Journal of Northeast Agricultural UniversityEnglish Edition最新文献

Mining provides a wealth of mineral raw materials to human beings, while also causes serious damage to environment and ecology. For decades, landscape renovation in mining wastelands has become a multi-disciplinary research focus. However, compared with the developed countries, China has disadvantages of the relevant theoretical researches developing slowly with lacking supporting technology. According to the design principle of “reservation and utilization”, we reviewed and summarized the methods of landscape transformation in mining wastelands, furthermore, using the way of researching successful cases at home and abroad. In lined with the specific circumstances in China, the target of landscape transformation and basic theories as methods of strategy was developed. Finally, the overall thinking and suggestions were put forward for the development of landscape transformation in mining wastelands.

To investigate the effects of Moringa oleifera leaf meal (MOLM) on the performance and haematology of broiler finisher using 120 Cobb chicks of 4 weeks old broiler chicks. The birds were assigned randomly into four dietary treatments containing MOLM at 0, 6%, 8%, and 10% (treatments 1, 2, 3 and 4) inclusion levels, respectively, in a complete randomized design experiment. The effect of the dietary treatments on the growth performance and blood parameters of the broiler finisher was determined. MOLM at a rate of 6% (T2), 8% (T3), and 10% (T4) of the diets (as fed basis) to replace 3.2%, 5.6% and 8.6% of the crude protein (CP) of the control diet. The daily feed, dry matter and CP intake of the chicks fed MOLM diets were higher (p<0.05) than those fed the control diet. Average weight gain (AWG) of birds fed MOLM diets reduced as inclusion levels increases (p<0.05) than those fed the control diet. Chicks fed T2 showed higher (p<0.05) AWG than those on T3 and T4. Feed conversion ratios (FCR, weight gain/g and feed intake) were higher for chicks fed MOLM. MOLM showed minimal deleterious effects in birds. However, birds fed T2 (6%) diets recorded significantly (p<0.05) the highest body weight gain. There were significant differences (p<0.05) among groups in packed cell volume (PVC) of birds. The haemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) counts showed no significant difference (p>0.05) among treatments. The results indicated that at 10% in the diets of broiler finisher chick, MOLM could be substituted with expensive conventional protein sources without any deleterious effects on performance and blood parameters of broiler finisher chicken.

The effects of FSH on the proliferation of sertoli cells of new born calves were studied in order to provide some data for theoretical research and practical use of spermatogenesis in vitro. Different concentrations of FSH (0, 0.01, 0.02, 0.04, and 0.08 IU · mL⁻¹) were taken to treat bovine sertoli cells in vitro culture, the number of sertoli cells and the expression of seven genes were determined at 6, 12 and 24 h after FSH treatments. FSH could significantly promote the proliferation of in vitro cultured sertoli cells. FSH had no significant effects on the expression of CDC25A and could significantly improve the expression of CDC25B. 0.04 IU · mL⁻¹ and 0.08 IU · mL⁻¹ FSH treatments decreased the expression of CDC25C at 12 h. 0.08 IU · mL⁻¹ FSH treatment decreased the expression of CDC25C at 24 h. 0.04 IU · mL⁻¹ FSH could significantly decrease the expression of GSK-3β and improve the expression of β-catenin at 6, 12 and 24 h. 0.02, 0.04 and 0.08 IU · mL⁻¹ FSH treatments enhanced the expressions of CYCLIND1 and C-MYC. In conclusion, FSH promoted the proliferation of sertoli cells and 0.04 IU · mL⁻¹ FSH concentration could significantly promote the proliferation of in vitro cultured sertoli cells. FSH promoted the proliferation of sertoli cells by CDC25B and WNT/β-catenin and CDC25B might be the key regulator to the proliferating rate of sertoli cells of bovine calf.

A method was developed for the simultaneous determination of four kinds of estrogens (hexoestrol, diethylstilbestrol, estrone, and 17-beta-estradiol) in feed by gas chromatography-mass spectrometry (GC-MS). After the sample was extracted by ethyl ether and cleaned-up on HLB phase extraction column, four kinds of estrogens were derived and quantified in gas chromatography-mass spectrometry. The results showed that the linear detectable ranged from 2.5 ng · mL⁻¹ to 250 ng · mL⁻¹ for hexoestrol and from 5 ng · mL⁻¹ to 500 ng · mL⁻¹ for three other estrogens with the correlation coefficients (R²) were no less than 0.990. The recoveries were in the range of 76.34%–96.33% and the relative standard deviation was no more than 22.7%. The limits of quantitation (LOQ) for all analytics were between 10 ug · kg⁻¹ and 20 ug · kg⁻¹. The method was accurate and sensitive and could meet the actual requirements for the analyses of feed samples.

The use of genetically modified organisms (GMOs) as food products becomes more and more widespread. The European Union has implemented a set of very strict procedures for the approval to grow, import and/or utilize GMOs as food or food ingredients. Thus, analytical methods for detection of GMOs are necessary in order to verify compliance with labelling requirements. There are few effective screening methods for processed GM (genetically modified) products. Three anti-herbicide genes (CP4-EPSPS, BAR and PAT) are common exogenous genes used in commercialized transgenic soybean, maize and rice. In the present study, a new SYBR^® Green qPCR screening method was developed to simultaneously detect the three exogenous anti-herbicide genes and one endogenous gene in a run. We tested seven samples of representative processed products (soya lecithin, soya protein powder, chocolate beverage, infant rice cereal, maize protein powder, maize starch, and maize jam) using the developed method, and amplicons of endogenous gene and transgenic fragments were obtained from all the processed products, and the sensitivity was 0.1%. These results indicated that SYBR^® Green qPCR screening method was appropriate for qualitative detection of transgenic soybean, maize and rice in processed products.

Many reviews and evaluations of contract farming and its importance for small-scale farmers in the developing nations have been conducted. While some scholars opined that contractual terms were unfavourable to farmers, others considerd them as being beneficial to them. These contrasting views were not likely to discourage it since it provided encouragement for farmers' involvement in markets. It was therefore worthwhile to investigate previous experiences with the aim of improving on it. This study investigated contract farming entered into by farmers in Delta State of Nigeria and livestock feed companies with the objective of seeking ways to make such contractual agreements beneficial to small-scale farmers. The study utilized convergence of science approach. The study unveiled the constraints experienced by farmers and they included technical and institutional challenges. The technical problem was the planting date, while the institutional problem was the contractual arrangements. It was recommended that all the stakeholders in the contract should converge and negotiate technological adoptions of the improved maize varieties; contract needed to be clearly defined and risks and uncertainties should be parts of the contract; scientific investigations should be carried out to determine the best planting date; and there was need for legislation to particularly protect farmers in contract farming.

In order to deeply study the leaf-stripping principle for corn stalk, the hexagon-enveloping leaf-stripping experimental device was designed. To achieve higher leaf-stripping percent and provide important references for the separation equipment for corn stalk, it is necessary to find out the laws of leaf-stripping of such mechanism and to select the main influencing factors of separation performance from a number of factors. Through the study on hexagon-enveloping leaf-stripping mechanism for corn stalks, the leaf-stripping principle of such mechanism was more clear, and the optimization of structural and kinematic parameters achieved by the experiment whose influencing factors were the four selected ones (feeding speed, rotary speed of leaf-stripping roll, clearance and included angle between two leaf-stripping plates) could be directly applied to the development of efficient rind-pith or leaf-stripping separation for corn stalks.

Sharecropping has been an age long practice from ancient times. Some scholars saw the practice as being exploitative of the tenants, yet it is still being practiced. The reasons behind it continual practice need to be unveiled. This study was therefore conducted to examine the sharecropping contract experience in Delta State, Nigeria. The landlords decided to practice sharecropping as a result of emigration of their household members, farm size and cost of labours, some of them gave age and their primary occupation as factors for their decisions to opt for sharecropping arrangement. The yields were shared on the basis of 60% for the landlord to 40% for the tenant. The landlords provided all the equipment and inputs, while the tenant's carried out all the farm operations. They faced the constraints of stress, but were able to cope with them, because of hospitals and health centres nearby. The result of the test of hypothesis confirmed the reasons given for deciding on sharecropping arrangement. It was concluded that sharecropping was not exploitative. It was recommended that the practice of sharecropping should be encouraged and not diversified into other sources of livelihood should do so.

In this study, two bacilli strains namely S2-3 and S4-5, isolated from Terasi, a traditional fermented seafood product of Indonesia, were studied in terms of their phenotypic and genotypic properties. Both strains are of great interests due to their high proteolytic activity. Initially, they were subjected to morphological determination and a series of biochemical tests. These bacteria were Gram-positive, endospore-forming bacilli. Based on 16S rRNA gene sequence analysis, the identities of the strains S2-3 and S4-5 were confirmed as Bacillus thuringiensis and B. subtilis, respectively. Additionally, the two strains were also evaluated for their antibiogram profiles. It was found that they were susceptible to chloramphenicol, erythromycin, kanamycin, tetracycline and vancomycin and resistant to ampicillin and intermediately susceptible to bacitracin.

Developing production and operation in scales in the major grain producing areas is the direction of the paper. Seizing the opportunity of modern agriculture comprehensive reform in two plains (Songnen Plain and Sanjiang Plain) of Heilongjiang Province and supporting to build a new type of production and management based on the big grain production householding, which plays demonstration and leading roles, have an important strategic position in improving agricultural comprehensive production capacity and ensuring national food security. In this paper, based on the survey data about the big grain production households production operations and analyses of the obstacles in expansion of production in Heilongjiang Province, specific suggestions in supporting the development of the big grain production household were put forward, such as, increasing agricultural production socialized level; perfecting the service system of land transferring; improving financial policies and farmer-friendly policy measures and perfecting the agriculture socialized service system.