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The difference in microbiota was examined for breeders with different egg-laying rates, and the impact of dietary Enterococcus faecium (EF) was also determined in the present study. A total of 256 Arbor Acres broiler breeders (48-wk-old) were used in a 2 × 2 factorial design, which encompassed 2 egg-laying rate levels [average (average egg laying: AP, 80.45 ± 0.91%) and low (lower egg laying: LP, 70.61 ± 1.16%)] and 2 different dietary groups [control (no additive), 6 × 108 cfu/kg EF]. The results showed that the AP breeders presented a lower egg weight, feed conversion ratio, abdominal fat rate, and serum leptin level (P(laying) ≤ 0.05) as well as a higher egg-laying rate (P(laying)

【Objective】 The plum rainy season from May to July in southern China is a period where rice accumulates nutrients. The purpose of this paper is to explore the effects of onset, duration of flooding and recession of waterlogging in this period on oxidation resistance and yield of rice in the catchment of Poyang Lake. 【Method】 Pot experiments with Semilate rice as the model plants were conducted when the crop was in the elongation stage. Sediment contents of the surface water was 0 kg/m3 (S0), 0.10 kg/m3(S1) and 0.25 kg/m3 (S2), respectively. For each sediment content, there were two waterlogging treatments with the duration of surface-flooding being 3d (F1) and 6 d (F2) respectively. For each sediment and waterlogging combination, there were two drainages with the duration of the surface water receding being 3 d (D1) and 6 d (D2) respectively. The control was without taking interferences (CK). In each treatment, we measured the SPAD, activity of antioxidant enzymes in the flag leaves and the rice yield. We then analyzed the response of the rice to waterlogging and its associated recession. 【Result】 ①The SPAD decreased with the increase in sediment content, duration of flooding and its recession; it peaked prior to the onset of the drainage. The greatest SPAD fall was in S2+F2+D2, decreasing by 46.20% compared to the CK. ②The activities of SOD and POD, as well as MDA content increased first followed by a decline as the waterlogging recessed; they all peaked prior to the starting of the drainage. ③Waterlogging reduced the 1 000-grain weight and hence the grain yield significantly, compared to the CK (P

【Objective】 Fertilizer applications in paddy soils are prone to leaching and improving irrigation and fertilization to improve water and fertilizer use efficiency is critical to sustaining rice production. Taking nitrogen (N) and phosphorous (P) as an example, this paper investigated how changes in irrigation and fertilization alert N and P migration in soils. 【Method】 The experiment was conducted from June to September 2019 in the lysimeters at the Zhanghe Irrigation District, Hubei Province. We compared continuous flooding irrigation (CF) and alternating wet and dry irrigation (AWD). For each irrigation there were two fertilizations: conventional fertilization (N1) and fertilization using slow-release fertilizers (N2). In each treatment, we measured the changes in nitrogen (N) and phosphorus (P) at different soil depths. 【Result】 The concentration of total nitrogen (TN), nitrate-nitrogen (NO3--N) and ammonium nitrogen (NH+ 4-N) in the top 0~25 cm of soil was higher under N1 than under N2. W1+N2 increased TN and NH+ 4-N concentrations significantly (P

The design ability of composite structures brings large-scale design variables, which makes it difficult to optimize structures by traditional methods, the optimization design of composite laminates is also one of the key problems. From the perspective of engineering design, multiple models are arranged for laying optimization, based on the design of composite super-ply variable definition, considering the overall engineering design constraints to sizing optimization, automatic strength checking process with the laying sequence library to optimize the laying sequence, forming a set of optimization design method of composite structure with three levels of laying optimization, initial size optimization and detailed laying optimization. Taking the structural design of composite vertical tail box of an aircraft as an example, this method is used to optimize the design of composite vertical tail box. The results show that: the three-level optimization design method proposed in this paper is a general method applicable to the optimization design of aeronautical composite structures. It reduces the weight of the structure and shortens the development cycle.