The effect of graded reductions in balanced crude protein (CP) on hen productive performance, egg quality, nitrogen balance, abdominal fat deposition, tibia traits, and relative economic outcomes from 26 to 44 wk of age (WOA) was investigated. A total of 252 26-wk-old Hy-Line Brown hens were housed in enriched cages (seven birds/cage) and randomly allocated to one of four different dietary CP levels of iso-energetic diets with nine replicates per treatment. The trial was conducted over two phases of 26 to 34 and 36 to 44 WOA. Diets included a high-protein (HP; 18.0% and 17.0% CP in Phases 1 and 2), medium-protein (MP), low-protein (LP), and very low-protein (VLP) series, representing stepwise reductions of 0.50, 1.00, and 1.50 percentage points relative to HP. Limiting amino acids (AA; lysine, methionine, and threonine) were supplemented to ensure balanced AA profiles. Collected data were analyzed using the general linear model (GLM) procedure for one-way ANOVA; statistical significance was set at P < 0.05, and trends were noted at 0.05 < P < 0.10. Balanced protein reduction tended to improve abdominal fat contents (2.66% to 2.85%; P = 0.059), but reduce body weight gain (141.66 to 95.66 g; P = 0.089), particularly with the VLP diet. Across 26 to 44 WOA, graded CP reduction lowered egg weight (60.36 to 59.40 g; P < 0.05) and feed conversion efficiency (1.93 to 1.97 g feed/g egg; P < 0.05); and tended to reduce egg mass (57.02 to 55.11 g/hen/day; P = 0.080), particularly in the VLP group. As to egg quality, Haugh units were higher (P < 0.05) with HP and MP diets (94.60 and 94.30) than LP and VLP diets (93.66 and 93.04) across 26-44 WOA. In contrast, LP and VLP diets tended to improve yolk color (8.38 to 8.49; P = 0.076) and egg-breaking strength (5.39 to 5.51 kg; P = 0.058) across 26-44 WOA. Dietary CP reduction linearly reduced nitrogen consumed and excreted by more than 10% (P < 0.05). Tibia-breaking strength tended to decline with dietary CP reduction (P = 0.094), decreasing from 27.62 kg in HP to 25.54-25.68 kg in the LP and VLP diets. Economically, reduced CP lowered egg income (P < 0.05) at weeks 34 and 44 (2.00 to 1.77$; 1.96 to 1.89$, respectively); and feed costs at week 34 only (0.54 to 0.52$; P = 0.088), but profit margins remained unaffected (P > 0.10). Conclusively, these results confirm the effectiveness of balanced dietary protein reduction in maintaining egg production rate and most egg quality traits while reducing nitrogen excreted and feed costs.

This experiment evaluated the effects of partially replacing soybean meal (SBM) with yellow mealworm (Tenebrio molitor L.) meal (MWM) reared on either wheat bran (CMW) or expanded polystyrene (EMW) on broiler chicken growth performance, carcass traits, nutrient digestibility, and the intestinal morphology for 35 days. A total of 336 one-day-old male Ross 308 broiler chicks were randomly assigned to seven dietary treatments, each consisting of six replicates (eight chickens per cage). Dietary treatments included: (i) corn-SBM diet (Control); (ii) a diet including CMW 5% (CMW5); (iii) a diet including CMW 10% (CMW10); (iv) a diet including CMW 15% (CMW15); (v) a diet including EMW 5% (EMW5); (vi) a diet including EMW 10% (EMW10); and (vii) a diet including EMW 15% (EMW15). Results indicated that MWM, irrespective of substrate type, improved body weight (P < 0.05), average daily gain, and daily feed intake in broiler chickens compared to the control group. On day 21, broilers in the EMW groups had a higher dressing percentage than CMW groups (P < 0.001). Compared to the control, crude fat digestibility increased in the CMW5, CMW15, EMW10 and EMW15 groups (P < 0.001). In conclusion, substituting SBM with up to 15% MWM, irrespective of rearing substrate (wheat bran or expanded polystyrene), improved broiler growth performance, carcass characteristics, and fat digestibility without adverse effects on intestinal morphology or nutrient digestibility. Moreover, mealworms raised on expanded polystyrene showed comparable performance to those raised on wheat bran, suggesting their potential as a sustainable protein source in broiler diets.

This study investigated the effects of far-infrared ray (FIR) radiation on broiler performance, carcass traits, meat quality, intestinal morphology, and blood metabolites in birds fed different energy and amino acid (EAA) levels with or without β-mannanase from hatch to day 35. A total of 384 one-day-old Ross 308 broilers were assigned to a 2 × 2 × 2 factorial design: FIR radiation (yes or no), dietary EAA level (normal or low), and β-mannanase supplementation (yes or no). Data were analyzed using three-way ANOVA to evaluate the main and interactive effects of these factors, with Tukey's test applied for multiple comparisons. FIR exposure improved (p < 0.001) average daily gain (ADG) and average daily feed intake (ADFI) on days 1-35. Feed conversion ratio (FCR) was reduced (p < 0.05) on days 1-10, 11-21, and overall. FIR combined with β-mannanase enhanced (p < 0.001) ADG on days 1-10 and 11-21. Broilers fed a low EAA diet and exposed to FIR had higher (p < 0.01) ADFI on days 1-10. On day 35, FIR increased (p < 0.001) moisture, crude protein, and ash content in breast meat and improved (p < 0.05) relative breast meat weight. FIR also enhanced (p < 0.01) water-holding capacity and pH, while reducing (p < 0.05) cooking loss. FIR improved intestinal morphology by increasing (p < 0.001) villus height on days 21 and 35. A significant three-way interaction (p < 0.01) among FIR, EAA level, and β-mannanase was observed for villus height on day 21. Immunologically, FIR reduced (p < 0.01) blood levels of IL-1β and TNF-α on days 21 and 35, and IFN-γ on day 35. FIR also lowered (p < 0.05) blood glucose and lactate levels on both days. In conclusion, FIR radiation, particularly under nutrient-challenged conditions, enhanced broiler growth performance, carcass yield, meat quality, and immune status, with β-mannanase providing additional early growth benefits. FIR technology shows potential as a non-invasive, feed-independent strategy to improve commercial broiler productivity, warranting further field evaluation.

This study aimed to measure the endogenous losses, the apparent (AID), and the standard ileal digestibility (SID) of phosphorus (P) using a diet containing corn, soybean meal, and wheat bran in 45-week-old Hy-line Brown laying hens. Hens were fed experimental diets containing inorganic phosphate supplements and plant-based phosphorus sources. Experimental diets included: (i) inorganic phosphate supplements (monocalcium phosphate [MCP], dicalcium phosphate [DCP], monosodium phosphate [MSP]); (ii) plant-based phosphorus sources (corn [CRN], soybean meal [SBM], and wheat bran [WB]); and (iii) a phosphorus-free diet (P-free). Measurements were collected from the ileum and excreta over three days with six replicates per dietary treatment and four hens per cage, under ad libitum feeding conditions. The study demonstrated interactions (p < 0.05) between diet type and sampling locations on endogenous phosphorus losses. Higher endogenous phosphorus losses (p < 0.05) were observed in the excreta of hens fed P-free, MCP, DCP, MSP, and WB diets. Increased endogenous P losses in the ileum (p < 0.05) were noted in hens-fed CRN, SBM, and WB diets compared to inorganic phosphate supplement diets. The AID and SID of P were significantly lower (p < 0.05) in the CRN diet compared to SBM, WB, MCP, DCP, and MSP diets. Among inorganic phosphate supplements, MCP exhibited the highest SID of P, while for plant-based sources, SBM and WB demonstrated higher SID values than CRN. The AID of P was higher (p < 0.05) in hens fed the MCP diet compared to SBM and WB diets, but diet type did not affect the AID of dry matter (p > 0.05). In conclusion, diet type and sampling location influence endogenous P losses in laying hens, with differences between ileal and excreta measurements. The results highlight the variability in P bioavailability among plant-based and inorganic phosphorus sources, emphasizing the need to account for ingredient-specific P digestibility when formulating diets for optimal P utilization.

Improving nutrient utilization in nutrient-restricted diets is an important strategy to reduce feed costs and maintain productivity in broiler production. Dietary emulsifiers are commonly used to improve lipid digestion and overall nutrient utilization in poultry diets. The objective of this study was to investigate the effects of a combination of lysophospholipids, synthetic emulsifier and monoglycerides (LEX) in energy- and amino acid-deficient broiler diets on growth performance, carcass traits, nutrient digestibility, and intestinal morphology from d 11 to 35. A total of 168 10-day-old Ross 308 male broiler chicks were randomly assigned to one of three dietary treatments in a completely randomized design, with seven replicates and eight birds per cage. The dietary treatments were as follows: 1) a positive control diet (PC) containing standard metabolizable energy and amino acid levels; 2) a negative control diet (NC) with 100 kcal/kg less metabolizable energy and 4.0% reduction in essential amino acids (lysine, methionine + cysteine, and threonine); 3) NC diet supplemented with 250 g/ton of LEX. Statistical analyses were conducted using the general linear model (GLM) procedure for one-way analysis of variance (ANOVA), with significance declared at P < 0.05. Broilers fed the LEX-supplemented NC diet exhibited improved (P < 0.001) growth performance, including body weight at d 35 (1,737.14 to 1,903.46 g), average daily gain (d 11-35; 58.49 to 64.95 g/d), and feed conversion ratio (1.60 to 1.41 g/g), compared to those fed the NC diet alone. Apparent digestibility of crude protein and crude fat in both the jejunum and ileum was higher (P < 0.001) in birds receiving the LEX-supplemented NC diet than in those on the NC diet. In addition, LEX improved intestinal morphology, evidenced by increased villus height (920.87 to 1,086.84 µm), crypt depth (126.74 to 161.28 µm) on day 35 (P < 0.05). However, there were no significant differences (P > 0.05) in carcass yield parameters, including breast and leg muscle weights and abdominal fat content, among the dietary treatments. In conclusion, supplementation of 250 g/ton of LEX to a broiler diet deficient in energy and amino acids effectively improved growth performance and nutrient utilization by enhancing protein and fat digestibility and promoting intestinal development. These findings suggest that a combination product based on lysophospholipids, synthetic emulsifier, and monoglycerides can serve as a practical and effective nutritional strategy to optimize production efficiency under nutrient-restricted feeding conditions in commercial broiler production.

Increased global production, and consumption of the hen egg; and the popularization of nutritional knowledge, places greater emphasis on egg quality, safety, and freshness. An understanding of the interaction between several egg quality indicators is necessary. A total of 300 freshly-laid eggs were analyzed within 24 hours of collection to investigate the phenotypic correlations between internal and external quality indicators. Eggs were analyzed for egg weight, breaking strength, shell color, albumen height, Haugh unit, yolk color, specific gravity, shell weight, shell percentage, and shell thickness at the blunt, equator, and sharp ends. Collected data was analyzed for Pearson's correlation coefficients and statistical significance was estimated at p < 0.05. Low positive correlations were observed between egg weight and shell weight (r = 0.336, p < 0.01). Moderate negative correlations were found between egg weight and shell percentage (r = -0.504, p < 0.01). While very strong positive correlations were found between Haugh units and albumen height (r = 0.949, p < 0.01), both parameters were not distinctly correlated to other quality indicators. Similarly, there were no significant correlations between egg yolk color and shell color to other quality indicators. While moderate positive correlations were observed between eggshell weight and shell percentage (r = 0.631, p < 0.01), both parameters were lowly correlated to the eggshell thickness and not distinctly correlated to the egg-breaking strength. High positive correlations were observed between the overall eggshell thickness and the measurements at the blunt, middle, and sharp edges (r = 0.975, r = 0.965, r = 0.923). Low positive correlations were observed between breaking strength and the overall, blunt edge, middle edge, and sharp edge eggshell thickness (r = 0.465 r = 0.447, r = 0.428, r = 0.453). Conclusively, no marked correlations were established between the eggshell and the internal egg quality indicators. This study contributes to understanding the relationship between shell quality and internal egg freshness, providing insights for optimizing laying hen production and egg quality assessment systems.

The objective of this study is to investigate the effect of β-mannanase in energy and amino acid-deficient broiler diets on the growth performance, carcass yields, ileal nutrient digestibility, viscosity, intestinal morphology, and blood metabolites of broilers from hatch to day 35. A total of 168 one-day-old Ross 308 broiler chicks were randomly assigned to one of three dietary treatments in a completely randomized design, with each treatment having eight replicates and seven birds per cage. The treatments were as follows: i) positive control diet (PC) containing standard energy and amino acids; ii) negative control (NC) with 150 kcal/kg metabolizable energy (ME) and 4.5 % amino acids reduction compared to PC; iii) NC supplemented with 100 g/ton β-mannanase (NC + β-mannanase). Broilers fed the PC and NC + β-mannanase diets showed improved growth performance, including body weight on day 35 (P < 0.001), average daily gain (Day 1-35; P = 0.001), and feed efficiency (Day 1-35; P < 0.001), alongside lower (P < 0.001) digesta viscosity and enhanced ileal digestibility of dry matter (P < 0.001), crude protein (P < 0.001), and energy (P < 0.001), as well as an improved (P < 0.001) villus height to crypt depth ratio, compared to those on the NC diet. Regarding carcass traits, liver yield was higher (P < 0.001) in broilers on the NC + β-mannanase diet compared to other treatments by day 35. Additionally, the NC + β-mannanase diet lowered (P < 0.001) IL-1β and IFN-γ levels and increased (P < 0.001) IL-10 levels compared to the other groups. In conclusion, β-mannanase supplementation with 100 g/MT β-mannanase in nutrient-deficient diets improved broiler performance by reducing intestinal viscosity and enhancing nutrient utilization efficiency. It also promoted the development of metabolic organs like the liver, as well as immune organs such as the spleen and thymus, while modulating inflammatory and anti-inflammatory cytokine responses.

Laying hen responses to supplemental multiprotease on performance, egg quality, digestibility, gut histomorphology, nitrogen excretion, and economic performance of laying hens until 37 weeks of age were investigated. A total of 189 25-week-old Hy-Line Brown hens were housed in enriched cages (7 birds/cage) and randomly allocated to 1 of 3 diets with 9 replicates per treatment. Dietary treatments included: an adequate positive control- PC [met the breed and age standards for crude protein (CP) and amino acids (AA)]; negative control- NC (90 % CP and AA requirement); and NC supplemented with multiprotease - NCMP. Multiprotease was supplemented at 300 g/t of feed equating to 2400 U/kg. Egg production rate and feed intake were not altered (P > 0.10) by the dietary treatments. Between 25 and 37 weeks of age (woa), the NCMP diet reduced the feed conversion ratios by 3 % (1.91 vs 1.97; P < 0.05) in comparison to the NC diet while improving (P < 0.05) the egg weights by 3 % (58.56 vs 56.68); Haugh units by 2 % (91.78 vs 90.20); and breaking strength by 1 % (4.65 vs 4.61). Marginally intensified yolk color and albumen height (P < 0.10) were also observed with the NCMP diet. Furthermore, the NCMP diet marginally improved the villus height, width, and absorptive surface area (P < 0.10) relative to NC. Multiprotease-supplemented NCMP diet improved (P < 0.05) the digestibility of crude protein; and amino acids including lysine, methionine, phenylalanine, isoleucine, leucine, glutamine, tyrosine, relative to the NC diet. Lowered AA/CP diets (NC and NCMP) reduced the N excreted and feed costs (P < 0.05) relative to the PC diet. Multiprotease increased the returns on investment (P < 0.10), and nitrogen retained in egg (P < 0.05) from 25- 37woa. Conclusively, feeding reduced CP/AA diets maintained the egg production rate while reducing the N excreted and feed costs. Multiprotease modulation of ileal absorptive capacity and nutrient digestibility is linked to improved feed efficiency, egg quality, and revenue estimates of supplemented hens.

The purpose of this study was to assess the optimal standardized ileal digestible (SID) lysine (Lys) requirement for male White Pekin ducklings with a specific focus on growth performance for the 3 weeks following hatching. A total of 384 one-day-old male White Pekin ducklings were allocated to six different dietary treatments, each containing varying levels of digestible Lys content ranging from 0.72% to 1.12%. All amino acids in the diets remained consistent except for Lys. The ducklings were randomly distributed into 24-floor pens, with each treatment group comprising eight pens, and each pen housing eight ducklings. The diets were offered ad-libitum throughout the study. Weekly measurements of body weight and feed intake were recorded to calculate the feed conversion ratio. The SID Lys requirement was determined by analyzing the data using both linear-plateau and quadratic-plateau models and calculating the mean value. The results demonstrated a significant linear (p < 0.001) and quadratic (p < 0.001) improvement in body weight gain and feed efficiency with increasing SID Lys content in the diet. According to the linear-plateau regression analysis, the estimated SID Lys requirements for final body weight, weight gain, and feed efficiency were 1.00%, 1.00%, and 0.98%, respectively. Conversely, the quadratic-plateau regression analysis yielded estimated SID Lys requirements of 1.11%, 1.11%, and 1.10%, respectively, for the same parameters. In summary, this study established that the recommended SID Lys levels for White Pekin ducklings for the 3 wk period after hatching were found to be 1.05%, 1.05%, and 1.04% for achieving the finest final body weight, daily gain, and feed efficiency, respectively.

OBJECTIVE:The study assessed the calcium (Ca) endogenous losses and digestibility in 45-week-old Hy-Line Brown laying hens fed diets incorporating different Ca-sourcing ingredients. METHODS:A total of 168 hens were randomly assigned to dietary treatments, with six replicates, and four hens were housed per cage. The seven diets included different Ca sources of monocalcium phosphate (MCP), dicalcium phosphate (DCP), limestone, corn, soybean, wheat bran, and a Ca-free diet. All diets included 0.3% Cr2O3 as a digestible marker as well. Hens were given ad-libitum access to feed and water. On day 3, fresh excreta and the ileal digesta were collected to analyze dry matter, Ca, and Cr2O3 for digestibility analysis. RESULTS:The Ca-free diets led to lower endogenous Ca losses at the ileum (p<0.05) compared to the Ca-supplemented groups. Among the Ca-sourcing diets, MCP resulted in higher Ca losses, whereas corn-based diets showed relatively lower losses at the ileum. Calcium losses at the excretory site were not significant, although the ileal losses were markedly higher (p<0.001), with diet-by-site interaction (p<0.05). Apparent and standardized ileal Ca digestibility were higher for inorganic sources (MCP, DCP, limestone) than for plant-based sources, with DCP showing greater digestibility (p<0.05). CONCLUSION:Inorganic Ca sources resulted in increased endogenous Ca loss and digestibility compared to plant seed-based layer diets, with these losses varying depending on the specific measurement sites.

Objective: Pre slaughter transportation adversely impacts the welfare, meat yield, and quality of broilers, yet the effects of different crate types on broiler chickens during winter remain underexplored. The goal of this study was to investigate the effect of plastic and iron crates in transit on meat quality, carcass, and physiological traits of broiler chickens during winter. Methods: A total of 175 (35day old) Ross 308 male broilers with an average body weight of about 1,708 +/- 33.3 g (mean +/- standard error of the mean) were picked after 4 hours of feed withdrawal before transport. The control group comprises birds in the farm (n = 15) without transportation at 173 cm(2)/kg density. The birds were transported into fixed iron (25 birds per crate) and plastic crates (15 birds per crate) with four replicates per crate type at the same 173 cm(2)/kg densities. The transportation distance was 20 km for 40 min at an average speed of 3050 km/h early morning at 8:00 am under -1 degrees C and 47% relative humidity. Results: There was no difference (p>0.05) in carcass traits among the treatments. Concerning meat quality, broilers transported in both crate types exhibited lower (p<0.01) a* values compared to the control group. Additionally, the iron crate group demonstrated higher (p<0.05) b* values for the breast meat compared to the other groups. In terms of blood metabolites, the iron crate group had higher (p<0.05) cortisol, glucose, and lactate levels compared to the control group that did not transport. Conclusion: Broilers transported in the iron crates increase stress levels in terms of higher cortisol, glucose, and lactate contents in the blood plasma compared to untransported broilers during the winter. Therefore, employing plastic crates, which induce significantly reduced cortisol and numerically lower glucose levels compared to iron crates, appears more favorable for animal welfare by mitigating stress.

This study investigated the effects of dietary crude protein (CP) levels on body weight (BW), laying performance, egg quality, and nitrogen (N) balance in laying hens from 18 to 62 weeks of age. A total of 84 Hy-Line Brown hens at 18 weeks old were randomly assigned to two groups, each with six replicates. The control group (CON) received diets with 17.5%, 16.5%, 15.5%, and 14.5% CP from weeks 18-38, 39-46, 47-54, and 55-62, respectively. The reduced protein group (RP) was fed diets with 1.5% less CP than the CON group during the same periods (16.0%, 15.0%, 14.0%, and 13.0%, respectively). The RP group showed significantly lower BW from weeks 30-62 (p < 0.05) and reduced hen-day egg production during weeks 18-38 and 54-62 (p < 0.05). Egg weight (EW) was significantly higher in the CON group than the RP group during weeks 54-62 (p = 0.003), and feed efficiency was also reduced in the RP group across multiple phases (p < 0.05). At week 38, Haugh units (HU) were lower in the RP group (p = 0.034), and yolk color was lighter at week 62 (p = 0.006). N balance parameters showed that the RP group had significantly lower N intake at weeks 46, 54, and 62 (p < 0.01), and N excretion was reduced throughout the trial (p < 0.05). Total N retention was lower in the RP group at weeks 26, 38, 54, and 62 (p < 0.05), and N retained in eggs was also reduced at weeks 26, 38, and 62 (p < 0.05). In summary, lowering dietary CP levels by 1.5% decreased N excretion, suggesting environmental benefits. In summary, reduction of dietary CP levels by 1.5% reduced N excretion but also compromised BW, laying performance, HU, and N retention. These findings highlight the need for further refinement of amino acid formulations to achieve both environmental and production goals.

The experiment was conducted to estimate the matrix value of xylanase and the effect of dietary xylanase supplementation on growth performance, viscosity, digestibility, and carcass traits in broiler chickens. A total of 588 one-day-old Ross 308 broiler chicks were raised with a commercial diet until day 7 and seven-day-old chicks were randomly allotted to one of seven dietary treatments with twelve replicates. Diets were corn-soybean meat based with wheat added. Dietary treatments were as follows; four basal diets (PC, energy sufficient diet; NC-1, -40 kcal/kg ME reduced from PC diet; NC-2, -80 kcal/kg ME reduced from PC diet; NC-3. -120 kcal/kg ME reduced from PC diet) and three different xylanase activity levels diet (NCX-1, 1,500 U/kg xylanase activity; NCX-2, 3,000 U/kg xylanase activity, NCX-3 4,500 U/kg xylanase activity) in the NC-3 diet. The standard xylanase dose was decided from the previous in vitro experiment. The weight gain and feed intake were measured and feed efficiency was calculated weekly. One bird per pen was selected and euthanized to harvest the intestinal digesta, breast meat, and leg meat samples on days 24 and 35. The linear and quadratic regression analysis and regression plateau were used to determine the xylanase recommendation and marginal level. The viscosity, digestibility, and proximate analysis of meat were analyzed from taken samples. Xylanase-added treatments were performed for higher (p < 0.05) body weight and body weight gain. Furthermore, xylanase-added treatments showed higher protein digestibility and lower viscosity compared to non-xylanase treatment. The maximum metabolizable energy compensation level of xylanase calculated by the regression was 120 kcal/kg and the marginal xylanase level showed maximum performances were 3,622 U/kg on the linear plateau and 4,000 U/kg on the quadratic plateau. Therefore, our experiment suggested that xylanase addition in an energy deficiency diet not only enhances growth performance but also reduces viscosity, and enhances protein digestibility and the maximum compensation level of metabolizable energy was 120 kcal/kg. The recommended levels of xylanase supplementation were determined to be 3,622 and 4,000 U/kg.

The current study investigated the optimal standardized ileal digestible (SID) methionine (Met) requirement for the growth performance of white Pekin ducks from hatching to 21 days of age. A total of 288 one-day-old male white Pekin ducklings were initially weighed and randomly assigned to six dietary groups, with six replicates per group. Eight ducklings were housed in each floor cage, pre-littered with rice hulls. Basal diets (corn-soybean-based) included 0.30%, 0.35%, 0.40%, 0.45%, 0.50%, and 0.55% SID Met, representing the dietary treatment groups. Ducklings were offered unrestricted access to experimental diets and freshwater for the duration of the study. Body weight and feed intake were recorded weekly, and the average daily gain and feed conversion ratios were calculated. Overlapping linear- and quadratic-plateau regression models were employed to estimate SID Met requirements. Final body weight, average daily gain, and feed conversion ratios in white Pekin ducks exhibited significant quadratic growth with increasing dietary SID Met concentrations. In conclusion, estimated SID Met requirements for white Pekin ducks from hatching to 21 days, based on an average of linear and quadratic model responses, were determined to be 0.51% for body weight improvement, 0.51% for average daily gain, and 0.50% for feed conversion efficiency. These findings provided invaluable insight into optimized nutritional strategies for early growth performance in white Pekin ducks.

Objective This study aimed to investigate the efficacy of Bacillus-based probiotics supplemented at two different levels to modulate the productive performance, egg quality, tibia traits, and specific cecal bacteria counts of Hy-Line Brown layers from 25 to 37 weeks of age. Methods A total of 216 twenty-five-week-old hens were randomly distributed into 3 experimental diets with 12 replicates of 6 birds per cage. Diets included basal diet supplemented with 0 (CON), 3×108 (PRO1), or 3×109 (PRO2) colony-forming unit (CFU) of the test probiotic containing Bacillus subtilis PB6, Bacillus subtilis FXA, and Bacillus licheniformis G3 per kilogram of feed. Results Improved egg weights and mass at 29 weeks; and feed intake at 31 weeks (p<0.10) were noticed with the probiotic-supplemented PRO1 and PRO2 diets. Considering egg quality, the shell thickness, Haugh units, and yolk color were improved; but yolk cholesterol was lowered (p<0.05) with PRO1 and PRO2 diets at 29 weeks. At both 33 and 37 weeks, the egg-breaking strength, shell color and thickness, albumen height, Haugh units, and yolk color were improved; but yolk cholesterol was similarly lowered (p<0.05) with the PRO1 and PRO2 diets. Improved tibia Ca, ash, weights, and density; and raised cecal counts of Bifidobacteria and Lactobacilli (p<0.05) were noticed with PRO1 and PRO2 diets. Improved tibia P but reduced Clostridia counts (p<0.10) were also observed with the PRO1 and PRO2 diets. Conclusion Probiotic supplementation of Bacillus subtilis PB6, Bacillus subtilis FXA, and Bacillus licheniformis G3 at 3×108 CFU/kg of feed is adequate to significantly improve egg quality, lower yolk cholesterol, enhance several tibia traits, and raise the populations of beneficial cecal bacteria. Modest improvements in several productive parameters and tibia P but reduced Clostridia were also observed; and could warrant further investigation of probiotic effects beyond the current test period.

The impact of dietary non-starch polysaccharides (NSP) on performance and carcass traits of broilers fed wheat-bran substituted into corn-soybean meal-based diets supplemented with xylanase was investigated. A total of 280 (7-day-old) Ross 308 broilers were randomly allotted to one of five dietary treatments with 8 replicates, 7 chicks per pen. Treatments were; i) CON: Control diet, ii) CON-X (CON + 3,000 U/kg xylanase), iii) L-X: low NSP (2% wheat bran in CON + 3,000 U/kg xylanase), iv) M-X: medium NSP (4% wheat bran in CON + 3,000 U/kg xylanase), v) H-X: higher NSP (8% wheat bran in CON+ 3,000 U/kg xylanase). Birds fed the H-X diet increased (p < 0.05) daily gains, and average daily feed intake and had marginally improved body weights (p = 0.074) on day 35. Relatively, the H-X diet tended to increase the average daily gains (p = 0.053; p = 0.073) of birds during the grower phase (d 24-35) and the entire experimental period (d 8-35), respectively. Moreover, there were no significant differences among treatments in the feed conversion ratio of birds throughout the entire experiment period. Birds fed diets CON-X, L-X, and M-X had improved (p < 0.05) the ileal digestibility of energy on d 24 and 35 compared to those fed the H-X diet. Furthermore, birds fed diet CON-X improved (p < 0.05) N digestibility on d 24. Improved carcass moisture content and lowered crude fat of leg meat (p < 0.05) were noted in birds fed the diet M-X and H-X on d 35, respectively. The intestinal viscosity was reduced (p < 0.05) in xylanase-supplemented treatments CON-X, L-X, M-X, and H-X diets when compared to CON. Our results suggest that supplementing 3,000 U/kg xylanase in a higher NSP (8% wheat bran substituted level) diet could improve the intestinal viscosity and growth performance of broilers.

The impact of crating density and prevailing weather conditions during transit on preslaughter losses, physiological characteristics, and meat quality in broilers was investigated. A total of 900 35-day-old Ross 308 male broilers with an average body weight of 1,860 +/- 17.458 g (mean +/- SEM) in summer and 1,864 +/- 17.454 g in winter were allotted to one of six groups arranged in a 3 x 2 factorial arrangement according to the three different crating densities (low: 0.039 m(2)/bird; medium: 0.031 m(2)/bird; high: 0.026 m(2)/bird) and two different weather conditions (low: -1 degrees C and high: 30 degrees C). Birds stocked at medium density recorded lower (p < 0.05) body weight loss compared to the low density group; and demonstrated higher (p < 0.05) lactate levels along with lower (p < 0.05) respiration rates when compared to the high crating density group. Extreme conditions of low crating density under low air temperature and high crating density under high air temperature led to higher (p < 0.001) body weight loss and glucose concentration compared to low crating density under high air temperature. In conclusion, both excessively high and low crating densities are not conducive to reducing preslaughter losses and blood stress indicators. Broiler transportation under high crating density in low air temperatures and low crating density in high air temperatures is recommended.