稻草与牛粪混合腐解的最佳配比筛选

【目的】以腐殖质组成特征为评价依据,筛选稻草与牛粪混合腐解的最佳配比,为两类农业固体废弃物的资源化应用提供参考。【方法】以稻草和牛粪为材料,采用室内培养法,研究稻草与牛粪质量比为10∶0(Rs),9∶1(Rd1),7∶3(Rd2),5∶5(Rd3),3∶7(Rd4),1∶9(Rd5)和0∶10(Dm)混合腐解90 d,各处理水溶性物质(WSS)、可提取腐殖酸(HE)、胡敏酸(HA)、胡敏素(Hu)组分的有机碳含量(依次表述为C_(WSS)、C_(HE)、C_(HA)、C_(Hu)),以及胡敏酸碱溶液E_4/E_6、腐殖化系数(C_(HA)/C_(FA))的动态变化,筛选稻草与牛粪腐解的最佳配比。【结果】与0 d相比,在腐解完成(90 d)后,各处理C_(WSS)含量均有不同程度降低,相比于稻草,牛粪腐解后更易促进微生物对C_(WSS)的利用,使其下降86.2%;Rd2和Rd5处理使物料C_(HE)含量分别增加10.2%和28.6%,其余处理C_(HE)均有不同程度消耗;与0 d相比,腐解完成后,Rd1、Rd3和Dm处理均有助于C_(HA)的积累,其中牛粪腐解更易促进C_(HA)的形成,使其增加30.5%。在各处理下,物料HA分子均先发生降解、脂族化,而后逐渐缩合、芳香化,但HA分子结构仍趋于简单;在促进HA分子脂族化方面,Rd4处理的优势最大,而Dm处理更有利于HA结构的稳定。Rd3处理在促进腐殖质品质方面的贡献最大,其次为Rd1处理,Dm和Rs处理次之,但Rd2和Rd5处理不利于腐殖质品质的改善;Rs、Rd1、Rd2、Rd3和Rd4处理在腐解过程中更有利于C_(Hu)的分解,且Rd3处理的优势最大,使C_(Hu)含量下降91.0%,而牛粪比例≥90%更有助于C_(Hu)的累积。【结论】稻草与牛粪按照质量比5∶5混合腐解,易促进C_(Hu)的分解和C_(HA)的积累,利于腐殖质品质提升。     

High‐oil residue camelina meal,a viable source of protein at low levels in diets for juvenile salmonids

The oilseed Camelina sativa has been studied as a lipid source for farmed salmonids, but recommended inclusion as a protein source has not been determined. This study evaluated low inclusion of camelina high‐oil residue meal (HORM) at 20, 40 and 60 g/kg of the diet, to determine an adequate level for Atlantic salmon parr (Salmo salar) and rainbow trout (Oncorhynchus mykiss). Salmon and trout were fed experimental diets containing up to 60 g/kg HORM for 16 weeks. At 40 g/kg HORM, trout and salmon growth performance were similar to those fed a control diet. However, at 60 g/kg HORM, trout showed lower final weight, weight gain and feed intake than those fed the control diet. Rainbow trout fed 40 and 60 g/kg HORM showed significantly lower whole body ash (p = .005), slightly lower whole body protein levels and higher fat than the control. In salmon fed 60 g/kg HORM diets, whole body ash (p = .024), and the submucosal layer of the intestine was thicker than the control (p = .007). Current results indicate that up to 40 g/kg HORM can be included in diets for rainbow trout and salmon juveniles.     

Comparative survival and growth performance of European lobster Homarus gammarus post‐larva reared on novel feeds

One approach to ongrow juvenile European lobster, Homarus gammarus, is to utilize land based rearing systems, incorporating automated feeding, individual culture and provision of stable pelleted feeds, preferably using sustainable ingredients. We initiated three feeding experiments to investigate the general suitability of ingredients produced from seafood by‐products as novel feeds for H. gammarus, in terms of promoting survival, development and growth of post‐larval lobsters from post‐larvae (PL) stage IV to the first juvenile stage (stage V). The first experiment was designed to screen an array of candidate, locally produced, novel protein sources on growth performance parameters. This initial experiment revealed that PL reared on a raw (i.e. wet, unprocessed shrimp) feed used as a reference showed superior performance to those reared on experimental feeds containing fishmeal, herring protein isolate or mussel meal; however, a novel type of shrimp meal, produced by flocculation from waste water, promoted the best PL performance of any experimental feed. A second experiment was designed to test the effect of drying method and to optimize the form of a wet shrimp reference feed used by lobster hatcheries. This showed that the performance of PL reared on experimental freeze‐dried shrimp feed was not significantly different to those reared on the wet, unprocessed shrimp used as a reference feed. However, lobsters offered experimental oven‐dried shrimp feed (with or without an immune supplement) resulted in significantly lower survival or growth performance. A third and final experiment was designed in an attempt to improve a candidate herring‐based protein source, by supplementing with nutrients found in shrimp. However, the results showed that PL reared on the wet reference shrimp feed still showed superior growth and survival than those reared on a herring feed alone, or supplemented with additives found in shrimp meal (either glucosamine, astaxanthin or both supplements combined). The high survival and growth, low incidence of moulting problems and high availability of waste shrimp material, suggest that non‐heat‐treated shrimp products are a promising feed ingredient for post‐larval European lobsters.     

固态热带假丝酵母菌菌剂的发酵工艺研究

试验在单因素优化试验的基础上,采用正交试验进一步对热带假丝酵母菌固态发酵工艺进行研究,包括发酵时间、接种量、料水比、碳源、氮源、无机盐等因素,最终确定热带假丝酵母菌的固态发酵工艺。发酵条件:在自然pH值条件下,发酵温度30℃、发酵时间48 h、接种量11%、料水比1∶0.75。培养基成分:麸皮与甘油8.5∶1.5 (g/g)、尿素0.5%、磷酸二氢钾0。依照此工艺进行发酵,热带假丝酵母菌活菌数最高可达32.94×10⁸个/g。     

泸沽湖省级自然保护区鱼类物种多样性调查研究

为对泸沽湖省级自然保护区的生物多样性及环境质量做出更好的评估,分别于2016年3月,6月,7月就其鱼类资源特点及其分布格局等开展了3次调查。结果表明,泸沽湖省级自然保护区记录鱼类6目8科15属17种,鲤形目鲤科鱼类种数最为丰富,共9种,占泸沽湖鱼类总种数的52.9%;土著鱼类仅2属4种,分别为泥鳅、厚唇裂腹鱼、宁蒗裂腹鱼、小口裂腹鱼。区系组成与云贵高原湖泊存在共同特点:种类贫乏,个体较小,生长稍慢。泸沽湖鱼类物种多样性匮乏、物种同域分化现象明显、鱼类特有性极强、物种群落脆弱性极高、物种组成自然性偏低。文中提出保护好鱼类产卵场,加强入湖河流的清淤治理,建立保育繁殖基地等保护策略。     

Selection efficiency of high inorganic phosphorus-low stachyose lines from soybean breeding populations of different genetic backgrounds

Reducing the antinutritional components of soybean (Glycine max) seed is necessary for producing animal feed with increased metabolizable energy and nutrient availability. The objective of this study was to evaluate marker-assisted and phenotypic selection for the high inorganic phosphorus (Pi) and low stachyose traits controlled by the Lpa and MIPS1 mutations in six breeding populations. Phenotypic selection for low phytate individuals carrying Lpa mutations using Pi was reliable, but the assay should include parental genotypes to construct thresholds before performing selections, as the effect of Lpa on Pi depends on genetic background. Phenotypic selection for low phytate individuals carrying MIPS1 using Pi should be complemented with sugar data because selection based solely on Pi may be inefficient, as this trait is not environmentally stable in MIPS1 germplasm. Marker-assisted selection for simple sequence repeat (SSR) linked to Lpa2 (Satt527, Satt561) depended on the pedigree of the population suggesting that perfect markers (e.g., single nucleotide polymorphism) should become the molecular tool for screening a large number of progenies with high efficiency.     

Effect of dietary protein content on growth rate,survival and body composition of juvenile cauque river prawn,Macrobrachium americanum (Bate 1868)

We determined the effect of four concentrations of dietary crude protein, 30.7, 37.2, 41.8 and 46.8% on growth rate, survival and body composition of the juvenile cauque river prawn (Macrobrachium americanum). The prawns were hatched in the laboratory from the spawn of one wild ovigerous female. Prawns consuming 37.2% crude protein reached a final weight of 0.58 g (feed conversion ratio of 2.15), which was significantly better than the other treatments. Survival was 100% in all treatments. Protein content in the diets had no significant effect on whole body proximate composition and amino acid profile. Juveniles consuming the 37.2% crude protein diet grew faster than those fed the other diets. Specific growth rate was adjusted to the two‐slope broken‐line regression analysis model to estimate the optimal protein requirement. In conclusion, these results demonstrated that the 37.2% protein level diet is optimal for juvenile cauque river prawn M. americanum in the experimental conditions of this study.     

全豆豆浆与传统豆浆感官品质和营养成分对比

以大豆为原料,通过感官评定对胶体磨技术自制的全豆豆浆和一般机械磨加工的传统豆浆中的永和豆浆和普通豆浆的感官品质进行了比较,通过营养成分检测对全豆豆浆和永和豆浆的营养成分进行了比较,同时将检测的全豆豆浆营养成分与中国食物成分表中的普通豆浆的营养成分进行比较。结果表明:全豆豆浆口感浓厚,细腻爽滑,豆香味浓郁,无豆腥味,感官评价总得分高于传统豆浆中的永和豆浆和普通豆浆,差异有统计学意义(P0.01);全豆豆浆中蛋白质、脂肪、总膳食纤维、维生素B1、维生素B2、钙、磷脂及大豆异黄酮等营养成分含量均高于永和豆浆,更高于普通豆浆。全豆豆浆的普及不仅可以提高豆浆的营养价值,还可以减少资源的浪费,具有一定的社会和经济效益。     

Broodstock conditioning of the Portuguese oyster (Crassostrea angulata,Lamarck, 1819): influence of different diets

The Portuguese oyster Crassostrea angulata shows great potential in oyster farming. The conservation of pure populations of this species is important for production diversification and biodiversity preservation. In this way, the zootechnological development for seed hatchery production is extremely important. Broodstock conditioning is a key step in the process of rearing bivalves in a hatchery. Many factors regulate the reproductive cycle, being food one of the most important ones. To evaluate the effect of different diets on C. angulata reproductive performance, broodstock were conditioned with different food regimes formulated fundamentally by flagellates (Diet 1 – Pavlova lutheri and Isochrysis galbana clone T‐ISO; Diet 2 – P. lutheri, T‐ISO and Skeletonema costatum) and constituted fundamentally by diatoms (Diet 3 – S. costatum and Chaetoceros calcitrans; Diet 4 – P. lutheri, S. costatum and C. calcitrans). During conditioning, samples of oysters were collected to evaluate condition index, gonadal development and biochemical composition. At the end of the conditioning period, oysters were induced to spawn to evaluate reproductive output (fecundity, fertilization rate and D‐larvae development). The diets had an impact on the gametogenesis process, energy storage and reproductive output performance, being the best results those obtained in broodstock fed with the diatoms‐predominant diets. However, those fed with diets majority flagellates had an unsuccessful performance. Holistic approaches incorporating all results in this study reveal and reinforce the idea that the diatom species used presented the nutritional requirements to C. angulata broodstock, being essential in the conditioning phase.     

Effects of dietary protein and lipid levels on growth performance,fatty acid composition and antioxidant‐related gene expressions in juvenile loach Misgurnus anguillicaudatus

Dojo loach (Misgurnus anguillicaudatus) is one of the most important cultured freshwater fish in several East Asian countries. However, a little information is available in its nutritional requirements. Thus, this study was conducted to evaluate the effects of feeding varying levels of dietary protein and lipid on growth, fatty acid composition and antioxidant‐related gene expressions in juvenile loach. Six practical diets at three levels of protein (30%, 40% and 50%) and two levels of lipid (6% and 12%) were fed to loach juveniles (initial weight 0.40 g) in triplicated groups (20 fish per replicated) for a period of 8 weeks. Results showed that regardless of lipid level, body weight gain of fish was significantly increased with incremental dietary protein level. Meanwhile, feed conversion ratio was significantly decreased by dietary protein levels, and the lowest value was observed in fish fed dietary protein levels of 50%, regardless of dietary lipid level. Moreover, the percentage of 22:6n‐3 in viscera was significantly increased by different protein levels. The expression level of catalase was significantly increased with incremental dietary protein level with both lipid levels. Meanwhile, the expression level of hepatic nuclear factor erythroid 2‐related factor 2 (Nrf2) was downregulated with incremental dietary protein level with 6% of lipid level, but the expression was upregulated with incremental dietary protein level with 12% of lipid level. In conclusion, these data suggested that 6% lipid and 50% protein in diet was optimal for loach during early development stage.