Effect of age on the relationship between metabolizable energy and digestible energy for broiler chickens

Enhancing diet specification to maximise feed efficiency and production characteristics of the Redbro slow growing broiler chicken

1. This study assessed the impact of feeding a high nutrient specification (HS) diet, recommended for fast growing broilers and a low nutrient specification (LS) diet, recommended for slow growing broilers, on growth performance variables, including feed intake (FI), weight gain (WG) and feed conversion ratio (FCR) and production characteristics of fast growing Ross 308 broilers and slow growing Redbro broilers.2. As hatched, Ross 308 (n = 210) and Redbro broilers (n = 210) were randomly allocated to 28 floor pens, 14 pens for each genotype and fed experimental diets from 0 to 42 d of age over four feeding phases. Each diet was fed to seven pens of each genotype, following a randomised, blocked, factorial design.3. Growth performance variables were determined for each feeding phase. Excreta were collected during the last 4 d of the study to determine dietary N-corrected apparent metabolisable energy (AMEn) and nutrient retention coefficients. At 42 d of age, one bird per pen was humanely killed and samples were obtained for determination of meat quality variables, jejunal histomorphology and liver triglycerides.4. Feeding the HS diet increased FI (p < 0.05), WG (p < 0.001) and reduced FCR (p < 0.001) in both genotypes from 0 to 42 d compared to feeding the LS diet. Feeding the HS diet increased AMEn intake (p < 0.001). Diet did not affect breast meat quality, except for increasing drip loss in Ross 308 broilers (p < 0.05), nor did it affect breast myopathies, jejunal morphology, or liver function. Therefore, feeding the HS diet, which was formulated to meet the nutrient recommendations for Ross 308, can be a practical strategy to improve the feed efficiency of Redbro broilers.

Soybean replacement value of canola meal as measured by growth performance and feed efficiency in broiler chickens: Insights from a meta-analysis: CANOLA MEAL HAS POOR REPLACEMENT POTENTIAL FOR SOYBEAN IN BROILER DIETS

While the use of canola meal (CM) as an alternative to soybean meal in broiler diets is well documented, the results are still conflicting. Therefore, this meta-analysis combines results from multiple studies to provide a more precise estimate of the effect size or relationship between dietary CM and feed intake (FI), average daily gain (ADG), and feed conversion ratio (FCR) in broiler chickens. This approach explores the inconsistencies, identifies knowledge gaps, and creates new insights using published data. Search were conducted in Google scholar, Scopus, Web of Sciences, and PubMed, yielding a total of nineteen (19) relevant articles for this study. The data generated analysed using OpenMEE software. Heterogeneity was explored by subgroup and meta-regression analyses using moderator variables (i.e., publication year, strain, gender, inclusion levels, treatment methods, and study periods). The results showed that dietary CM significantly reduced FI [standard mean difference (SMD) = -0.33; 95% confidence interval (CI) = -0.41 to -0.25] and ADG [SMD = -0.68; 95% CI -0.85 to -0.50] while increasing FCR [SMD = - 0.37; 95% CI = 0.24 to 0.51] compared to the control group. Restricted subset analysis showed that studied moderators influenced the outcomes of this meta-analysis. Meta-regression revealed that the stage of development of the birds and treatment methods on CM were the significant predictors of FI while gender and treatment methods significantly predicted both ADG and FCR. In conclusion, the inclusion of CM in broiler diets resulted in poor growth performances, possibly due to anti-nutritional compounds such as glucosinolates, erucic acid, sinapine, and tannins. Thus, innovative research on processing methods to enhance the soybean replacement value of CM in broiler production is necessary.

Effect of dietary treatments on performance, oocysts shedding and lesion scores in broiler chickens experimentally challenged with Eimeria infection

Although anticoccidials effectively control coccidiosis, a needed reduction in the reliance on antimicrobials in animal production leads to the exploration of alternative compounds. The present study aimed to test five different dietary treatments to counteract the negative impact of coccidiosis on broiler chickens' health and performance. 1-day-old male Ross 308 broilers (n = 960) were randomly assigned to one of eight treatments, with six cages per treatment (20 birds/cage). To the diet of the broiler chickens of treatments (Trt) 1-5, a synbiotic was added from d0-10. From d10-28, birds of Trt1 and Trt2 were fed synbiotics, whereas birds of Trt3 were fed diets with glutamine, and birds of Trt4 and Trt5 were fed diets with a combination of β-glucans and betaine. From d28-35 onwards, birds of Trt1 were fed a diet with a synbiotic, whereas birds of Trt2-4 received diets with glutamine, and birds of Trt5 were fed a non-supplemented diet. Birds of the positive control group (PC; Trt6) were fed a standard diet supplemented with an anticoccidial (Decoquinate). The challenged negative control (NCchall; Trt7) and non-challenged negative control (NC) Trt8 were fed a standard diet without anticoccidial or other dietary treatment. At 7 days (d) of age, all birds were inoculated with 1 023, 115, and 512 sporulated oocysts of E. acervulina, E. maxima, and E. tenella, respectively, except for Trt8. Body weight gain (BWG), feed intake, and feed conversion ratio were assessed for each feeding phase (d0-10, d10-28 and d28-35) and overall experimental period (d0-35). Oocyst shedding, Eimeria lesion scores, cecal length, and relative weight were assessed at d13, d22, d28 and d35. Additionally, oocyst shedding was determined at d9 and d17. Litter quality was evaluated at d27 and d34, and footpad lesions at d34. During the starter (d0-10) and finisher (d28-35) periods, performance did not differ between the treatments. During the grower period (d10-28), Trt6 (PC) and Trt8 (NC) chickens had the highest BWG of all treatments (P < 0.001). Dietary treatment had no effect on litter quality and severity of footpad lesions. In the PC group (Trt6), low oocyst excretion and lesion scores were found. When comparing Trt1-5 with NCchall (Trt7), none of the treatments significantly reduced oocyst output or lesion scores. In conclusion, in this experiment, none of the dietary treatments performed similar or better compared to the PC group (Trt6) regarding performance or reducing Eimeria oocyst shedding or lesion scores.

Effects of the Addition of Trichoderma reesei Cellulase to Broiler Chicken Diets for a 21-Day Period

The cellulose present in the cell wall of vegetables prevents the greater release of nutrients to the animal. Therefore, the use of the cellulase enzyme is a viable strategy as it is capable of breaking cellulose bonds, releasing nutrients such as glucose, increasing dietary energy, and thus improving the productive performance of birds. Trichoderma reesei is efficient in the production of cellulase, which is produced via submerged fermentation followed by purification, formulation, and drying. Therefore, an experiment was carried out using 240 male broilers of the Cobb-500® lineage to verify the effects resulting from the addition of powdered (500 g/t and 1000 g/t) and liquid (500 mL/t) cellulase over a period of 1 to 21 days. A completely randomized experimental design was used, consisting of four treatments with six replications and ten birds per replication that were housed in an experimental cage. It was observed that performance and digestibility results were significantly different with cellulase supplementation. Also, the relative weight of the large intestine in the period between one and seven days increased when cellulase was added at 1000 g/t. In the period of between eight and 14 days of life, the birds that consumed only the basal diet obtained higher levels of liver protein than those that received the treatments with the addition of the enzyme. However, 15 and 21 days, the consumed feed effect did not occur between thus, it is not conclusive whether hepatotoxicity occurs with the addition of cellulase. For the blood parameters, at 21 days, the diets with added cellulase were not significantly different regarding electrolytes. It was concluded that this cellulase produced by Trichoderma reesei can be included in the animals' diet.

Broiler Age Differently Affects Apparent Metabolizable Energy and Net Energy of Expanded Soybean Meal

Accurately determining the energy values of ingredients is crucial for meeting energy requirements and achieving maximum production performance of animals. This study was conducted to measure the available energy values of three expanded soybean meals (ESBMs) for Arbor Acres male broilers from 14 to 16 day and 28 to 30 day using the difference method. A corn-soybean basal diet was formulated, and test diets were developed with 25% ESBMs as substitutes for energy-yielding ingredients. A completely randomized design was used for determining heat production and energy balance of broilers in 12 open-circuit respiration chambers, with six replicates per group. Prior to measurement, four (14 to 16 day) or two (28 to 30 day) birds per chamber were given a 4-day adaption to diets and chambers. The period lasted for 3 days to determine the apparent metabolizable energy (AME), nitrogen balance, gas exchanges, and heat production. Broilers fed test diets with 25% ESBM exhibited higher nitrogen intake (p < 0.05), nitrogen excreta (p < 0.05), and increased energy deposition as protein irrespective of age (p < 0.05). Furthermore, results showed that AME, nitrogen corrected AME (AMEn), and net energy (NE) values of 3 ESBMs averaged 10.48, 8.93, and 6.88 MJ/kg for broilers from 14 to 16 day, while averaged 11.91, 10.42, and 6.43 MJ/kg for broilers from 28 to 30 day. Broilers from 28 to 30 day showed significantly higher AMEn values but lower NE/AME values of ESBMs compared with those from 14 to 16 day (p < 0.05). Therefore, age-dependent energy values of a single ingredient should be considered in feed formulations to optimize economic returns.

Prediction of net energy of feeds for broiler chickens

Net energy (NE) enables the prediction of more accurate feed energy values by taking into account the heat increment which is approximately 25% of apparent metabolizable energy (AME) in poultry. Nevertheless, application of NE in poultry industry has not been practiced widely. To predict the NE values of broiler diets, 23 diets were prepared by using 13 major ingredients (wheat, corn, paddy rice, broken rice, cassava pellets, full-fat soybean, soybean meal, canola meal, animal protein, rice bran, wheat bran, palm kernel meal and palm kernel oil). The diets were formulated in order to meet the birds' requirements and get a wide range of chemical compositions (on DM basis; 33.6% to 55.3% for starch; 20.8% to 28.4% for CP, 2.7% to 10.6% for ether extract [EE] and 7.0% to 17.2% for NDF), with low correlations between these nutrients and low correlations between the inclusion levels of ingredients allowing for the calculation of robust prediction equations of energy values of diets or ingredients. These diets were fed to Ross 308 broilers raised in 12 open-circuit respiratory chambers from 18 to 23 d of age (4 birds per cage) and growth performance, diet AME content and heat production were measured, and dietary NE values were calculated. The trial was conducted on a weekly basis with 12 diets measured each week (1 per chamber), 1 of the 23 diets (reference diet) being measured each week. Each diet was tested at least 8 times. In total, 235 energy balance data values were available for the final calculations. Growth performance, AME (15.3 MJ/kg DM on average) and AME/GE (79.4% on average) values were as expected. The NE/AME value averaged 76.6% and was negatively influenced by CP and NDF and positively by EE in connection with efficiencies of AME provided by CP, EE and starch for NE of 73%, 87% and 81%, respectively. The best prediction equation was: NE = (0.815 × AME) - (0.026 × CP) + (0.020 × EE) - (0.024 × NDF) with NE and AME as MJ/kg DM, and CP, EE and NDF as % of DM. The NE prediction equations from this study agree with other recently reported equations in poultry and are suitable for both ingredients and complete feeds.

Maintaining the physical quality and digestibility of pellet feed through the use of plant-based pellet binder

Objectives

This study aimed to analyze the effects of the use of binders on the physical quality and digestibility of Alabio ducks (Anas platyrinchos Borneo).

Materials and Methods

Pellet binders used tapioca meal (TM) (Manihot utilissima), sago meal (SM) (Metroxylon sagu Rottb.), and sweet potato meal (SPM) (Ipomoea batatas) pelleted feed. Laying Alabio ducks, around 120 birds, aged 20 weeks with an average body weight of 1,426 ± 113.5 gm, were used. A fully randomized design with 4 treatments and 15 repeats was used in this study. The variables measured include the physical quality and digestibility of pellet feed. Data analysis used a Fisher test. For the distinction between treatments, the Duncan multiple-range test was conducted.

Results

The finding showed that the plant-based pellet binder had a natural effect on physical properties, including pellet durability index, moisture content, threshold power, stack density, and stack compacted density. The strength of the pellet binder is seen in the durability index of TM 98.12%, SM 97.64%, and SPM 97.35%, respectively. However, these variables did not differ significantly in terms of specific gravity and stack angle. Pellet binders considerably affect the consumption of feed and vary markedly in dry matter, organic matter, and metabolizable energy digestibility.

Conclusion

Plant-based pellet binders influence the physical quality and digestibility of pelleted feed in Alabio ducks. TM can maintain physical quality and digestibility compared to SM and SPM as plant-based pellet binders.

Use of Cactus Pear Meal in the Feeding of Laying Hens in Semi-Intensive System

Little information is available in the literature on the use of cactus pear meal (CPM) in poultry diets; therefore, it is important to evaluate diets that provide excellent performance and lower production costs. Our objective was to study the use of Miúda CPM in the diets of laying hens. In the first study, two diets for male and female chicks were used-1: 80% reference diet + 20% Miúda cactus pear meal (CPM) and 2: 80% reference diet + 20% Gigante cactus pear meal (CPM). The variety Miúda provided a better use of metabolizable energy, as well as a greater digestibility coefficient of dry matter, protein, and mineral matter. In the second study, a control diet was compared to three diets with different levels of Miúda CPM for laying hens in the proportions of 3%, 6%, and 9%. No significant differences were found in productive performance. However, there were significant differences in the some parameters egg quality, texture and color profile of the cooked yolk, egg composition, fatty acids and cholesterol in the yolk. It is possible to use 9% Miúda CPM in the diet of laying hens in a semi-intensive system that does not compromise performance and egg quality, and using 3% Miúda CPM provides a higher economic return.

Age-Related Variations in the Apparent Metabolizable Energy of Meat and Bone Meal for Broilers

The influence of broiler age on the apparent metabolizable energy (AME) and nitrogen-corrected AME (AMEn) of meat and bone meal (MBM) was investigated. A corn-soy basal diet and an experimental diet wherein 300 g/kg of the basal diet was replaced (w/w) with MBM were developed. The diets, in pellet form, were fed to six replicate cages across six age groups, namely d 1 to 7, 8 to 14, 15 to 21, 22 to 28, 29 to 35 or 36 to 42 d post-hatch. Birds were fed either a starter diet from d 1-21 or a finisher diet from d 22-35. Basal and experimental diets were introduced on d 1, 8, 15, 22, 29 and 36 with 10 (d 1-7), 8 (d 8-14) and 6 (d 15-42) birds per replicate. Total collection of excreta was carried out during the last 4 d of each age period. A linear decrease (p < 0.001) in the retention of dry matter and nitrogen was observed with advancing age. The AMEn of MBM showed a linear increase (p < 0.05), rising from 12.56 MJ/kg during d 1-7 to 13.90 MJ/kg during d 29-35, followed by a decline to 13.41 MJ/kg during d 36-42. The current findings showed that the energy utilization of MBM increased with the advancing age of broilers. Age-dependent AMEn values of MBM may need to be considered when MBM is included in feed formulations.

Nutritional, Productive, and Qualitative Characteristics of European Quails Fed with Diets Containing Lipid Sources of Plant and Animal Origin

The objective of this study was to investigate the impact of alternative lipid sources on nutrient metabolism, performance, carcass characteristics, and meat quality in European quails. Trial 1 determined the energy values and nutrient metabolizability of non-conventional lipid sources. Six treatments (control, soybean oil, conventional corn oil, distilled corn oil, poultry fat, and beef tallow) were randomly assigned with 10 replicates per treatment. Trial 2 evaluated animal performance, carcass characteristics, and meat quality using a randomized design with five treatments and 10 replicates each. Statistical analysis showed no significant difference in apparent metabolizable energy corrected by nitrogen (AMEn) and coefficients of metabolizability (CM%) among the lipid sources. The AMEn values found were 8554 for soybean oil, 7701 for corn, 7937 for distilled corn oil, 7906 for poultry fat, and 7776 for beef tallow (kcal/kg). The CM values were 88.01% for soybean oil, 79.01% for corn oil, 84.10% for distilled corn oil, 81.43% for poultry fat, and 79.28% for beef tallow. The inclusion of lipid sources of plant and animal origin in the diet of 7-35-day old meat quails did not influence performance or carcass and cut characteristics. The inclusion of distilled corn oil increased carcass yield and influenced skin and meat color parameters. AMEn values varied for each lipid source. The inclusion of distilled corn oil positively influenced skin and meat color as well as carcass yield in quails.

Broiler chicken response to xylanase and fermentable xylooligosaccharide supplementation

A study was conducted to determine the effect of dietary fiber (DF), xylanase (XYL), xylooligosaccharides (XOS), and a combination of XYL and xylooligosaccharides (STBIO) on chicken growth performance, N-corrected apparent metabolizable energy (AMEn), and nutrient availability, characteristics of the gastrointestinal tract (GIT), and cecal content of short-chain fatty acids (SCFA). A 35-day experiment was performed on 1,920 as hatched Ross 308 broiler chicks, reared in 96 pens and fed ad libitum. Experimental diets were split into 2 phases: starter (0-21 d) and finisher (22-35 d). There were 2 basal diets, first contained 54% maize and in the second, 5% of the maize was replaced by wheat bran as DF. The diets were split into 4 batches: one of them was used as a control, and each of the others were supplemented either with XYL or XOS or with the STBIO. Each diet was fed to 12 pens following randomization. The data were analyzed in GenStat (20th edition) by ANOVA using a 2 × 4 factorial design. The addition of STBIO improved feed conversion ratio (FCR) and increased weight gain (WG) from 21 to 35 d and from 0 to 35 d (P < 0.05). The inclusion of DF had a negative effect on N and fat retention coefficients at 35 d as well as AMEn and dry matter retention at 21 and 35 d. At 21 d, neutral detergent fiber (NDF) retention was increased when xylanase and STBIO were added to the diet (P < 0.001) and at d 35 the highest retention was noted when the diet was supplemented with DF and XYL or STBIO (P = 0.001). There was no dietary effect on jejunum histomorphometry (P > 0.05). The addition of DF increased the concentration of cecal SCFA in particular valeric and propionic acid at 35-day-old birds (P < 0.05). It can be concluded that addition of STBIO in diet could provide benefits in terms of fiber degradation, WG, and feed efficiency.

Sunflower and rapeseed meal as alternative feed materials to soybean meal for sustainable egg production, using aged laying hens

1. This study assessed the impact of replacing two thirds of a soybean meal (SBM) based diet with an alternative protein (AP) based diet (sunflower and rapeseed meal), when fed to end of production Hy-Line Brown laying hens.2. Diets were fed in seven cages, each containing six birds aged from 75 to 83 weeks old. Measured variables included bird performance, egg production, quality variables of fresh eggs, total tract digestibility of dry matter (DMD), neutral detergent fibre (NDFD), fat (FD), and nitrogen corrected apparent metabolisable energy (AMEn).3. No significant differences were observed (P > 0.05) for egg production, egg composition or egg quality. However, birds fed the AP diet had darker yolks (P < 0.05), possibly linked to natural pigments in AP.4. The SBM diet had higher AMEn, DMD and NDFD (P < 0.05), although FD was higher in the AP diet (P < 0.05).5. Diets based on AP sources can be fed to aged laying hens without deteriorating productive performance, providing care is taken in formulating diets (e.g. amino acid levels, balance etc). Using AP sources may reduce reliance on SBM associated with land use change, contributing towards sustainability for the egg industry.

Feeding Black Pepper (Piper nigrum) or Exogenous Xylanase Improves the Blood Lipid Profile of Broiler Chickens Fed Wheat-Based Diets

This study aimed to determine the impact of dietary black peppercorn (BP) and xylanase (XYL) alone or in combination on growth performance, dietary energy, nutrient digestibility and blood lipid profile when fed to male Ross 308 broiler chickens from the ages of 7 to 21 d. A wheat-soy-based basal feed that was formulated to be 0.42 MJ lower in metabolizable energy (ME) was mixed. The basal feed was then split into four batches, with the first batch set aside as the basal control; the second batch was supplemented with freshly milled BP; the third batch was supplemented with XYL; the fourth batch was supplemented with both BP and XYL, as in the previous two batches. Each diet was fed to eight pens, with two birds in a pen, following randomization. Feeding BP reduced bird growth and most of the digestibility coefficients but increased blood high-density lipoprotein (p < 0.05). Dietary XYL increased bird growth, dietary ME and nutrient digestibility (p < 0.05). In addition, XYL increased hepatic carotenoids and coenzyme Q10, but reduced blood low-density lipoprotein (p < 0.05). There were no BP by XYL interactions (p > 0.05) observed. Further research is needed to identify the optimum level of BP in broiler diets.

Refining the metabolisable energy value of field beans for turkeys

1. This study examined the feeding value of ten UK grown field bean (Vicia faba L. var. minor) cultivar samples from the same harvest year on nitrogen corrected apparent metabolisable energy (AMEn) and nutrient retention coefficients when fed to young female turkeys.2. A balancer feed (BF) was formulated to contain 12.39 MJ/kg ME and 269 g/kg crude protein. Ten nutritionally complete, mash diets were prepared by mixing 200 g/kg of each ground field bean cultivar with 800 g/kg of the BF, totalling eleven diets. Diets were fed to female BUT Premium turkeys from 40 to 50 d of age. Each diet was fed to eight raised floor pens, housing two birds, following randomisation. The AMEn was determined by the total collection technique over the last 4 d of the study. Relationships were examined between AMEn, chemical composition and quality variables of the field bean samples.3. The overall determined AMEn value of the beans ranged from 7.72 MJ/kg DM to 9.87 MJ/kg DM, giving an average AMEn of 8.80 MJ/kg DM (P < 0.05). The soluble non-starch polysaccharide (NSP) content of the beans negatively correlated with their determined AMEn (r = -0.730; P < 0.05). Bean flour lightness-darkness degree (L*) correlated positively with the AMEn (r = -0.643; P < 0.05)4. A positive correlation was observed between the degree of yellowness-blueness of bean flour and condensed tannins content (r = 0.696; P < 0.05). Step-wise regression indicated that soluble NSP + L* of field beans provided explanatory variables suitable for estimating the AMEn value for turkeys (r2 = 0.737; P < 0.05).

Determination of metabolisable and net energy contents of corn fed to Arbor Acres broilers and Beijing You chickens

This study was done to compare the energy and nutrient utilisation of corn in Arbor Acres (AA) broilers and Beijing You (BJY) chickens. BJY chickens with the same age as AA broilers were named BJY1 chickens, and with the same body weight as AA broilers were named BJY2 chickens. Three groups of broilers (36 male AA broilers, 72 male BJY1 chickens, and 36 male BJY2 chickens), 2 treatments per group, 6 replicates per treatment, 3 chickens or 6 chickens per replicate. During each period, birds were fed in chambers for 11 days, including 5 days for adaptation to the feed, 3 days for excreta and gas data collection and another 3 days for fasting were recorded. Results showed that the fasting heat production (FHP) of AA, BJY1 and BJY2 chickens gradually stabilised after fasting for 72 h, the FHP of AA, BJY1 and BJY2 chickens were 486.54, 536.22 and 548.90 KJ/kg BW^0.70 /day respectively. AA broilers had significantly lower (p < 0.01) apparent total tract digestibility (ATTD) of starch in corn than that of BJY1 and BJY2 chickens, whereas there were no significant differences (p > 0.05) observed in ATTD of dry matter, crude protein, ether extract and crude fibre. The apparent metabolisable energy (AME) values of corn in AA, BJY1 and BJY2 chickens were 16.18, 16.81, and 16.39 MJ/kg dry matter (DM) and the corresponding nitrogen-corrected AME (AMEn) values were 15.71, 16.38 and 15.99 MJ/kg DM respectively. The net energy (NE) values of corn in AA, BJY1 and BJY2 chickens were 12.03, 12.28 and 11.97 MJ/kg DM respectively. In conclusion, BJY chickens had a higher maintenance energy requirement than that of AA broilers, and AA broilers of the same age and weight as BJY chickens showed no significant differences in AME, AMEn and NE values of corn.

Broiler Age Influences the Apparent Metabolizable Energy of Soybean Meal and Canola Meal

The effects of broiler age on the apparent metabolizable energy (AME) and nitrogen-corrected AME (AMEn) of soybean meal (SBM) and canola meal (CM) were examined. A corn-SBM basal diet was developed, and two test diets were formulated by substituting (w/w) 300 g/kg of the basal diet with SBM or CM. Six groups of broiler chickens, aged 1−7, 8−14, 15−21, 22−28, 29−35 or 36−42 d post-hatch, were utilized. Each diet, in pellet form, was randomly allocated to six replicate cages in each age group. Except for the 1−7 d age group, the birds were fed a starter (d 1−21) and/or a finisher (d 22−35) diet prior to the introduction of the experimental diets. The number of birds per cage was 10 (d 1−7), 8 (d 8−14) and 6 (d 15−42). The AME and AMEn of SBM and CM were determined by total excreta collection. The data for each protein source were subjected to orthogonal polynomial contrasts using the General Linear Models procedure. Bird age decreased the retention of dry matter quadratically (p < 0.001) for both SBM and CM. The retention of nitrogen decreased linearly (p < 0.001) with the advancing age of broilers for SBM and CM. The AMEn of SBM and CM decreased quadratically (p < 0.001) as the birds grew older. The highest AMEn was observed during week 1 for both SBM and CM, then declined until week 3, followed by increases thereafter. The current results showed that the age of broiler chickens influenced the AMEn of SBM and CM and supported the use of age-dependent AMEn of feed ingredients in diet formulations.

The age-related metabolizable energy of cereal grains, oilseed meals, corn gluten meals, and feather meals for broilers

A 2 × 3 factorial arrangement of treatments with two ages of broilers (11 to 14 or 25 to 28 d of age) and three samples of feed ingredients was utilized to compare metabolizable energy (ME) and ratio of ME to gross energy (GE) in each group of three cereal grains (CG, including one corn, two wheat flour), three oilseed meals (OM, including one soybean meal, one peanut meal, and one cottonseed meal), three corn gluten meals (CGM A, B, and C), and three feather meals (FM A, B, and C). Each treatment contained six replicates of four Arbor Acre male broilers in energy balance experiments. Trends toward interactions between age and source of CG were observed on the ME and ME/GE of CG (0.05

Collapse

Key Words

• age
• broiler
• feed ingredient
• metabolizable energy

Collapse

MESH Headings

• Male
• Animals
• Digestion
• Edible Grain
• Chickens
• Flour
• Feathers
• Glutens
• Animal Feed/analysis
• Triticum
• Diet/veterinary
• Energy Metabolism
• Zea mays
• Animal Nutritional Physiological Phenomena

Collapse

Grants

• BAIC06-2022 Poultry Research Team of Beijing Innovation Consortium of Agriculture Research System
• 2020-YF-03 Cooperative Project between IASCAAS-Newhope Liuhe Co. Ltd

Collapse

Affiliation(s)

Mingqiang Song The State Key Laboratory of Animal Nutrition, Institute of Animal Sciences of Chinese Academy of Agricultural Sciences, Beijing 100193, China
Yuming Wang The State Key Laboratory of Animal Nutrition, Institute of Animal Sciences of Chinese Academy of Agricultural Sciences, Beijing 100193, China
Youyou Liu The State Key Laboratory of Animal Nutrition, Institute of Animal Sciences of Chinese Academy of Agricultural Sciences, Beijing 100193, China
Cong Ren The State Key Laboratory of Animal Nutrition, Institute of Animal Sciences of Chinese Academy of Agricultural Sciences, Beijing 100193, China
Lei Yan Newhope Liuhe Co. Ltd., Beijing 100102, China Shandong New Hope Liuhe Group, Qingdao, Shandong 266000, China
Jingjing Xie The State Key Laboratory of Animal Nutrition, Institute of Animal Sciences of Chinese Academy of Agricultural Sciences, Beijing 100193, China
Jinliang Lai Newhope Liuhe Co. Ltd., Beijing 100102, China
Guilian Zhou Newhope Liuhe Co. Ltd., Beijing 100102, China
Yong Li Newhope Liuhe Co. Ltd., Beijing 100102, China
Feng Zhao The State Key Laboratory of Animal Nutrition, Institute of Animal Sciences of Chinese Academy of Agricultural Sciences, Beijing 100193, China

Collapse

Collaborators Collapse

Rapeseed meal processing and dietary enzymes modulate excreta inositol phosphate profile, nutrient availability and production performance of broiler chickens

This study aimed to assess the effect of rapeseed meal (RSM) processing method, where solvent extraction occurred under standard industry conditions (ST) or cold-pressed hexane extraction was employed (MT), and exogenous enzyme supplementation (phytase [PHY] and xylanase [XYL]) alone or in combination on key nutritional factors of broiler chickens. A randomized control experiment was performed using 144 male Ross 308 broilers in a 2 × 2 × 3 factorial arrangement. Three diets including a nutritionally complete wheat-based basal diet (BD), a diet containing 200 g/kg of RSM extracted under ST and another diet containing 200 g/kg of RSM extracted under MT were produced. Each diet was then split into 4 parts and was fed as is, or supplemented with PHY at 1,500 FTU/kg or XYL at 16,000 BXU/kg, alone or in combination, resulting in 12 diets in total. Response criteria: feed intake (FI), weight gain (WG), and feed conversion ratio (FCR), from 7 to 21 d age, AMEn, retention coefficients for dry matter (DMR), nitrogen (NR), fat (FR), and the profile of inositol phosphate esters (IP2-6) and myo-inositol (MI) in excreta. Diets containing MT had higher AMEn compared to ST diets (P < 0.05). There was RSM by PHY interaction for FI, as only birds fed MT diet responded to PHY supplementation with reduced FI and FCR (P < 0.001). Feeding XYL reduced overall FI and FCR (P < 0.05). Feeding PHY reduced IP6 and increased MI in excreta (P < 0.001). Feeding XYL and PHY in combination reduced MI in excreta compared to PHY only (P = 0.05). Compared to BD, birds fed RSM diets had an increased IP6 (P < 0.05) and MI concentration in excreta (P < 0.01). This may be due to IP ester differences in RSM and BD.

Autoclaving time-related reduction in metabolizable energy of poultry meal is greater in growing pigs compared with broiler chickens

The objective of this study was to determine the energy utilization responses of growing pigs and broiler chickens to poultry meal that was autoclaved at 134 °C for 0 to 180 min. Poultry meal from the same batch was autoclaved at 134 °C for 7 autoclaving times of 0, 30, 60, 90, 120, 150, or 180 min to generate 7 samples. Eight experimental diets consisting of a basal diet based on corn and soybean meal, and seven test diets in which 15% of energy-contributing ingredients in the basal diet were replaced with each of the seven poultry meal samples were used. In experiment 1, there were 64 barrows (initial body weight = 19.4 ± 1.0 kg) allotted to 8 experimental diets in a randomized complete block design with body weight as a blocking factor. Each pig received an experimental diet during 5 d of adaptation followed by 5 d of quantitative total, but separate, collection of urine and feces. In experiment 2, a total of 512 male broiler chickens at day 17 post-hatching (initial body weight = 660 ± 80 g) in 8 replicate cages were allotted to 8 experimental diets in a randomized complete block design with body weight as a blocking factor. Excreta were collected from days 20 to 22 post-hatching, and birds were euthanized by CO2 asphyxiation for ileal digesta collection. Data from experiments 1 and 2 were pooled together for statistical analysis as a 2 × 7 factorial treatment arrangement with the effect of species (pigs or broiler chickens) and autoclaving time of poultry meal (7 autoclaving times between 0 and 180 min). An interaction between species and their linear effect of autoclaving time was observed (P < 0.05) in metabolizable energy (ME) of poultry meal. Specifically, linear decrease in ME values in poultry meal with increasing autoclaving time was greater (P < 0.05) in growing pigs (4,792 to 3,897 kcal/kg dry matter) compared with broiler chickens (3,591 to 3,306 kcal/kg dry matter). The ME value of unautoclaved poultry meal was greater (P < 0.01) for pigs than broiler chickens at 4,792 vs. 3,591 kcal/kg dry matter. Although decrease in ME values with autoclaving time of poultry meal was greater in growing pigs than in broiler chickens, the ME in autoclaved poultry meal fed to pigs was greater than ME in non-autoclaved poultry meal fed to broiler chickens. Furthermore, the ratio of cysteine to crude protein concentration is a potential indicator for estimating the ratio of ME to gross energy in poultry meal for growing pigs (r2 = 0.81) and broiler chickens (r2 = 0.84).

Age-dependent response to fasting during assessment of metabolizable energy and total tract digestibility in chicken

Fasting is typically used to empty the gastrointestinal tract (GIT) and assess feed metabolizable energy (ME). However, the effects of fasting on energy and nutrient utilization are not well understood. This study aimed to explore the difference in GIT emptying, energy and nutrient utilization of broilers and adult roosters fed corn-soybean meal-based diet upon fasting. In experiment 1, 7 cages of broilers/adult roosters were selected and fasted for 72 h, and excreta were collected from 12 h of fasting and analyzed every 12 h to explore GIT emptying. Results indicated the GIT emptying time of free-feeding broilers or adult roosters is 12 or 24 h, respectively. In experiment 2, 4 treatments were used that consisted of 2 ages of birds (25 d broilers and 30 wk adult roosters) and 2 feeding forms (fed ad libitum or fasted for 36 h before formal feeding). Excreta was collected during refeeding, and the total collection method (TCM) and the index method (IM) were used for data analysis. Compared to non-fasted group, fasting increased the total tract digestibility of ME, gross energy (GE), and ether extract (EE) (by 1.80, 3.50 and 18.56%, respectively, all P < 0.05) in broilers, but decreased the total tract digestibility of nitrogen by 8.10% (P < 0.05). Conversely, fasting increased total tract digestibility of nitrogen in adult roosters (−0.37% vs. 11.65%, P < 0.05). The comparative analysis found that total tract digestibility of nitrogen obtained by TCM was greater than the result calculated by IM (17.76 % vs. −0.37). Similarly, total tract digestibility of GE calculated by TCM was significantly higher than the value observed by IM (P < 0.05). However, the results of total tract digestibility of GE and nitrogen in broilers calculated by TCM were consistent with those obtained by IM. Overall, fasting increases total tract digestibility in broilers and total tract digestibility of nitrogen in adult roosters, respectively. Additionally, total tract digestibility calculated by TCM may be overestimated.

Nutritional interventions to support broiler chickens during Eimeria infection

Different combinations of gut health-promoting dietary interventions were tested to support broilers during different stages of Eimeria infection. One-day-old male Ross 308 broilers (n = 720) were randomly assigned to one of 6 dietary treatments, with 6 pens per treatment and 20 birds per pen, for 35 d. At 7 d of age (d7), all birds were inoculated with 1000, 100, and 500 sporulated oocysts of E. acervulina, E. maxima, and E. tenella, respectively. A 4-phase feeding schedule was provided. The dietary treatments (TRT) 1 to 4 included the basal diet supplemented with multispecies probiotics from d0 to 9 and coated butyrate and threonine from d28 to 35 but received four different combinations of prebiotics and phytochemicals from d9 to 18 and d18 to 28. The basal diet for the positive control (PC, TRT5) included diclazuril as a anticoccidial. The negative control (NC, TRT6) contained no anticoccidial. Performance was assessed for each feeding phase, and oocyst output, Eimeria lesion scores, cecal weight, litter quality, and footpad lesions were assessed at d14, d22, d28, and d35. Body weight gain (BWG) and feed intake (FI) were not affected by dietary treatment. PC broilers had the best feed conversion ratio (FCR) of all treatments from d0 to 35 (P < 0.001). None of the dietary treatments resulted in better litter quality or reduced footpad lesions compared to the PC. Moreover, the PC was most effective in reducing oocyst output and lesion scores compared to all other treatments. However, broilers that received the multispecies probiotics (d0 to 9), saponins (d9 to 18), saponins, artemisin, and curcumin (d18 to 28), and coated butyrate and threonine (d28 to 35) had the best FCR (P < 0.001) and lowest oocyst output and lesion scores compared to other dietary treatments. This study suggests that although the tested compounds did not perform as well as the anticoccidial, when applied in the proper feeding period, they may support bird resilience during coccidiosis infection.

Effects of the inclusion of black soldier fly larvae (Hermetia illucens) meal on growth performance and blood plasma constituents in broiler chicken (Gallus gallus domesticus) production

The aim of this study was to identify the effect of inclusion of defatted black soldier fly larvae (Def-BSFL) meal as a protein source on the performance and blood plasma constituents of broiler chickens. A total of 360-day-old chicks were assigned into four dietary groups, which included four different levels of Def-BSFL meal namely control (0% BSFL), T1(4% BSFL), T2 (8% BSFL) and T3 (12% BSFL) for six weeks experimental feeding period. At the end of the experiment, the blood samples of three birds from each treatment were collected to measure plasma constituents. Birds fed control and T1 diets demonstrated higher feed intake during the finisher stage compared with T2 and T3 diets. The heaviest weight for the 6-week feeding trial was recorded at T1 (1043.8 ± 65.9 g). Birds fed T1 (1.1 ± 0.0) and T3 (0.9 ± 0.1) diets displayed lower feed conversion ratio during the finisher stage than those fed control (1.7 ± 0.1) and T2 (1.8 ± 0.3) diets. Birds fed the control diet demonstrated the highest red blood cell with mean and standard deviation of 7.5 ± 0.34, whereas those fed the T2 diet showed the highest haemoglobin levels with mean and standard deviation of 15.8 ± 0.24. Birds fed T1, T2, and T3 diets exhibited a higher number (P < 0.05) of monocytes than those fed a control diet. There were no differences in white blood cell count across all the groups. In addition, birds fed the T2 diet showed higher (P < 0.05) blood urea nitrogen followed by the T3, control, and T1 diets. As a conclusion, the 4% Def-BSFL in the broiler chicken diet could be used to replace fish meal (FM) and soybean meal (SBM) without compromising bird performance and blood traits.

Influence of Broiler Age on the Apparent Metabolizable Energy of Cereal Grains Determined Using the Substitution Method

Simple Summary

Knowledge of the metabolizable energy content of cereal grains is critical for their economical and sustainable use and precise poultry feed formulation. The current practice in the feed industry is to use the apparent metabolizable energy (AME) or nitrogen-corrected AME (AMEn) values of ingredients from prediction equations or reference tables, which have been estimated using (5-week-old birds). Several factors, including age, ingredient type, and methodology, can affect the AMEn value of ingredients in poultry. Currently, there are no data available on the age effect, from hatch to 6 weeks of age, on the AMEn of grains in broilers. The aim of the present study was to investigate the influence of age on the AMEn of wheat, sorghum, barley, and corn from hatching to day 42 using the substitution method. The results showed that the age influence on the AMEn of cereal grains was grain dependent. In wheat and sorghum, AMEn was influenced by age, while the AMEn of barley and corn were unaffected. Poultry nutritionists might need to consider age-dependent AME or AMEn values for some grains in feed formulations.

Abstract

The present study investigated the influence of broiler age on the AMEn of wheat, sorghum, barley, and corn using the substitution method at six different ages (days 7, 14, 21, 28, 35, and 42). A corn-soybean meal basal diet was formulated and, the test diets were developed by replacing (w/w) 300 g/kg of the basal diet with wheat, sorghum, barley, or corn. Bird age influenced (p < 0.001) the AMEn of wheat and sorghum but had no effect (p > 0.05) on those of barley and corn. The AMEn of wheat increased with age (p < 0.001) from 12.53 MJ/kg DM in week 1 to 14.55 MJ/kg DM in week 2, then declined subsequently, but no linear or quadratic responses were observed. The AMEn of sorghum demonstrated a quadratic response (p < 0.05), increasing from 12.84 MJ/kg DM in week 1 to 13.95 MJ/kg DM in week 2, and then plateauing to week 6. Overall, the present results suggest that the effect of broiler age on the AMEn varies depending on the grain type. The current data suggest that the application of age-dependent AME or AMEn of wheat and sorghum will lead to more precise feed formulations.

Research note: Estimation of individual feed intake of broiler chickens in group-housing systems

In most experiments, broiler chickens are group-housed and share the same feeder in a given cage or pen. Correction of feed intake in a given pen is sometimes required in the event of mortality or identification of birds within a pen as outliers. For this reason, an accurate estimation of individual feed intake (IFI) is important. The objective of this study was to compare 3 different methods of estimating the IFI of broiler chickens in group-housing systems. The methods utilized in the current study consisted of an averaging method, a ratio method, and a partitioning method. The assumption of the averaging method is that birds in a cage consume an equal amount of feed, whereas feed intake of a given bird is proportional to its BW gain in the ratio method. The partitioning method bifurcates IFI into IFI for maintenance and growth. To validate these methods, 32 male broiler chickens (initial BW = 161 ± 19 g) at d 7 post hatching were individually housed in cages. Birds were fed a corn-soybean meal-based diet for 28 d, and body weight and feed disappearance were recorded on d 14, 21, 28, and 35. Excreta were collected over the last 3 d of each week. As age of broiler chickens increased, body weight gain, feed intake, and dietary metabolizable energy both linearly and quadratically increased, whereas gain-to-feed ratio both linearly and quadratically decreased (P < 0.05). The partitioning method estimated IFI more accurately compared with the averaging method and the ratio method (P < 0.05). The current result implies that the partitioning method would accurately estimate IFI of broiler chickens in group-housing systems.

Apparent metabolizable energy of cereal grains for broiler chickens is influenced by age

The current study was conducted to investigate the influence of broiler age on the AME and AMEn of 4 common cereal grains (wheat, sorghum, barley, and corn). Four experimental diets with the same inclusion (962 g/kg) of each grain were developed and fed to groups of broiler chickens aged 1 to 7, 8 to 14, 15 to 21, 22 to 28, 29 to 35, or 36 to 42 d post-hatch. Each diet, in pellet form, was randomly allocated to 6 replicate cages in each age group. Except for the 0 to 7 d age group, the birds were fed a starter (d 0-21) and/or a finisher (d 21-35) diet before the introduction of experimental diets. The number of birds per cage were 10 (d 1-7) and 8 (d 8-42). Excreta were collected over the last 4 d of each age period. The AME and AMEn of the grains were determined by the total excreta collection. Bird age influenced (P < 0.001) the AME and AMEn of all cereal grains. The AMEn of wheat declined quadratically (P < 0.01) with advancing age, from 3,461 kcal/kg in wk 1 to 3,219 kcal/kg in wk 2 and then plateaued. The AMEn of sorghum grain declined linearly (P < 0.001) with advancing age, from 3,762 kcal/kg in wk 1 to 3,614 kcal/kg in wk 2, plateaued to wk 5 and then declined to 3,556 kcal/kg in wk 6. A quadratic (P < 0.001) reduction in the AMEn of barley was observed as birds grew older, with the AMEn decreasing between wk 1 (3,286 kcal/kg) and wk 2 (2,988 kcal/kg), increasing in wk 3 (3,117 kcal/kg) and then plateauing. The AMEn of corn declined quadratically (P < 0.05) with advancing broiler age; the highest AMEn was observed in wk 1 and 5, the lowest AMEn in wk 2, with the other weeks being intermediate. In conclusion, the present results showed that broiler age has a substantial impact on the AME and AMEn of cereal grains and the effect varied depending on the cereal grain. These data suggest that age dependent AME and AMEn values may need to be considered when formulating broiler diets to improve the precision of feed formulation and production efficiency.

Balanced nutrient density for broiler chickens using a range of digestible lysine-to-metabolizable energy ratios and nutrient density: Growth performance, nutrient utilisation and apparent metabolizable energy

Currently, specific nutrient concentration, metabolizable energy (ME) and digestible amino acids are used as feed formulation criteria. A balanced nutrient density (BND) concept based on 2 criteria of nutrient density and balanced amino acids-to-ME ratio may offer more flexibility in optimisation of profit in formulation of diets compared with current formulation based on set values per unit of feed mass. A total of 672 one-d-old off-sex male Ross 308 broiler chickens were used across two 42-d performance trials in a 3 × 2 factorial arrangement of treatments with each diet replicated 8 times (14 birds per replicate). The experimental factors were 2 nutrient density levels (low [LD] and high [HD]) and 3 digestible lysine-to-ME ratios (DLYS:ME; low, medium, and high). Low density diets had ME of 2,876 and 3,023 kcal/kg for starter and finisher, respectively, while values for HD diets were 3,169 and 3,315 kcal/kg with proportionally higher non-nitrogenated nutrients. Separate digestibility and apparent metabolizable energy (AME) assays were conducted at d 21 and 42. Digestibility assays at d 7 were conducted on birds used for performance trials. Regardless of the diet density, birds fed low DLYS:ME had a lower (P < 0.01) feed intake (d 0 to 42) than medium and high DLYS:ME. Without interaction, birds fed low and medium DLYS:ME had a similar body weight gain being the heaviest while birds low DLYS:ME were the lightest. By an interaction (P < 0.05), the highest overall FCR value was observed for birds fed LD × low DLYS:ME and improved linearly when DLYS:ME increased to the highest level reaching a limit for birds fed HD × medium DLYS:ME. Calorie conversion linearly decreased (P < 0.001) with increments in DLYS:ME. Jejunal and ileal starch and protein digestibility were affected on d 21 and 42 but not on d 7 of age. Given the independence of response on BW and feed consumption, the use of BND as a flexible system in diet formulations has the potential to enable more accurate formulation for optimisation of growth performance of broiler chickens.

Feeding dry stevia leaf (Stevia rebaudiana) or xylanase improves the hepatic antioxidative status of broiler chickens

Four diets, formulated with and without stevia and with and without exogenous xylanase, following a 2 × 2 factorial design, were prepared. Each diet was fed ad libitum to birds in eight pens (three birds in each pen) in a randomised block design. It was found that birds fed xylanase grew faster, used the feed more efficiently and had an increased concentration of hepatic α-tocopherol and vitamin E concentrations (P < 0.05). Feeding stevia did not affect growth performance (P > 0.05), but increased hepatic CoQ₁₀ (P = 0.05), lutein, zeaxanthin and total carotenoids (P < 0.001) concentrations. There were no dietary stevia by xylanase interactions (P > 0.05) for any of the studied variables. The results showed that alone, dietary stevia and dietary xylanase can improve the antioxidative status of birds through enhancing dietary antioxidant availability.

Environmental temperature and broiler age on corn energy value

Abstract This study aimed to assess the effects of environmental temperature and age of broilers on the energy value of corn. A total of 288 Cobb 500 chicks were distributed in a complete randomized design with a split-plot arrangement and six replications of six chicks each. The main plot consisted of three temperatures (cold: 18 ºC; thermoneutral: 25 ºC; and hot: 33 ºC), while the secondary plot consisted of age (initial: 11 to 14 days; growing: 25 to 28 days; and final: 39 to 42 days). The basal diet was based on corn and soybean meal. The test diet was produced by replacing the basal diet for test food: 40% corn + 60% basal diet. The mean values of AMEn observed for broiler chicks under cold, thermoneutral, and hot temperatures were 3322, 3279, and 3233 kcal/kg of natural matter, respectively, and 3215, 3218, and 3400 kcal/ kg of natural matter for the initial, growing, and final phases, respectively. Overall, the metabolizable energy values of corn and the balance and coefficients of metabolizability of nutrients in the test diet increased with the broiler age, but the true metabolizable energies of corn were not affected by environmental temperature. The balance and coefficients of metabolizability of nutrients in the test diet decreased due to heat exposure during the growing and final phases.

Feeding dihydroquercetin and vitamin E to broiler chickens reared at standard and high ambient temperatures

The use of natural antioxidants, in particular polyphenols such as dihydroquercetin (DHQ), in animal nutrition has recently increased in popularity. This may partly be due to the risk of increased incidences of heat stress associated with raising livestock in warmer ambient temperatures, facilitated by global warming, reducing antioxidant capacity. The current research demonstrates the effect of dietary DHQ, vitaminEand standard or high ambient temperatures on growth performance, energy and nutrient metabolism, gastrointestinal tract (GIT) development, jejunal villus morphometry and antioxidant status in broiler chickens. Each of the four experimental diets was fed to 16 pens of five birds, which were allocated to four rooms (four pens in each room). The temperature in two rooms was maintained at aconstant 35°C (high temperature; HT), and the temperature in the other two rooms was gradually reduced from 27°C at 7 dof age to 22°C at 20 dof age (standard temperature; ST). Rearing birds at HT reduced feed intake, weight gain, weight of small intestine, total GIT, liver, spleen, heart, villus height, villus surface area and lowered blood glutationperoxidase (GSH-Px). Dietary DHQ increased blood GSH-Px and total antioxidant status, increased heart weight and reduced caecal size. When fed separately, DHQ and vitamin E improved hepatic vitamin E concentration. Feeding vitamin Eincreased spleen and liver weights. When fed together, DHQ and vitamin Ereduced villus height, villus height to crypt depth ratio and villus surface area. Temperature and antioxidants did not affect energy and nutrient metabolism. There were no effects of dietary antioxidants on growth performance of broiler chickens and there were no mortalities. At present, it is unclear if feeding antioxidants (in particular DHQ) at different levels, using different dietary formulations, and rearing birds under arange of environmental conditions may be effective at enhancing production performance and bird health in hot ambient climates.

Dietary microbial muramidase improves feed efficiency, energy and nutrient availability and welfare of broilers fed commercial type diets containing exogenous enzymes

1. The aim of this study was to evaluate the effect of graded levels of the microbially derived feed lysozyme, muramidase (MUR) on feed intake (FI), weight gain (WG), feed conversion ratio (FCR), European Performance Index (EPI), dietary N-corrected apparent metabolisable energy (AMEn), footpad dermatitis score (FPD) and other welfare variables, when fed to broilers from 0 to 42d age. 2. A four-phase dietary programme and four experimental pelleted diets were used; a control diet (following breeder recommendations without MUR supplementation), and three diets based on the control diet supplemented with 25,000, 35,000 and 45,000 LSU (F)/kg of MUR, respectively. In addition, all experimental diets contained exogenous xylanase, phytase and a coccidiostat. Each diet was fed to birds in 24 pens (20 male Ross 308 chicks in each pen) following randomisation. Dietary AMEn was determined at 21 d of age, and FPD was evaluated at the end of the study. Data were analysed by ANOVA, using orthogonal polynomials for assessing linear and quadratic responses to MUR activity. 3. The inclusion of MUR did not change FI (P > 0.05), but increased WG in a linear manner (P < 0.05) and reduced FCR in a quadratic manner, with optimum WG and FCR observed in birds fed approximately 35 000 LSU (F)/kg. In accordance with the improvement in FCR, 35 000 LSU (F)/kg MUR supplementation produced the highest EPI (P < 0.05). FPD score was linearly decreased with increased addition of MUR (P < 0.05). Dietary AMEn responded in a quadratic fashion to the MUR inclusion, as the highest values were obtained with the highest inclusion rate (P < 0.05). 4. In conclusion, the results showed that inclusion of MUR improved feed efficiency and the foot health of birds.

Measurement of ileal endogenous energy losses and true ileal digestible energy of cereal grains for broiler chickens

Two experiments were conducted to determine the ileal endogenous energy losses (IEEL) and nitrogen-corrected apparent metabolizable energy (AMEn) and true ileal digestible energy (TIDE) of 4 cereal grains (corn, sorghum, wheat, and barley) for broilers. In experiment 1, a glucose-based purified diet was used to determine the IEEL for correcting the apparent ileal digestible energy (AIDE) values to TIDE. The diet was randomly allocated to 6 replicates (6 birds per replicate) of male broilers and fed from 18 to 21 d after hatch. The jejunal and ileal digesta were collected on day 21. The results showed that glucose absorption continued beyond the jejunum but was complete in the terminal ileum demonstrating that endogenous energy losses can be quantified in the ileal digesta of birds by feeding a glucose-based diet. The IEEL were determined to be 347 ± 29.4 kcal/kg DM intake. In experiment 2, 4 experimental diets with similar inclusion (957 g/kg) of grains were developed to determine the AMEn, AIDE, and TIDE. Titanium dioxide (5.0 g/kg) was added to all diets as an indigestible marker. Each diet was randomly allocated to 6 replicates (8 birds per replicate) and fed from 14 to 21 d after hatch, and the ileal digesta were collected on day 21. The AIDE was corrected to TIDE using the IEEL value determined in experiment 1. The TIDE of corn, sorghum, wheat, and barley were determined to be 3,920, 3,650, 3,138, and 2,885 kcal/kg DM, respectively, and was higher (P < 0.05) than the corresponding AMEn values of 3,439, 3,284, 2,576, and 2,371 kcal/kg DM, respectively. No differences were observed between the AMEn and AIDE. The AMEn:TIDE ratio tended (P = 0.06) to be lower for viscous cereals (wheat and barley) than that for nonviscous cereals (corn and sorghum). The apparent ileal digestibility of DM, nitrogen, and starch was positively correlated (P < 0.001) with TIDE (r = 0.990, 0.703, and 0.705, respectively) and the AMEn (r = 0.873, 0.483, and 0.656, respectively). Further studies are warranted to determine the TIDE of a range of ingredients and to investigate the application of TIDE as a potential available energy system in poultry feed formulations.