in weaned piglets.MethodsA total of 13 commercially available fibrous materials were first compared in chemical composition and in vitro hydration property. Subsequently, 40 weaned piglets were randomized to five experimental dietary groups (8 piglets per group): control diet (a basal diet without dietary fiber, CON), basal diet supplemented with 5% microcrystalline cellulose (MCC), 5% wheat bran (WB), 5% Moringaoleifera leaf powder (MOLP), or 5% sugar beet pulp (SBP), followed by analyzing their growth performance and diarrhea rate in a 28-d experiment. After the feeding experiment, anaesthetized piglets were killed, and their intestinal and colon content or plasma samples were analyzed in nutrient digestibility, intestinal morphology, intestinal barrier, short-chain fatty acids (SCFAs), and bacterial population.ResultsIn vitro studies showed low hydration properties for WB and MCC, while medium hydration properties for MOLP and SBP. In vivo studies indicated that compared with medium hydration property groups, low hydration property groups showed (1) exacerbated diarrhea, impaired intestinal health, and reduced apparent fecal digestibility of dry matter, gross energy, acid detergent fiber, and neutral detergent fiber; (2) decreased SCFAs concentration and relative levels of Lactobacillus and Bifidobacterium, but increased levels of Escherichia coli and Brachyspira hyodysenteriae in colon contents. Additionally, SBP showed optimal performance in reducing diarrhea and increasing SCFAs production. Correlation analysis revealed a positive correlation of fiber hydration properties with in vitro SCFAs production, and diarrhea index and nutrient digestibility were negatively and positively correlated with SCFAs levels in the colon contents of weaned piglets, respectively.ConclusionsDifferent-source dietary fibers varied in their hydration properties and impacts on diarrhea, microbial composition and SCFAs production in weaned piglets. WB and MCC could exacerbate diarrhea and impair nutrient digestibility, probably because their low hydration properties were detrimental to gut microbial homeostasis and fermentation. Our findings provide new ideas for rational use of fiber resources in weaned piglets.

Effects of Protein Restriction and Succedent Realimentation on Jejunal Function and Bacterial Composition of Different Colonic Niches in Weaned Piglets.

Recent studies have proved that protein succedent realimentation could rescue the loss of growth performance in weaning piglets caused by a prior protein restriction. However, how the protein restriction and succedent realimentation influence the jejunal function and bacterial composition of different colonic niches microbiota in weaning piglets needs a further investigation. After protein succedent realimentation, we found that the treatment group (TRE) piglets had a higher IGF-1 content and IGF-1R gene expression level in jejunal mucosa than the control group (CON) piglets. The ZO-1 gene expression level was up-regulated in the jejunal mucosa of TRE piglets during protein restriction and succedent realimentation, while the jejunal permeability of TRE piglets was only decreased after protein succedent realimentation. In addition, we found that protein restriction and succedent realimentation increased the gene expression of Pept-1 and the fecal apparent digestibility of crude protein in TRE piglets, but decreased the fecal nitrogen content. After 16S rRNA MiSeq sequencing of bacteria in different colonic niches (mucosa and digesta), TRE piglets had a higher relative abundance of beneficial bacteria and a lower relative abundance of potential pathogens than CON piglets in different colonic niches after protein restriction and succedent realimentation. Our data showed that protein restriction and succedent realimentation decreased the concentrations of branch chain fatty acids and ammonia-N in the colon of TRE piglets. In addition, protein succedent realimentation increased the concentration of total short chain fatty acids in the colon of TRE piglets. All these findings demonstrated that the strategy of protein restriction and succedent realimentation is an effective way to improve intestinal health of weaning piglets, and provided new insights into the nutrition management of piglets during the weaning period.

Evaluación de las características fisicoquímicas y digestibilidad de un extrudido con frijol común para cerdos

Objetivo. Evaluar las propiedades fisicoquímicas, digestibilidad In vitro y digestibilidad aparente de nitrógeno en materia fecal y orina de cerdos de un alimento extrudido usando frijol (Phaseolus vulgaris L.) como sustituto de harina de soya. Materiales y métodos. Se estandarizó el proceso de extrusión para dos formulaciones de harina de frijol (Pinto Saltillo), harina de maíz (Cafime) y harina de soya a diferentes proporciones: 20/67/13% y 30/60/10%, respectivamente. Las muestras se procesaron en un extrusor monotornillo a 120-150°C y 18-22% de contenido de humedad. Las propiedades fisicoquímicas evaluadas fueron: índice de expansión, densidad aparente, índice de absorción de agua, índice de solubilidad en agua, dureza, actividad de agua y parámetros de color: L*, a* y b*. La digestibilidad In vitro y digestibilidad aparente de nitrógeno en materia fecal y orina de cerdos se evaluaron usando el tratamiento óptimo previamente obtenido buscando disminuir costos de procesamiento. Resultados. Las condiciones óptimas para la formulación de 20% de harina de frijol fueron 124.4°C y 18.59% de contenido de humedad. La temperatura de extrusión redujo la densidad aparente, dureza y actividad de agua, pero incrementó L* y el índice de expansión. El contenido de humedad redujo la densidad aparente, actividad de agua, dureza y a*. La digestibilidad In vitro de materia seca fue mayor para la dieta de frijol extrudido en comparación a la dieta control (92.33% vs. 85.33%). Conclusiones. Los resultados indican que la harina de frijol es una opción viable para el consumo animal en términos de valor nutricional y digestibilidad.

Effect of Feed Supplementation with Clostridium butyricum, Alone or in Combination with Carob Meal or Citrus Pulp, on Digestive and Metabolic Status of Piglets.

Simple SummaryDuring the intensive production of weaned piglets, frequent digestive disorders need to be avoided, as it is a critical phase; however, there are limitations to using antibiotics and ZnO at high levels. In this study, we investigate the inclusion of a probiotic (Clostridium butyricum) in combination with sources of fiber that might have a potential prebiotic effect, generating an optimal digestive status for weaned piglets. A trial is carried out using 30 post-weaning piglets for 27 days using five dietary treatments: a negative control, a positive control with high levels of ZnO, and three dietary treatments supplemented with Clostridium butyricum (alone or in combination with carob meal or citrus pulp). Supplementation with this probiotic could improve the piglets’ intestinal wellness status by increasing butyric acid, without being altered by the inclusion of carob meal or citrus pulp at 5%, obtaining digestibility values comparable with those realized by the incorporation of high levels of ZnO in the diet. In addition, carob meal could decrease the concentration of serum interleukin-8 (a type of pro-inflammatory cytokine). However, a growth performance trial of piglets in commercial conditions needs to be developed to confirm these effects.This work studied the effects of the inclusion of Clostridium butyricum on feed, alone or with carob meal or citrus pulp, on the digestive and metabolic status of weaned piglets. A total of 30 male piglets (weaned at 21 days) is used. There are five dietary treatments: negative without ZnO at high doses (C−), a positive control supplemented with ZnO at 2500 ppm of Zn (C+), supplemented with Clostridium butyricum as a probiotic (PRO), and supplemented with probiotic and 5% carob meal (PROC) or 5% citrus pulp (PROP). During the experiment (27 days), the piglets were periodically weighed and sampled for a serum biochemical, fecal microbiological, intestine histological, and digestive status analysis. The body weight, apparent ileal digestibility of dry matter (DM), and fecal microbiology were not affected by the treatments (p ≥ 0.05). However, the apparent fecal digestibility of DM was lower for the C− treatment than for C+ (p < 0.05), and the total concentration of volatile fatty acids (VFAs) in feces with C+ was lower than that for the PROC treatment (p < 0.05). The treatments with the probiotic had a higher molar proportion of butyric acid in feces than C+, and it was found that C− reached an intermediate value (p < 0.01). No general effects of diet were found on the histological measures performed on the jejunum and ileum, and in the serum biochemical analysis (p ≥ 0.05), only the concentration of interleukin-8 was lower for the PROC treatment compared to the C−, C+, and PRO treatments (p < 0.05). In conclusion, the intestinal wellness of piglets could be improved with the supplementation of Clostridium butyricum by increasing butyric acid, and this effect was not altered with the inclusion of carob meal or citrus pulp. More studies under commercial conditions are needed, as the effects might be different in more challenging environmental circumstances.

Variation in faecal digestibility values related to feed efficiency traits of grower-finisher pigs

Providing pigs a diet that matches their nutrient requirements involves optimizing the diet based on the nutrient digestibility values of the considered feed ingredients. Feeding the same quantity of a diet to pigs with similar BW but with different requirements, however, can result in a different average daily gain (ADG) and backfat thickness (BF) between pigs. Digestibility may contribute to this variation in efficiency. We investigated variation in feed efficiency traits in grower-finisher pigs associated with variation in faecal digestibility values, independent of feed intake at the time of measuring faecal digestibility. Considered traits were ADG, average daily feed intake (ADFI), feed conversion ratio (FCR), BF and residual feed intake (RFI). Feed intake, BW, and BF data of one hundred and sixty three-way crossbreed grower-finisher pigs (eighty female and eighty male) were collected during two phases, from day 0 of the experiment (mean BW 23 kg) till day 56 (mean BW 70 kg) and from day 56 to slaughter (mean BW 121 kg). Pigs were either fed a diet based on corn/soybean meal or a more fibrous diet based on wheat/barley/by-products, with titanium dioxide as indigestible marker. Faecal samples of one hundred and five pigs were collected on the day before slaughter and used to determine apparent faecal digestibility of DM, ash, organic matter (OM), CP, crude fat (CFat), crude fibre (CF), and to calculate the digestibility of nonstarch polysaccharides (NSPs) and energy (E). The effects of diet, sex and covariate feed intake at sampling (FIs) on faecal digestibility values were estimated and were significant for all except for CFat. Faecal digestibility values of each individual pig determined at the day before slaughter, corrected for diet, sex and FIs, were used to estimate their association with ADG, ADFI, FCR, BF, and RFI. In the first phase, a one percent unit increase in faecal digestibility of DM, ash, OM, E, CP, CFat, CF, NSP, and Ash individually was related to 0.01–0.03 unit reduction in FCR and 6–23 g/day reduction in RFI. A unit increase in CP digestibility was related to 0.1 mm increase in BF and 10 g/day increase in ADG. In the second phase, a one percent unit increase in faecal digestibility of DM, CP and Ash was related to a decrease of 16–20 g/day in RFI. In conclusion, the relationship between variation in feed efficiency traits and faecal digestibility values is different across the developmental stages of a pig.

Production performance and plasma metabolite concentrations of broiler chickens fed low crude protein diets differing in Thr and Gly.

The aim of the study was to test the interaction between Thr and Gly in low crude protein (CP) diets in 7 to 28 d broilers on production performance and plasma metabolites. A total of 2,040 broilers were allocated to 17 treatments. A positive control (PC) diet (20.5% CP) was formulated to be adequate in dietary Thr and Gly. A negative control (NC) diet (18.5% CP, deficient in Thr and Gly) was supplemented with crystalline l-Thr and Gly to obtain a 4 Thr × 4 Gly design. Dietary Thr was tested at an apparent faecal digestibility (AFD) Thr-to-Lys ratio, which was 55%, 58%, 61% or 64%, and dietary Gly was tested at an AFD (Gly + Ser)-to-Lys ratio, which was 135%, 142%, 149% or 156%. Plasma samples were collected at 28 d. The low CP diet, formulated at 64% Thr and 156% Gly, resulted in a higher body weight gain (BWG) (P < 0.01) and similar feed conversion ratio (FCR) as the high CP treatment (PC). FCR was improved (P < 0.001) by l-Thr supplementation. Quadratic response to dietary Thr was significant for feed intake (FI), BWG and FCR (P < 0.01). A near-significant interaction for Thr × Gly was observed for FI and BWG (Plinear = 0.091 and P = 0.074, respectively). Gly did not affect production performance. An interaction between Thr × Gly on plasma free AA level was observed (P < 0.05). Free AA concentration in plasma linearly decreased with increase in AFD Thr-to-Lys ratio, and increased with increase in AFD (Gly + Ser)-to-Lys ratio. Plasma uric acid concentration was higher in PC than in all of the other diets, and plasma triglyceride concentration was decreased by l-Thr supplementation, but not by Gly. In conclusion, Gly was not limiting for growth at low dietary CP level unless Thr was deficient, showing that adequate amounts of Thr in broiler diets can overcome marginal supply of Gly and Ser and allow reduction of dietary CP from 20.5% to 18.5% for broilers from 7 to 28 d of age.

Tepary bean (Phaseolus acutifolius) lectin fraction provokes reversible adverse effects on rats' digestive tract.

The Tepary bean (Phaseolus acutifolius) lectin fraction (TBLF) exhibits differential cytotoxicity on colon cancer cells and inhibition of early tumorigenesis in the colon (50mg/kg, three times per week, for 6weeks). TBLF showed low toxicity with the ability to activate the immune system; however, some adverse effects are the loss in body weight gain, intestinal atrophy, and pancreatic hyperplasia. After a recovery period of 2weeks after treatment, reversion of pancreatic hyperplasia but no recovery of intestinal atrophy was observed. As TBLF has shown anticancer effects on the colon, it is important to characterize the adverse effects and how they can be reversed. Sprague Dawley rats were administered with TBLF (50mg/kg) for 6weeks, three times per week, and then allowed to recover for 6weeks post-treatment. After TBLF administration, small intestine atrophy, villus atrophy, and cryptic hyperplasia were confirmed, as well as increased intestinal mucus production, increased permeability and a decrease in the apparent ileal digestibility of crude proteins. The colon showed damage in the simple prismatic tissue and decreased crypt depth, and changes in microbiota and a decrease in the apparent fecal digestibility of crude protein were determined. Our results show that the adverse effects provoked by TBLF were partially reversed after 6weeks of recovery post-treatment, suggesting that increasing the recovery period it could be possible to reverse all adverse effects observed.

A Novel Corn-Expressed Phytase Improves Daily Weight Gain, Protein Efficiency Ratio and Nutrients Digestibility and Alters Fecal Microbiota in Pigs Fed with Very Low Protein Diets.

Simple SummaryFeeding pigs with very low crude protein (CP) diets with reduced calcium (Ca) and phosphorous (P) may be an effective strategy to decrease the nutrient excretion; however, this practice can negatively impact the growth performance of animals. Thus, there is an urgent need to improve the utilization of nitrogen, Ca and P in pigs. This study aimed to assess the effect of a novel corn-expressed phytase on growth performance, nutrients digestibility, gut microbial population, bone mineral density and content and blood metabolites in nursery pigs fed with low-CP, -Ca, and -P diets. Supplementation of very low protein diets with a corn-expressed phytase decreased the negative effects of these diets on average daily gain and protein efficiency ratio of pigs, increased the digestibility of Ca and P regardless of the levels of these minerals in the diet, improved bone characteristics and altered the fecal bacterial composition. This study suggests that corn-expressed phytase can be potentially useful for improving the growth performance of weaned pigs fed with low protein diets and should be considered for sustainable swine production. The objective of this study was to assess the effect of a novel corn-expressed phytase (CEP) on growth, nutrients digestibility, bone characteristics and fecal microbiota of pigs fed with very low-protein, -calcium (Ca) and -phosphorous (P) diets. Forty-eight barrows were subjected to 6 groups for 4 weeks: positive control-adequate protein (PC), negative control-reduced protein (NC), NC + low-dose CEP, i.e., 2000 FTU/kg (LD), NC + high-dose CEP, i.e., 4000 FTU/kg (HD), LD with 0.12% unit reduced Ca and 0.15% unit reduced available P (LDR), and HD with 0.12% unit reduced Ca and 0.15% unit reduced available P (HDR). Compared to NC, LD and HDR had a higher average daily gain (ADG) and gain:protein ratio (G:P), HD and HDR had greater apparent fecal digestibility of Ca and P and bone mineral density and LDR and HDR had lower serum osteocalcin. The feces of LD was enriched in Lachnospiraceae, while the HD had a higher abundance of Succinvibrio and LDR had a higher abundance of Bifidobacterium and Actinobacteria. In conclusion, supplementation of protein-restricted diets with a CEP decreased their negative effects on ADG and G:P ratio, increased the digestibility of Ca and P regardless of the levels of these minerals in the diet, improved bone characteristics and produced differential effects on fecal bacterial population.

Evaluation of an extruded diet for adult dogs containing larvae meal from the Black soldier fly (Hermetia illucens)

Insects have experienced an increasing interest as a protein source in recent years. However, their suitability as a protein source for dogs was not yet widely investigated. Therefore, the aim of the study was to compare two extruded diets for adult dogs containing either larvae meal from black soldier fly (Hermetia illucens; HI) or lamb meal as the predominant protein source with regard to apparent fecal nutrient digestibility and the influence on fecal and immunological parameters. Twelve Beagles were used in this cross-over study and divided into two groups. The test diet with 200 g/kg HI larvae meal (HI) was compared with a control diet containing lamb meal (CON). Dogs were fed each diet for a period of five weeks. Blood samples for a complete blood count, lymphocyte phenotyping and lymphocyte proliferation tests were taken at the end of each feeding period. The latter was either mitogen- or feed antigen-induced with different protein concentrations of HI larvae meal (30–500 μg protein/mL). Fecal samples were collected for five days during each feeding period. The coefficient of the total apparent fecal digestibility (CTTAD) of macronutrients, fecal metabolites, the output and the dry matter content of the feces were analyzed. d-Glucosamine as indicator for chitin was analyzed by high-performance anion-exchange chromatography with pulsed amperometric detection in the diet and the feces. The chitinase activity was determined in the feces. The fecal output was reduced in dogs fed the HI diet (P = 0.038). The CTTAD of dry matter was higher (P = 0.002) when dogs were fed HI compared to CON (0.832 vs. 0.818) and the CTTAD of crude protein was higher (P = 0.002) when dogs received CON compared to HI (0.792 vs. 0.773). Concentrations of acetate (P = 0.011) and ammonium (P = 0.001) were higher in CON. The fecal score differed (P = 0.041) between HI (2.25) and CON (2.04), but both feeding groups had a formed and dry fecal consistency. The chitin concentration was numerically higher in the feces of dogs fed HI (92.2 g/kg DM) compared to CON (2.9 g/kg DM), the fecal chitinase activity did not differ between both diets. Complete blood counts, lymphocyte phenotyping and proliferation were not affected. In conclusion, the HI larvae meal in a dry dog diet was tolerated without adverse signs and did not affect immunological measurements compared to a commercial dry diet with lamb meal, indicating that larvae meal from HI can be considered an “alternative” protein source for dog nutrition.

Preliminary evaluation of fenugreek (Trigonella foenum-graecum) seed gum as a potential prebiotic for growing rabbits in Tunisia: effects on in vivo faecal digestibility and in vitro fermentation

&lt;p&gt;This study aims to determine the effect of dietary inclusion of fenugreek seed gum (FSG), rich in galactomannans, on nutrient apparent digestibility and caecal environment, as well as on &lt;em&gt;in vitro&lt;/em&gt; caecal fermentation of Tunisian growing rabbits. Three experimental diets were formulated, including 0, 0.25 and 0.5% of FSG (FSG0, FSG0.25 and FSG0.5, respectively) for the &lt;em&gt;in vivo&lt;/em&gt; trial and 0, 0.125, 0.25, 0.5 and 100% of FSG (FSG0, FSG0125, FSG0.25, FSG0.5 and FSG100, respectively) for the &lt;em&gt;in vitro&lt;/em&gt; trial. In the &lt;em&gt;in vivo&lt;/em&gt; trial, 45 weaned rabbits 31 d old (15 per treatment) were housed in individual cages until 94 d of age. Apparent digestibility coefficients were determined at two ages, from 38 to 41 and from 56 to 59 d old, and caecal traits were recorded after slaughtering. In the &lt;em&gt;in vitro&lt;/em&gt; trial, the five experimental diets were incubated with a rabbit caecal inoculum. Gas production was measured and modelled until 72 h and the fermentation traits were measured. Apparent faecal digestibility coefficients of main nutrients and main caecal environment traits were not significantly affected by the dietary inclusion of FSG (&lt;em&gt;P&lt;/em&gt;&amp;gt;0.05). However, animals fed with FSG showed lower caecal pH (–0.15; &lt;em&gt;P&lt;/em&gt;&amp;lt;0.05) values. Regarding the in vitro fermentation, FSG100 increased asymptotic gas production (+11.25, &lt;em&gt;P&lt;/em&gt;&amp;lt;0.001), sharpness of the switching characteristic of the profile (+1.98, &lt;em&gt;P&lt;/em&gt;&amp;lt;0.001) and the maximum substrate degradation rate (RM) (+0.188, &lt;em&gt;P&lt;/em&gt;&amp;lt;0.001), but decreasing the time after incubation at which half of the asymptotic amount of gas has been formed (–5.86, &lt;em&gt;P&lt;/em&gt;&amp;lt;0.001) and at which RM occurs (–4.53, &lt;em&gt;P&lt;/em&gt;&amp;lt;0.01). Likewise, FSG100 significantly decreased caecal pH (–1.035, &lt;em&gt;P&lt;/em&gt;&amp;lt;0.001), lactic acid (–9.51, &lt;em&gt;P&lt;/em&gt;&amp;lt;0.069) and N-NH&lt;sub&gt;3&lt;/sub&gt; concentrations (–12.81, &lt;em&gt;P&lt;/em&gt;&amp;lt;0.001). Meanwhile, it increased the total volatile fatty acids (VFA) production (+43.15, &lt;em&gt;P&lt;/em&gt;&amp;lt;0.001). Gradual dietary inclusion of FSG from 0 to 0.5% only significantly increased total VFA production in the caecum (+100 mmol/L per percentage point of FSG inclusion; &lt;em&gt;P&lt;/em&gt;&amp;lt;0.05). In conclusion, FSG is highly and rapidly in vitro fermented by rabbit caecal bacteria. However, dietary inclusion of FSG up to 0.5%, might be insufficient to affect the apparent digestibility and fermentation profile of growing rabbits to a great extent.&lt;/p&gt;

The drying temperature and the moisture content at harvest affect the apparent metabolisable energy of two maize varieties in broiler chickens

ABSTRACT 1. The grain drying process may affect the feeding value of maize but until now, no general consensus has been reached. This knowledge is essential to manage maize nutritional value in feed and ensure optimal growth performance of broiler chickens. 2. A total of 72 male Ross 308 were used in a complete randomised block design to assess the effect of initial moisture content (MC) at harvest (high or low MC after the appearance of the black layer) and drying temperature (54°C, 90°C or 125°C) on the apparent faecal digestibility and the AMEn value of two maize grain types (flint and flint-dent varieties). Moreover, the relationship between in vitro dry matter digestibility coefficient (IVDMD) and salt-soluble protein (SSP) content of dried maize grain with AMEn was assessed. 3. High drying temperature (125°C) significantly decreased the AMEn (by 0.41 MJ/kg) of the maize. Maize with high-moisture content at harvest had significantly higher AMEn than maize with low moisture content (0.38 MJ/kg) depending on the variety. Based on the combination of MC at harvest and drying temperature, an AMEn difference of about 0.65 MJ per kg of dry matter was measured during this experiment. The faecal digestibility of starch remained close to 98% with low variation between the treatments. The decrease in AMEn at high drying temperature was related to the decrease in non-starch organic matter retention (NSOMR). IVDMD and SSP content were not correlated with AMEn of dried maize (R2 < 0.1). 4. This study showed that using drying temperature below 90°C for maize grain harvested at high MC, just after the black layer development, can enhance its AMEn. The IVDMD and SSP content failed to predict the AMEn of the dried maize, but further research is required to validate the results of this study.

A moderate protein diet does not cover the requirements of growing rabbits with high growth rate

Genetic selection for feed efficiency has increased the growth rate and requirements of growing rabbits, while the protein content of commercial feeds has been adjusted to avoid digestive disorders. The aim of this work was to evaluate how a diet with moderate levels of protein content [146 g crude protein (CP)/kg] could be affecting protein and amino acids acquisition depending on the growth rate of the animals. From 189 weaned rabbits (28 days old), only 41 animals were selected at 42 days, in order to ensure the greatest variability for growth rate during fattening. To achieve this goal, animals came from three genetic lines: H and LP (maternal lines selected by litter size) and R (paternal line selected for growth rate), characterised by normal, moderate and high growth rate during the fattening period, respectively. Apparent faecal digestibility of dry matter (DM), CP and gross energy (GE) of the diet from 49–53 days of age, as well as the ileal apparent digestibility of DM, CP and amino acids at 63 days of age, was determined in all the selected animals. Protein, energy and amino acids retained in the empty body during the fattening period were also determined by slaughtering 15 weaning rabbits at 28 days, and the 41 selected animals at 63 days of age. Animals from the R line showed higher feed intake than those from maternal lines, as well as lower feed conversion ratio, even below that expected from their growth rate. Apparent faecal digestibility of GE and apparent ileal digestibility of DM, CP and cystine of the diet were higher in LP than in H rabbits (P < 0.05), showing intermediate values in R rabbits. However, apparent ileal digestibility of glutamic acid and glycine was significantly higher in R than in H rabbits (P < 0.05), showing intermediate values in LP rabbits. As expected, both daily protein and energy retained in the empty body increased as growth increased. However, R growing rabbits seem to have lower protein retained and higher energy retained in the empty body than that expected from their growth. In fact, protein to energy retained ratio was clearly lower for R growing rabbits. These results seem to show the possible existence of some limiting amino acid when current moderate protein diets are used in growing rabbits with high growth rates, recommending a review of the amino acid requirements for the growing rabbits from paternal lines.

Safety and efficacy of APSA PHYTAFEED® 20,000 GR/L (6-phytase) as a feed additive for pigs for fattening.

Following a request from the European Commission, the EFSA Panel on Additives and products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of APSA PHYTAFEED ® 20,000 GR/L (6‐phytase) as a feed additive for pigs for fattening. The additive is a preparation of 6‐phytase produced by a genetically modified strain of Komagataella phaffii and has been previously assessed by the FEEDAP Panel in the context of three applications for its use in different species. The Panel concluded in those opinions that the production strain is safe, and that the use of the additive as a feed additive would raise no safety concerns for the consumers and the environment. The additive was also considered not to be irritant to skin or eyes or a dermal sensitiser but it should be considered as a respiratory sensitiser. The Panel considered that the new use in pigs for fattening would not modify the previously drawn conclusions with respect to the consumers, users and the environment. A tolerance trial in weaned piglets and a subchronic oral toxicity study were made available to support the safety for the new target species. From the results obtained, the Panel concluded that the additive is safe for pigs for fattening at the level of 1,000 U/kg feed. The applicant submitted three efficacy trials to support the efficacy of the additive. In two trials the apparent faecal digestibility of phosphorus and bone ash/phosphorus content were measured and in the third the effects on the performance of the animals were studied. The results of the studies submitted showed an improvement on the faecal digestibility of phosphorus in two trials, with no improvements on the bone mineralisation. Significant improvements on zootechnical parameters were found in the performance of pigs for fattening that were fed 1,000 U/kg feed in the long‐term trial. Since significant effects in relevant parameters were found only in one trial the FEEDAP Panel could not conclude on the efficacy of the product in pigs for fattening.

Relation between feeding behaviour and energy metabolism in pigs fed diets enriched in dietary fibre and wheat aleurone

Feed intake and its daily pattern are regulated both at a short and a long term by several control pathways, including energy balance regulation. This trial aimed to determine the effect of dietary fibre (DB) (mix of wheat, soy and sugar beet pulp fibres) and aleurone supplementation and their interaction on energy and nitrogen balances in growing pigs with ad libitum access to feed. Forty pigs (BW: 35 kg) were fed diets differing by fibre concentration (NDF concentration: 10% or 14% DM) and aleurone supplementation (0, 2 or 4 g/kg) during 3 weeks. Pigs were housed individually in a respiration chamber during the last week to record feeding behaviour and measure energy and nitrogen balances (n = 36). Glucose oxidation was studied on the 6th day with an injection of [U-13C] glucose and measurement of 13CO2 production. There was no significant interaction between DB inclusion and aleurone supplementation on any variables characterizing feeding behaviour. Pigs had less but longer meals with high level of DB, with an increased interval between two meals without effect on daily feed intake. The meal frequency significantly decreased when aleurone supplementation increased. Total tract apparent digestibility coefficient of DM, organic matter, ash, nitrogen and gross energy decreased when pigs received high DB level. Dietary fibre level increased significantly faecal excreted nitrogen. Aleurone supplementation decreased nitrogen retention. Free access to the feed induced a great individual variability not only in feed intake level (from 784 to 2290 g/day) but also in feeding behaviour (from 5.5 to 21.5 meals per day). This variability can be linked with the importance of underlying feed intake regulation pathways and difference in energy balance and metabolism efficiency. Several profiles of metabolism efficiency can be discriminate, thanks to a clustering based on feeding behaviour and pre-prandial concentrations of metabolites and hormones. In conclusion, DB inclusion decreased meal frequency, increased average meal size, decreased total tract apparent faecal digestibility coefficient of nitrogen and gross energy. Supplementation of aleurone decreased average daily feed intake with a reduction of the meal number per day, without modification of average meal size. Aleurone supplementation decreased nitrogen retention and nutrient deposition. Independently of experimental diets, the high individual variability permitted discriminating different profiles with different metabolic strategies. Efficient pigs with a high energy retention as protein and lipid seem to be able to adapt their metabolism according to energy sources.

PSII-5 Corn-expressed phytase improved the growth performance, nutrients digestibility and bone mineral density of nursery pigs fed with low protein, calcium and phosphorous diets

Abstract Feeding pigs with moderately reduced crude protein (CP), calcium (Ca) and phosphorous (P) diets may be an effective strategy to decrease the nutrients excretion; however, this practice can negatively impact the growth performance. Thus, there is an urgent need to improve the utilization of nitrogen, Ca and P in pigs. The objective was to assess the effect of phytase (GraINzyme®) on growth performance, nutrient digestibility, body composition, and serum amino acid profile in pigs fed with low-CP, -Ca and -P diets. Following 2-week acclimation period, forty-eight weaned barrows weighing ~ 10 kg were subjected to one of following groups (n = 8/group) for 4 weeks: A) standard-protein (~24% CP), B) low-protein (~13% CP), C) low-protein+2000 FTU/kg phytase, D) low-protein+4000 FTU/kg phytase, E) low-protein, -Ca and -P+2000 FTU/kg phytase and F) low-protein, -Ca and -P+4000 FTU/kg. The data were analyzed by univariate GLM with Tukey’s post-hoc test (SPSS®). Feed intake and body weight were measured daily and weekly, respectively. At week 4, feed, fecal and blood samples were collected and pigs were scanned using dual-energy X-ray absorptiometry. Pigs fed with diets C and F had higher average daily gain than those fed with diet B (P &amp;lt; 0.05). The apparent fecal digestibility of Ca and P and bone mineral density was higher for diets D and F than diet B (P &amp;lt; 0.05). Pigs fed diet C and F had a higher fat mass than those fed with diet B (P &amp;lt; 0.05). Serum lysine, methionine and threonine of pigs fed with diets B-F were greater than those received diet A (P &amp;lt; 0.05). In conclusion, our data provide evidence that phytase, in particular at 4000FTU/kg, improved the growth performance, digestibility of Ca and P and bone mineral density in pigs fed with moderately low protein diets with reduced Ca and P content.

Safety and efficacy of APSA PHYTAFEED® 20,000 GR/L (6-phytase) as a feed additive for piglets (suckling and weaned) and growing minor porcine species.

Following a request from the European Commission, the EFSA Panel on Additives and products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of APSA PHYTAFEED ® 20,000 GR/L (6‐phytase) as a feed additive for piglets and growing minor porcine species. The additive is a preparation of 6‐phytase produced by a genetically modified strain of Komagataella phaffii and has been previously assessed by the FEEDAP Panel in the context of an application for its use in feed for chickens for fattening. The Panel concluded in that opinion that the production strain is safe, and that the use of the additive as a feed additive would raise no safety concerns for the consumers and the environment. The additive was also considered not to be irritant to skin or eyes or a dermal sensitiser but that should be considered as a respiratory sensitiser. The Panel considered that the new use in piglets would not modify the previously drawn conclusions with respect to the consumers, users and the environment. A tolerance trial and a subchronic oral toxicity study were made available to support the safety for the new target species. From the results obtained, the Panel concluded that the additive is safe for piglets (suckling and weaned) and for growing minor porcine species at the recommended enzyme activity of 250 U/kg feed with a wide margin of safety. The applicant submitted three efficacy trials to support the efficacy of the additive. In the trials, the apparent faecal digestibility of phosphorus and bone ash/phosphorus content were measured. From the results obtained, the FEEDAP Panel concluded that APSA PHYTAFEED ® GR/L is efficacious for piglets (suckling and weaned) and for growing minor porcine species at an enzyme activity of 1,000 U/kg feed.