A total number of 135 Nile tilapia (O. niloticus) were used to study the effect of dietary supplementation with black cumin seed (Nigella sativa) on growth performance and some blood constituents. The fish were randomly divided into three treatment groups each of 45 fish, and each group was divided into 3 subgroups (15 fish / unit). These groups received N. sativa at 1% (T1) and 2% (T2) and control group (C) which fed on basal diet without N. sativa. Body weight and length were recorded biweekly all over the experimental period (12 weeks). Blood samples from each fish were collected to determine each of hemoglobin (Hb), packed cell volume (PCV%), serum glucose, total protein, albumin, globulin, and alkaline phosphatase. Ten fish were scarified to determine hepatosmatic index (HSI), spleen somatic index (SSI), and gonadosomatic index (GSI). Other ten fish were transported to wet laboratory and reared without oxygen supplementation to determine the resistance under oxygen deficiency. The results showed that there was insignificant increase in body weight, body weight gain, total length, and length increment in T2. Also, the hemoglobin increased insignificantly (P > 0.05) in T2 than the control. Moreover, the serum albumin improved insignificantly (P > 0.05) in T1 and T2 than the control. Serum alkaline phosphatase was significantly (P 0.05) increased in treated fish with N. sativa; while serum glucose decreased significantly (P 0.05) as compared with control ones. The hepatosoatic index (HSI) insignificantly (P > 0.05) decreased in T1 and increased insignificantly (P > 0.05) in T2 compared to the control. Also, the dietary 1 and 2 % N. sativa did not affect spleenosomatic index (SSI). The fish group which reared under oxygen deficiency exhibited remarkable decreased activity and increased random movement elicited by hypoxia changes in direction of swimming, while the fish groups fed diets with N. sativa showed slightly abnormal behavior changes. The mortality rates under oxygen deficiency were 100, 40 and 20% for control, T1 and T2, respectively. Under oxygen deficiency stress, the Hb and glucose did not differ between T1 and T2, while PCV% was increased significantly (P > 0.05) in T2 than that of T1; the same occurred (P 0.05) with serum total protein concentration, globulin, and alkaline phosphatase activity, but serum albumin in T1 was higher than that of T2 (P 0.05). There were no significant (P > 0.05) in HIS, SSI and GSI between treated groups with N. sativa and control ones. To conclude, the dietary supplementation with N. sativa at 1% and 2% displayed slight beneficial effects on growth performance and major effects on some blood constituents of O. niloticus.

A total number of 135 Nile tilapia (O. niloticus) were used to study the effect of dietary supplementation with black cumin seed (Nigella sativa) on growth performance and some blood constituents. The fish were randomly divided into three treatment groups each of 45 fish, and each group was divided into 3 subgroups (15 fish / unit). These groups received N. sativa at 1% (T1) and 2% (T2) and control group (C) which fed on basal diet without N. sativa. Body weight and length were recorded biweekly all over the experimental period (12 weeks). Blood samples from each fish were collected to determine each of hemoglobin (Hb), packed cell volume (PCV%), serum glucose, total protein, albumin, globulin, and alkaline phosphatase. Ten fish were scarified to determine hepatosmatic index (HSI), spleen somatic index (SSI), and gonadosomatic index (GSI). Other ten fish were transported to wet laboratory and reared without oxygen supplementation to determine the resistance under oxygen deficiency. The results showed that there was insignificant increase in body weight, body weight gain, total length, and length increment in T2. Also, the hemoglobin increased insignificantly (P > 0.05) in T2 than the control. Moreover, the serum albumin improved insignificantly (P > 0.05) in T1 and T2 than the control. Serum alkaline phosphatase was significantly (P 0.05) increased in treated fish with N. sativa; while serum glucose decreased significantly (P 0.05) as compared with control ones. The hepatosoatic index (HSI) insignificantly (P > 0.05) decreased in T1 and increased insignificantly (P > 0.05) in T2 compared to the control. Also, the dietary 1 and 2 % N. sativa did not affect spleenosomatic index (SSI). The fish group which reared under oxygen deficiency exhibited remarkable decreased activity and increased random movement elicited by hypoxia changes in direction of swimming, while the fish groups fed diets with N. sativa showed slightly abnormal behavior changes. The mortality rates under oxygen deficiency were 100, 40 and 20% for control, T1 and T2, respectively. Under oxygen deficiency stress, the Hb and glucose did not differ between T1 and T2, while PCV% was increased significantly (P > 0.05) in T2 than that of T1; the same occurred (P 0.05) with serum total protein concentration, globulin, and alkaline phosphatase activity, but serum albumin in T1 was higher than that of T2 (P 0.05). There were no significant (P > 0.05) in HIS, SSI and GSI between treated groups with N. sativa and control ones. To conclude, the dietary supplementation with N. sativa at 1% and 2% displayed slight beneficial effects on growth performance and major effects on some blood constituents of O. niloticus.

The high cost of phosphate fertilizers, as well as pollution with heavy and radioactive elements, motivated us to find clean alternatives for phosphate fertilizers to conserve the environment such as bone char. Also, the groundwater used in the agricultural activity of desert soils is considered to be saline. Therefore, the specific objective of this incubation experiment was to investigate the application of bone char with different levels of water salinity on changes of phosphorus (P) availability and some soil quality indicators of calcareous sandy soil. The results of this study revealed that applying bone char (BC) combined with saline water significantly increased the available P (Olsen-P) in calcareous sandy soil compared to the control (unamended soil) and bone char with distilled water treatment. The P release from bone char increased with increasing water salinity levels. The increase of incubation time results in an increment of Olsen-P concentration at a high level of saline water. Soil pH values declined with the addition of bone char combined with saline water, while the electrical conductivity (EC) of the soil in this study increased gradually with increasing the water salinity level in the presence of bone char. The soluble sulfate (SO42−) increased by applying bone char and saline water. Based on this, we can suggest the use of bone char under the presence of saline water as an alternative to phosphate fertilizer, especially in sustainable agriculture because it is economically and environmentally friendly. The bone char can be a substitute for chemical fertilizers produced from rock phosphate.

Two experiments were carried out to investigate the dietary methionine requirement for fast and slow-growing Chinese yellow-feathered breeds during the starter phase, based on growth variables and regression models. In Experiment 1, a total of 2880 one-day-old Lingnan chicks (fast growing breed) were used to test the methionine requirement from 1 to 21 days of age for males and females separately. Of each gender, 1440 birds were allocated into 6 dietary methionine levels (0.28%, 0.32%, 0.37%, 0.43%, 0.50% and 0.63%), each with 6 pen replicates of 40 chicks. Experiment 2 had the same design with Guangxi chicks (slow growing breed) from 1 to 30 d of age. Results indicated that significant nonlinear or quadratic responses to increasing dietary methionine levels were observed in body weight, daily gain, feed intake and feed conversion ratio of both breeds. In summary, the quadratic polynomial regression showed that the optimal methionine requirements for maximal growth performance of Lingnan chickens were 0.52–0.58% in males, 0.51% in females, and 0.53% in mixed genders. The corresponding values for Guangxi breed were 0.53% in males by quadratic polynomial regression and 0.43% in females, and 0.48% to 0.49% in mixed sexes by exponential asymptotic models.

This study investigated the influence of dietary supplementation with some antibiotic alternatives on growth performance, intestinal barrier, and immunity of lipopolysaccharide (LPS) challenged chicks. Wenshi females, aged 4 days, were allocated randomly into eight groups, each with six replicates of 20 birds (n = 120/treatment), which received a basal diet supplemented with 0 (control), 0 (LPS), 200 mg/kg aureomycin, 50 mg/kg mushroom polysaccharide, 100 mg/kg mushroom polysaccharide, 500 mg/kg nano-copper, 300 mg/kg copper loaded chitosan, and 500 mg/kg lysozyme for 21 days. On day 18 and 20, the control birds were injected with 0.5 mL saline solution, the other treatments were injected with 0.5 mL saline containing 500 µg LPS/kg body weight (BW). The results indicated that LPS treatment reduced the BW, average daily gain (ADG), and daily feed intake (ADFI) than the controls (p 0.05), and the antibiotic and the tested alternatives could not retrieve the normal BW, ADG, and ADFI. The tested additives reduced several negative effects of LPS; they reduced diamine oxidase activity and inflammatory mediators in plasma, jejunal mucosa, spleen and thymus, increased content of immunoglobulin in plasma and jejunal mucosa, and decreased gene expression of inducible nitric oxide synthase and Cyclooxygenase 2 in jejunal mucosa

This study aimed to establish the optimal dietary zinc requirement of Chinese yellow-feathered Lingnan broiler breeders. A total of 576 breeder hens aged 58 weeks were randomly assigned to six treatments, each with 6 replicates of 16 birds (n = 96/treatment). The hens were fed either a basal diet (22.81 mg/kg Zn) or the same basal diet supplemented with additional 24, 48, 72, 96, and 120 mg Zn/kg up to 65 weeks of age. Compared to the results of birds fed the basal diet (22.81 mg Zn/kg), the dietary supplementation with additional Zn (mg/kg) showed higher egg laying rate (at 48–120 mg), EM (at 96 mg/kg), yolk Zn content (at 24–120 mg/kg), fertility (at 48–120 mg/kg), hatchability (at 48–96 mg/kg), tibial breaking strength (at 24–48 mg/kg), tibial ash content (at 48 mg/kg), serum CuZnSOD activity (at 72 mg/kg) and T-AOC (at 48 mg/kg), and ovarian CuZnSOD and GSH-Px activities (at 96–120 mg/kg), and lower FCR (at 96 mg/kg). The regression model showed that the optimal supplemental Zn for maximal egg laying rate, yolk Zn content, fertility, and hatchability of Chinese yellow-feathered broiler breeders aged 58 to 65 weeks were 71.09, 92.34, 94.44 and 98.65 mg/kg diet, respectively.

A dose-response study was conducted to investigate the metabolizable energy (ME) requirement for Lingnan chickens from 9 to 15 weeks of age. One thousand two hundred 8-week-old slow-growing yellow-feathered male chickens were allotted to five dietary ME levels (2805, 2897, 2997, 3095 and 3236 kcal/kg). The results revealed that the daily metabolizable energy intake increased (p 0.01), whereas the feed intake and feed:gain ratio decreased linearly (p 0.01) with the increment in dietary ME level. The final body weight and daily gain of the highest ME treatment tended (p > 0.05) to be greater than those obtained with the lower ME levels. The fat content in breast muscle showed a quadratic response (p 0.05) to the increase in dietary energy level. The shear force values of breast muscle in the 2897, 3095 and 3236 kcal/kg treatments were lower (p 0.05) than those of the 2997 kcal/kg treatment. In conclusion, among the tested ME levels, 3095 kcal/kg was adequate for feed intake, shear force, and plasma uric acid, and 3236 kcal/kg tended to increase the body weight, body gain, and feed conversion ratio of Lingnan males between 9 and 15 weeks of age; further studies are still required for testing higher levels

The fatty acid composition of chicken’s meat is largely influenced by dietary lipids, which are often used as supplements to increase dietary caloric density. The underlying key metabolites and pathways influenced by dietary oils remain poorly known in chickens. The objective of this study was to explore the underlying metabolic mechanisms of how diets supplemented with mixed or a single oil with distinct fatty acid composition influence the fatty acid profile in breast muscle of Qingyuan chickens. Birds were fed a corn-soybean meal diet supplemented with either soybean oil (control, CON) or equal amounts of mixed edible oils (MEO; soybean oil : lard : fish oil : coconut oil = 1 : 1 : 0.5 : 0.5) from 1 to 120 days of age. Growth performance and fatty acid composition of muscle lipids were analysed. LC-MS was applied to investigate the effects of CON v. MEO diets on lipid-related metabolites in the muscle of chickens at day 120. Compared with the CON diet, chickens fed the MEO diet had a lower feed conversion ratio (P 0.05), higher proportions of lauric acid (C12:0), myristic acid (C14:0), palmitoleic acid (C16:1n-7), oleic acid (C18:1n-9), EPA (C20:5n-3) and DHA (C22:6n-3), and a lower linoleic acid (C18:2n-6) content in breast muscle (P 0.05). Muscle metabolome profiling showed that the most differentially abundant metabolites are phospholipids, including phosphatidylcholines (PC) and phosphatidylethanolamines (PE), which enriched the glycerophospholipid metabolism (P 0.05). These key differentially abundant metabolites – PC (14:0/20:4), PC (18:1/14:1), PC (18:0/14:1), PC (18:0/18:4), PC (20:0/18:4), PE (22:0/P-16:0), PE (24:0/20:5), PE (22:2/P-18:1), PE (24:0/18:4) – were closely associated with the contents of C12:0, C14:0, DHA and C18:2n-6 in muscle lipids (P 0.05). The content of glutathione metabolite was higher with MEO than CON diet (P 0.05). Based on these results, it can be concluded that the diet supplemented with MEO reduced the feed conversion ratio, enriched the content of n-3 fatty acids and modified the related metabolites (including PC, PE and glutathione) in breast muscle of chickens.

Ovarian follicle selection is a natural biological process in the pre-ovulatory hierarchy in birds that drives growing follicles to be selected within the ovulatory cycle. Follicle selection in birds is strictly regulated, involving signaling pathways mediated by dietary nutrients, gonadotrophic hormones and paracrine factors. This study aimed to test the hypothesis that dietary Ca may participate in regulating follicle selection in laying ducks through activating the signaling pathway of cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)/extracellular signal-regulated kinase (ERK), possibly mediated by gonadotrophic hormones. Female ducks at 22 weeks of age were initially fed one of two Ca-deficient diets (containing 1.8% or 0.38% Ca) or a Ca-adequate control diet (containing 3.6% Ca) for 67 days (depletion period), then all birds were fed the Ca-adequate diet for an additional 67 days (repletion period). Compared with the Ca-adequate control, ducks fed 0.38% Ca during the depletion period had significantly decreased (P 0.05) numbers of hierarchical follicles and total ovarian weight, which were accompanied by reduced egg production. Plasma concentration of FSH was decreased by the diet containing 1.8% Ca but not by that containing 0.38%. The ovarian content of cAMP was increased with the two Ca-deficient diets, and phosphorylation of PKA and ERK1/2 was increased with 0.38% dietary Ca. Transcripts of ovarian estradiol receptor 2 and luteinizing hormone receptor (LHR) were reduced in the ducks fed the two Ca-deficient diets (P 0.05), while those of the ovarian follicle stimulating hormone receptor (FSHR) were decreased in the ducks fed 0.38% Ca. The transcript abundance of ovary gap junction proteins, A1 and A4, was reduced with the Ca-deficient diets (P 0.05). The down-regulation of gene expression of gap junction proteins and hormone receptors, the increased cAMP content and the suppressed hierarchical follicle numbers were reversed by repletion of dietary Ca. These results indicate that dietary Ca deficiency negatively affects follicle selection of laying ducks, independent of FSH, but probably by activating cAMP/PKA/ERK1/2 signaling pathway.

Pre-slaughter transport exerts negative effects on broilers’ welfare, meat yield, and meat quality, but little is known about the effect of transport on medium-growing broiler chickens. This study aimed at evaluating the effects of different durations of transport (0, 0.5, 1, 2, and 3 h) on stress biomarkers and meat quality of medium-growing Yellow-feathered broiler chickens. One hundred and eighty Chinese Yellow-feathered broilers aged 75 days (marketing age), of 2.02 kg average BW, were allotted into five groups; each group contained six replicates (six birds/replicate (crate)). Each crate with dimensions 74 × 55 × 27 cm (length × width × height) was loaded with six birds, that is, 30 kg live BW/m2 crate. The tested transport durations increased BW loss (linear, P 0.01), plasma concentrations of ACTH (linear, P 0.10), cortisol and corticosterone (quadratic, P 0.05), and activity of glutathione peroxidase (linear, P 0.05), whereas plasma glucose was not affected. In breast muscle, contents of glycogen, lactic acid, malondialdehyde, and reduced glutathione were not affected (P > 0.05), but total antioxidant capacity decreased (linear, P 0.01). The drip loss of breast muscle increased (linear, P 0.01), whereas shear force, pH at 24 h postmortem, and breast meat color lightness (L*), redness (a*), and yellowness (b*) scores were not affected. In conclusion, the tested transport durations (from 0.5 to 3 h) increased BW loss and some plasma stress biomarkers in 75-day-old Yellow-feathered broiler chickens, but the effect on meat quality attributes was minor.