水稻施用缓释尿素免追肥试验、示范初报

在盘山县对水稻进行缓释尿素和磷、钾肥做基肥一次施入免追肥试验和示范研究,结果表明,缓释尿素可提供水稻整个生育期的氮素供应,该施肥法可确保水稻产量,省工省事,可以大面积推广应用。     

The Effects of Photoperiod Length,Light Intensity,and Feed Energy on Growth Responses and Meat Yield of Broilers

A study was conducted to assess the effects of photoperiod length (constant 23L:1D vs. a photoperiod program going from decreasing to increasing quantity of light), light intensity (bright vs. a dim, reducing intensity), and feed ME levels (low vs. high) on performance and carcass characteristics of female broilers grown to 56 d. Use of a treatment with early decreasing photoperiod followed by an increasing photoperiod reduced feed consumption and subsequent BW early. However, growth compensation occurred and feed consumption and BW were similar across photoperiod treatments by study end. Likewise, reducing light intensity (from 1 to 0.25 fc) stimulated feed consumption and a subsequent BW improvement early, as compared with high-intensity (2 fc) lighting maintained at a constant level. However, the disparity in feed consumption and BW, as influenced by light intensity, did not persist throughout the growing period. Feed conversion was not noticeably affected by photoperiod or light intensity treatments. Minimal effects of lighting were observed for carcass or part yields; however, there appeared to be a subtle substitution effect between leg, wing, and breast yield influenced by lighting program. Birds exposed to the decreasing–increasing photoperiod and dim, reducing light treatments yielded more leg and wing at the expense of breast. Feeding a low ME diet resulted in increased feed consumption and feed conversion. However, birds consuming a low ME diet were more uniform. No effects of treatment on mortality were measured. These data indicate that a decreasing–increasing photoperiod can be used effectively to reduce early growth, yet allow birds to compensate as they approach market age. Low intensity lighting, however, appears to stimulate early feed consumption and growth, although this effect is transitory. Furthermore, the increased feed conversion of birds grown on the low energy diet may make its use less desirable.     

Effect of Metal Ion Adulterant on the Photocatalytic Degradation Properties of TiO2 Photocatalyst

TiO_ 2 photocatalyst can degrade organic pollutant in waste water efficiently. Metal ion-doped TiO_ 2 nanoparticles are prepared with different doping amount by sol-gel method. The prepared sample are evaluated by the photo-catalytic oxidation degradation experiment of methyl orange. The experiment results indicate that the photo-catalytic activities of Cr~(3+)-doped TiO_ 2 are photoactive than bare TiO_ 2, and that in the Cr~(3+)-doped TiO_ 2 system, 1.0% is optimal amount of doping. Furthermore, it is studied that the degradation rate of methyl orange can reach 92% in UV light of 4 hours and 85% in visible light of 6 hours.It can be expected that M~(n+)- TiO_ 2 photocatalyst is widely applied to the degradation of organic pollutant in waste water treatment.     

Tolerance response to water pH in larvae of two marine fish species, gilthead seabream, Sparus aurata (L.) and Senegal sole, Solea senegalensis (Kaup), during development

Gilthead seabream, Sparus aurata (L.) and Senegal sole, Solea senegalensis (Kaup) are two fish of primary importance in Mediterranean aquaculture. In the present study, the larvae of these species were exposed to different rearing‐water pH during 24 h to examine their tolerance. The 24‐h pHL50 values were calculated with low and high pH values at 7, 20 and 32 days after hatching (DAH) in S. senegalensis larvae, and 12, 20 and 52 DAH in S. aurata larvae. Low 24‐h pHL50 values ranged between 4.88 and 5.76, whereas high 24‐h pHL50 values ranged between 8.94 and 9.57 in S. senegalensis larvae. S. aurata larvae showed values of low 24‐h pHL50 that ranged between 4.82 and 5.55, whereas values of high 24‐h pHL50 ranged between 8.66 and 9.26. Both species showed similar tolerance response at all the tested ages. The high 24‐h pHL50 values found were close to pH values that eventually can be reached in the rearing tanks. The pH should be carefully controlled in rearing water during the first development stages of both species.     

鸭疫里氏杆菌生长曲线的测定

采用P L琼脂平板涂布法 ,测定鸭疫里氏杆菌WJ4株 (血清 1型 )、FXb7株 (血清 2型 )在P L肉汤中静置培养和振荡培养情况下的生长曲线。结果表明 ,在P L肉汤中振荡培养时 ,WJ4株培养 10h达生长最高峰 ( 4 7× 10 1 0 CFU mL) ,FXb7株 11h活菌数最高达 ( 4 2× 10 1 0 CFU mL) ;在静置培养时 ,WJ4株培养 2 2h达最高峰 ( 1 8× 10 9CFU mL) ,FXb7株 2 3h可达最高峰 ( 1 3× 10 9CFU mL)。     

雏鸡马立克氏病疫苗免疫后细胞免疫功能的变化

雏鸡用马立克氏病(MD)三价疫苗免疫后,其脾脏和胸腺T淋巴细胞增殖反应比未免疫健康对照雏鸡和以火鸡疱疹病毒(HVT)疫苗免疫的雏鸡显著增强(P<0.05),外周血液T辅助细胞(T_M)和单核细胞数量显著增加(P<0.01或P<0.05);雏鸡HVT疫苗免疫后,脾脏T淋巴细胞增殖反应比未免疫健康对照雏鸡显著增强(P<0.05),而胸腺T淋巴细胞增殖反应虽有增强,外周血液T_M数量虽有增加,但均无统计学显著性差异(P>0.05).     

五种草坪草生态适应性的研究

通过对5种草坪草在不同极限温度、水分和光照条件下的生理反应研究了这几种草坪草的生态适应能力。结果表明，狗牙根和高羊茅有较强的环境适应性，早熟禾、黑麦草和紫羊茅的环境适应性相对较弱。但它们有特殊的生理环境适应性。如普通早熟禾经研究是短日照喜温植物，有较好的耐荫性。     

The effect of eradication of lice on the occurrence of the grain defect light flecks and spots on cattle hides.

The influence of an eradication programme for lice on the prevalence of light flecks and spots on cattle hides was studied in 33 dairy cattle herds during a period of two and a half years. Lice were eradicated from the main group of herds after 9 to 12 months and the quality of the hides before and after treatment was compared. Hides from slaughtered animals were collected during the study period, tanned and examined with special emphasis on the occurrence of the grain damage light flecks and spots. The prevalence of hides without light flecks and spots increased from 24.2% before treatment to 61.6% after treatment. The prevalence of hides free from the damage increased significantly in all examined anatomical regions. The improvement in hide quality was most marked in the shoulders and neck region which corresponded to the major predilection site of cattle lice. The prevalence of hides with light flecks and spots started to decrease in the first period (2-40 days) after eradication. The changes after treatment suggested that most healing process took place over a period of about 4 months. The eradication programme eliminated the seasonal variation in the prevalence of light flecks and spots which was present before treatment.     

Antibody response in sea bass (Dicentrarchus labrax L.) in relation to water temperature and oxygenation

The influence of water temperature and water oxygenation on the specific antibody response was evaluated by indirect ELISA in sea bass (Dicentrarchus labrax L.) immunized against human‐γ‐ globulins emulsified in Freund's complete adjuvant. A higher antibody response was observed in fish reared at 24 and 30 °C, than at 12 and 18 °C. For the fish group reared at 24 °C, the immunological observation was carried out until 300 days after immunization. At the end of this period, fish kept at 24 °C still showed immunological competence, although the antibody response began to decrease significantly from 120 days after the immunization. Fish reared under mild hyperoxia and normoxia conditions had higher antibody responses than fish reared under mild hypoxia conditions. Moreover, at the end of the experimental period of 56 days the antibody response of fish reared under hyperoxia conditions was significantly higher than the immune response detected in fish reared under normoxia and hypoxia conditions.     

Mesangioproliferative Glomerulonephritis in Mink with Encephalitozoonosis

Renal specimens from 6 mink with encephalitozoonosis were studied by light and electron microscopy and immunohistochemistry. The glomeruli of affected kidneys had a mesangioproliferative glomerulonephritis which was characterized by an increase in mesangial cells and matrix in most glomeruli. Some glomeruli were partially or completely sclerosed. There were protein or granular casts in the cortical and medullary tubules. Interstitial nephritis, vasculitis and tubular cysts were found. Electron microscopy demonstrated extensive matrix and increased cellularity in the mesangial areas. Glomeruli showed segmentally thickened or wrinkled capillary basement membranes. Electron dense deposits were found in the glomerular basement membranes and mesangium. Peroxidase-anti-peroxidase immunohistochemistry demonstrated that IgG and IgM positive material was present as granular deposits in the glomerular basement membrane and occasionally in the mesangium.