Optimizing the dietary calcium (Ca) level is essential to maximize the eggshell quality, egg production and bone formation in poultry. This study aimed to establish the Ca requirements of egg-type duck breeders from 23 to 57 weeks of age on egg production, eggshell, incubation, tibial, plasma and ovary-related indices, as well as the expression of matrix protein-related genes. Totally, 450 Longyan duck breeders aged 21 weeks of age were allotted randomly into five treatments, each with six replicates of 15 individually caged birds. The data collection started from 23 weeks of age and continued over the following 35 weeks. The five groups corresponded to five dietary treatments containing either 2.8%, 3.2%, 3.6%, 4.0% or 4.4% Ca. The tested dietary Ca levels increased (linear, P <0.01) egg production and egg mass, and linearly improved (P <0.01) the feed conversion ratio (FCR). Increasing the dietary Ca levels from 2.8% to 4.4% increased (P <0.01) the eggshell thickness and eggshell content. The tested Ca levels showed a quadratic effect on eggshell thickness and ovarian weight (P <0.01); the highest values were obtained with the Ca levels 4.0% and 3.6%, respectively. Dietary Ca levels affected the small yellow follicles (SYF) number and SYF weight/ovarian weight, and the linear response (P <0.01) was significant vis-à-vis SYF number. In addition, dietary Ca levels increased (P <0.05) the tibial dry weight, breaking strength, mineral density and ash content. Plasma and tibial phosphorus concentration exhibited a quadratic (P <0.01) response to dietary Ca levels. Plasma calcitonin concentration linearly (P <0.01) increased as dietary Ca levels increased. The relative expression of carbonic anhydrase 2 in the uterus rose (P <0.01) with the increment of dietary Ca levels, and the highest value was obtained with 3.2% Ca. In conclusion, Longyan duck breeders fed a diet with 4.0% Ca had superior eggshell and tibial quality, while those fed a diet with 3.6% Ca had the heaviest ovarian weights. The regression model indicated that the dietary Ca levels 3.86%, 3.48% and 4.00% are optimal levels to obtain maximum eggshell thickness, ovarian weight and tibial mineral density, respectively.

This study was aimed at estimating the dietary manganese (Mn) requirement for laying duck breeders. A total of 504 Longyan duck breeders (body weight: 1.20 ± 0.02 kg) aged 17 wk were randomly allocated to 6 treatments. The birds were fed with a basal diet (Mn, 17.5 mg/kg) or diets supplemented with 20, 40, 80, 120, or 160 mg/kg of Mn (as MnSO₄·H₂O) for 18 wk. Each treatment had 6 replicates of 14 ducks each. As a result of this study, dietary Mn supplementation did not affect the productive performance of laying duck breeders in the early laying period (17–18 wk), but affected egg production, egg mass, and feed conversion ratio (FCR) from 19 to 34 wk (P < 0.05), and there was a linear and quadratic effect of supplement level (P < 0.05). The proportion of preovulatory ovarian follicles increased (P < 0.01) linearly and quadratically, and atretic follicles (weight and percentage) decreased (P < 0.05) quadratically with dietary Mn supplementation. The density and breaking strength of tibias increased (quadratic; P < 0.05), the calcium content of tibias decreased (linear, quadratic; P < 0.01), and Mn content increased (linear, quadratic; P < 0.001) with increase in Mn. The addition of Mn had a quadratic effect on serum contents of estradiol, prolactin, progesterone, luteinizing hormone, and follicle-stimulating hormone (P < 0.001). Dietary Mn supplementation decreased serum contents of total protein (linear, P < 0.05), glucose (quadratic, P < 0.05), total bilirubin, triglycerides, total cholesterol, low-density lipoprotein cholesterol, and calcium (linear, quadratic; P < 0.05). The serum total antioxidant capacity and total and Mn-containing superoxide dismutase activities increased (linear, quadratic; P < 0.001), and malondialdehyde content decreased (linear, quadratic; P < 0.001) in response to Mn supplemental levels. The dietary Mn requirements, in milligram per kilogram for a basal diet containing 17.5 mg/kg of Mn, for Longyan duck breeders from 19 to 34 wk of age were estimated to be 84.2 for optimizing egg production, 85.8 for egg mass, and 95.0 for FCR. Overall, dietary Mn supplementation, up to 160 mg/kg of feed, affected productive performance, tibial characteristics, and serum biochemical and antioxidant status of layer duck breeders. Supplementing this basal diet (17.5 mg/kg of Mn) with 85 to 95 mg/kg of additional Mn was adequate for laying duck breeders during the laying period.

This study evaluated the effects of barley inclusion and glucanase supplementation on the productive
performance and digestive function in laying ducks. The experiment used a randomized design with a
5
2 factorial arrangement of 5 graded levels of barley (0%, 15%, 30%, 45% and 60%) with or without 1.5 g/
kg b-1,3-1,4-glucanase (15,000 U/kg). During the experimental period of 120 d, the weight and total
number of eggs within each pen were recorded daily, and egg quality was determined every 4 wk. At the
end of the experiment, 3 randomly selected ducks within each replicate were sacrificed, then duodenal
digesta and jejunal mucosa was collected. Dietary inclusion of barley had no effects on egg production,
daily egg mass or FCR, but supplementation with glucanase improved egg production and FCR (P < 0.01).
Barley did not affect feed intake of laying ducks, but glucanase tended to increase feed intake (P ¼ 0.09).
Neither barley nor b-glucanase had effects on the egg quality variables, except for yolk color score, which
was decreased with increasing barley supplementation. Glucanase, but not barley, increased the activity
of chymotrypsin and amylase in duodenal digesta. Barley inclusion affected the activity of alkaline
phosphatase and maltase in jejunal mucosa (P < 0.05), but b-glucanase had no effects on the activity of
these brush border enzymes. Barley inclusion increased the glucan content in duodenal digesta, but
supplementation of glucanase to barley-based diet reduced digesta glucan content and reduced total
volatile fatty acids and increased the proportion of acetic acid in cecal contents. The results indicate that,
without glucanase, the optimal dietary barley level in the diets of laying ducks is about 13% for maximal
production performance; glucanase supplementation of the barley diets improved production performance,
probably through enhancing digestive function.
 

This study investigated dietary supplementation with Bacillus subtilis (BS) ATCC19659 on growth performance, biochemical indices, intestinal morphology, and cecum microflora in broiler chicks. A total of 600 Arbor 1-day Acres broilers of either sex were allotted to 5 treatments: chicks were fed a corn- and soybean-based diet (CON); chicks were fed basal diet containing 500 mg ZnB/kg (ZnB); chicks were fed basal diet containing 1 × 10⁸ CFU/g feed of BS-ATCC19659 (BS-1); chicks were fed basal diet containing 3 × 10⁸ CFU/g feed of BS-ATCC19659 (BS-3); and chicks were fed basal diet containing 5 × 10⁸ CFU/g feed of BS-ATCC19659 (BS-5). Each treatment comprised 6 replicates with 20 birds for each replicate pen. Chicks in the BS-5 and BS-3 groups had higher body weight at the 21^st and 42^nd days and average daily gain from 1 to 21 days than that in the CON group (p < 0.05). Chicks in the BS-5 and ZnB groups had higher serum antioxidant activities and immunity response than those in the CON group (p < 0.05). Compared with the CON group, the liver mRNA abundance of GHR, TGF-β, IGF-1, IFN-γ, SOD, CAT, and GPX of chicks in three BS groups and the ileum villus length (μm) of chicks in BS-3 and ZnB groups was increased (p < 0.05). Compared with the CON group, the villus height-to-crypt depth ratio of the ileum of chicks in the BS-5 and BS-3 groups and the crypt depth and villus height-to-crypt depth ratio of the jejunum in the BS-5 and ZnB groups were increased (p < 0.05). The abundance of the Cyanobacteria phyla in the cecum decreased in response to treatment with both BS-ATCC19659 and ZnB groups (p < 0.05). Compared with the CON group, the cecum abundance of genera GCA-900066575 (Lachnospiraceae), Anaerofustis, and Papillibacter (Firmicutes phylum) in three BS groups were increased (p < 0.05); The abundance of genus Escherichia–Shigella reduced in the BS-3 group (p < 0.05). Compared with the CON group, the cecum abundance of genus Clostridia_unclassified in ZnB and BS-5 groups was decreased (p < 0.05) of broilers. Generally, Bacillus subtilis ATCC19659 as feed additive positively affected growth performance, immunity response, and cecal microflora of broilers.

High-energy diets improve growth rates and shorten the growth period while resulting in excessive fat deposition in the liver of birds. The effect of different energy diets on lipid content and liver transcriptome in finisher Huxu chickens was examined here. A total of 200 90-d-old Huxu chickens with an average BW of 1.08 kg were randomly divided into two dietary treatments. The birds were fed diets either containing 12.06 MJ ME/kg (low metabolic energy, LME) or 13.31 MJ ME/kg (high metabolic energy, HME) for 45 days. Chickens fed the HME diet had significantly higher total triglyceride and total cholesterol concentrations in both plasma and liver than did those fed the LME diet. Transcriptomic profiling showed 480 known differentially expressed genes (DEG), with 180 down-regulated and 300 up-regulated chickens from the HME diet compared with the LME diet. Notably, these genes were mostly enriched in lipid metabolism including the PPAR signalling pathway, fatty acid elongation, and glycerophospholipid metabolism. The relative mRNA expression level of 14 lipid metabolism-related genes, included 13 up-regulated (MBOAT2, PLA2G2E, AGPAT2, AGPAT3, PCYT2, PEMT, ELOVL2, HADHA, ACOT1L, FABP3, FABP1, PLIN1, RXRG) and one down-regulated (LCAT) gene. In conclusion, the present findings indicate that a high-energy diet likely regulates gene expression of the 14 lipid metabolism-related genes through the PPAR signalling pathway, fatty acid elongation, and glycerophospholipid metabolism resulting in excessive fat accumulation in the liver of Huxu chickens. These results provide a better understanding of the biological mechanisms by which the increased dietary energy induces fat accumulation in the liver.

There is an urgent need to evaluate and introduce alternatives for the unsustainable and traditional feed
stuffs in poultry. This study evaluated the effects of graded replacement of soybean meal (SBM) by peanut
meal (PNM) on egg production, egg quality, oxidative status, and yolk fatty acid profile in laying ducks. In
total, 360 Longyan ducks aged 21 weeks were allocated to five treatments, each containing six replicates
of 12 birds. Birds were fed the diets containing PNM replacing 0 (control), 25, 50, 75 or 100% of SBM for
16 weeks. With the increase of PNM level, egg production was improved (quadratic, P < 0.05), egg weight
and feed consumption were decreased, feed conversion ratio and egg mass were impaired at 100% PNM,
and yolk colour was enhanced (quadratic, P < 0.05). Plasma malondialdehyde concentration was
increased at 100% PNM, while plasma glutathione concentration was decreased (quadratic, P < 0.01) as
PNM substitution increased. Total cholesterol content in yolk decreased (P < 0.01) in response to
increased PNM substitution. The contents of saturated fatty acids C20:0 and C22:0 in yolk increased (linear
or quadratic, P < 0.05) with increased PNM substitution, but the contents of saturated fatty acid C18:0,
monounsaturated fatty acid C22:1, and polyunsaturated fatty acids C18:3n-3 and C22:6n-3 in yolk were
decreased (linear, P < 0.05) as PNM replacement increased. The contents in yolk of polyunsaturated fatty
acid C18:2n-6, C20:2n-6, C20:3n-6, C20:4n-6, and total amount of polyunsaturated fatty acids increased
with the highest contents obtained at 75% PNM substitution. The ratio between n-6 and n-3 increased
(linear, P < 0.05) as PNM substitution increased. The transcript abundance in liver of peroxisome
proliferators-activated receptors c and fatty acid synthase showed quadratic (P < 0.05) responses with
PNM replacement, with the highest expression of both genes being obtained with 75% substitution with
PNM. Replacement of dietary SBM with 100% PNM decreased egg production and antioxidant capacity
and increased the ratio of omega fatty acid in yolk between n-6 and n-3 in laying ducks. The obtained
results indicate that PNM can be used to replace up to 75% of SBM in the diet of laying ducks without
negative effects on the egg-laying production or egg quality. The regression model indicated that the
maximal egg mass was obtained at no more than 67.6% replacement of SBM with PNM in the diet of laying
ducks.

This study was designed to evaluate the effects of different dietary levels of cassava starch extraction residue meal (CReM) on egg production, egg quality, oxidative status, egg yolk fatty acid profile, and hepatic expression of fatty acid metabolism-related genes. In total, 288 Longyan laying ducks aged 21 wk with similar BW were randomly assigned to 4 dietary treatments, each consisting of 6 replicates of 12 birds. The birds were fed a typical corn-soybean meal diet, which contained 0% (control), 5%, 10%, and 15% CReM, mainly replacing wheat bran, and the experiment lasted for 16 wk. The tested CReM levels did not show significant effects on the egg production, nonmarketable egg percentage, egg weight, daily egg mass, and FCR (g feed: g egg), but daily feed intake was reduced with increased CReM level (linear P < 0.001, quadratic P < 0.05). Yolk color increased (linear and quadratic, P < 0.01) with the increase in CReM level, but the Haugh unit, yolk proportion, albumen proportion, shell proportion, eggshell thickness, and eggshell strength were unaffected. Yolk contents of C11:0 and C12:0 (linear, quadratic, P < 0.01) and total saturated fatty acids increased, and the C22:1 level decreased (linear P < 0.01, quadratic P < 0.05) with the increase in CReM level, but the total monounsaturated fatty acids, the individual and total polyunsaturated fatty acids and n−6 and n−3 fatty acids, triglycerides, and total cholesterol in egg yolk were not affected. Hepatic gene expression revealed a significant increase in peroxisome proliferators-activated receptors γ (linear, quadratic, P < 0.001), but the expression of fatty acid synthase, sterol regulatory element binding protein 1 and apolipoprotein A1 genes were unaffected by CReM level. In conclusion, the results of the current study indicated that the CReM could be included up to 15% in laying duck diets without negative effects on the egg-laying rate, egg quality, and oxidative status. Dietary inclusion of CReM increased the yolk content of total saturated fatty acids and SOD activity in the liver.

Abstract: Wheat is one of the most important sources of food worldwide. A selection index helps in making selection decisions and permits the exploitation of information on correlated traits to improve yields. Two cycles of pedigree selection based on the desired-genetic-gain selection index were  imposed to identify the best index to isolate promising lines. The base population was composed of 120 families of bread wheat in the F6 generation. Eight combinations were constructed from six traits, i.e., days to heading (DH), number of spikes/plant (NS/P), grain yield/plant (GY/P), number of grains/spike (NG/S), mean spike weight (MSW) and mean grain weight (GW). The narrow-sense
heritability of NS/P, NG/S, MSW and GW increased from cycle 1 to cycle 2, revealing an increase in the observed gain and homogeneity of the selected families for these traits from cycle to cycle. After the second cycle, the observed gain in GY/P ranged from 9.5 to 23.75% of the mid-parent. The best index for improving GY/P was index 2 (composed of GY/P, NS/P, NG/S, MSW and GW). The indices involving DH were inferior for improving GY/P. The desired-genetic-gain index was efficient in simultaneously improving several involved traits and was a good method to preserve genetic variability. Furthermore, six superior promising families were identified.
Keywords: Triticum aestivum L.; selection index; narrow-sense heritability; observed genetic gain;
crop breeding

Abstract: Two cycles of pedigree selection for grain yield/plant (GY/P) and grain weight (GW) (100-grain weight) were imposed under drought stress and normal irrigation to study the direct and indirect selection of GY/P and GW in bread wheat. The selection started in the F6-generation (Cycle0-C0) of bread wheat (Triticum aestivum L.) traced back to the cross (Giza 164/Sids 4) of two Egyptian cultivars. The narrow sense heritability was higher under drought than under normal irrigation and increased by selection. Under drought, the observed direct gain after two cycles of selection for GW was 21.51% (p  0.01), and accompanied with an indirect gain in GY/P of 15.52%. The observed direct gain for GY/P was 17.98% and the indirect gain in GW was 13.81%. Under normal irrigation, the observed direct gain for GW was 12.86% and the indirect gain for GY/P was 16.04%. The direct gain in GY/P was 16.04% and the indirect gain in GW was 11.95%. The genotypic
correlations were different in both environments before and after selection. Single trait selection was effective in improving the selection criterion, and selection greatly affected gene associations Keywords: pedigree selection; Triticum aestivum; drought stress; heritability; genotypic correlation; observed gain

Abstract: Sesame (Sesamum indicum L.), the Queen of oilseeds, is infected with different pathogens,restricting its yield. Fusarium oxysporum f. sp. sesami is the most destructive disease of sesame worldwide, causing economic losses. This work aimed to develop new high-yielding strains, resistant and/or tolerant to Fusarium. Two cycles of pedigree selection were achieved under infection of Fusarium oxysporum f. sp. sesami. Two populations in the F2 (600 plants each) were used. The selection criteria were five single traits and another three restricted by yield. The restricted selection was better
in preserving variability than the single trait selection. The observed genetic gain in percentage from the mid-parent in the F4-generation was significant for the eight selection criteria. Single trait selection proved to be an effective method for improving the selection criterion, but it caused deleterious effects on the other correlated traits in most cases. The seed yield increased by 30.67% and 20.31% from the better parent in the first and second populations, respectively. The infection% was significantly reduced by 24.04% in the first, and 9.3% in the second, population. The selection index improved seed yield, and its attributes can be recommended.
Keywords: pedigree selection; restricted selection; observed genetic gain; heritability