This study assessed the relationships between the energy efficiency of productive energy (Arkansas Net Energy; PE) or classic net energy (CNE) and heat increment (HI), net energy (NE) for gain (NEg) or maintenance (NEm), performance, protein accretion, and dietary total digestible amino acids (TDAA) or digestible CP (dCP). Eight experiments were conducted, each with 240 day-old chicks distributed in 12 pens, each fed one of twelve diets with varying concentrations of TDAA (or dCP), digestible starch, digestible fat, and non-starch polysaccharides. All birds were placed at the same time. Each experiment received the test diets for seven days starting each week, one after the other. A digestibility study determined N-corrected apparent metabolizable energy (AMEn). Variables measured were BW gain (BWG), feed conversion ratio (FCR), protein accretion (PAC; g/bird per day), efficiency of PAC (PACe; g/kg), fat gain (FG, g/bird per day), and energy gain (NEg; kcal/kg) with Dual-Energy X-Ray Absorptiometry, fed (HP) and fasting (FHP) heat production (FHP = NEm; kcal/kg), HI (kcal/kg), CNE (CNE = AMEn – HI; kcal/kg), total NE (NEt; = NEg + NEm; PE is Net; kcal/kg), PE efficiency (PE/AMEn), and CNE efficiency (CNE/AMEn). A mixed models design, with 12 treatments, eight replications, and the experiment set as the random factor, was used to assess pairwise relationships in JMP. NEg and NEm explained 95% of the variability in PE/AMEn (P < 0.001); however, HI showed no influence on PE/AMEn (P = 0.814). HI explained 98% of the variability in CNE/AMEn (P < 0.001); however, NEg or NEm showed no influence on CNE/AMEn (P ≥ 0.534). Improvements in PACe or FCR increased the PE/AMEn efficiency but reduced the CNE/AMEn efficiency (P < 0.05). Higher BWG increased PE/AMEn and CNE/AMEn (P = 0.001). TDAA or dCP favored PAC and FCR (P < 0.008). Higher PACe values were associated with increased HI, NEg, and NEt, whereas PAC rose the NEm (P < 0.03).
Article Quarter: FY24 Q4
Unsupported assumptions in classic net energy calculation for broilers
Classic net energy (CNE) is CNE = ME – heat increment (HI), being HI = fed (HP) – fasting (FHP) heat production. Productive energy (PE) measures net energy for gain (NEg) and maintenance (NEm) and is superior to CNE for predicting performance and economics. In vivo and in silico experiments (E) in this study assessed the reliability of CNE assumptions: A1) diet alone determines NE, A2) FHP is a constant of metabolic body weight (MBW), A3) broiler MBW power is 0.70, A4) diet does not influence FHP, A5) old FHP values work, A6) crude protein (CP) only increases HI, A7) HI is the only effect of diet on energy metabolism and A8) CNE validation studies are informative. In E1, 2400 broilers were fed 3 CP levels to induce performance and body composition (Dual-Energy X-Ray Absorptiometry; DEXA) changes. FHP was measured in calorimetry chambers (CHA). Mixed models determined the influence of body composition on FHP and MBW power. In E2, birds were fed 12 diets varying in TDAA and digestible nutrients. Performance, DEXA, and CHA were run (HP, FHP, CNE, PE, body composition). Data was modeled to determine CNE and PE variations associated with other variables, and the influence of changes in TDAA and CP on performance, body composition, and HI, CNE, NEg, NEm, and PE. In E3, a literature meta-regression model reporting increasing broiler HP through the years determined the deviation in FHP in CNE studies using old FHP values. A mechanistic model built in E4 integrated findings explaining divergent influences of CP on CNE and PE. Linear mixed models modeled the data and Tukey test (P<0.05) or mean 95% confidence interval (95CI) compared mean values. A model from E1 (R2=0.98) showed FHP a function of body composition (P<0.001), age (P=0.039), and body weight (BW; P<0.001) or MBW (P<0.001), proving A1 and A2 unsupported. E1 showed fitting metrics remain the same with MBW or BW if body composition is included, implying body composition explained the MBW concept and that A3 was unsupported. E1 also showed the determined MBW was not different than 0.75, based on its 95CI (P>0.05), also implying A3 was unsuported. E2 showed differences (P=0.001) across treatments, implying A4 was unsupported. The meta-regression model from E3 indicated HP increases by 2.68 kcal/kg BW0.75/d each year, implying old FHP overlooked a 53% shift in FHP in 23 years and that A5 was unsupported. The mechanistic model in E4 revealed CP increases HI but also improves protein turnover, feed conversion ratio, and NEg and NEm, proving A6 and A7 unsuported.
Evaluation of the metabolizable energy of soybean meal in poultry diets
The objective of this study was to reevaluate the metabolizable energy (ME) of dehulled solvent extracted soybean meal (SBM) for poultry diets. Experiment 1 was a precision-fed rooster assay to determine TMEn of 4 SBM. Single Comb White Leghorn roosters were fasted for 26 hours and then were crop intubated with 25 to 30 grams of a SBM sample and excreta were collected quantitatively for 48 hours post feeding. Excreta were freeze-dried and analyzed for gross energy and nitrogen. In Experiment 2, AMEn of the same 4 SBM was determined using commercial broiler chickens. A nutritionally complete corn- SBM basal diet was fed from 0 to 17 days of age. Five diets consisting of 100% basal diet or 70% basal diet and 30% test SBM were then fed from 17 to 21 days of age, and titanium dioxide was used as a digesta marker. The AMEn of the diets was determined, and the AMEn of the SBM was calculated by difference. Experiment 3 was another precision-fed rooster assay to determine TMEn of 17 SBM using the same procedures described above. In addition to the SBM, 2-5 corn samples were included in each experiment so that TMEn and AMEn of the SBM could be compared relative to corn. In the rooster assays (Experiments 1 and 3), 10 individually caged roosters were assigned to each SBM or corn. In the AMEn assay (Experiment 2), 12 replicate pens of 5 chicks were assigned to each dietary treatment. Data were analyzed by ANOVA for completely randomized designs for all experiments, and significance of differences among TMEn and AMEn values within experiments was determined at P < 0.05. In Experiment 1, mean TMEn of the 4 SBM was 3,076 kcal/kg DM with a range of 3,044 to 3,122. Mean AMEn of the 4 SBM in Experiment 2 was 2,843 kcal/kg DM with a range of 2,509 to 3,045. In Experiment 3, mean crude protein and fat for the 17 SBM were 47.1 and 1.5%, respectively, on an 88% DM basis. Mean TMEn of the 17 SBM was 3,000 kcal/kg DM with a range of 2,796 to 3,196 in Experiment 3. There were significant differences (P < 0.05) among TMEn and AMEn values for several SBM within each experiment.
Effects of full-fat high-oleic soybean meal in layer diets on performance, egg quality and chemical composition
The utilization of full-fat high-oleic soybean meal in layer diets could lead to value-added poultry products. To test this idea, 336 hens were randomly assigned to four isonitrogenous (18.5% CP) and isocaloric (2927 kcal/kg) diets and fed the following diets for eight weeks: conventional control; extruded expelled defatted soybean meal (EENO); full fat normal-oleic soybean meal (FFNO); or full fat high-oleic soybean meal (FFHO). Body weights (BW) were collected at week 0 and week 8. Eggs were collected daily and enumerated. Feed consumption was measured weekly, and egg quality was measured bi-weekly. Eggs were collected at week 0 and week 8 for fatty acid analysis. All data were analyzed for variance using a one-way analysis of variance at P < 0.05 significance level. There were no significant treatment differences in any of the production parameters measured, BW, feed consumption, feed conversion ratio or egg production (P > 0.05). Eggshell strength was significantly greater in eggs produced from the EENO group as compared to the control (P < 0.01), while egg yolk color was significantly darker in eggs of the control and EENO treatment groups relative to the FFNO and FFHO treatments (P < 0.0001). Eggs produced by hens fed the FFHO diet had a 52% increase in monounsaturated n-9 oleic acid content (P < 0.0001), with reduced palmitic (P < 0.01) and stearic (P < 0.0001) saturated fatty acid levels as compared to the conventional controls.
Effects of feeding extruded high oleic soybeans on growth performance, blood profile, and meat fatty acid composition in broiler chickens
High oleic Trusoya soybeans, have the potential to enhance not only broiler growth performance but also carcass fatty acid composition. However, there is a lack of information on feeding high oleic soybeans to broilers. The objective of this study was to determine the effects of extruded high oleic soybeans (Trusoya), conventional commercial soybean meal (SBM) and extruded conventional soybeans on growth performance, carcass characteristics, blood immune and antioxidant status in broiler chickens. A total of 288 one-day-old male broiler chicks (Cobb500; initial body weight [BW] of 37.2 g) were allotted to one of three treatments in 36 pens (8 birds/pen) and fed experimental diets over 3 phases in a randomized complete block design: Phase 1: 0 to 2 weeks, Phase 2: 2 to 4 weeks, and Phase 3: 4 to 6 weeks. The diet nutrient composition met or exceeded the breeder’s recommendation. Experimental diets were: 1) a corn-based diet with conventional SBM (CSBM); 2) a corn-based diet with extruded conventional soybeans (ExSoy); 3) a corn-based diet with extruded high oleic soybeans (ExTrusoya). At the end of each phase, BW and feed consumption were measured to calculate body weight gain and feed conversion ratio (FCR). At the end of the feeding trial (d 42), one bird from each pen was bled for blood profile analysis, and two birds from each pen were euthanized to collect the breast and thigh meats for meat fatty acid analysis. Data were subjected to analysis of variance using the MIXED procedure of SAS (SAS Inst. Inc., Cary, NC), and the pen was used as the experimental unit. Broilers fed the CSBM diet had greater (P < 0.05) BW and daily weight gain during the overall period compared with ExSoy and ExTrusoya diets fed broilers. Also, ExTrusoya diets showed greater (P < 0.05) final BW and overall daily weight gain than ExSoy diets by 10.6% and 10.7%, respectively. Dietary treatment did not affect the white blood cells, lymphocytes, and blood antioxidant status. However, ExTrusoya diets increased (P < 0.05) the blood basophil concentration compared with the CSBM diet (15.7% vs. 7.6%). Birds fed ExTrusoya diets had greater (P < 0.05) breast weight (g/kg BW) than ExSoy diets by 8.2%, and birds fed ExTrusoya diets had greater (P < 0.05) thigh weight (g/kg BW) than those fed CSBM diets by 9.9%. The oleic acid contents for breast and thigh meat from the birds fed the ExTruosoya diets were higher (P < 0.05) than those of birds fed the CSBM and ExSoy diets by 63% and 53%, respectively.
Influence of the origin of the soybeans on the metabolizable energy and ileal digestibility of the protein and amino acids of the corresponding soybean meals in broilers
We studied the metabolizable energy content and the apparent (AID) and standardized (SID) ileal digestibility of CP and amino acids (AA) of soybean meals (SBM) from Argentina (ARG), Brazil (BRA), and USA in 21 d-old broilers. These samples (CP = 46.0 ± 0.97%, on 88% DM) were randomly collected from European feed mills and analyzed for key components, including proximal analysis, carbohydrate fraction, AA, and protein quality indicators. The broilers were initially fed a commercial crumble diet from 0 to 14 d of age followed by their corresponding experimental diet in mash form for 7 d. The experimental diets consisted of 53% of a N-free diet based on dextrose, and 47% of each of the 27 SBM tested, as the unique source of N. The experimental design was completely randomized with 3 SBM origins and 9 samples per origin. The experimental unit was a cage with 8 broilers. Data were analyzed as a completely randomized design using an ANOVA with SBM origin as main effect. In addition, Pearson correlation (r) analyses were conducted to study the relationship among chemical traits of the SBM and the in vivo data. From 15 to 21 d of age, broilers fed the USA SBM grew faster (42.7 vs. 38.7 and 39.2 g/d; P < 0.01) and had better feed conversion ratio (FCR; 1.74 vs. 1.90 and 1.88 g/g; P < 0.001) than broilers fed the ARG and BRA meals. On 88% DM basis, the USA meals had higher AME (2,412 vs. 2,349 and 2,344 kcal/kg; P = 0.062) and AMEn (2,276 vs. 2,224 and 2,216 kcal/kg; P = 0.092) than the ARG and BRA meals. Also, the SID of Lys (88.7 vs. 87.5 and 86.9%; P < 0.05) and Cys (77.2 vs. 73.4 and 73.0%; P < 0.01) were higher for the USA meals than for the ARG and BRA meals. The AMEn (CV = 8.10 and 7.04 vs. 8.88%) and the SID of CP (CV = 4.90 and 5.06 vs. 6.62%) and Lys (CV = 4.23 and 4.21 vs. 5.72%) were more uniform for the ARG and USA meals than for the BRA meals. Independent of the origin of the soybeans, the AMEn values of the SBM were correlated negatively with the FCR (r = – 0.390; P < 0.05) of the birds, and positively with the protein dispersibility index (r = 0.438; P < 0.05) and the SID of CP (r = 0.347; P < 0.05) and Lys (r = 0.342; P = 0.081) of the SBM. Also, the SID of Lys was correlated negatively with FCR (r = – 0.365; P < 0.061), and positively with trypsin inhibitor activity (r = 0.358; P < 0.067), SID of CP (r = 0.969; P < 0.001) and the total tract apparent retention of CP (r = 0.514; P < 0.001) of the SBM
Influence of the origin of the soybeans on the chemical composition and protein quality indicators of the soybean meal arriving to European ports
We studied the chemical composition and quality of the protein fraction of 27 soybean meals (SBM) from Argentina (ARG), Brazil (BRA), and USA, collected at random at European crushing plants and feed mills during the 2022/2023 harvest season. These samples were analyzed for their physicochemical characteristics, including particle size, Minolta color, crude protein (CP), amino acids (AA), non-starch polysaccharides (NSP), crude fiber, neutral detergent fiber (NDF), α-galactosides, and minerals. In addition, urease activity (UA), protein solubility in KOH (KOH), protein dispersibility index (PDI), trypsin inhibitor activity (TIA), and reactive Lys (RLys) were determined. Data were analyzed as a completely randomized design using an ANOVA, with SBM origin as main effect. In addition, Pearson correlation (r) analyses were conducted to determine the relationships between chemical composition and protein quality indicators of the SBM. The BRA meals had higher a* (redness) and lower L* (luminosity) values than the ARG and USA meals (P < 0.001). Particle size distribution was similar for all SBM. On 88% DM basis, CP content was higher for the BRA and USA meals than for the ARG meals (46.6 and 46.2 vs. 45.1%; P < 0.001) whereas sucrose (7.26 and 7.93 vs. 6.08%; P < 0.001) and stachyose (5.41 and 4.96 vs. 4.01%; P < 0.001) were higher for the USA and ARG meals than for the BRA meals. The NSP (15.6, 14.4, and 15.0% P = 0.093) and NDF (10.0, 8.5, and 9.1%; P < 0.05) contents were higher for the BRA than for the ARG meals, with the USA meals being intermediate. Per unit of protein, Lys (6.16 vs. 6.05 and 5.93%; P < 0.001), total sulfur AA (2.77 vs. 2.71, and 2.65%; P < 0.01) and the sum of Lys, Met, Cys, Thr, and Trp (14.2 vs. 14.1, and 13.8%; P < 0.001) were higher for the USA meals than for the ARG and BRA meals. The values for all protein quality indicators (UA, PDI, KOH, TIA, and RLys) were higher for the USA meals than for the South American meals (P < 0.05). Among the minerals, the main difference observed was for Fe that was higher for the BRA meals than for the USA and ARG meals (172 vs. 108 and 113 mg/kg; P < 0.01). Independently of the origin of the soybeans, the most important correlations (P < 0.01) observed were between stachyose and sucrose contents (r = 0.814) and between TIA and PDI (r = 0.808), RLys (r = 0.702), and KOH (r = 0.657) values. In summary, the chemical composition, AA profile, and protein quality indicators of the SBM vary with the country of origin of the soybeans.
Recent advancements in less limiting amino acids
The inclusion of feed-grade amino acids in diet formulation has allowed nutritionists to formulate diets more economically to enhance the efficiency of growth and reproduction in commercial poultry production. Diets had been traditionally formulated on a crude protein basis. Synthetic Met was used in diet formulation in the 1970’s and this technology significantly reduced dietary cost. In the 1980’s, crystalline Lys was manufactured to further reduce diet cost and later contributed to enhancing meat yield with the development of the deboning market with less emphasis being placed on whole birds. The industry was unable to fully utilize the concept of reduced crude protein diets without a minimum being placed on the next limiting amino acid as crude protein could be reduced over 3% points and negatively impacting performance. Crystalline Thr was introduced in the late 1990’s and after 15 years of research the broiler industry adopted this technology to further reduce diet cost by $5.0 per ton with a 1 kg inclusion of L-Thr. In 2009, L-Val was commercially available to be included in poultry diets to further decrease dietary cost with the use of reduced crude protein diets without compromising growth performance and meat yield. Dietary Ile, Arg, and Trp are regarded as the fifth, sixth, seventh limiting amino acids in corn-soybean meal-based diets. Knowledge gaps in the literature exist in broilers of different growth phases with these less limiting amino acids, but these amino acids are important in diet formulation. In addition to determining optimum digestible ratios of these less limiting amino acids for various growth phases, it is also important to evaluate amino acid interactions, specifically with amino acids involved in antagonisms. Moreover, less limiting amino acids need to be assessed for reproduction and the use of L-Trp with behavioral issues during rearing and laying periods.
Evaluation of the interactions of different crude protein levels in high and low-energy diets on growth performance and carcass yield in Ross 708 broilers
Protein and energy are the two most important components in broiler diets for good growth and health. This study evaluated the interaction effect of crude protein (CP) reduction by balancing limiting amino acids (AA) and 2 different energy levels on broiler’s growth performance and processing yield. Six corn-soy-based diets, including 3 high-energy (HE) and 3 low- energy (LE) with a 100 kcal/kg AMEn difference but with same dLys to dAA ratio were formulated to meet or exceed Ross708 broiler specifications. Comparative HE and LE diets had same CP and AA level supplemented with 3 (Lys, Met, Thr), 4 (Lys, Met, Thr, Val), and 5 synthetic AA (Lys, Met, Thr, Val, Ile), respectively. However, as synthetic AA inclusion increased, average CP levels were reduced by 0.72%, 0.65%, and 0.61% in the starter (0-14 d), grower (15-28 d), and finisher (29-42 d) diets. A total of 960-day-old straight-run Ross 708 chicks (6 treatments x 8 replicates x 20 birds) were randomly placed. Performance was evaluated at 14, 28, and 42 d. Litter nitrogen (N) and moisture were measured at 42 d. At 43 d, 8 broilers (4 males and 4 females)/pen were processed, and weights of live birds, hot carcass, cold carcass, and parts were recorded. Data were analyzed using two-way ANOVA (CP x energy), and mean separation was done by Tukey’s test at a significance level of P<0.05. An interaction effect (CP x energy) was observed on overall body weight gain (BWG, P<0.001), feed intake (FI, P=0.0002), and feed conversion ratio (FCR, P=0.0081). A reduction in CP showed contrasting trends (P<0.001) on growth in HE and LE diets. Specifically, BW, BWG, and FI increased with CP reduction in HE diets, while opposite occurred in LE diets. This interaction trend (CP x energy, P<0.0001) continued in live, hot carcass, and cold carcass weight with LE-low CP diets showing the lowest values and HE-low CP showing the highest values. For parts (CP x energy), pectoralis major was heavier in broilers fed on LE and HE with the highest and lowest CP, respectively, and lighter in LE-low CP group (P<0.0001). In contrast, leg weight was higher in broilers fed either the highest CP with HE or the lowest CP with LE (P=0.0016). No differences were found in litter N and moisture contents (P>0.05). In conclusion, effects of CP reduction with balanced limiting AA exhibited contrasting trends in performance and carcass yield in HE and LE diets. Reducing CP in LE diets showed negative impacts, but reducing CP in HE diets positively impacted performance and carcass yield. No effect of CP and energy was observed on litter N and moisture.
Assessing soybean processing add-backs in soybean meal via broiler performance testing
This experiment assessed the feeding value of soybean meal with the inclusion of soybean crush plant “add-backs” ingredients (i.e. gums and soapstocks) fed to Cobb MX x 500 male broilers from 0-45d of age. Five corn and soy-based diets were formulated with soybean meal containing various levels of soybean gum and soapstock inclusion or the addition of an inert filler. Diet 1 contained soybean meal with no add backs whereas diets 2-5 contained either 4% gums, 4% soapstock, 2% gums and 2% soapstock, or 4% inert filler, respectively. Diets were fed to 1,200 male broilers placed in 10 replicate pens of 24 birds in a randomized complete block design. Birds were weighed on day 0, 14, 28, and 45 and live performance was assessed from 0-45d. Additionally, on each weigh day, one bird per pen was selected for body composition analysis using dual x-ray absorptiometry (DEXA). On day 45, six birds per pen were randomly selected and processed for determination of carcass traits. Moreover, on d45, 2 birds per pen were administered 8.32 mg/kg, MW 3-5 kDa Fluorescein isothiocyanate-dextran; blood was collected l h post gavage and fluorescence was measured at an excitation wavelength of 428 nm and emission wavelength of 528 nm using the Synergy HT multi-mode micro plate reader for determination of gut integrity. All data were analyzed using a One-way ANOVA using JMP software with diet as the fixed effect and block as a random effect with pen as the experimental unit. Statistical significance was considered at P ≤ 0.05. Diet 1 had significantly higher feed conversion from 0-45d than treatments 2-5. On d28 birds fed Diet 1 had significantly higher DEXA analysis mineral, calcium, and phosphorus mass compared to birds fed diets 2-5. No significant responses were observed for carcass yields, gut integrity, or woody breast measurements.
