Apparent Metabolizable Energy Research Articles

Generalized Ketogenic Diet Induced Liver Impairment and Reduced Probiotics Abundance of Gut Microbiota in Rat

The ketogenic diet is becoming an assisted treatment to control weight, obesity, and even type 2 diabetes. However, there has been no scientific proof supporting that the ketogenic diet is absolutely safe and sustainable. In this study, Sprague–Dawley (SD) rats were fed different ratios of fat to carbohydrates under the same apparent metabolizable energy level to evaluate the effects of a ketogenic diet on healthy subjects. The results showed that the ketogenic diet could relatively sustain body weight and enhance the levels of serum alanine aminotransferase (ALT) and serum alkaline phosphatase (SAP), leading to more moderate lipoidosis and milder local non-specific inflammation in the liver compared with the high-carbohydrate diet. In addition, the abundance of probiotic strains such as Lactobacillus, Lactococcus, and Faecalitalea were reduced with the ketogenic diet in rats, while an abundance of pathogenic strains such as Anaerotruncus, Enterococcus, Rothia, and Enterorhabdus were increased with both the ketogenic diet and the high-carbohydrate diet. This study suggests that the ketogenic diet can lead to impairments of liver function and changed composition of the gut microbiota in rats, which to some extent indicates the danger of consuming a generalized ketogenic diet.

Effects and interactions of dietary lysine and apparent nitrogen corrected metabolizable energy on yellow-feathered broiler breeder hens

BackgroundDietary lysine and apparent nitrogen-corrected metabolizable energy (AMEn) are two key variables affecting the production of breeder hens. In this study, the effects and interactions of lysine and AMEn on yellow-feathered broiler breeder hens were investigated. A total of 720 30-week-old breeder hens were fed in a 5 (lysine: 0.56%, 0.68%, 0.80%, 0.92%, and 1.04%) × 2 (AMEn: 11.50 and 11.10 MJ/kg) factorial arrangement for 12 weeks. The productive performance, reproductive traits, biochemical variables of breeder hens, the amino acid concentration and quality of eggs, and the growth performance of offspring broilers were determined.Result(1) Dietary lysine had quadratic effects (P < 0.05) on laying rate, average daily egg mass and feed intake/egg mass of breeder hens; birds with 11.50 MJ/kg AMEn (high AMEn) had higher (P < 0.05) BW than those with 11.10 MJ/kg AMEn (low AMEn); (2) dietary lysine significantly affected on the relative ovarian weight (quadratic and linear), and numbers of large yellow follicles (LYF, quadratic); birds with high AMEn had longer fallopian tube and more LYF than those with low AMEn (P < 0.05); (3) dietary lysine had significant effects (linear and quadratic) on eggshell thickness and shell strength of eggs from breeder hens; birds with high AMEn had thinner eggshells and deeper yolk color than those with low AMEn (P < 0.05); (4) there were higher (P < 0.05) contents of protein and concentrations of all measured animo acids (AAs) in eggs from birds fed low AMEn; (5) supplementation with high AMEn to breeder hens significantly increased the hatchability of fertilized eggs; (6) neither dietary lysine level or AMEn affected growth performance of offspring broilers; (7) both dietary lysine level and AMEn significantly affected gonadotropin concentrations and biochemical variables of breeder hens.ConclusionsDietary lysine had significant influences on productive performance, reproductive traits, and egg quality of yellow-feathered breeder hens. Based on productive performance, the optimal levels of dietary lysine were 0.81% to 0.83%, while 0.71% to 72% lysine was enough to obtain the best quality of breeding eggs. High AMEn was more beneficial to breeder hens for reproductive traits and hatchability of the fertilized eggs, while it showed detrimental effects on eggshell thickness and AA concentrations of breeding eggs.

Effect of dietary β-mannanase supplementation on growth performance and nutrient retention in broiler chickens fed corn-soybean meal-based diets with low energy and amino acid density

The present study was conducted to evaluate the effect of two different β-mannanases on growth performance and nutrient retention of broiler chickens fed a diet with low energy and amino acid density. A total of 312 one-day-old male broiler chickens (Ross 308) were placed in floor pens and fed a standard starter diet for 16 days. They were then randomly moved to stainless steel cages and distributed into three groups, with 13 replicates of 8 chickens each. The control group received a corn-soybean meal-based grower diet with reduced metabolizable energy by ∼100 kcal/kg and a 10-12% reduction of digestible amino acids (lysine, methionine, and threonine). Titanium oxide was added at 0.5% of diet as an indigestible marker. The other groups were fed the same diet supplemented with either β-mannanase A derived from Thermothelomyces thermophilus (100 g β-mannanase/MT grower diet) or β-mannanase B derived from Paenibacillus lentus (350 g β-mannanase/MT grower diet). The trial lasted for 7 days from d 17 to d 23, comprising 4 days of acclimatization followed by 3 days of sample collection. Final body weight (d 23), body weight gain (d 17-23), and feed intake (d 17-23) of broiler chickens did not differ among the groups. However, both β-mannanases significantly improved the feed conversion ratio during d 17-23 (P = 0.039) and nitrogen retention (P = 0.028) in broiler chickens compared to the control group. Moreover, dietary supplementation with β-mannanase A significantly increased dry matter retention (P = 0.050), organic matter retention (P = 0.028), and nitrogen-corrected apparent metabolizable energy (AMEn; P = 0.033) compared to the control group. In conclusion, supplemental β-mannanase, regardless of the product, improved the growth performance of broiler chickens by improving nutrient retention and dietary AMEn.

Effect of dietary energy levels on productivity, fat deposition, and biochemical parameters of Woorimatdag1 breeder pullets.

This study aimed to investigate effects of apparent metabolizable energy (AMEn) levels in diets on productivity, fat deposition, and biochemical parameters of Woorimatdag1 (WMD1) breeder pullets. A total of 240 four-week-old WMD1 breeder pullets were divided into four dietary groups with five replicates (12 birds per replicate). These groups had the following dietary energy levels: standard ME (SME), SME-200, SME-100, and SME+100 (diets containing 2,800, 2,600, 2,700, and 2,900 kcal AMEn/kg, respectively). These pullets were provided with diets and water ad libitum until 16 weeks old. Weight gain was significantly (p < 0.05) higher in SME-100, SME, and SME+100 groups than in the SME-200 group. SME+100 and SME groups exhibited significantly (p < 0.05) improved feed conversion ratio compared to the SME-200 group. Laying ages of 30% egg production occurred significantly (p < 0.05) earlier in SME-100, SME, and SME+100 groups than in the SME-200 group. SME and SME+100 groups had significantly (p < 0.05) higher liver fat (%) than the SME-200 group. Additionally, the SME+100 group had higher (p < 0.05) abdominal fat (%) than other groups. However, blood parameters were not significantly different among dietary groups. SME-100 (2,700 kcal AMEn/kg) might be suitable for improving productivity and fat deposition of WMD1 breeder pullets.

Evaluation of protease plus a precision-biotic on body weight gain and feed conversion ratio in broilers from 0 to 42 days of age

This study aims to evaluate the effects of a protease combination with a precision biotic on body weight gain (BWG) and feed conversion ratio (FCR) of broilers from day 0 to 42. 1,400 Cobb 500 male chicks were reared on seven different diets, including an unrestricted positive control (PC–Diet 1) and a negative control (NC–Diet 2) with slightly reduced crude protein, apparent metabolizable energy (AME), and digestible amino acids. Five additional treatment diets were formulated using the negative control and varying concentrations of a protease (Diets 3-4; 33ppm and 50ppm, respectively) and in combination with a precision biotic (Diets 5-7; 33ppm + 700ppm; 50ppm + 500ppm; and 50ppm + 700ppm, respectively). The PC treatment showed significantly different feed intake and FCR compared to all other treatments in all production phases (P &lt; 0.05). There are no significant differences in non-PC treatments in all production phases for BWG and FCR (starter p=0.230 and 0.300; grower p=0.443 and 0.237; finisher p=0.450 and 0.896; overall p=0.111 and 0.497, respectively), nor is there any in terms of mortality (p=0.800). These findings may provide valuable information to producers to optimize flock performance efficiently and cost-effectively.

Effects of low energy diets supplemented with emulsifier on growth performance, nutrient digestibility, and intestinal morphology of broiler chickens

This study was conducted to investigate the effects of adding an emulsifier to energy-deficient diets on growth performance, intestinal morphology, and nutrient digestibility in broiler chickens. A total of 540 one-day-old male broiler chickens were randomly assigned to a 3 × 3 factorial arrangement of treatments with 4 pens and 15 broiler chickens/pen for 6 wk. Nine treatments consisted of 3 inclusion rates of emulsifier (0, 250, and 500 mg kg-1) and the standard, moderate, and low energy concentrations [45 and 90, 60 and 105, and 75 and 120 kcal apparent metabolizable energy (AME)/kg less for the moderate- and low-energy concentrations than the standard energy requirements during the starter (d 0 to 10), grower (d 10 to 24), and finisher (d 24 to 42) phases, respectively]. The average daily weight gain (ADWG) and average daily feed intake (ADFI) were recorded in the starter, grower, finisher, and total rearing (d 0 to 42) phases and feed conversion ratio (FCR) was calculated. The AME, digestibility of crude protein (CP), lipid, and organic matter (OM) of experimental diets, were determined from d 5 to 10 and from d 35 to 40. Broiler chickens fed moderate- or low-energy diets containing emulsifier showed greater ADWG and LBW, than those fed the standard diets along with lower FCR, compared to the same diets without emulsifier (P < 0.05). Live body weight increased, while both ADFI and FCR decreased linearly and quadratically with an increase in emulsifier inclusion rate in the diets (P < 0.05). Broiler chickens fed moderate-energy diets with 500 mg emulsifier /kg or low-energy diets containing 250 mg emulsifier /kg had greater villus height compared to those fed other diets (P < 0.05). The addition of emulsifiers to diets led to a linear increase in villus height, epithelium height, and the villus height to crypt depth ratio (P < 0.05). In moderate- and low-energy diets, the inclusion of emulsifiers resulted in greater AME and digestibility of lipid and OM (P < 0.05). The AME and digestibility of lipid and OM increased linearly and quadratically with an increase in emulsifier inclusion rate in the diets (P < 0.05). In conclusion, the addition of emulsifier at a rate at least 250 mg kg-1 to moderate- or low-energy diets during the starter, growth, and finisher phases can enhance broiler chicken performance by improving the histological characteristics of small intestine and enhancing lipid digestibility.

Evaluation of Apparent Metabolizable Energy of Five Oil Sources in Broiler Chickens

تم إجراء تجربة الهضم لتقييم الطاقة الأيضية الواضحة (AME) لزيت النخيل الخام (CPO)، وزيت فول الصويا (SO)، وزيت ثمار النخيل الخام (CPFO)، وتم تقييم أولين النخيل RBD (RBDPO) وأولين النخيل RBD + الليسيثين. تم شراء عدد 100 فرخ لاحم عمر يوم واحد من المفرخ المحلي. في اليوم 21، تم اختيار الطيور ذات الوزن المماثل عشوائيا ووزعت على الوحدات التجريبية بواقع ثلاثة طيور لكل وحدة (قفص) وخمسة مكررات لكل وحدة تم توزيعها عشوائيا. تم تغذية الطيور لمدة ثمانية أيام بخمسة أنظمة غذائية اختبارية تحتوي على مصادر زيتية مختلفة (CPO، وSO، وCPFO، وRBDPO، وRBDPO+L)، والتي تم تطويرها عن طريق استبدال 60 جم/كجم من النظام الغذائي الأساسي والنظام الغذائي الأساسي للذرة وفول الصويا. أظهرت النتائج عدم وجود اختلاف معنوي (P&gt;0.05) بين المعاملات في الطاقة الأيضية الواضحة للزيوت المختلفة.

Evaluating the effectiveness of Toxfin and Novasil as dietary aflatoxin-binding agents in broilers for sustaining hepatic antioxidant capacity and intestinal health status during aflatoxin B1 exposure.

To assess the efficacy of Toxfin and Novasil as aflatoxin-binding agents in broilers exposed to aflatoxin B1 (AFB1) from 11 to 30days, 288 mixed-sex Ross 308 broiler chickens were randomly allocated to four dietary groups: control feed, control feed + 0.25mg/kg AFB1, AFB1 feed + 0.3% Toxfin, and AFB1 feed + 0.3% Novasil. The evaluation encompassed growth performance for the grower (11-20days), finisher (21-30days), and overall (11-30days) phases, carcass characteristics, serum biochemical components, liver function enzymes, hepatic antioxidant capacity, AFB1 residue in the liver and kidney, and ileal morphology at 30days, and apparent nutrient digestibility during 29-30days. Exposure to AFB1 significantly resulted in reduced growth efficiency, lowered carcass yields, liver hypertrophy, impaired metabolic and hepatic functions, liver oxidative stress, disrupted ileum architecture, diminished nutrient digestibility, and accumulated AFB1 in the liver and kidney. Conversely, supplementation of Toxfin or Novasil significantly augmented body weight gain (BWG) and reduced feed conversion ratio (FCR) during the finisher and overall phases, elevated BWG in the grower phase, heightened levels of glucose, hepatic protein, and glutathione peroxidase, declined malondialdehyde content, improved apparent metabolizable energy, and lowered AFB1 residues in the liver and kidney. Furthermore, Toxfin inclusion significantly reduced FCR during the grower phase, enhanced European production efficiency factor during the grower and overall phases, augmented dressing percentage, declined proportional liver weight, elevated concentrations of total protein, albumin, and total antioxidant capacity, heightened villus surface area, and boosted crude protein digestibility. To conclude, incorporating 0.3% Toxfin into broilers' feeds confers a more effectual safeguard than Novasil against the deleterious consequences of AFB1 exposure.

Influence of different levels of black soldier fly larvae meal on growth performance and carcass quality of broiler chickens

A study was conducted to examine the impact of two inclusion levels of Black soldier fly larvae meal (BSFLM) replacing soybean meal on growth performance, nutrient utilization, carcass characteristics and meat quality of broilers. Three experimental diets based on corn-soybean meal were developed to contain 0 (control), 6 (BSF 6) and 12% (BSF 12) BSFLMfor both starter and grower phases. Each experimental diet was randomly allotted to six replicate pens (eight birds per pen). The birds were offered starter pellets from 0 to 14 day post-hatch and grower pellets from 15 to 28 day post-hatch. The experimental diets were tested for pellet durability index (PDI). There was an interaction between diet and growth phase (P < 0.001) for pellet durability index where starter diets had always a higher PDI than the grower diets, but the difference was greater for control diet than BSF 6 and BSF 12 diets. Apparent metabolizable energy (AME) of diets and coefficients of apparent ileal digestibility (CAID) of nutrients were measured on day 28 using titanium dioxide marker ratios in the diet and excreta/ileal digesta. On day 28, the weights of live body, carcass, fat pad, breast and gizzard were recorded, and then breast meat quality (meat pH, drip loss and cooking loss) was examined. Inclusion of BSFLM of up to 12% did not reduce live weight gain or feed intake. Live weight and carcass weight were heavier in broilers fed 12% BSFLM than controls (P < 0.02), but were not different than those fed 6%, while controls were not different than those fed 6%. Breast weight (percentage live weight) was lower in birds offered 12% BSFL than in others (P < 0.04). No differences were observed between diets for the percentage weight as carcass, fat, pad and gizzard. The AME and AMEc of diets were the highest in broilers fed 6% BSFLM diet (P < 0.005), but there were no differences between controls and those fed 12% BSFLM. The CAID of DM, ash and N in birds fed 6% BSFLM were greater than (P < 0.03) birds fed 12%, but were not different than controls, which were also not different than those fed 12%. Broiler breast meat quality was unaffected by dietary treatments. In conclusion, BSFLM at 12% can be used effectively as a SBM replacement in starter and grower diets, without affecting the growth performance, nutrient utilization, carcass characteristics and meat quality of broiler chickens.

Investigations into the chemical composition and nutritional value of different batches of rapeseed meals for turkey poults

ABSTRACT A study was conducted to investigate the chemical composition and feeding value of rapeseed meal (RSM) batches produced at the same plant when fed to turkey poults. In total, seven RSM samples were obtained from a single manufacturer within a period of 90 days. Although the manufacturer followed the same procedures during oil extraction and RSM production, different batches of rapeseed were used. A balancer feed (BF) was formulated to contain 11.85 MJ/kg ME and 265 g/kg crude protein. Seven nutritionally complete test mash diets were prepared by mixing 200 g/kg of each RSM batch sample with 800 g/kg of the BF, totalling 8 diets. Diets were fed to female B.U.T. Premium turkeys from 12 to 21 d of age. Each diet was fed to six raised floor pens, housing two birds, following randomisation. During the experiment, a nitrogen corrected apparent metabolisable energy (AMEn) assay was performed using a total collection technique. The AMEn in RSM samples was calculated based on the differences between the AMEn values of basal and test diets. Associations were examined between AMEn and the chemical composition of the RSM samples. The overall determined AMEn value of the RSM ranged from 5.50 MJ/kg DM to 8.53 MJ/kg DM, giving an average AMEn of 7.29 MJ/kg DM. There was no difference (p > 0.05) in AMEn content between batches. There was a negative correlation (r = – 0.864; p < 0.05) between AMEn values and the neutral detergent fibre (NDF) content of the RSM samples. The results suggest that the NDF could be a good predictor of the AMEn of industry produced RSM. It may be inferred that processing rather than cultivar could be the main factor determining the feeding value of RSM for turkeys.

The interactivity of sources and dietary levels of resistant starches – impact on growth performance, starch, and nutrient digestibility, digesta oligosaccharides profile, cecal microbial metabolites, and indicators of gut health in broiler chickens

In a 21-d study, 480 Cobb 500 (off-sex) male broiler chicks were used to investigate the effects of feeding different sources and levels of resistant starches (RS) on growth performance, nutrient and energy utilization, and intestinal health in broiler chickens. The birds were allocated to 10 dietary treatments in a 3 × 3 + 1 factorial arrangement. The factors were 3 RS-sources (RSS): banana starch (BS), raw potato starch (RPS), and high-amylose corn starch (HCS); each at 3 levels (RSL) 25, 50, or 100 g/kg plus a corn-soybean meal control diet. Birds and feed were weighed on d 0, 8, and 21. On d 21, samples of jejunal tissue and digesta were collected for chemical analysis. Data were analyzed using the mixed model procedure of JMP with factor levels nested with the control. In the 0 to 21 phase, the birds fed the RPS diets had higher (P = 0.011) FI than those fed HCS or control diets, and FCR was greater (P = 0.030) in birds that received BS diets than in other diets. RSS × RSL was significant (P < 0.05) for total tract nutrient retention, AME, and AMEn on d 21. The starch digestibility was higher (P < 0.001) in birds that received the control diet than in RS diets, and decreased as RS levels increased, except for HCS. The apparent metabolizable energy (AME) and nitrogen-corrected AME (AMEn) were higher (P < 0.001) in birds fed 100 g/kg HCS diet, with both decreasing with increasing levels of BS and RPS, except for HCS. Relative ileal oligosaccharides profile showed significant (P < 0.05) RSS × RSL with a higher relative abundance of Hex(3) (P = 0.01) and Pent(3) (P = 0.001) in HCS diets. In conclusion, RS may influence gut health and growth performance in broiler chickens through modulation of cecal SCFA and nutrient digestion, but these depend largely on the botanical origin and concentrations of individual RS.

Development of prediction equations for apparent metabolizable energy corrected for nitrogen of fish meal and poultry by-product meal in broiler chickens

Development of prediction equations for apparent metabolizable energy corrected for nitrogen of fish meal and poultry by-product meal in broiler chickens

PSII-17 Effect of dietary β-mannanase supplementation on energy and nutrient utilization in diets fed to broiler chickens: A meta-analysis

Abstract Beta-mannan (β-mannan) is a polysaccharide composed of repeating units of mannose, galactose, and glucose. The increased amount of β-mannan is present in various plant protein sources such as soybean meal, palm kernel meal, copra meal, and guar meal. β-mannan is considered an antinutritional factor for non-ruminant animals. Endo-β-mannanase enzymes are endo-hydrolases that can cleave the internal glycosidic bonds of the mannan backbone. As a result, β-mannanase is used to break down β-mannan in animal feeds, thereby aiming to reduce its potential anti-nutritional effects. Previous research has demonstrated that dietary β-mannanase supplementation improves energy and nutrient utilization in broiler diets possibly by decreasing digesta viscosity in the gastrointestinal tract. However, results from previous studies have been inconsistent, mainly due to variable experimental conditions including animals, experimental design, and environment. Meta-analysis is a useful method to comprehensively evaluate and integrate various results from previous studies, thereby providing reliable and practical insights. Therefore, the objective of this study was to conduct the meta-analysis to evaluate the effect of dietary β-mannanase supplementation on digesta viscosity, and energy and nutrient utilization in diets for broiler chickens. Through an extensive literature search conducted on Scopus, PubMed, Web of Science, and Google Scholar between January 2003 and December 2023, we identified 10 eligible studies. The meta-analysis was performed using the “metafor” package in R software version 4.1.3. (R Core Team, 2023), and the standardized mean difference (SMD) and its 95% confidence interval (CI) were calculated using the random effect model. The results revealed that dietary β-mannanase supplementation increased apparent total tract retention (ATTR) of dry matter (SMD = 1.84; 95% CI: 0.46 to 3.21; P = 0.016), gross energy (SMD = 2.16; 95% CI: 1.19 to 3.12; P = 0.001), and nitrogen-corrected apparent metabolizable energy (AMEn) in broiler diets (SMD = 3.38; 95% CI: 1.63 to 5.14; P = 0.002; Table 1). Moreover, dietary β-mannanase supplementation increased apparent ileal digestibility (AID) of gross energy (SMD = 6.65; 95% CI: 3.78 to 9.53; P = 0.002) and nitrogen (SMD = 1.41; 95% CI: 0.55 to 2.27; P = 0.006) in broiler diets (Figures 1 and 2). Finally, digesta viscosity (SMD = -3.35; 95% CI: -4.69 to -2.02; P &amp;lt; 0.001) in broiler chickens was decreased by dietary β-mannanase supplementation. In conclusion, the current meta-analysis indicates that dietary β-mannanase supplementation improves the overall utilization of energy and nutrients in diets with decreasing digesta viscosity in broiler chickens.

497 Amylase supplementation influences nutrient digestibility regardless of corn type in broiler chicken diets

Abstract Corn is the primary energy supply in the broiler chicken diet. Physical and nutritional characteristics related to corn endosperm can affect nutrient utilization, as well as the inclusion of exogenous enzymes. This study aimed to evaluate two different corn types classified according to endosperm traits in diets for broiler chickens supplemented or not with amylase. Male broiler chickens (n = 360; 1-d old Cobb 500) were allocated in metabolic battery cages and randomly assigned in a 2 x 2 factorial arrangement (2 corn types; 2 amylase doses: 0 and 90 g/t of diet). A hardness test was performed to categorize and classify each corn type according to breakage force. Corn endosperms were assessed through scanning electron microscopy to investigate structure variations of starch granules. From 19 to 21 d, excreta samples were collected to estimate apparent total tract retention (ATTR) of nutrients and apparent metabolizable energy (AME). On d 26, ileal digesta content was collected to determine apparent ileal nutrients digestibility (AID) and ileal digestible energy (IDE). Data were analyzed using the Student t-test for hardness test (P &amp;lt; 0.05). The Tukey test was performed with a significance declared of 5% to compare the averages obtained for ATTR and AID using the GLM procedure on R Software. Differences were observed in the hardness test (P &amp;lt; 0.05), which classified each corn type either as hard (217 N) or soft (166 N; Table 1). The SEM highlighted structural variations between the floury and vitreous endosperm of each corn. In soft corn, starch granules were more dispersed in the floury endosperm, with a less dense distribution observed in the vitreous endosperm compared with hard corn (Figure 1). However, hard corn exhibited a more compact starch granules distribution in both floury and vitreous endosperm. No differences were observed (P &amp;gt; 0.05) in ATTR of dry matter, crude protein, or AME attributed to corn type, but amylase supplementation improved ATTR of dry matter (P = 0.015) and crude protein (P = 0.020; Table 2). On AID, corn type affected (P = 0.041) dry matter coefficient, and amylase supplementation significantly improved dry matter (P = 0.019), crude protein ileal digestibility (P = 0.012), and IDE (P = 0.018). No interactions between corn type and amylase supplementation were observed (P &amp;gt; 0.05). These findings demonstrated that amylase supplemented in broiler diets impacts nutrient utilization regardless of the corn type used.

Dietary starch structure modulates nitrogen metabolism in laying hens via modifying glucose release rate

The objective of this study was to investigate the effects of starch structure (Amylopectin/Amylose, AP/AM) in a low-protein diet on production performance, nitrogen utilization efficiency, and cecal flora in laying hens. Four hundred eighty 45-wk-age Hy-Line Gray laying hens were randomly allocated to five dietary groups and subjected to a 12-wk feeding trial. The AP/AM ratios of the five experiment diets were 1.0, 1.5, 2.0, 3.0, and 4.0. The results indicated that compared to other groups, laying hens fed with AP/AM 4.0 diets showed significantly improved average egg weight and feed conversion ratio (P < 0.05). Furthermore, as the AP/AM ratio increased, there was a significant linear enhancement in intestinal amino acids apparent digestibility, apparent metabolizable energy, and villus area (P < 0.05). Compared to the high AP groups, high-AM diets significantly increased eggshell thickness, crude protein digestibility, and reduced energy supply from amino acid oxidation in ileum (P < 0.05). Additionally, moderate-AM diets enriched with short-chain fatty acid-producing bacteria in the cecum, such as Lactobacillus, Rikenellaceae_RC9_gut_group, and Christensenellaceae_R-7_group, which are associated with the promoting nitrogen utilization. These findings may offer useful information on optimizing starch structure for the design of food products and relevant therapies due to the potential effects on nutrient metabolism and gut homeostasis.

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

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

Metabolizable Energy Value of Fat and Meals Obtained from Black Soldier Fly Larvae (Hermetia illucens) for Broiler Chickens

An experiment was conducted to determine the apparent metabolizable energy (AME) and nitrogen-corrected AME (AMEn) of defatted black soldier fly larvae meal (BSM), full-fat dry larvae meal (BSL), and larvae fat (LF) for broiler chickens. The BSM, BSL, and LF contained on a g/kg basis, respectively, crude protein, 459, 399, 0; crude fat, 171, 240, 923; dry matter, 963, 940, 997; neutral detergent fiber, 210, 333, 0; acid detergent fibers, 95, 93, 0; and gross energy (MJ/kg), 22.04, 22.78, 38.16. An AME bioassay was performed wherein broilers were fed four experimental diets (a maize–wheat–soy basal diet and three test diets containing 100 g/kg BSM, BSL, or LF, respectively). The AME of BSM, BSL, and LF was calculated based on the differences between the AME values of basal and test diets (substitution method). The AME and AMEn for BSM, BSL, and LF were determined to be 18.20 and 17.40; 17.60 and 16.50; and 36.50 and 35.60 MJ/kg DM, respectively. There were no significant differences (p &gt; 0.05) between nutrient retention coefficients of dry matter, N, and fat. The results showed that the examined products from black soldier fly larvae are a good source of available energy and crude protein (BSL and BSM) and can be incorporated in broiler diets as alternative protein and energy sources.

Effect of increasing β-mannanase supplementation in diets containing copra meal on growth performance, meat quality, liver health, intestinal morphology, and nutrient utilization in broiler chickens.

The current study aimed to investigate the effect of increasing β-mannanase supplementation in diets containing copra meal (CM) on growth performance, meat quality, liver health, intestinal morphology, and nutrient utilization in broiler chickens. A total of 1,600 3-d-old Ross 308 broiler chickens (initial body weight [BW] ± SD = 43.3 ± 1.08 g) were randomly allotted to 1 of 5 treatment groups with 8 replicates. One group was fed a corn-soybean meal-based diet (control). Other 4 diets were prepared by inclusion of 10% commercial CM in the control diet with 0, 400, 800, and 1,600 U β-mannanase/kg. Experiments lasted for 32 d. Birds fed the control diet had less (p=0.001) feed conversion ratio (FCR) than those fed diets containing 10% CM without β-mannanase supplementation. Increasing supplementation of β-mannanase in diets containing 10% CM had no linear and quadratic effects on body weight gain, feed intake, and FCR in broiler chickens. The control diet had greater (p<0.01) apparent total tract retention (ATTR) of DM, GE, and N as compared to the diets containing 10% CM without β-mannanase supplementation; however, no differences in the ATTR of Ca and P were identified between 2 diets. There were no linear and quadratic effects of increasing supplementation of β-mannanase on the ATTR of DM, GE, N, Ca, and P in broiler diets containing 10% CM. Both inclusion of 10% CM and increasing supplementation of β-mannanase in broiler diets did not affect apparent ME (AME) and N-corrected ME (AMEn) values in treatment diets. The use of 10% CM in broiler diets during growing and finishing period impairs growth performance by decreasing energy and nutrient utilization in diets. Increasing β-mannanase supplementation in diets containing 10% CM has no positive effects on performance, meat quality, liver health, intestinal morphology, and nutrient utilization in broiler chickens.

Apparent metabolizable energy concentration and ileal amino acid digestibility in cereal grains fed to broiler chickens.

This study aimed to determine apparent metabolizable energy concentrations and ileal amino acid (AA) digestibility in cereal grains and to compare those metabolizable energy values between the total collection and index methods for 21-day-old broilers. On day 17 post-hatch, a total of 336 Ross 308 male broilers were assigned to 6 dietary treatments with 8 replicate cages (7 birds/cage). Five experimental diets were formulated to incorporate non-extruded corn, extruded corn, wheat, wheat flour, and barley as the sole source of AA and energy. Retention of dry matter and nitrogen, and energy concentrations in cereal grains determined by the total collection method were greater (p<0.05) than those determined by the index method. Energy concentrations of non-extruded and extruded corn were greater (p<0.05) than those of wheat, wheat flour, and barley. Wheat flour exhibited greater (p<0.05) ileal AA digestibility than non-extruded and extruded corn. Extruded corn and wheat showed comparable ileal AA digestibility values, whereas barley had the lowest among cereal grains. Energy concentrations of cereal grains determined by the total collection method were greater than those determined by the index method. Energy concentrations of non-extruded and extruded corn were greater compared to wheat, wheat flour, and barley, irrespective of the method used. The ileal AA digestibility in wheat flour was the greatest, followed by non-extruded corn, extruded corn, wheat, and barley in broilers.

Nutrient utilisation and growth performance of broiler chickens fed standard or moderately reduced dietary protein diets with and without β-mannanase supplementation

Use of reduced protein diets in broiler chicken production provides potential benefits for performance and environmental footprint of production. The effectiveness of β-mannanase supplementation in wheat and soy based standard protein (SP) and reduced protein (RP) diets was tested for growth performance, nutrient utilisation and selected intestinal gene expression of broiler chickens. In a 2×2 factorial arrangement of treatments, two main factors included dietary protein (standard and reduced protein) and β-mannanase supplementation (with or without). All diets contained phytase and carbohydrases (xylanase and glucanase). A total of 480 Ross 308 male off-sex day-old chickens were assigned to the four experimental diets in a 35-d study. Each diet was replicated 12 times with 10 birds per replicate. Using an additional 160 birds, separate apparent metabolizable energy (AME) and nutrient digestibility assays were undertaken for the 4 experimental diets from d 21 to 24 of age. Selected gene involved in gut integrity, inflammation and immune response were quantified using quantitative PCR assays. There was no interaction between β-mannanase and dietary protein for any of the studied parameters except ileal viscosity. Enzyme had no effect on feed intake but tended to increase body weight gain (BWG) from d 0 to 35 of age (P=0.079). Birds fed RP diet consumed more feed when assessed from d 0 to 35 of age (P=0.029). At the same time, β-mannanase tended to reduce feed conversion ratio independent of dietary protein (P=0.069). β-mannanase reduced ileal viscosity of the birds fed RP diet (P<0.001). Reducing dietary protein increased nitrogen retention, nitrogen digestibility coefficient and digestibility coefficients of 11 amino acids (P<0.001). β-mannanase significantly improved digestibility coefficients of nitrogen and Arg, Gly, Thr, Lys, and Ile (P<0.05). Dietary treatments had no effect on AME or gene expression of selected tight junction proteins, interleukin-10, interleukin-1β, mucin-2 and nuclear factor-kappa B. In conclusion, supplementation of β-mannanase tended to improve feed efficiency and increased nutrient digestibility of broilers fed wheat-based diets independent of a moderate reduction in dietary protein. Complementary mode of actions of β-mannanase for intestinal health requires further investigation.