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911.
Bu Naishun Wu Siqi Yang Xiao Sun Yuyang Chen Zhonglin Ma Xiping Song Youtao Ma Fang Yan Zhuojun 《Journal of Soils and Sediments》2019,19(2):579-587
Journal of Soils and Sediments - Wetlands are the largest natural sources of atmospheric methane (CH4) and are often susceptible to plant invasion and hydrological fluctuations. However, the effect... 相似文献
912.
Aijing Chen Xingbiao Liu Cunhe Cui Chenghui Yang Yuyu Wang Xianyong Bu Yuhong Yang 《Aquaculture Nutrition》2019,25(1):215-224
This study evaluated the effect and phosphorus equivalency value of dietary microbial phytase based on growth performance and nutrient utilization of Channel catfish (Ictalurus punctatus). An all plant‐protein basal diet containing 7.9 g/kg total Phosphorus (P) (Phytate P of 4.5 g/kg) was supplemented with graded levels 0, 300, 500, 1,000, 1,500 and 2,000 U phytase/kg of diet or with 3, 5, 8, 12 g/kg of Ca(H2PO4)2, namely with 0.7, 1.2, 2.0, 3.09 g/kg P as Ca(H2PO4)2. Triplicate groups of Channel catfish (Ictalurus punctatus) juveniles (initial weight, 1.70 ± 0.04 g) were fed the experiment diets for 90 days. The results indicated that dietary phytase supplementation significantly improved growth performance, apparent digestibility coefficient of P and P retention, and decreased feed conversion ratio (FCR), faecal P content and P excretion per gain. Line relation was found between the effects of P and phytase supplementation levels, and the linear response equations of the effects of P and phytase levels were generated and used to calculate the P equivalency values. The average function of P equivalency values (Y, g/kg) of microbial phytase (X, U/kg of diet) was developed: Y = 0.1695 + 0.0021X; R2 = 0.996. The results showed that about 0.38 g of P/kg diet was released by per 100 U of phytase over the range of 300–2,000 U of phytase/kg diet for Channel catfish (Ictalurus punctatus) fed all plant‐protein diet. 相似文献
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He Li Xiufeng Li Yang Xu Hualong Liu Mingliang He Xiaojie Tian Zhenyu Wang Xiuju Wu Qingyun Bu Jie Yang 《水稻科学》2020,27(6):445-448
917.
宜机收玉米新品种‘LT5918’选育报告及栽培技术 总被引：1，自引：0，他引：1
玉米机械化粒收减少了收获过程中的人工剥除苞叶和脱粒晾晒环节,大大节省了劳动力成本,对于提高种植玉米的经济效益有着重要意义,但目前适合机械粒收的品种还鲜有报道。本研究以高产、耐密、多抗、宜机械化粒收为选育目标,通过多年多生态区筛选和鉴定,选育出适合山西春播早熟和中晚熟区域种植的宜机械粒收新品种‘LT5918’,并于2018年通过山西省农作物品种审定委员会审定。该品种较对照品种平均产量增产5%以上,且茎秆粗壮、抗倒伏、脱水快、宜机械粒收,为提高玉米机械化收割程度降低劳动成本和保障粮食安全提供材料基础。 相似文献
918.
The increasing number of depleted, overexploited and recovering world marine stocks, together with increasing demand for fish and need for sustainable management of aquatic resources has led to a gradual shift to inland intensive aquaculture with water reuse. Intensive recirculating systems are becoming a rapidly developing sector of aquaculture, with the objectives to increase production and minimize environmental impact. However, transfer of technologies from original sites to locations of different climate is not always successful. The present study evaluates the use of an open recirculating system in a temperate climate. The 3‐year study showed successful production with better fish growth and feed utilization than in a flow‐through facility at the same site, but presented significant issues necessitating changes in technology as well as physical adaptations. A positive effect of the technology with respect to the environment is possible, but systems must be adapted to temperate climatic conditions. 相似文献
919.
Fangquan Yan Bai Xue Liangrong Song Dalecuo Jun Xiao Siyan Ding Xiaofei Hu Dengpan Bu Tianhai Yan 《Animal Science Journal》2016,87(11):1352-1362
This study aimed to determine the net energy requirement of Holstein cows in mid‐lactation under heat stress. Twenty‐five multiparous Holstein cows were randomly allocated to five groups corresponding to five isonitrogenous total mixed rations, with net energy for lactation (NEL) content of 6.15 (NE‐6.15), 6.36 (NE‐6.36), 6.64 (NE‐6.64), 6.95 (NE‐6.95), 7.36 (NE‐7.36) MJ/kg of dry matter (DM), respectively. Throughout the experimental period the average temperature humidity index at 07.00, 14.00 and 22.00 hours was 72.1, 88.7, and 77.6, respectively. DM intake decreased significantly with the elevated dietary NEL concentration. Fat corrected milk increased quadratically, and milk fat content and milk energy (MJ/kg) reached the greatest in the NE‐6.95 group with increasing dietary NEL content. Strong correlations were found between dietary NEL content and: (i) DM intake; (ii) NEL intake; (iii) milk energy (El); (iv) El/metabolizable energy intake (MEI); (v) El/NEL intake, as well as between NEL intake and fat corrected milk yield (FCM). The suitable net energy required for dairy cows producing 1 kg FCM ranged from 5.01 to 5.03 MJ, was concluded from the above‐stated regressions. Correlation between heat production (HP) and MEI could be expressed as: Log (HP) = ?0.4304 + 0.2963*MEI (n = 15, R2 = 0.99, Root Mean Square Error (RMSE) = 0.18). Fasting HP was 0.3712 MJ/kg0.75 when extrapolating MEI to zero. 相似文献
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