Effects of expeller soybean on growth performance, amino acid digestibility and intestinal integrity

Expeller soybean (ESB) is a widely used protein source in broiler diets due to its high amino acid digestibility. However, improper heat processing of ESB can negatively affect nutrient digestion, absorption, and metabolism leading to decreased growth performance. The study aimed to investigate the impact of varying processing temperatures on growth performance, amino acid digestibility (AID), and intestinal integrity using 3 different commercial batches of ESB processed at distinct temperatures. These temperatures were 182°C (normal-control), 199°C (overcooked), and 154°C (undercooked). 1,860 off-sex male Cobb 500 broilers were allocated randomly to these treatments, with 10 replicate floor pens (62 birds/pen) from 1 to 35 d of age. Birds consuming the overcooked ESB exhibited significantly lower body weight gain (BWG) and feed intake (FI) on d 14, 28, and 35. They also showed higher feed conversion ratio (FCR) and smaller relative right pectoralis major (RPM) weights at d 35. Meanwhile, birds fed undercooked ESB demonstrated reduced BWG at d 14. Serum fluorescein isothiocyanate-dextran (FITC-d; 4 kD) concentrations on d 16 were notably elevated in birds fed overcooked ESB, indicating increased gut permeability. Overcooked ESB reduced the AID coefficients of several amino acids on d 14 and 28, with Lys experiencing the highest reduction (8%). Undercooked ESB, however, mainly affected the AID of Val, and Phe at d 28. In conclusion, overcooked ESB decreased amino acid digestibility, impaired gut barrier function, and led to diminished growth performance. Conversely, undercooked ESB primarily affected the digestibility of Val and Phe and resulted in reduced BWG at d 14. These findings underscore the critical role of proper heat processing in preserving the nutritional quality of ESB in broiler diets, influencing optimal growth performance, and maintaining intestinal health.

Influence of Expander Conditioning Prior to Pelleting on Pellet Quality, Broiler Digestibility and Performance at Constant Amino Acids Composition while Decreasing AMEN

Physical pellet quality and AMEN concentration are strongly related to each other in broiler feeding. A study was conducted to evaluate the relationship between dietary AMEN concentration and feed processing on pellet quality, nutrient digestibility, broiler performance, serum markers, and yield of commercial cuts. Six diets were formulated. The first diet had the recommended AMEN concentration, each further diet was calculated with 40 kcal/kg less, from 0 to −200 kcal/kg, resulting in six levels for each feed phase: starter (1−14 d), grower (15−28 d), and finisher (29−35 d). These diets were processed with and without expander conditioning prior to pelleting, using an average corn particle size of 1.6 mm, ground with a roller mill. A total of 1008 one-day-old male Ross 308 broiler chickens were placed in a 6 × 2 (6 energy levels and 2 conditionings) factorial trial with six boxes as replications, with three in each broiler performance trial period. Excreta were collected 2 days before the end of each feed phase for apparent total tract digestibility measurement. On day 36, four broilers from each replication (pen) were weighed and then euthanized for blood collection, following which the gastrointestinal organs were weighed, and the ileal and gizzard contents were collected. On day 37, all remaining broilers were slaughtered after fasting to measure commercial cuts and abdominal fat. The results show that the pellet durability index (PDI) was most affected by energy reducing and expander conditioning prior to pelleting, and it was better when diets had energy reduced by 40 to 200 kcal/kg (p > 0.001), as when expander conditioning was used. Digestibility of nutrients was slightly affected by treatments, as was the broiler performance; however, feed efficiency was improved in broiler-fed diets without AMEN reduction and when an expander was used, with p = 0.050 and p = 0.031, respectively. No effects were observed on the weight of gastrointestinal tract organs and serum markers, except for liver (p = 0.037) and α-amylase (p = 0.047). The lowest liver weight and lowest serum protein, cholesterol, triglyceride, gamma-glutamyl, and lipase concentrations were obtained when diets were formulated without energy reduction (Ross-0). There was no effect on commercial cuts relative to live weight at slaughter. The energy reduction was well reflected in the proportion of abdominal fat, which decreased when AMEN was reduced (p = 0.001). The present study shows it is possible to use diets with up to 200 kcal/kg reduction in AMEN without losses in performance, and the use of expander conditioning prior to pelleting promotes higher pellet quality and broiler feed efficiency.

Effect of Two Soybean Varieties Treated with Different Heat Intensities on Ileal and Caecal Microbiota in Broiler Chickens

Simple Summary

Soybeans are an essential part of today’s poultry nutrition diets because of their high protein content and quality. To ensure optimum digestibility in monogastric animals, soybeans need to be thermally processed. As required heat intensities depend on individual soybean properties, the emergence of highly heterogenic soybean batches is a challenge for adequate processing conditions. Molecular changes occurring during heat treatment can alter the microbial communities colonizing the animals’ guts. Gut microbiota is of great importance for both its host animal’s performance and health. To investigate the effect of heat treatment and soybean variety on the chickens’ microbiota, two soybean varieties were selected, treated at two different heat intensities and subjected to a feeding trial. DNA was then extracted and sequenced to identify different bacterial populations in the digesta of certain gut sections. Results showed that both the soybean variety and the applied heat treatment affected the abundance of certain bacterial species in the gut of chickens, but no effect on the taxonomy level of family or genus appeared. This underlines the sensitivity and reactivity of the highly complex microbial community to apparently small dietary differences.

Abstract

Soybean products are of high importance for the protein supply of poultry. Heat treatment of soybeans is essential to ensure optimal digestibility because of intrinsic antinutritive factors typical for this feed category. However, excessive treatment promotes the Maillard reaction and reduces protein digestibility. Furthermore, Europe’s efforts are to decrease dependence on imports of soybean products and enlarge local production. This process will include an increase in the variability of soybean batches, posing great challenges to adequate processing conditions. Intrinsic soybean properties plus heat treatment intensity might be able to modulate the gut microbiota, which is of crucial importance for an animal’s health and performance. To assess the influence of heat treatment and soybean variety on gut microbiota, 2 soybean cakes from 2 varieties were processed at 110 °C or 120 °C and subsequently fed to 336 one-day-old broiler chickens. After 36 days, the animals were slaughtered, and the digesta of the ileum and caecum was collected. Next, 16S rRNA amplicon sequencing of the extracted DNA revealed a high discrepancy between gut sections, but there were no differences between male and female birds. Significant differences attributed to the different soybean varieties and heat intensity were detected for certain bacterial taxa. However, no effect on specific families or genera appeared. In conclusion, the results indicated the potential of processing conditions and soybean variety as microbiota-modulating factors.

Effect of Graded Substitution of Soybean Meal by Hermetia illucens Larvae Meal on Animal Performance, Apparent Ileal Digestibility, Gut Histology and Microbial Metabolites of Broilers

Simple Summary

Soybean meal (SBM) constitutes the major protein source in European poultry production, meaning a high dependency on imports and a reduced sustainability of produced meat. To cope with this challenge, alternative protein sources are needed, and insects are considered as a novel, alternative protein source in broiler nutrition. The objective of the present study was to evaluate the replacement of 15 or 30% of crude protein (CP) from SBM with Hermetia illucens (HI) defatted larvae meal CP regarding broiler performance, carcass traits, apparent ileal CP and amino acid (AA) digestibility, intestinal morphology, and microbial metabolites. The data showed impaired performance and lower ileal CP and AA digestibility with 30% substitution of CP from SBM with HI larvae meal CP. However, lower substitution, i.e., 15% substitution of SBM CP with HI larvae meal, for broiler feeds seems possible without impairment in animal performance and digestion variables and should be pursued in the future.

Abstract

The usage of insects as an alternative protein source for broiler feeds may help to reduce the dependency on soybean meal (SBM) imports. Therefore, the present study aimed to evaluate the replacement of 15 (SL15) or 30% (SL30) of crude protein (CP) from SBM with Hermetia illucens (HI) defatted larvae meal regarding broiler performance, carcass traits, apparent ileal digestibility, intestinal morphology, and microbial metabolites. Concerning the performance, body weight was similar for the control (CON) and SL15, but lower for SL30 during all feeding phases. In addition, average daily feed intake was higher in SL15 and SL30 compared to CON in the starter phase, but this effect vanished during grower and finisher phase. The apparent ileal digestibility decreased for CP and some amino acids with increasing HI larvae meal in the diet. No or marginal alterations were observed for the intestinal morphometry as well as cecal microbial metabolites. In conclusion, partial replacement of 15% SBM CP with HI larvae meal in broiler diets without impairing animal performance or health seems possible. The growth suppression with 30% CP substitution may be caused by reduced apparent ileal digestibility but could not be clearly associated with adverse effects of hindgut fermentation or altered gut morphology.

Effect of digestible amino acids to energy ratios on performance and yield of two broiler lines housed in different grow-out environmental temperatures

Two broiler lines, Line A and Line B, were fed experimental diets from 22 to 42 d with objectives to determine effects of digestible amino acids (AA) to metabolizable energy ratios on feed intake (FI), performance, and processing yield. Experimental diets were formulated to 3,150 kcal/kg with 5 levels of digestible lysine (dLys)—80, 90, 100, 110, and 120% of recommended AA level giving g dLys/Mcal values of 2.53, 2.85, 3.17, 3.48, and 3.80, respectively. All other AA were formulated to a fixed ratio to dLys. A total of 4,050 chicks were utilized in each trial (9 replicate pens for each AA level and each line; 45 chicks/pen) conducted twice: one in hot environmental temperature (HT) (24 h mean ∼85.3 °F; 80.9% RH) and another in cool environmental temperature (CT) (24 h mean ∼71.6 °F; 61.7% RH). Results showed that FI was not impacted by dietary AA levels in HT for both lines. Higher FI (P < 0.05) was observed in CT for lower dietary AA levels (<100% AA level) for both lines, with overall higher FI occurring in Line B. Higher FI for Line B was also accompanied by higher body weight in HT and CT. Treatment diets had quadratic effects on average daily gain (ADG), feed conversion ratio (FCR), and processing yields (breasts and tenders) in both HT and CT, with broilers in CT performing better (P < 0.05). The optimal response values for ADG in HT and CT were 89.72 g and 113.44 g occurring at 120 and 109.5% AA level, respectively. The optimal response values for FCR in HT and CT were 1.79 and 1.58 occurring at 120 and 117.5% AA level, respectively. The optimal response values for breast meat yield in HT and CT were 575.9 g and 776.5 g occurring at 112.6 and 114.5% AA level, respectively. The optimal response values for tender meat yield in HT and CT were 119.8 g and 154.9 g occurring at 120 and 115% AA level, respectively. Line A had a higher breast and tender yield % (of live weight) for both environmental temperatures which correlated to body composition data with higher % protein mass and % digestible AA retention. In this study, findings indicated that effects of increased digestible AA density on FI, performance, and processing yield are specific to strain and grow-out temperature, but the optimum response was attained for both lines with diets containing 110 to 120% AA levels (3.48–3.80 g dLys/Mcal) during the 22 to 42 d finisher period.

Short-chain arabinoxylans prepared from enzymatically treated wheat grain exert prebiotic effects during the broiler starter period

Carbohydrate-degrading multi-enzyme preparations (MEP) are used to improve broiler performances. Their mode of action is complex and not fully understood. In this study, we compared the effect of water-soluble fractions isolated at the pilot scale from wheat grain incubated with (WE) and without (WC) MEP. The fractions were incorporated in a wheat-based diet (0.1% w/w) to feed Ross PM3 broilers and compared with a non-supplemented control group (NC). The body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) until d 14 were determined. At d 14, ileal and cecal contents and tissue samples were collected from euthanized animals. The intestinal contents were used to measure the short-chain fatty acids (SCFA) concentration using gas chromatography and to determine the abundance and composition of microbiota using 16S sequencing. Villi length of ileal samples was measured, while L-cell and T-cell densities were determined using immuno-histochemistry. The MEP treatment increased the amount of water-soluble arabinoxylans (AX) and reduced their molecular weight while retaining their polymer behavior. The WE fraction significantly (P < 0.05) increased FI by 13.8% and BWG by 14.7% during the first wk post hatch when compared to NC. No significant effect on FCR was recorded during the trial. The WE increased the abundance of Enterococcus durans and Candidatus arthromitus in the ileum and of bacteria within the Lachnospiraceae and Ruminococcaceae families, containing abundant butyrate-producing bacteria, in the ceca. It also increased the concentration of SCFA in the ceca, decreased the T-lymphocyte infiltration in the intestinal mucosa, and increased the glucagon-like-peptide-2 (GLP-2)-producing L-cell density in the ileal epithelium compared with WC and NC. No significant effects were observed on villi length. These results showed that AX present in the WE fraction altered the microbiota composition towards butyrate producers in the ceca. Butyrate may be responsible for the reduction of inflammation, as suggested by the decrease in T-lymphocyte infiltration, which may explain the higher feed intake leading to improved animal growth.

Covalent immobilization of lysozyme on stainless steel. Interface spectroscopic characterization and measurement of enzymatic activity

A new strategy aiming at the protection of metallic surfaces against the growth of biofilms is presented here. This work reports the grafting of primary amines by aminosilanization of oxidized stainless steel followed by chemical coupling of the glycosidase lysozyme from hen egg white using glutaraldehyde as homobifunctional cross-linking agent. Controlled characterization of a stainless steel surface by X-ray photoelectron spectroscopy and Fourier transform infrared reflection-absorption spectroscopy at each step enabled the mode of binding, coverage, and orientation of the grafted molecules to be addressed. As a result, the stainless steel samples covered with a covalently immobilized layer of lysozyme showed some lytic activity on a suspension of bacteria Micrococcus lysodeikticus.

Determination of the optical and thermal properties of semiconductors with the photothermal method

The photothermal method has been used for the determination of several thermal and optical material properties. We demonstrate the use of the photothermal method for the investigation of thermal and optical properties of the GaAlAsSb and GaInAsSb layers which are, respectively, the confinement layer and the active layer of the GaAlAsSb/GaInAsSb/GaAlAsSb/GaSb laser heterostructure. These layers were deposited on a GaSb substrate in its liquid phase by means of epitaxy.