Dietary threonine requirement of fingerling Indian major carp,Labeo rohita (Hamilton)

An 8‐week feeding experiment was conducted in a water flow‐through system (26–28 °C) to determine the dietary threonine requirement of fingerling Labeo rohita (3.90±0.03 cm; 0.58±0.02 g). Growth, feed utilization and body composition of fish fed test diets (40% crude protein; 17.9 kJ g^?1 gross energy) with graded levels of l ‐threonine (0.75%, 1.0%, 1.25%, 1.50%, 1.75% and 2.0% dry diet) to apparent satiation were response variables used to assess threonine adequacy. Diets were made isonitrogenous and isoenergetic by adjusting the levels of glycine and dextrin. The amino acid profiles of the test diets were formulated to that of 40% whole chicken egg protein except for threonine. The performance of fish fed experimental diets was evaluated using calculated values for weight gain (g fish^?1), feed conversion ratio (FCR), protein efficiency ratio (PER) and protein productive value (PPV) data. Maximum weight gain (g fish^?1) (1.79), lowest FCR (1.39), highest PER (1.76) and PPV (0.33) were recorded at 1.50 g per 100 g dietary threonine. Statistical analysis of weight gain, FCR, PER and PPV data reflected significant differences (P<0.05) among treatments. Except for reduced growth performance in fish fed threonine‐deficient diets, no deficiency signs were noted. Weight gain, FCR, PER and PPV data were also analysed using second‐degree polynomial regression analysis to obtain a more accurate threonine requirement estimate, which was found, using each response variable, to be at 1.70, 1.63, 1.65 and 1.51 g per 100 g of dry diet, corresponding to 4.2, 4.07, 4.12 and 3.77 g per 100 g of dietary protein respectively. Based on the second‐degree polynomial regression analysis of the live weight gain, FCR, PER and PPV data, the optimum dietary level of threonine for fingerling L. rohita was found to be in the range of 1.51–1.70 g per 100 g of the dry diet, corresponding to 3.77–4.2 g per 100 g of dietary protein.     

Detection of Antibodies Against Peste des Petits Ruminants Virus in Sera of Cattle,Camels, Sheep and Goats in Sudan

Detection of antibodies against peste des petits ruminants virus in sera of cattle, camels, sheep and goats in Sudan.     

Morphinandienone alkaloids from Dehaasia longipedicellata

Five morphinoid alkaloids have been isolated from Dehaasia longipedicellata, namely (-) pallidine, a new alkaloid (+) pallidinine (1), (+)-milonine, (-) 8,14-dehydrosalutaridine and (-) sinoacutine.     

番茄对晚疫病的株龄相关抗性及Ph-3的抗性机制

目前已明确番茄抗晚疫病R基因表现明显的株龄相关抗性(Age-related Resistance,ARR),但抗晚疫病QTL的抗性规律尚不明确。以携带抗晚疫病基因Ph-3的栽培种番茄(Solanum lycopersicum)‘CLN2037B’和野生种醋栗番茄(S.pimpinellifolium)‘L3708’以及易感病材料栽培种番茄(S.lycopersicum)‘LA2818’为对照,对含有抗晚疫病QTL的多毛番茄(S.habrochaites)‘LA2099’、‘LA1033’和‘LA1777’是否也存在株龄相关抗性进行了分析。结果表明,携带抗晚疫病QTL的3个材料的6叶期和9叶期植株病情级数均比3叶期明显降低,表明QTL抗性与株龄相关。利用乙烯、水杨酸和茉莉酸素合成或缺失的突变体和病毒诱导基因沉默(Virus Induced Gene Silencing,VIGS)技术,初步明确了乙烯和水杨酸参与6叶期Ph-3基因介导的对晚疫病的抗性,而茉莉酸不参与。     

Agronomic Efficiency of Feldspar,Quartz Silica,and Zeolite as Silicon (Si) Fertilizers in Sandy Soil

ABSTRACT

Partial replacement of synthetic chemical fertilizers by naturally occurring alternatives is environmentally recommended. Feldspars (F), quartz silica (S), and zeolites (Z) are silicon (Si)-rich minerals that may be utilized as Si fertilizers. This study aims to assess the agronomic efficiency (AE) of the mentioned minerals as Si fertilizers and to estimate Si-use efficiency (Si-UE) in sandy soil. A field experiment was carried out (summer seasons of 2016 and 2017) in which F, S, and Z were mixed with surface soil in an application rate 500 mg kg^?1 soil with and without potassium humate (K-H, 2 mg kg^?1 soil). Treatments were distributed in a complete randomized block design (CRBD) with three replicates including control before cultivation of soybean (Glycine max L.). Yield (kg ha^?1) of soybean, available Si (mg kg^?1) in soil and uptake (mg kg^?1) of N, P, K, Cu, Fe, Mn, Zn, and Si by soybean seeds and straw were estimated. The most significant increase was by 67.87% followed by 38.69% was recorded for the S and S K-H treatments, compared to the control. Same treatments showed nonsignificant decrease in the available Si (mg kg^?1) that may refer to partial replenishment of plant available Si (PAS) in soil and avoid significant deficiency. Silica treatments resulted in the most significant increase in the uptake (mg kg^?1 soil) of Si, N, P, K, Cu, Fe, Mn, and Zn by seeds and almost by straw. Silica was more efficient agronomically than feldspar and zeolite. Absorption of more biocompatible Si-organo species may depend on Si source.     

Does silicon and irrigation have impact on drought tolerance mechanism of sorghum?

Silicon absorption by crops in the form of silicic acid confers efficient utilization of available irrigation water by minimizing transpiration losses. In present study, silicon and irrigation effects on sorghum growth dynamics and drought tolerance mechanism were evaluated during 2007-2008. Two sorghum cultivars: PARCSS2 and Johar1 were treated with two levels of silicon (Si₀ = control and Si₂₀₀ = 200 ml l⁻¹ of potassium silicate per kg of soil) and irrigation (W₀ = control, crop lower limit and W₄₀ = 40 mm of water, crop upper limit). The results depicted that silicon absorption led to increased leaf water potential, growth, transpiration, net photosynthetic rate and decreased shoot to root ratio in sorghum cultivars compared to control treatment. It can be concluded that synergistic effect of silicon fertilization with ample irrigation may improve the crop stand under drought and biotic stresses.     

Dietary copper requirement of fingerling Heteropneustes fossilis for formulating copper‐balanced commercial feeds

Dietary copper requirement of Heteropneustes fossilis (6.74 ± 0.03 g) was determined by feeding purified diets containing same protein (400 g/kg) and gross energy (17.89 kJ/g) but different levels of copper for 12 weeks. Graded amount of CuSO₄.5H₂O (0, 1.96, 3.93, 5.89, 7.86, 9.82, 11.79 mg/kg) was supplemented to basal diet to attain desired dietary copper levels (0, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 mg/kg). Analysed dietary copper concentrations were 4.28, 4.63, 5.28, 5.70, 6.19 and 6.69 mg/kg. Absolute weight gain, feed conversion ratio and protein gain improved with the increasing levels of dietary copper up to 5.28 mg/kg. Further inclusion of copper at a level of 5.70 mg/kg did not improve the above parameters. Significantly higher (p < .05) plasma ceruloplasmin, liver copper‐zinc superoxide dismutase, catalase activities and lower thiobarbituric acid reactive substances were evident in fish receiving diets with 5.28 and 5.70 mg/kg copper compared to other groups. Whole body and liver copper concentrations increased significantly (p < .05) with increasing dietary copper levels. Quadratic regression analysis of absolute weight gain, feed conversion ratio, protein gain and broken‐line regression analysis of plasma ceruloplasmin activity and liver TBARS value against the variable dietary copper levels depicted the dietary copper requirements for fingerling H. fossilis in the range of 5.24–5.68 mg/kg.     

Evaluation of feeding rate based on growth,feed conversion,protein gain and carcass quality of fingerling Indian major carp,Catla catla (Hamilton)

The effects of feeding rates on growth, feed conversion, protein deposition and carcass quality of fingerling Catla catla (3.61 ± 0.03 cm; 0.71 ± 0.04 g) were worked out by conducting a 16‐week feeding trial. Fingerlings were fed with a casein‐gelatin‐based purified diet (40% crude protein CP; 14.95 MJ kg^?1 digestible energy; DE) at 1%, 2%, 3%, 4%, 5%, 6% and 7% body weight per day. The absolute weight gain (AWG; 10.50 g fish^?1) and feed conversion ratio (FCR; 1.41) were highest at the feeding rate of 5% body weight per day. However, protein gain (PG; 0.36 g fish^?1) and carcass protein content attained the maximum values at 4% BW day^?1. Quadratic regression analyses of AWG g fish^?1 and PG g fish^?1 at 95% maximum response indicated that these parameters attained the best values at 4.19% and 3.81% BW day^?1. On the basis of the above results it is recommended that the feeding rate in the range of 3.81–4.19% BW day^?1 with a P:E ratio of 26.69–27.74 mg protein MJ^?1 DE is optimum for maximum growth, efficient feed conversion and best carcass quality in fingerling C. catla.     

Dietary methionine requirement of Indian major carp fry,Cirrhinus mrigala (Hamilton) based on growth,feed conversion and nitrogen retention efficiency

This study was aimed at quantifying methionine requirement of Indian major carp fry, Cirrhinus mrigala (2.2 ± 0.2 cm; 0.19 ± 0.02 g) by conducting a 12‐week feeding trial. Casein–gelatine‐based isonitrogenous (40 g 100 g^?1 crude protein) and isoenergetic (15.42 kJ g^?1 DE) amino acid test diets were prepared to contain six levels of l ‐methionine (1.1, 1.3, 1.5, 1.7, 1.9 and 2.1 g 100 g^?1 dry diet) at a fixed level of cysteine (0.85 g 100 g^?1 dry diet) and fed to apparent satiation thrice daily to triplicate groups of fish. When absolute weight gain (g per fish), feed conversion ratio, protein deposition (g per fish) and nitrogen retention efficiency data were subjected to broken‐line and second‐degree polynomial regression analysis, 95% of the plateau of above parameters was achieved at dietary methionine concentrations between 1.60 and 1.69 g 100 g^?1 dry diet or 0.10 to 0.11 g methionine kJ^?1 DE, corresponding to 4.1–4.22 g 100 g^?1 protein or 0.44–0.47 g methionine kJ^?1 DE. Based on these results, dietary methionine requirement of fry C. mrigala is recommended 1.60–1.69 g 100 g^?1 diet or 0.10–0.11 g methionine kJ^?1 DE.     

Dietary protein requirement for fingerling Channa punctatus (Bloch), based on growth, feed conversion, protein retention and biochemical composition

An 8-week feeding trial was conducted in a flow-through system (1–1.5 L min⁻¹) at 27°C to determine dietary protein requirement for Channa punctatus fingerlings (4.58 ± 0.29 g) by feeding six isocaloric diets (18.39 kJ g⁻¹, gross energy). Diets containing graded levels of protein (300, 350, 400, 450, 500 and 550 g kg⁻¹) were fed to triplicate groups of fish to apparent satiation at 09:00 and 16:00 h. Maximum absolute weight gain (AWG; 8.11 g fish⁻¹), specific growth rate (SGR; 1.82%) and best feed conversion ratio (FCR; 1.48) were recorded in fish fed diet containing 450 g kg⁻¹ protein, whereas protein efficiency ratio (PER; 1.52), protein retention efficiency (PRE; 25%), energy retention efficiency (ERE; 78%) and RNA/DNA ratio (3.01) were maximum for the group fed dietary protein at 400 g kg⁻¹. Second-degree polynomial regression analysis of AWG, SGR and FCR data against varying levels of dietary protein yielded optimum dietary protein requirement of fingerling between 462.24 and 476.72 g kg⁻¹, whereas the regression analysis of PER, PRE, ERE and RNA/DNA ratio data showed a lower protein requirement of 438.28–444.43 g kg⁻¹ of the diet. Considering the PER, PRE, ERE and RNA/DNA ratio as more reliable indicators, this protein requirement is recommended for developing quality protein commercial feeds for C. punctatus fingerlings.