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Objective: The objective of this study was to determine whether a dietary vitamin E (VE) supplement could alleviate any detrimental effects of aged corn on lipid metabolism and antioxidant status in laying hens. Methods: The experiment consisted of a 2×3 factorial design with two corn types (normal corn and aged corn (stored for 4 yr) and three concentrations of VE (0, 20, and 100 IU/kg). A total of 216 Lohmann laying hens (50 wk of age) were randomly allocated into six treatment diets for 12 wk. Each treatment had 6 replicates of 6 hens per replicate. Results: The results show that aged corn significantly decreased the content of low-density lipoprotein cholesterol (p<0.05), and reduced chemokine-like receptor 1 (CMKLR1) mRNA expression (p<0.05) in the liver compared to controls. Diet with VE did not alter the content of crude fat and cholesterol (p>0.05), or acetyl-CoA carboxylase, lipoprotein lipase, fatty acid synthase or CMKLR1 mRNA expression (p>0.05) in the liver among treatment groups. Aged corn significantly increased the content of malondialdehyde (MDA) (p<0.05) and decreased superoxide dismutase (SOD) activity (p<0.05) in the liver. The VE increased the content of MDA (p<0.05) but decreased glutathione peroxidase (GSH-Px) activity in serum (p<0.01) and in the ovaries (p<0.05). Adding VE at 20 and 100 IU/kg significantly increased GSH-Px activity (p<0.05) in liver and in serum (p<0.01), 100 IU/kg VE significantly increased SOD activity (p<0.05) in serum. Aged corn had no significant effects on GSH-Px mRNA or SOD mRNA expression (p<0.01) in the liver and ovaries. Addition of 100 IU/kg VE could significantly increase SOD mRNA expression (p<0.01) in the liver and ovary. Conclusion: Aged corn affected lipid metabolism and decreased the antioxidant function of laying hens. Dietary VE supplementation was unable to counteract the negative effects of aged corn on lipid metabolism. However, addition of 100 IU/kg VE prevented aged corninduced lipid peroxidation in the organs of laying hens. [ABSTRACT FROM AUTHOR]

Genetic selection and intensive nutrition for increased growth rate in meat-type ducks has resulted in an imbalance between pectorales increment and sternal mass, which is detrimental to productivity and welfare. Reducing body weight and increasing sternal mass probably reverses these adverse effects. Therefore, 2 experiments (Expt.) were conducted to investigate the effects of 25-hydroxycholecalciferol (25-OH-D3), a vitamin D3 metabolites, on sternal mass. In Expt. 1, 512 1-day-old male ducks were randomly assigned to 4 low-nutrient density diets and received following treatments in a 2 × 2 factorial arrangement: (i) NRC or China Agricultural industry standards (NY/T) vitamin premixes and (ii) 0.069 mg/kg 25-HyD in feed or not. At 49 D of age, regardless of 25-OH-D3, NY/T vitamin regimen inhibited bone turnover and consequently increased sternal trabecular bone volume and mineral deposition compared with NRC vitamin premix. Supplementing 25-OH-D3 to NRC but not NY/T vitamin regimen significantly improved sternal microarchitecture and mineral content, which companied by decreased serum bone resorption markers concentration, as well as downregulation of the gene expressions of osteoclast differentiation and activity. In Expt. 2, 256 1-day-old male ducks were fed a standard nutrient density diet contained NRC vitamin premix with 0 or 0.069 mg/kg of 25-OH-D3. Results also showed that 25-OH-D3 treatment significantly improved sternal mineral accumulation and microarchitecture, along with decreasing osteoblast and osteoclast numbers in bone surface, declining serum bone turnover markers levels, and increasing serum Ca concentration. Collectively, these findings indicated that the dietary administration of 25-OH-D3 increased sternal mass in NRC vitamin diet by suppressing bone resorption in 49-day-old meat duck. [ABSTRACT FROM AUTHOR]

Three experiments were conducted to investigate the effects of maternal dietary canthaxanthin (CX) and 25-hydroxycholecalciferol (25-OH-D3) supplementation on antioxidant status and calciumphosphate metabolism of progeny ducks. Cherry Valley duck breeders (38 wk old) were fed either a control diet or the same diet plus CX (6 mg/kg) and 25-OH-D3 (0.069 mg/kg) for 32 weeks. Experiments 1, 2, and 3 were conducted with progeny ducks hatched from eggs laid by duck breeder hens at 54, 62, and 70 wk of age, respectively. Progeny ducks from both maternal treatments were fed with the same NRC (1994) vitamin regimen starter (1 to 14 d) and finisher (15 to 35 d) diets in experiments 1 and 2, and fed with the same high vitamin regimen starter (1 to 14 d) and finisher (15 to 35 d) diets in experiments 3. High vitamin regimen had higher levels of all vitamins, except biotin, than the NRC (1994) vitamin regimen. In experiment 1, maternal CX and 25-OH-D3 increased (P < 0.05) shank pigmentation and tibiotarsus ash and tended to decrease (P < 0.1) liver total superoxide dismutase activity (T-SOD) of one-day-old progeny ducks; and increased (P < 0.05) shank pigmentation, decreased (P = 0.05) liver protein carbonyl, and tended to increase (P < 0.1) liver total antioxidant capacity (T-AOC) of 14-day-old progeny ducks. In experiment 2, maternal CX and 25-OH-D3 increased (P < 0.05) shank pigmentation and liver T-AOC and decreased (P < 0.05) liver protein carbonyl of one-day-old progeny ducks, but increased (P < 0.05) the serum phosphate level of 14-day-old progeny ducks. In experiment 3, maternal CX and 25-OH-D3 increased (P < 0.05) shank pigmentation of one-, 14-, and 35-day-old progeny ducks and tended to increase (P < 0.1) liver T-SOD and tibiotarsus ash, but decrease (P < 0.1) liver malondialdehyde of one-day-old progeny ducks. It can be concluded that progeny dietary high vitamin regimen could partially prevent maternal CX-derived progeny shank pigmentation from bleaching. Maternal CX- and 25-OH-D3-derived effects are influenced by the hen's age and progeny's dietary vitamin regimen. [ABSTRACT FROM AUTHOR]

A study was conducted to establish the response of Pekin ducks to dietary Met from 15 to 35 d age. Experimental diets were formulated to contain 0.35, 0.45, 0.55, 0.65, and 0.75% Met (0.30, 0.39, 0.45, 0.56, and 0.68% on an analyzed basis, respectively) and 0.3% cysteine (0.25, 0.27, 0.26, 0.26, and 0.28% on an analyzed basis, respectively). Each diet was fed to 10 pens of 55 ducks/pen. Carcass yields and feather growth were determined at 28 and 35 d. Results showed that feeding 0.30% Met (0.55% Met+Cys) significantly impaired ADG, feed-to-gain (F:G) ratio, breast meat yield, and feather growth in comparison to the other dietary treatments (P < 0.05). BW, ADG, F:G, carcass and breast meat weight and yield, breast skin and subcutaneous fat weight and yield, the fourth primary wing feather length, and feather coverage showed significant quadratic broken-line or quadratic polynomial response to increasing dietary Met (P < 0.05). From 15 to 28 d age, the optimal Met requirement for the BW, breast meat yield, and the fourth primary wing feather length were 0.510, 0.445, and 0.404%, respectively, based on quadratic broken-line model, and correspondingly were 0.606, 0.576, and 0.559% by quadratic regression. For ducks from 15 to 35 d age, the optimal Met requirement for BW, breast meat yield, and feather coverage were 0.468, 0.408, and 0.484%, respectively, by quadratic broken-line model, and 0.605, 0.564, and 0.612%, by quadratic regression, respectively. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the responses of meat ducks of 15 to 35 d of age to free gossypol (FG) from cottonseed meal (CSM) and to establish the maximum limits of dietary FG concentration based on growth performance, blood parameters, and tissue residues of gossypol. Nine hundred 15-d-old ducks were randomly allocated to 5 treatments with 10 cages/treatment and 18 ducks/cage on the basis of BW. Five isonitrogenous and isocaloric experimental diets were formulated on a digestible amino acid basis to produce diets in which 0% (without FG), 25% (36mg FG/kg), 50% (75mg FG/kg), 75% (111 mg FG/kg), and 100% (153 mg FG/kg) of protein from soybean meal were replaced by that from CSM. Increasing dietary FG content, BW, and ADG decreased (linearly, P < 0.05, except for ADG of days 29 to 35), and F/G linearly increased (P < 0.05). At 35 d, blood hemoglobin, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration linearly decreased (P < 0.05), while serum total protein, albumin, and globulin content linearly decreased (P < 0.05), and the residue of gossypol in liver, kidney, heart, breast, and leg muscle linearly increased (P < 0.001) with increases in dietary FG concentration. Ducks fed 36 mg FG/kg (5.83% CSM of diet) diet had a normal histological structure of liver, and muscle (breast and leg) had no residue of gossypol. The maximum limit of dietary FG concentration was estimated to range from a low of 36 mg/kg to maximize serum globulin concentration to a high of 124 mg/kg to minimize feed intake for 22 to 28d on the basis of a quadratic broken-line model. [ABSTRACT FROM AUTHOR]

A study was conducted to determine the influence of dietary energy and protein concentrations on growth performance and carcass traits of Pekin ducks from 15 to 35 d of age. In experiment 1, 14-d-old ducks were randomly assigned to 3 dietary metabolizable energy (11.8, 12.8, and 13.8 MJ/kg) and 3 crude protein concentrations (15, 17, and 19%) in a 3 × 3 factorial arrangement (6 replicate pens; 66 ducks/pen). Carcass characteristics were evaluated on d 28, 32, and 35. In Experiment 2, 15-d-old ducks (6 replicate cages; 6 ducks/cage) were randomly allotted to the 9 diets that were remixed with 0.5% chromic oxide. Excreta were collected from d 17 to 19, and ileal digesta was collected on d 19 to determine AMEn and amino acid digestibility. In Experiment 1, there were interactions (P < 0.05) between dietary metabolizable energy and crude protein (CP) on body weight (BW) gain and feed intake, wherein BW gain increased more to increasing dietary CP as dietary metabolizable energy increased. However, feed intake was only influenced by dietary crude protein at 11.8 MJ ME/kg and not 12.8 or 13.8 MJ/kg. As dietary CP increased from 15 to 19%, breast meat yield increased by 10.8% on d 35 (P < 0.01). Conversely, increasing metabolizable energy from 11.8 to 13.8 MJ/kg increased dressing percentage, breast skin, and subcutaneous fat, but decreased breast meat yield (% but not weight) on d 35 (P < 0.01). In Experiment 2, the determined AMEn for diets formulated to contain 11.8, 12.8, or 13.8 MJ ME/kg were 11.66, 12.68, and 13.75 MJ/kg, respectively; determined standardized ileal digestible Lys was 0.95, 1.00, and 1.21% for diets formulated to contain 15, 17, or 19% crude protein, respectively. The best body weight gain and feed conversion ratio was obtained when ducks were fed a high dietary AMEn (13.75 MJ/kg) and high CP (19%, 1.21% SID Lys). These results provide a framework for subsequent modeling of amino acid and energy inputs and the corresponding outputs of growth performance and carcass components. [ABSTRACT FROM PUBLISHER]

This study evaluated the effects of dietary canthaxanthin (CX) and 25- hydroxycholecalciferol (25-OH-D3) supplementation on the antioxidant status and tibia quality of duck breeders and newly hatched ducklings. In total, 780 female and 156 male duck breeders were randomly allotted to 2 treatments. Duck breeders were fed either a commercial diet (containing 3,000 IU/kg vitamin D3) or the same diet plus a mixture of CX (6 mg/kg) and 25-OH-D3 (0.069 mg/kg) for 40 wk. The antioxidant status of duck breeders, egg yolk, and ducklings; tibia quality of duck breeders and ducklings; and shell quality of breeder eggs were investigated. The total antioxidant capacity of breeder female liver (P = 0.028), breeder male testis (P = 0.049), egg yolk (P = 0.032), one-day-old duckling liver (P = 0.024), and one-day-old duckling yolk sac (P = 0.012) were increased by dietary supplementation of the mixture of CX and 25-OH-D3. The inclusion of CX and 25-OH-D3 decreased liver protein carbonyl of breeder females (P = 0.030), and liver malonaldehyde (P = 0.050) and protein carbonyl (P = 0.030) of breeder males. Yolk (P < 0.001), shank (P < 0.001), and yolk sac pigmentation (P < 0.001) of one-day-old ducklings were increased by the supplementation of the CX and 25-OH-D3 mixture. No differences (P > 0.05) were observed in tibia quality or eggshell quality between treatments. In conclusion, the inclusion of the mixture of CX and 25-OH-D3 in a diet sufficient in vitamin D3 increased antioxidant status but not tibia quality of duck breeders and newly hatched ducklings. [ABSTRACT FROM AUTHOR]

Dietary vitamin E supplementation has been indicated to enhance the antioxidant capacity of breeders. As breeders age, the productive and reproductive performance rapidly decline, and dietary vitamin E supplementation may play a positive role in this process. Two trials were conducted to evaluate the effects of dietary vitamin E supplementation on laying performance, hatchability traits and antioxidant status in molted broiler breeder hens beyond 70 wk. A total of 512 (71-week-old) and 576 (75-week-old) molted Ross 308 breeder hens were assigned to 2 dietary vitamin E groups (6 or 100 mg/kg) and 3 dietary vitamin E groups (100, 200 or 400 mg/kg) for 12 wk, respectively. Eggs were collected and incubated at wk 9. Dietary vitamin E supplementation did not affect the laying performance of hens and the hatchability traits of eggs (P > 0.05). As dietary vitamin E concentration increased, the malonaldehyde (MDA) content in ovarian of hens, egg yolks and serum, brain, and yolk sac of chicks decreased (P < 0.05), the total antioxidant capacity (T-AOC) in serum and ovarian of hens, egg yolks and yolk sac of chicks increased (P < 0.05), and the alpha-tocopherol content in egg yolks increased (P < 0.05). In conclusion, dietary vitamin E supplementation did not influence egg production and hatchability traits. However, based on optimizing the antioxidant status of egg yolks and newly hatched chicks, the suitable vitamin E concentration in the molted broiler breeder hen (beyond 70 wk) diet is at least 200 mg/kg. [ABSTRACT FROM AUTHOR]

A total of 560 one-day-old Pekin ducks were randomly allocated to 7 treatments with 8 replicate cages of 10 ducks per cage. The treatments included a corn-rice bran-soybean meal-based diet with recommended nonphytate phosphorus (NPP) (0.40% for 1-14 D/0.35% for 15-35 D, positive control; PC), NPPdeficient diet (0.22% for 1-14 D/0.18% for 15-35 D, negative control; NC), and NC diets supplemented with different levels of phytase (500, 2,500, 5,000, 7,500, 10,000 FTU/kg). Compared with the PC diet, feeding the NC diet significantly decreased (P, 0.05) the bird growth performance, serum total protein, and albumin concentration as well as tibia bone mineralization and strength and increased (P, 0.05) serum calcium (Ca), urea content, and alkaline phosphatase activity throughout the experimental period. Phytase supplementation to NC diets at 5,000 to 10,000 FTU/kg restored (P, 0.05) growth performance, serum biochemical parameters, and tibia traits when compared with the levels of the PC. Moreover, the addition of phytase linearly increased (P, 0.05) dietary protein, Ca, and phosphorus (P) utilization as well as nitrogen output, and excreta iron, copper, manganese, and zinc concentration quadratically increased (P, 0.05) as well as P output. In conclusion, phytase at 5,000 FTU/kg was effective in ameliorating the negative effects of NC diets and reducing trace mineral supplementation in diet of Pekin ducks. [ABSTRACT FROM AUTHOR]

This study was conducted to determine whether protein solubility (PS) of rapeseed meals (RSM) can affect standardized ileal amino acid digestibility (SIDAA) in meat ducks. A total of 1,168, 14-days-old ducks were randomly allotted to 23 treatments (6 cages per diet, 8 ducks per cage) and 1 nitrogen-free diet treatment (8 cages, 8 ducks per cage) based on body weight. The 23 experimental diets consisted of a corn–soybean meal basal diet, and 22 diets containing 15% RSM: 85% basal diet. Titanium dioxide (0.5%) was included in all diets as an indigestible marker. On day 18, all ducks were euthanized by carbon dioxide asphyxiation and digesta samples from the ileum. The contents of PS, ether extract (EE), glucosinolate, isothiocyanate, and oxazolidine were significantly different (P < 0.05) in the 22 RSM, with the CV being 52.62, 49.23, 86.84, 90.19, and 81.98%, respectively. The content of lysine (Lys) and methionine in the 22 RSM samples ranged from 1.03 to 2.71% (CV 24.19%) and from 0.33 to 0.65% (CV 15.17%), respectively. The SIDAA, except for leucine (Leu) and tyrosine, of the 22 RSM samples varied significantly (P < 0.05). A positive correlation was observed (P < 0.05) between PS and standardized ileal digestibility (SID) of Lys, isoleucine, valine, phenylalanine, histidine, serine, cysteine, and tyrosine. The R² value of multiple linear regression equations for predicting the SID of amino acids (AA) was best for Lys (R2 = 0.958 using dry matter, crude protein, EE, crude fiber, acid detergent fiber, and PS) and least significant for Leu (R² = 0.348 using crude fiber and ash) with intermediate values for other AA (R² = 0.359–0.837, P < 0.05). These results suggest that PS varying from 15.06 to 98.08%, also varied considerably in the proximate nutrient content, AA composition, and antinutritional factor content, which was reflected in considerable differences in the duck's SID of AA in RSM. Therefore, PS value can partly reflect the quality of RSM. [ABSTRACT FROM AUTHOR]

Foot pad dermatitis (FPD) is a serious problem of the modern poultry industry, negatively affecting birds' welfare and health status, walking and feeding activity, growth performance, carcass quality, and economic performance of meat production. The gut microbiome in poultry with FPD has not been previously investigated. Therefore, we compared the cecal microbiomes of 8 breeding ducks with FPD to 8 control ducks (breeders with apparently healthy feet) by pyrosequencing the bacterial 16S ribosomal RNA gene. The results showed a significant β-diversity (P < 0.05) of cecal microbiota presented between healthy and FPD-affected breeder ducks. The plasma endotoxins, interleukin 1β (IL-1β), IL-17, IL-6, IL-10, and tumor necrosis factor-α concentration, and the abundance of class Clostridia in FPD-affected ducks was markedly higher (P < 0.05), however, the abundance of genus Prevotella, Lactobacillus, Lachnospiraceae UCG-008, and the Firmicutes to Bacteroidetes ratio in FPD-affected ducks was significantly lower (P < 0.05) when compared to healthy ducks. These findings suggest when duck breeders are affected with FPD, ducks show an increased inflammatory response and a difference of structure and composition of the cecal microbiome. [ABSTRACT FROM AUTHOR]

This study was to determine the effects of rapeseed oil on production performance, egg quality, and serum parameters in laying hens. A total of 1,080 hens (33-wk-old) were randomly divided into a 1 plus 4 × 2 factorial design including four different rapeseed oil sources [high erucic acid of Mianyang city (MH); high erucic acid of Deyang city (DH); low erucic acid of Mianyang (ML); low erucic acid of Deyang (DL)] at two levels (2% and 4%) for 12 wk. The egg production and egg weight were decreased (P < 0.05) during 9 to 12 wk and 1 to 12 wk, while the average daily feed intake (ADFI) and feed conversion ratio were decreased (P < 0.01) in all phases compared to the control group. Adding ML as oil source had higher (P < 0.05) egg weight compared to DH in all periods in spite of levels. Meanwhile, layers fed 4% rapeseed oil decreased (P < 0.01) egg production compared with 2% in all phases except 1 to 4 wk. Regardless of rapeseed oil sources, hens fed 4% oil decreased (P < 0.05) egg weight in contrast to 2% during the whole experiment except 5 to 8 wk. The ADFI was lower (P < 0.01) in 4% oil inclusion groups compared with 2% during overall phase. Rapeseed oil decreased the yolk color (P < 0.01) and yolk ratio (P = 0.02) and increased (P < 0.01) the albumen height and Haugh unit at 12 wk. Dietary rapeseed oil supplementation resulted in a decreased total triglyceride (TG; P < 0.01) and increased high-density lipoprotein cholesterol (P = 0.02). Regardless of rapeseed oil levels, layers fed MH had higher TG (P < 0.01), TC (P < 0.05), low-density lipoprotein cholesterol (P < 0.05), alanine transaminase (P < 0.01) than those fed other sources. Taken together, the addition of rapeseed oil decreased laying performance, reduced TC and TG in the serum, and increased Haugh unit, with low erucic acid or 2% group showed more pronounced results among all treatments. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the effect of dietary energy concentration on growth performance, serum biochemical indices, and the mRNA expression of inflammatory cytokines in the liver of meat ducks challenged with lipopolysaccharide (LPS). A total of 600 1-d-old Cherry Valley meat ducks were randomly assigned to 10 treatments with six replicate cages of 10 birds/pen. A 5 × 2 factorial arrangement in a complete randomized design experiment was used to study the effect of five concentrations of dietary metabolizable energy (ME, 2,800, 2,900, 3,000, 3,100, and 3,200 kcal/kg) with or without a challenge with LPS in meat ducks. All experimental ducks were intraperitoneally injected with either 0.5 mg/kg body weight (BW) LPS or an equivalent amount of sterile saline at 15, 17, and 19 d of age. The results showed that LPS challenge significantly decreased (P < 0.05) BW (d 21), body weight gain (d 15–21) and average daily feed intake (ADFI; d 15–21), and markedly increased (P < 0.05) relative spleen weight, serum total protein concentration, and the mRNA expression of interleukin 6 (IL-6), interleukin 10, transforming growth factor β (TGF-β), and Avian Beta Defensin 10 (AVBD-10) in the liver of meat ducks. Ducks fed 3,200 kcal/kg ME diet had the lowest (P < 0.05) ADFI than those fed with the other diets. Additionally, there were significantly LPS by diet interactions on IL-6, interferon-γ, TGF-β, AVBD-10, and inducible nitric oxide synthase mRNA expression (P < 0.05), wherein a more pronounced liver inflammatory response was observed in birds fed high-energy diets (3,100 and 3,200 kcal/kg ME) than birds fed low-energy diet (2,800 and 2,900 kcal/kg ME). The results indicated that 3,100 and 3,200 kcal/kg ME of diets increased hepatic inflammatory markers induced by LPS challenge in ducks but did not influence performance responsiveness during this challenge. [ABSTRACT FROM AUTHOR]

The objective of the study was to investigate the effects of deficiency or high level addition of methionine (Met) in diet on homocysteine (Hcy) metabolism and hepatic lipid metabolism in broiler. A completely random design was used with 3 dietary treatments with the addition of Met from DL-methionine (DLM) at 0%, 0.22%, and 0.32% in a basal diet. The analyzed dietary Met was 0.271%, 0.485%, and 0.584% respectively for the Met-deficient, sufficient, and excessive diet. A total of 360 one-day-old male Ross 308 broiler chicks were randomly assigned to the treatments. The trial was last for 21 d. Compared to the Met-sufficient diet, the Met-deficient diet significantly resulted the decrease of 1 to 21 d growth performance and the increase of liver ether extract (EE). Compared to the Met-sufficient group, the expression of lipid transport gene apolipoprotein B (APOB) in both Met-deficient and Met-excessive group was decreased (P < 0.05). However, compared to the Met-sufficient group, a decreased of serum low-density lipoprotein cholesterol (LDLC) was only shown in birds fed a Met-deficient diet (P < 0.05). Although the plasma Hcy content was decreased, the expression of Cystathionine β-synthase (CβS) and hepatic inflammatory cytokines included interleukin-1 (IL-1) and interleukin-8 (IL-8) was significantly decreased in birds fed the Met-deficient diet when compared to those in Met-sufficient group (P < 0.05). When compared to the Met-sufficient group, the broilers in high dietary Met group had increased levels of catabolic enzyme genes expression especially acyl-coenzyme A oxidase 1 (ACOX1) and carbohydrate response element-binding protein (CHREBP) (P < 0.05), and a decreased content of liver EE. In conclusion, dietary Met deficiency decreased the hepatic lipid export and subsequently increased the hepatic lipid accumulation. High dietary Met addition increased the hepatic lipid catabolism and subsequently decreased the liver lipid accumulation. [ABSTRACT FROM AUTHOR]

The study was conducted to distinguish the effect of dietary non-phytate phosphorus (NPP) levels on the community diversity and structure of the cecal microbiota in meat duck based on 16S rDNA high-throughput sequencing. In total, 525 1-d-old ducklings were fed diets (105 ducklings, 7 pens of 15 ducklings, on each diet) containing five levels of NPP (0.22, 0.34, 0.40, 0.46, and 0.58%) for 21 days. The results showed that dietary NPP levels linearly and quadratically increased (P < 0.05) 21 d body weight, 1 to 21 d feed intake and NPP intake, and contrarily, linearly decreased (P < 0.05) β-diversity of cecal microbial population in ducks. ß-diversity analyses showed that microbiota clustering based on dietary NPP levels occurred, with 0.22% NPP groups distinctly different from the 0.46% and 0.58% NPP group samples. Moreover, dietary NPP levels could change the relative abundance of the phylum Proteobacteria (linear, P < 0.05), genera Eubacterium coprostanoligenes (quadratic, P < 0.05), Ruminococcaceae UCG-014 (quadratic, P < 0.05) and Subdoligrannulum (linear, P < 0.05), and Lachnospiraceae family (quadratic, P < 0.05) in cecal microbiota of ducks. Increasing the dietary NPP level influenced the cecal microbiota and positively affected the growth of meat ducks. [ABSTRACT FROM AUTHOR]

This study was conducted to determine the effect of tea polyphenols (TP) on production performance, egg quality, and hepatic-antioxidant status of laying hens in vanadium-containing diets. A total of 300 Lohman laying hens (67 wk old) were used in a 1 plus 3 x 3 experiment design in which hens were given either a diet without vanadium and TP supplementation (control) or diets supplemented with 5, 10, or 15 mg V/kg and TP (0, 600, 1,000 mg/kg) diets for 8 wk, which included 2 phases: a 5-wk accumulation phase and a 3-wk depletion phase. During the accumulation phase, dietary vanadium addition decreased (linear, P < 0.01) albumen height and Haugh unit (HU), and TP supplementation mitigated (linear effect, P < 0.01) this reduction effect induced by vanadium. Eggshell thickness (linear, P < 0.01), redness (linear and quadratic, P < 0.05), and yellowness (linear and quadratic, P < 0.05) were decreased by vanadium and increased by the effect of TP when a vanadium-containing diet was fed. In the depletion phase, the bleaching effect on eggshells induced by vanadium disappeared one wk after vanadium withdrawal. Eggshell thickness, eggshell strength, albumen height, and HU were lower (P < 0.05) in the 15 mg/kg vanadium group compared with the control diet until 2 wk post vanadium challenge, but hens fed 15 mg/kg vanadium and 600 mg/kg TP showed no difference from the control diet only after 1 wk withdrawal. In the liver, the activity of glutathione S-transferases and glutathione peroxidase was increased (linear, P < 0.01) with the TP addition at 5 wk in the accumulation phase in the vanadium-containing diet; the malondialdehyde content increased (linear effect, P = 0.02) with the addition of vanadium. The results indicate that supplementation of 10 and 15 mg/kg vanadium resulted in reduced albumen quality, bleaching effect on eggshell color, and antioxidant stress in the liver. The effect of TP addition can prevent laying hens from the adverse effect of vanadium on egg quality, liver antioxidant stress and shorten the recovery time. [ABSTRACT FROM AUTHOR]

Our study aimed to investigate the effects of different dietary vitamin D (VD) combinations during the grower (1-32 d of age) and feed restriction (33-52 d of age) phases on growth performance. We also evaluated sternal morphology, mineralization, and related genes expression of bone metabolism as well as absorption of calcium and phosphorous in duodenal mucosa and kidney in Pekin ducks. During the grower phase, we used 2 VD regimes (Group A: 3,160 IU/kg VD 3 ; Group B: 400 IU/kg VD 3 + 69 μg/kg 25-OH-D 3 ). Each dietary treatment had 50 replicate pens of 10 ducks per pen. During the feed restriction phase, 30 replicate pens selected from Group A and Group B, repetitively, were redivided into 5 different dietary VD regimes to form a 2 × 5 experimental design. Each group consisted of 6 replicates, each with 10 ducks. During the feed restriction phase, we evaluated 5 different dietary VD combinations were as follows: T1: 2,000 IU/kg VD 3 ; T2: 5,000 IU/kg VD 3 ; T3: 3,620 IU/kg VD 3 + 34.5 μg/kg 25-OH-D 3 ; T4: 2,240 IU/kg VD 3 + 69 μg/kg 25-OH-D 3 ; T5: 1,800 IU/kg VD 3 + 80 μg/kg 25-OH-D 3 ). Results showed that Group B combinations with T5 had a better growth performance and breast meat deposition (P < 0.1). Regardless of 5 dietary VD regimes during the feed restriction phase, Group B significantly increased (P < 0.05) 52 d sternal depth and tended to increase (P < 0.1) 52 d sternal defatted weight, ash content, and phosphate (P) content of ducks. A significant interactive effect (P < 0.05) was observed on the mRNA abundance of DMP1 and Sost1 as well as RANKL/OPG in sternum and of VDR in duodenal mucosa of ducks at 52 d of age between dietary VD combinations during 2 phases. These results indicated that dietary VD regimes during the grower phase could affect the effectiveness of dietary VD regimes during the feed restriction phases; Dietary VD combinations of both phases could affect the genes expression of bone formation and the absorption as well as reabsorption of calcium and phosphorus in duodenum and kidney., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

In our previous experiment, we found that fats with pre-emulsification (PreE), a new supplemented mode of emulsifier, had an improved bioavailability for Pekin ducks than fats without PreE based on dietary EE utilization. Therefore, this study was conducted to investigate the effects of the supplemented mode of emulsifier (PreE vs. emulsifier direct supplementation) on the growth performance, serum biochemical index, quality of meat and skin fat, and nutrient utilization in Pekin ducks. A total of 640 healthy 10-day-old Pekin male ducks (408.65 ± 12.00 g) were randomly allocated into 4 treatments with 16 replicates of 10 birds each. The 4 dietary treatments were as follows: the positive control group (PC; the oil supplemented amount of 6%), the negative control group (NC; the oil supplemented amount of 5.4%), the emulsifier group (E; NC diet with an emulsifier added directly), and the oil pre-emulsification group (PreE; NC diet with oil PreE). The results showed reducing the amount of fat in the diet (NC vs. PC) significantly decreased growth performance and quality of skin fat, and affected serum lipid metabolism (P < 0.05). Interestingly, the body weight (BW), body weight gain (BWG), and the shear force of skin fat were increased, but the feed to gain ratio (F/G) was markedly decreased in the PreE group (P < 0.05) compared to those in the NC group, and these levels were similar to those in the PC group (P > 0.05). Additionally, the utilization of dietary dry matter (DM), ether extract (EE), and total phosphorous (TP) were increased, but the activity of aspartate aminotransferase (AST) in serum was decreased in the PreE group compared to those in the NC group (P < 0.05). Furthermore, compared to the E group, the F/G was decreased (P < 0.05), and the utilization of dietary EE, the shear force of skin fat and content of collagen in skin fat were markedly increased (P < 0.05) in the PreE group. However, no differences were observed (P > 0.05) in growth performance between the group administered a direct supplementation of emulsifier and the control groups (PC and NC). These results indicate that the negative effect of reducing the oil supplementation amount (-0.6%) in the diet can be restored by supplementation with emulsifier, especially by oil with PreE., Competing Interests: DISCLOSURES None of the authors have any conflicts of interest to declare., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

This study aimed to investigate the effect of a high-fat diet on the growth performance, serum, liver, and skin lipid metabolism as well as the fatty acids composition of liver and skin fat in Pekin ducks from 10 to 40 d of age based on a pair-fed group. Two hundred forty healthy male ducks (10 d old, 470.53 ± 0.57 g) were randomly divided into 3 groups (8 replicates per cage of 10 ducks): a normal diet (ND, 3% fat), a high-fat diet (HFD, 9% fat), and a pair-fed diet (PFD, given the ND in an amount equal to that consumed of the HFD to eliminate the effects of feed intake). The results were as follows: compared to ND feeding, HFD feeding significantly decreased (P < 0.05) the feed intake and feed:gain ratio (F:G), along with serum triglyceride and nonesterified fatty acid contents. When compared with the ND and PFD, the HFD significantly decreased (P < 0.05) the liver weight and inhibited hepatic de novo lipogenesis (glucose-6-phosphate dehydrogenase and malate dehydrogenase activities), β-oxidation (carnitine palmitoyltransferase-1 content), and decreased saturated fatty acids and monounsaturated fatty acids deposition. Moreover, the HFD significantly increased (P < 0.05) the total fat content, lipid droplet area, and polyunsaturated fatty acids (PUFAs) content in the liver, as well as the abdominal fat weight, subcutaneous fat weight, the total fat and PUFAs content in skin fat. These results suggested that the HFD improved feed efficiency, which was related to HFD feeding inhibiting hepatic de novo lipogenesis and β-oxidation and promoting the deposition of fat in skin as well as altering the fatty acids composition of the liver and skin fat in Pekin ducks., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

The study aimed to investigate the effects of dietary distillers dried grains with solubles (DDGS) levels on growth performance, carcass characteristic, serum biochemical indexes, meat physical and chemical quality, nutrient utilization, and standardized ileal digestibility of amino acids (SIDAA) in Pekin ducks aged 11 to 42 d based on the evaluation of its SIDAA. A total of 560 eleven-day-old Cherry Valley ducks were randomly allotted to 5 treatments with 7 replicate pens per treatment and 16 ducks per pen based on the average body weight. Six isonitrogenous and isocaloric experimental diets were formulated on a digestible amino acid basis to produce diets containing 0, 5, 10, 15, and 20% DDGS, respectively. With increasing of dietary DDGS levels, a linear and quadratic reduction (P < 0.05) was observed in the body weight (BW) at d 42, average day gain (ADG) and average day feed intake (ADFI) from d 11 to 42, breast meat yield, the moisture and protein content in the breast meat, and dietary DM and EE utilization. Moreover, a linear and quadratic increase (P < 0.05) was observed in the b* value of the breast meat and serum total cholesterol and triglyceride concentrations. Compared with the control group, the group with 10% inclusion of DDGS exhibited no adverse effect on growth performance, carcass characteristics, serum biochemical indexes, meat physical and chemical quality, nutrient utilization, and the SIDAA of the diets (P > 0.05). These results suggested that 10% of corn DDGS can function as an alternative ingredient to corn and soybean meal, and the optimal levels of DDGS in the diets of ducks aged from 11 to 42 d depends more on its quality., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

The study aimed to determine the ileal phosphorus (P) digestibility (iPD) and the excreta P retention (ePR) of 5 monodicalcium phosphate (MCP) samples and 3 dicalcium phosphate (DCP) samples in broiler chickens and in Pekin ducks using the substitution method. A total of 720, 21-d-old Arbor Acres broiler chickens in experiment 1 and 720, 15-d-old Pekin ducks in experiment 2 were randomly allocated to 9 dietary treatments with 8 replicate cages (10 birds/cage) based on the similar mean body weight, respectively. The collection of excreta (for 72 h after a 3-d acclimation) and ileal digesta (after 6 d of feeding experimental diets) was done. The results showed the average iPD/ePR of MCP and DCP for broilers were 83.11%/74.52% and 75.34%/69.46% and for ducks were 79.37%/80.02% and 75.74%/76.44%, respectively. The iPD/ePR of MCP in broilers and the ePR of MCP in ducks were markedly higher (P < 0.05) than those of DCP. Our data suggest that using the substitution method to evaluate the bioavailability of feed phosphates has its own advantages; MCP has higher biological availability than DCP for broilers and ducks., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

The study aimed to investigate the effects of dietary corn germ meal (CGM) levels on growth performance, carcass characteristic, serum biochemical indexes, meat physical and chemical quality, and standardized ileal digestibility of amino acids (SIDAA) in Pekin ducks from 10 to 42 d of age. A total of 420 ten-day-old Cherry Valley ducks were randomly allotted to 5 treatments with 6 replicate cages per treatment and 14 ducks per cages based on mean body weight. Five isonitrogenous and isocaloric experimental diets were formulated on a digestible amino acid basis to produce diets containing 0, 3, 6, 9, or 12% CGM. Results showed: 1) Compared with other groups, ducks fed 12% CGM significantly increased (P < 0.05) the feed to gain ratio. 2) Dietary CGM levels had no effect (P > 0.05) on the carcass traits and breast meat physical quality; but the content of crude protein presented a linear decrease (P < 0.05) in breast meat with increasing dietary CGM levels. 3) Serum biochemical indices (e.g., alanine aminotransferase, aspartate aminotransferase, glucose, high density lipoprotein cholesterol, total cholesterol, triglyceride, total protein, and urea) showed no significant differences among all groups (P > 0.05). 4) The levels of CGM had no significant effect on SIDAA of diets (P > 0.05), except for cysteine which showed a quadratic increase (P < 0.05). These results suggested that the optimal levels of CGM in diets for meat duck aged from 10 to 42 d should be below 9% based on feed to gain ratio and the content of crude protein in breast meat., (Copyright © 2022. Published by Elsevier Inc.)

This study was conducted to investigate the effect of different varieties of rapeseed meal (RSM) with different concentrations of glucosinolates (Gls) and erucic acid (EA) on performance and egg quality of laying ducks. A total of 576 twenty eight-wk-old laying ducks were randomly allocated to 4 treatments. Each treatment had 8 replicates of 18 laying ducks raised in 6 adjacent cages with 3 laying ducks per cage. The control diet was corn soybean meal based without RSM. Three varieties of RSM varying in Gls concentrations were supplemented to the base diet at 10% by substituting soybean meal to formulate the three RSM diets. The experiment lasted 12 wk. Diets with 10% RSM decreased average egg weight (P < 0.01) and feed intake (P = 0.07) compared with the control diet, but there was no significant difference in laying performance among the 3 RSM diets. RSM increased color value (P < 0.05) and crude protein (CP) content (P < 0.05) of yolk compared with the control diet, but had no significant effects on the other egg quality indexes including eggshell strength, albumen height, Haugh unit, and the composition ratio of eggshell, albumen and yolk. RSM decreased total monounsaturated fatty acids (MUFA) (P < 0.01) and increased total polyunsaturated fatty acids (PUFA) (P < 0.01) of yolk, but total saturated fatty acids (SFA) proportions and UFA/SFA ratio of egg yolk were not significantly affected by RSM. RSM increased deposition of trimethylamine (TMA) and 5-vinyl-1,3-oxazolidine-2-thione (5-VOT) in yolk (P < 0.01); moreover, the high Gls RSM increased deposition of TMA (P < 0.01) and 5-VOT in yolk (P < 0.01) compared with the RSM varieties low in Gls. These results suggested that dietary inclusion of 10% RSM decreased egg weight of laying ducks, and affected yolk quality especially yolk color, fatty acid profile, CP, TMA, and 5-VOT content of yolk. Moreover, RSM with higher Gls concentration resulted in higher deposition of TMA and 5-VOT in egg yolk., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

It has been shown that enzyme-treated plant protein can increase performance and promote intestinal health, and save dietary protein. However, our understanding of the effects of enzyme-treated soy protein on performance and intestine function in laying hens, and its rational use, remains limited. The experiment was conducted to study the effect of enzyme-treated soy protein (ETSP) in different nutrient density diets on performance, egg quality, digestive enzyme activity and mRNA expression of amino acid transporters of laying hens. A total of 1 200 Lohmann laying hens (52 wk of age) was randomly divided into a 3 × 2 factorial design that included three nutrient levels: [positive control (PC), metabolisable energy (ME): 2 680 kcal/kg, CP: 15.5%; negative control 1 (NC1), ME: 2 630 kcal/kg, CP: 15%; negative control 2 (NC2), ME:2 580 kcal/kg, CP: 14.5%] and 2 ETSP levels (0 and 0.5%) for 12 weeks. Each treatment had 10 replicates with 20 birds. With the decrease of dietary nutrition density, egg production rate (P = 0.07) and feed conversion ratio (FCR) (P = 0.06) were reduced. Yolk colour was decreased, and yolk index was increased. Supplemented ETSP improved FCR (P = 0.05) and qualified egg rate (P < 0.05). The mass loss rate of egg was decreased after storage for 30 days (P < 0.05). An interaction between nutrient density and ETSP was observed on albumen height and Haugh unit (P < 0.05), and the effects were most noticeable in hens fed 0.5% ETSP in NC2 group. An increase in the activity of trypsin in duodenum (P < 0.05) and the relative expressions of jejunum peptide transporter 1 (PepT1) (P < 0.05) and B 0 system neutral amino acid transport carrier (B 0 AT) mRNA (P < 0.01) was observed during ETSP supplementation. The nutrient density and ETSP supplementation had no significant effect on microbiota in the cecal contents. Overall, the results in this study indicated that the ME decreased 100 kcal/kg and CP decreased 1% in diet of laying hens had a decreasing trend on production performance, no effects on enzyme activity, amino acid transporter mRNA, and gut microbiota, whereas 0.5% ETSP can increase activity of trypsin, PepT1 and B 0 AT mRNA relative expressions, and improve FCR, qualified egg rate., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Two trials were designed to investigate the impacts of egg storage time and maternal dietary vitamin E (VE) supplementation on the growth performance and antioxidant capacity of progeny chicks. In total 512 Ross 308 broiler breeder hens (71-wk-old) were assigned to 2 dietary VE treatments (6 and 100 mg/kg) for 14 wk. Progeny chicks used in trials 1 and 2 were originated from eggs laid at week 10 (stored 0 d) and week 8 (stored 14 d), and week 14 (stored 0 d) and week 12 (stored 14 d), respectively. The 4 groups in trial 1 consisted of 2 levels of maternal VE (6 and 100 mg/kg) and 2 egg storage time (0 and 14 d). The 8 groups in trial 2 consisted of 2 levels of maternal VE (6 and 100 mg/kg), 2 egg storage time (0 and 14 d) and progeny sex (male and female). In trial 1, egg storage decreased the body weight, the liver total superoxide dismutase and total antioxidant capacity of 21-day-old offspring (P < 0.05), and the body weight gain and feed intake from 8 to 21 d and 1 to 21 d (P < 0.05); and increased the serum and liver malonaldehyde (MDA) of 7-day-old offspring and the ratio of feed: gain (F/G) from 1 to 7 d (P < 0.05). Maternal VE (100 vs. 6 mg/kg) decreased the F/G from 1 to 7 d and increased the serum total superoxide dismutase of 21-day-old offspring (P < 0.05). In trial 2, egg storage decreased the body weight of 42-day-old offspring, and the body weight gain and feed intake from 22 to 42 d and 1 to 42 d (P < 0.05); and increased the serum and liver MDA of 21- and 42-day-old offspring (P < 0.05). Maternal VE (100 vs. 6 mg/kg) reduced the serum MDA of 7-day-old offspring (P < 0.05). Interactively, maternal VE (100 vs. 6 mg/kg) reduced the serum MDA of offspring originated from stored eggs (P < 0.05), but not for that of offspring originated from unstored eggs in the two trials. It can be concluded that egg storage (14 vs. 0 d) decreased the growth performance and antioxidant capacity of offspring, while maternal dietary VE (100 vs. 6 mg/kg) supplementation could partly alleviate the reduction of antioxidant capacity (except for growth performance) of offspring induced by egg storage for the early phase post-hatch., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

This study investigated whether dietary resistant potato starch (RPS) inclusion could ameliorate the negative impact of a low nonphytate phosphorus (nPP) diet on growth performance, feather growth, feather follicles (FF) development, and carcass traits by improving nutrient utilization and cecal microbiome fermentation capacity in Pekin ducks. The experiment was performed with a 2 × 2 randomized block design with 2 levels of RPS (0 or 12%) and 2 levels of nPP (low or normal, low: 0.22% at 1-14 d and 0.18% at 15-35 d of age; normal: 0.40% at 1-14 d and 0.35% at 15-35 d of age) for a total of 4 treatments, each with 8 replicate pens per treatment of 12 birds per pen. As regards growth performance and carcass traits, RPS inclusion markedly increased (P < 0.05) BW of 14 and 35 d, BWG and FI of 1-14 d, 15-35 d, and 1-35 d as well as abdominal fat and breast meat percentage of 35 d in ducks fed low nPP diets; moreover, RSP inclusion significantly reduced (P < 0.05) mortality in ducks fed low nPP diets. As regards feather growth and follicles development of 35 d, RPS inclusion significantly increased (P < 0.05) the fourth primary feather length, absolute feather weight, and the density of primary FF in the back skin in ducks fed low nPP diets. In regard to nutrition utilization, RPS supplementation significantly increased (P < 0.05) the availability of DM, CP, and energy, as well as dietary AME at 35 d of age in ducks fed low nPP diets. However, RPS supplementation had no effect (P > 0.05) on the concentration of cecal short-chain fatty acids and the activities of cecal phytase and cellulase in ducks fed low nPP diets. These results indicate that RPS can improve nutrient availability to ameliorate the negative effects on performance and feather development caused by a low nPP diet in Pekin ducks., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

The objective of this study was to investigate the effects of low-protein diets with low digestibility of feed ingredients on intestinal damage and to explore whether the protease supplementation can alleviate the damage in Pekin ducks. A total of 576 Pekin ducklings (6 replicate pens, 16 ducks/pen) were randomly assigned to 6 dietary treatments (3 × 2 factorial arrangement) in a randomized complete block design. Factors were CP levels (13.5%, 15.5%, and 17.5%) and protease (0 or 20,000U/kg). Compared with the diets containing 17.5% CP, low-protein diets (13.5% CP) showed suppressed (P < 0.05) growth performance and feed intake (FI); reduced (P < 0.05) serum-free arginine, isoleucine, leucine, methionine, phenylalanine, valine, and proline as well as the cecal acetate and propionate concentration; increased (P < 0.05) plasma and ileal mucosal tumor necrosis factor-α (TNF-α) concentration; and downregulated (P < 0.05) mRNA expression of TNF-α, nuclear transcription factor-κb, interferon gamma, and Occludin in ileal mucosa. Irrespective of the dietary CP levels, protease supplementation significantly increased (P < 0.05) the serum-free glutamic acid concentration while decreasing (P < 0.05) the plasma endotoxin, IL-6, and the cecal isovalerate concentration. A significant interactive effect was observed between low-protein diets and protease supplementation (P < 0.05) on serum-free arginine concentration, the ratio of ileal villus height to crypt depth, and the IL-6 concentration in ileal mucosa. These results indicated that low-protein diets could damage intestinal integrity to induce systemic inflammation response and at last to suppress growth performance. Protease supplementation could partly attenuate the negative effects on gut health caused by low-protein diets in Pekin ducks., (Copyright © 2020. Published by Elsevier Inc.)