Dairy cow reproduction under the influence of heat stress

Dairy farming is vulnerable to global warming and climate change. Improving and maintaining conception rates (CRs) have a paramount importance for the profitability of any dairy enterprise. There is an antagonistic relationship between fertility and milk yield, and intensive selection for milk yield has severely deteriorated reproductive efficiency. Irrespective of geography and husbandry, modern dairy cows experience heat stress (HS) effects leading to fertility declines, but it worsens in tropical climates. The threshold of HS experience among modern dairy cow has lowered, leading to decreased thermal comfort zone. Studies show that this threshold is lower for fertility than for lactation. HS abatement and robustness response to lactation yield lead to negative energy balance, and cow's reproductive requirements remain unfulfilled. The adverse effects of HS commence from developing oocyte throughout later stages and its fertilization competence; the oestrus cycle and oestrus behaviour; the embryo development and implantation; on uterine environment; and even extend towards foetal calf. Even cows can become acyclic under the influence of HS. These harmful effects of HS arise due to hyperthermia, oxidative stress and physiological modifications in the body of dairy cows. Proper assessment of HS and efficient cooling of dairy animals irrespective of their stage of life at farm is the immediate strategy to reduce fertility declines. Other long- and short-term mitigation strategies to reduce fertility declines during HS include feeding care, reducing disease and mastitis rates, using semen from cooled bulls, timed artificial inseminations (AI), allied hormonal interventions and use of embryo transfer technology. Ultimate long-term solution should be well-planned breeding for fertility improvement and HS tolerance.     

Evaluation of efficiency of hemi-nested PCR assay for the detection of ‘Candidatus Liberibacter’ infecting citrus

Journal of Plant Diseases and Protection - The present study reports the development and evaluation of a hemi-nested polymerase chain reaction (hnPCR) assay for the efficient detection of...     

Application of bispyribac‐sodium provides effective weed control in direct‐planted rice on a sandy loam soil

An increasing water crisis, as well as the unavailability and high cost of labor, in Pakistan has forced rice‐growers to plant rice directly into the field. However, severe weed infestation causes disastrous effects on the productivity of this rice system. In this study, three herbicides (pendimethalin, penoxsulam and bispyribac‐sodium) were evaluated for weed control in direct‐planted rice on a sandy loam soil. Weedy check and weed‐free plots were established for comparison. Weed infestation decreased the rice yield by 75.2%. However, the application of herbicides suppressed the weed infestation, with a simultaneous increase in the rice yield. The postemergence application of bispyribac‐sodium was the most effective herbicide in reducing the total weed density and dry weight over the weedy check, followed by penoxsulam and pendimethalin, respectively. Bispyribac‐sodium increased the number of productive tillers, 1000‐grain weight, number of grains per panicle and grain yield over the control, as well as improved the water productivity and economic returns of direct‐planted rice. The weeds' proliferation increased the number of unproductive tillers and decreased the plant height. In conclusion, the postemergence application of bispyribac‐sodium can be used effectively to control weeds, increase water productivity and improve the economic returns and yield of direct‐planted rice on a sandy loam soil in Pakistan.     

Micropropagation and accumulation of essential oils in wild sage (Salvia fruticosa Mill.)

A protocol for in vitro propagation of the wild three-lobed sage (Salvia fruticosa Mill.) (Synonym, Salvia triloba L.) was developed. Shoot tips were excised from in vitro seedlings and established on MS, Nitch and Nitch (NN), or B5 medium. For shoot proliferation, in vitro nodal and apical explants were cultured on MS medium containing 0.25–2 μM 6-benzylaminopurine (BA), 6-furfurylaminopurine (kinetin), or thidiazuron (TDZ). Proliferated microshoots were rooted on MS medium supplemented with 2.7–11.4 μM indole-3-butyric acid (IBA), indole-3-acetic acid (IAA), or α-naphthaleneacetic acid (NAA). Results indicated that shoots established at 100% regardless of media type, however, shoot height, nodes per shoot, and leaf number were highest for explants established on MS medium compared to NN or B5. Number and height of proliferated shoots, nodes per shoot, and leaf number were highest for nodal explants cultured on a medium containing 0.75 μM BA. Microshoots cultured on a medium supplemented with 2.7 μM IBA exhibited the highest rooting percentage compared to those cultured with IAA or NAA. Essential oil composition in microshoots and shoots of greenhouse-grown plants was determined by gas chromatography/mass spectrometry. The major essential oils detected in both plant materials were α-pinene, 1,8-cineole, camphor, and borneol. No α-thujone or β-thujone was detected. The content of essential oils, camphor, and borneol were higher in the microshoots than in shoots of greenhouse-grown plants.     

不同生物质来源生物炭品质的因子分析与综合评价

【目的】建立一套适合生物炭品质评价的方法,探求影响生物炭品质的主要影响因子。【方法】选用8种不同生物质材料,在3种温度下制备并获得24种生物炭材料(Y1～Y24),测定16项相关品质指标,采用隶属函数法对各项指标数据进行转化,采用软件SPSS19.0进行因子分析,采用四次方最大旋转法获得因子载荷矩阵,计算样品每个公因子分值与相应权重之积的累加和,得到综合评价分值。对16项指标进行相关性分析和因子分析,建立基于因子分析的生物炭品质的综合评价体系,并根据综合评价得分对生物炭进行优良度排序。【结果】24种生物炭16个品质指标经因子分析,提取了5个特征根1的公因子,累计方差贡献率达到77.910%,第1公因子以C含量、阳离子交换量(CEC)和pH贡献率较大,达到31.090%,第2公因子以比表面积和孔容贡献率较大,达到19.878%,第3公因子以H原子含量贡献率较大,达到12.819%,第4公因子以磷、钾含量贡献率较大,达到7.479%,第5公因子以NH4+-N吸附量贡献率较大,达到6.643%。【结论】因子分析方法可以作为评价生物炭品质的方法,根据因子分析评价方法,确定影响生物炭品质最关键的因子是化学性质因子(C含量、C/N比、C/H比、pH、CEC)、物理性质因子(比表面积和孔容)、活化能量因子(H原子含量)、营养因子(P和K含量)和氨态氮吸附能力因子。     

Rhizoctonia seedling disease of hemp and its control

Rhizoctonia solani Kuhn was isolated from hemp (Hibiscus cannabinus) seedlings affected by damping-off disease. The fungus was highly pathogenic on artificial inoculation. There is no earlier record of this disease in Iraq. Of nine fungicides tested as seed treatment, Bavistin (carbendazim), Homai (thiram), Vitavax (carboxin), Topsin (thiophanate), Fundazol and Benlate (benomyl) gave effective control of the disease.     

Adrenal-testis interaction in the stallion.

The authors describe the short and long term effects of synthetic adrenocorticotrophin and of cortisol on peripheral plasma testosterone concentrations in 2 stallions. A single injection of either hormone temporarily raised plasma testosterone concentrations but repeated injection (twice daily for 5 days) depressed plasma testosterone concentrations. Cessation of treatment was followed by a rise in plasma testosterone to concentrations higher than those in the pretreatment period. These findings are briefly discussed.     

Adsorption Kinetics of Acid Red on Activated Carbon Web Prepared from Acrylic Fibrous Waste

In this work, activated carbon (AC) web was prepared using physical activation under the layer of charcoal in high temperature furnace. The carbonization of acrylic fibrous waste was performed at different temperatures (800 °C, 1000 °C, and 1200 °C) with heating rate of 300 °C/h and at different holding time. At 1200 °C, the heating rate of 300 °C/h and no holding time provided better results of surface area as compared to carbonization at 800 °C and 1000 °C. The activated carbon web (AC) prepared at 1200 °C was used for removal of Acid Red 27 dye from aqueous media by varying different parameters like initial concentration of dye, stirring speed, adsorbent dosage, and pH. The results were evaluated using non-linear forms of Langmuir and Freundlich isotherms. The Freundlich isotherm was found to describe the results more effectively because of non-homogenous surface of activated carbon web. Further, the kinetics of adsorption was examined using linear and nonlinear forms of pseudo 1st order and pseudo 2nd order.