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.

The present study was conducted to evaluate the effects of dietary addition of capsaicin (CAP) on egg production performance, follicular development and ovarian antioxidant capacity in laying ducks. Three hundred and seventy eight 58-week-old laying ducks were randomly divided into three treatments, each treatment was consisted of 6 replicates, with 12 individually caged laying ducks per replicate. Ducks fed a basal diet served as control, the other two groups of ducks were fed the same diet containing 150 mg/kg CAP, but in the manner of feed restriction (pair-fed) or ad libitum ad libitum fed. The experiment lasted for 8 weeks. The results showed that the dietary supplementation with capsaicin under condition of free intake increased feed intake (P 0.001), and tended (P 0.1) to increase egg production and egg weight in laying ducks, but had no effects on daily egg mass and feed conversion ratio. The relative weight of large yellow follicles from the two CAP-supplemented groups at 64 wk of age were significantly higher than that of controls (P = 0.01). The relative weight of the small yellow follicles in the CAP free-fed group was significantly higher than that of the other two groups (P 0.01). CAP supplementation under ad libutum fed conditions tended to increase the number of dominant follicles in laying ducks (P = 0.06). The ovarian mRNA expression of TRPV4, ATP2A2, ITPR1, and CaM in the CAP ad libitum fed groups were significantly higher than those of the other two groups (P 0.05). The ovarian mRNA expression of CDK1 in CAP free-fed ducks was significantly higher than that of the other two groups (P = 0.01). CAP supplementation significantly increased the plasma Gpx activity (P 0.01) in comparison to the control group, but reduced the MDA content in the ovaries of laying ducks (P 0.01). The results of this study indicates that dietary supplementation of CAP increased feed intake and improved egg production performance probably by activating calcium signaling pathway and improving redox status.

The multiscale structural, physicochemical, and digestible properties of potato starch before and after heat–moisture treatment were investigated, and further compared between repeated heat–moisture treatment (RHMT) and continuous heat–moisture treatment (CHMT). After heat–moisture treatment, there appeared partial disruption and pits on the starch granules, and the birefringence edges of HMT starch particles became blurred. Besides, the molecular weight of samples conspicuously decreased after two kinds of treatments. The crystal type of HMT starches transformed from B‐type to C‐type according to X‐ray analysis. A decrease in the solubility and swelling power in high temperatures were identified. The pasting temperature, the gelatinization transition temperature (To, Tp, Tc), and the slowly digestible starch (SDS) content of HMT starches were significantly higher than native potato starch, while the peak viscosity, the trough viscosity, the final viscosity, the breakdown, and the gelatinization enthalpy (ΔH) of RHMT and CHMT potato starches decreased compared to the native. RHMT potato starches displayed significantly higher relative crystallinity degree and gelatinization transition temperatures. The cooling process of RHMT in which the linkage between the recombinant amylose/amylopectin was enhanced compared with CHMT, which contributed to that RHMT potato starches exhibited greater advantages in practical applications.

Naked barley grains were germinated at 25 °C for 12, 24, and 36 h, followed by hot air and infrared drying. Changes in structural, physicochemical, and functional properties of naked barley flour and starch after germination and drying were evaluated. Germinated and dried flour showed loose structure in starch granules surface. Germination and drying enhanced bulk density and water solubility of flour, while oil absorption capacity decreased. Treated barley starch showed greater water holding capacity, viscosity, and gelatinization temperature than those of native ones, and the maximum increase in water holding capacity of germinated barley was 20.25% of the native ones. Moreover, molecular weight, amylopectin long chains, and crystallinity of treated starch decreased, and the maximum decrease in the crystallinity of germinated barley was 78.36% of the native ones. Generally, germination for 24 and 36 h by infrared drying induced significant changes of flour and starch compared with hot air drying ones. Therefore, the combination of germination and infrared drying can be suggested as a promising method for modifying the properties of naked barley flour and starch to promote their application in the food industry.

Three distyryl-containing compounds, namely, 2-((cyanomethyl)thio)-4,6-distyrylnicotinonitrile (2), 3-amino-4,6-distyrylthieno[2,3- b]pyridine-2-carbonitrile (3) and 2-((2-cyanoethyl)thio)-4,6-distyrylnicotinonitrile (4) have been prepared and characterized by elemental and spectroscopic analyses. The three compounds contain the pyridine moiety and are considered neonicotinoids analogues. Because neonicotinoids were considered the most effective pesticides, the biological activity of the distyryl-containing compounds as potential insecticides against cowpea aphid, Aphis craccivora Koch was evaluated. The agricultural bioactivity results of these compounds showed that the insecticidal activity varied from good to moderate against cowpea aphid insects.

Three distyryl-containing compounds, namely, 2-((cyanomethyl)thio)-4,6-distyrylnicotinonitrile (2), 3-amino-4,6-distyrylthieno[2,3- b]pyridine-2-carbonitrile (3) and 2-((2-cyanoethyl)thio)-4,6-distyrylnicotinonitrile (4) have been prepared and characterized by elemental and spectroscopic analyses. The three compounds contain the pyridine moiety and are considered neonicotinoids analogues. Because neonicotinoids were considered the most effective pesticides, the biological activity of the distyryl-containing compounds as potential insecticides against cowpea aphid, Aphis craccivora Koch was evaluated. The agricultural bioactivity results of these compounds showed that the insecticidal activity varied from good to moderate against cowpea aphid insects.

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