A feeding trial was performed to assess the effects of dietary raw amaranth (Amaranthus hybridus chlorostachys) grain (RAG), with or without an enzyme blend, on the productive performance, blood biochemistry, and antioxidant status in laying hens. The trial was conducted following a completely randomized design by factorial method, including five levels of RAG (0, 10, 20, 30, and 40%, respectively) and two levels of enzyme blend (0 −E and 0.025 +E %). A total of 960 White Leghorn (Hy-line W-36) laying hens (56 weeks of age) were divided into 10 groups with eight repetitions, including 12 birds. The trial period was ten weeks. Results showed that RAG levels in feed (>10%) led to a significant decrease in blood total cholesterol (TC), but they also significantly decreased feed conversion ratio (FCR) (p ˂ 0.05) as measured by feed intake (FI), hen daily production (HDP), egg weight (EW), and mass (EM), leading to overall worse productivity compared to the control group. On the contrary, the addition of the enzyme blend led to an improvement in the investigated production traits (p ˂ 0.05), with the exception of HDP. The enzyme blend was also capable of recovering productive performance when combined with low concentrations of RAG (10%) (p ˂ 0.05), and RAG × enzyme blend groups showed the lowest values of TC (p ˂ 0.05). Moreover, the interaction effects for atherogenic index (LDL/HDL) indicated a significant and promising reduction in response to the addition of RAG both in the presence and absence of the enzyme blend (p ˂ 0.05), and this additive also significantly reduced levels of egg yolk cholesterol (p ˂ 0.05). In summary, the evidence gathered in this trial showed that dietary RAG had positive effects on egg quality characteristics, leading to the production of low-cholesterol eggs, and, at the same time, it may improve the health status of laying hens. Furthermore, the addition of an enzyme blend allowed feeding up to 10% RAG in the diet, leading to an optimal balance between animal productivity and the beneficial effects of RAG.

The aim of this study was to investigate the influence of dietary supplementation of bovine lactoferrin (bLF) on growth performance, carcass traits, histomorphology of jejunum, immune function and hepatic and splenic gene expression of interferon‐gamma (IFN‐γ) and interleukine‐2 (IL‐2) in broiler chickens. A total of 240 one‐day‐old Ross 308 male broiler chickens were randomly allotted into six dietary treatments with four replicate pens (10 chicks per pen) and fed experimental diet in 3 feeding phases (starter: d 0–10, grower: d 11–24 and finisher: d 25–42). The experimental treatments were (1) corn–soya bean meal‐based basal diet (control), (2–5) basal diet supplemented with 200, 400, 600, 800 mg/kg bLF, respectively, and (6) basal diet supplemented with 200 mg/kg oxytetracycline (OTC). The average body weight gain (ABWG) of broilers fed 800 mg/kg bLF was 8.48% higher than those fed a corn–soybean meal‐based diet during the starter period (d 0–10) (linear effect, p = 0.002; quadratic effect, p = 0.24). Average daily feed intake (ADFI) and the feed conversion ratio (FCR) were not affected (p>0.05) by bLF supplementation. At 42 days of age, the breast meat percentage and carcass yield of broilers fed 800 mg/kg bLF compared with the control group significantly increased by 9.51% and 6.03% respectively (p < 0.05). Compared with the chicks fed the control diet, the chicks fed diets supplemented with bLF had higher villus height, muscle thickness and villus surface area (p > 0.05). Dietary bLF inclusion increased the total immunoglobulin (IgT) titre against sheep red blood cells (SRBCs) antigen (linear effect, p = 0.031; quadratic effect, p = 0.035) and improved the phytohaemagglutinin‐P (PHA‐P)‐skin test of broilers. Compared with the control, bLF enhanced the gene expression of IFN‐γ in spleen (p = 0.048, linear effect, p = 0.009; quadratic effect, p = 0.093) and liver (p = 0.012, linear effect, p = 0.008; quadratic effect, p = 0.01) and IL‐2 expression in spleen (p = 0.021, linear effect, p = 0.026; quadratic effect, p = 0.103). The bLF supplementation had no effect on IL‐2 gene expression in liver (p > 0.05, linear effect, p = 0.213; quadratic effect, p = 0.159). In conclusion, we found that supplementation of broiler diets with 800 mg/kg bLF can improve the growth performance, carcass yield, cell‐mediated and antibody‐mediated immune responses and enhance the IL‐2 and IFN‐γ gene expression of broilers.

Context Selenium (Se) is an essential trace element and plays pivotal roles in poultry nutrition. Aims The present study was designed to compare the impact of dietary supplementation of different sources of Se on growth performance, Se concentration of breast meat, and immune response of broiler chickens. Methods In total, 300 1-day-old as hatched broilers were randomly allocated to six dietary treatments, with five replicates of 10 birds per each. The experimental diets were as follows: (1) corn–soybean meal-based diet supplemented with 0.30 mg/kg of sodium selenite, (2) basal diet supplemented with 0.30 mg/kg of Se-enriched yeast, and (3–6) basal diet supplemented with 0.15, 0.30, 0.90 and 1.50 mg/kg of nano-Se respectively. Humoral immunity was assessed by antibody titer against a 5% sheep red blood-cell suspension and cellular immunity was measured by administration of phytohaemagglutinin-p at 38 days. Key results Results indicated that during the periods from 1 to 10 days, from 11 to 24 days, from 25 to 42 days and from 1 to 42 days, average daily gain, average daily feed intake, and feed conversion ratio did not differ among the treatments (P &gt; 0.05). Assessment of orthogonal contrasts at the whole phase of feeding showed that the average daily gain in the broilers fed organic Se was significantly (P &lt; 0.05) higher than that in those fed inorganic Se, as well as nano-Se in comparison to organic Se; such effects were not observed in earlier feeding stages. Se supplementation significantly increased the Se concentration of breast muscle (P &lt; 0.0001). The birds that received 1.50 mg/kg of diet nano-Se showed higher (P &lt; 0.05) total immunoglobulin and IgG titers in primary and secondary immune responses against sheep erythrocytes respectively. Toe web swelling after 24 h and 48 h of receiving phytohaemagglutinin-p was not affected by Se supplementation (P &gt; 0.05). Conclusions In conclusion, the addition of nano-Se gave better results than did inorganic (sodium selenite) and organic (yeast selenium) forms of Se in performance traits, breast meat Se concentration and antibody response of broilers. Implications Novel elemental nanometer particulates, including nano-Se, exhibit new characteristics and a different mode of actions in comparison with organic and inorganic forms of Se sources in poultry diets. Inclusion of the nano form of Se in broiler diets and study of productive performance, immunity responses and meat quality leads to improve balanced broiler diets formulation in view of Se.

An experiment was carried out to investigate the effect of multi-enzyme in high and low levels of metabolizable energy (13.81 and 11.51 MJ kg -1 diet) on performance and energy utilization of broilers fed wheat-soybean meal diets from 0 to 21 days of age. Result showed that birds fed diets containing 11.51 MJ kg -1 consumed significantly (p < 0.05) more feed than diets containing 13.81 MJ kg -1 , whereas daily gain and feed conversion ratio improved (p < 0.05) when enzyme was added to 11.51 MJ kg -1 diet. There was significant improvement in metabolizable energy, net energy for production, organic and dry matter digestibility in 0-21 when diets supplemented with enzyme (p < 0.05). Addition of enzyme to 11.51 MJ kg -1 containing diet significantly (p < 0.05) reduced heat production of birds in 0-10 d, whereas heat production was not changed in 21 days. Supplementation of 11.51 MJ kg -1 diet with enzyme improved the efficiency of ME use for carcass energy and protein retention of broilers (p < 0.05). Generally, the results of current study demonstrated that addition of enzyme to wheat-soybean diets improved NEp of broiler chickens while MEI was not changed and it seems NEp is a more sensitive energy utilization response criterion to use in evaluating broilers response to enzyme supplementation.

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