Enzyme Immunoassays for the Determination of Ovine LH and FSH

The development of competitive enzyme immunoassays for ovine plasma LH (oLH) and FSH (oFSH) is described. Standards and plasma samples were preincubated with diluted antiserum to oLH or oFSH and the reacted solution (100 μl per well) was transferred to plates previously coated with oLH or oFSH, respectively. The second antibody used was anti‐rabbit IgG horseradish peroxidase. The measuring range was 0.39–50 ng/ml for each hormone and the 50% relative binding sensitivity was 9 ng/ml for oLH. The respective value for oFSH was 3.5 or 34 ng/ml with different hormone and antibody preparations used for the assay. The enzyme immunoassays were used to determine oLH and oFSH levels in plasma from ewes of two breeds during the oestrous cycle. The assays detected the first FSH surge coincident with the LH surge, the second FSH surge about 24 h later and the periodic fluctuations of FSH concentrations during the luteal phase of the oestrous cycle. These enzyme immunoassays are an efficient and economic alternative to the established radioimmunoassays (RIA) for oLH and oFSH.     

The resistance of meat chickens vaccinated by aerosol with a live V4 Newcastle disease virus vaccine in the field to challenge with a velogenic Newcastle disease virus

Meat chickens housed on a commercial broiler farm in Australia were vaccinated once at 10 to 11 days-of-age by aerosol with live V4 Newcastle disease virus (NDV) vaccine. Groups of vaccinated and unvaccinated birds were flown to Malaysia, where they were challenged with a virulent strain of NDV. Survival rates in vaccinated chickens challenged 7, 14, 21 or 31 d after vaccination were 0.47, 0.77, 0.97 and 0.92, respectively. All unvaccinated chickens died due to Newcastle disease (ND) following challenge. Chickens in Australia and Malaysia were bled and the serums tested for haemagglutination-inhibiting (HI) antibody to NDV. Many vaccinated birds with no detectable antibody, and all birds with a log2 titre of 2 or greater, survived challenge. The results showed that this V4 vaccine induced protective immunity in a significant proportion of chickens within 7 d of mass aerosol vaccination. This early immunity occurred in the absence of detectable circulating HI antibody. Non-HI antibody mediated immunity continued to provide protection up to 31 d after vaccination. Almost all vaccinated birds were protected within 3 w of vaccination. It is concluded that the V4 vaccine is efficacious and could be useful during an outbreak of virulent ND in Australia.     

Phosphofructokinase and Malate Dehydrogenase Participate in the In Vitro Maturation of Porcine Oocytes

Oocyte maturation depends on the metabolic activity of cumulus–oocyte complex (COC) that performs nutritive and regulatory functions during this process. In this work, the enzymes [phosphofructokinase (PFK) and malate dehydrogenase (MDH)] were tested to elucidate the metabolic profile of porcine COCs during the in vitro maturation (IVM). Enzymatic activity was expressed in U/COC and U/mg protein (specific activity) as mean ± SEM. In vitro maturation was performed with 2‐oxoglutarate (5, 10 and 20 mm ) or hydroxymalonate (30, 60 and 100 mm ) inhibitors of PFK and MDH, respectively. The PFK and MDH activities (U) remained constant during maturation. For PFK, the U were (2.48 ± 0.23) 10^?5 and (2.54 ± 0.32) 10^?5, and for MDH, the U were (4.72 ± 0.42) 10^?5 and (4.38 ± 0.25) 10^?5 for immature and in vitro matured COCs, respectively. The specific activities were significantly lower after IVM, for PFK (4.29 ± 0.48) 10^?3 and (0.94 ± 0.12) 10^?3, and for MDH (9.08 ± 0.93) 10^?3 and (1.89 ± 0.10) 10^?3 for immature and in vitro matured COCs, respectively. In vitro maturation percentages and enzymatic activity diminished with 20 mm 2‐oxoglutarate or 60 mm hydroxymalonate (p < 0.05). Viability was not affected by any concentration of the inhibitors evaluated. The U remained unchanged during IVM; however, the increase in the total protein content per COC provoked a decrease in the specific activity of both enzymes. Phosphofructokinase and MDH necessary for oocyte IVM would be already present in the immature oocyte. The presence of inhibitors of these enzymes impairs the meiotic maturation. Therefore, the participation of these enzymes in the energy metabolism of the porcine oocyte during IVM is confirmed in this study.     

Multi-criteria decision making methods to address rural land allocation problems: A systematic review

Land allocation has been an important issue in land use planning research studies. Land allocation involves different multifunctional activities of maximizing environmental, economic and social benefits. Multi-criteria decision making (MCDM) method is the most popular tool to optimize land allocation problems by considering decision variables, conflicting objectives, and criteria. Hence, decision-makers face problems on how to optimize the land allocation while minimizing the conflicting trade-offs existing in the decision analysis. With this review study, we aim at identifying and extracting information on MCDM methods to solve land allocation problems from English language articles published between 2000 and 2019 and indexed by four scientific literature databases (Web of Science, Science Direct, Scopus, Google scholar). To this end, we applied a systematic literature review approach, i.e. the Preferred Reporting Items for Systematic Reviews and Meta-Analysis procedure (Moher et al., 2009), with a structured database search expression. 120 articles were selected of which, after careful screening of title, keywords and abstract, 69 were retained for detailed review. This review study report compiles comprehensive information by classifying the papers into application area, optimization objectives, criteria used, decision techniques, publication year and study region. In summary, we found that in the last two decades, the use of the MCDM method has increased, particularly in Europe and China. AHP (analytical hierarchal process) is frequently used for multi-attribute land allocation problems with reference to ecotourism and ecosystem management. LP (linear programming) and SA (simulating annealing) methods are predominantly used to optimize multi-objectives complex agricultural and forest land allocation problems respectively.     

Chronic vascular catheterisation of the koala and the rabbit

SUMMARY: Vascular access ports were surgically placed, first in rabbits maintained under laboratory conditions, and then in koalas maintained in a wildlife park. The ports remained patent for 9 months in rabbits and for up to 13 months in the koalas and were removed successfully. They allowed collection of blood samples without assistance or disturbance in koalas, and without stress as reflected by plasma cortisol concentration. The use of retention rings on the cannula tubing is recommended.     

Clonal and seasonal differences in leaf osmotic potential and organic solutes of five hybrid poplar clones grown under field conditions

Leaf osmotic potential at full turgor (Psi(pio)) and the major solutes that contribute to osmotic potential were characterized in five hybrid poplar clones of Populus trichocarpa Torr. & Gray x P. deltoides Bartr. (TD) and P. deltoides x P. nigra L. (DN), growing under field conditions at two sites in eastern Washington and Oregon, USA. Trees were drip irrigated with 46, 76 or 137 cm of supplemental irrigation during each growing season. Trees at Wallula, WA, which were in their third growing season in 1994, were sampled twice a year for two years (1994 and 1995), and trees at Boardman, OR, which were in their second growing season in 1994, were sampled once a year for three years (1994-1996). At Wallula, the TD and DN clones exhibited lower predawn leaf water potentials in the 46-cm treatment than in the 137-cm treatment (-1.2 versus -0.7 MPa) during a hot, dry period in July 1994. Clone TD had a lower Psi(pio) than Clone DN (-1.67 versus -1.56 MPa) during the same period and the difference was also evident in 1995 (-1.81 versus -1.72 MPa) when trees were in their fourth growing season. There was also a significant treatment effect on Psi(pio) in Clone TD, with trees in the 46-cm treatment having lower Psi(pio) than trees in the 137-cm treatment in July 1994. At Boardman, Psi(pio) was generally high with no treatment differences during the 1994-96 samplings. The TD clones had significantly lower Psi(pio) than the DN clones in 1994 (-1.44 versus -1.36 MPa) and 1996 (-1.72 versus -1.54 MPa), but there was no difference between clones in 1995 (-1.40 versus -1.43 MPa). In 1995, at Wallula, osmotic adjustment in Clone TD was largely accounted for by an increase in sucrose, which constituted 70% of total organic solutes. Although the total concentration of free primary amino acids in this clone was 28% higher in trees in the 46-cm treatment than in trees in the 137-cm treatment, amino acids constituted only a small fraction of the total solute pool. Sixty-two percent of total solutes were inorganic ions in Clone TD compared to 52% in Clone DN, and potassium was the main ion constituting about 30% of total solutes and 50% of total ions. However, the clonal difference in Psi(pio) was not fully accounted for by the difference in solute concentration. Osmotic potential at full turgor declined over the growing season and with age. We conclude that, because the extent of osmotic adjustment exhibited by these clones was small, other drought resistance mechanisms contributed to the clonal differences in field performance.     

Osmotic potential of several hardwood species as affected by manipulation of throughfall precipitation in an upland oak forest during a dry year

Components of dehydration tolerance, including osmotic potential at full turgor (Psi(pio)) and osmotic adjustment (lowering of Psi(pio)), of several deciduous species were investigated in a mature, upland oak forest in eastern Tennessee. Beginning July 1993, the trees were subjected to one of three throughfall precipitation treatments: ambient, ambient minus 33% (dry treatment), and ambient plus 33% (wet treatment). During the dry 1995 growing season, leaf water potentials of all species declined to between -2.5 and -3.1 MPa in the dry treatment. There was considerable variation in Psi(pio) among species (-1.0 to -2.0 MPa). Based on Psi(pio) values, American beech (Fagus grandifolia Ehrh.), dogwood (Cornus florida L.), and sugar maple (Acer saccharum Marsh.) were least dehydration tolerant, red maple (A. rubrum L.) was intermediate in tolerance, and white oak (Quercus alba L.) and chestnut oak (Quercus prinus L.) were most tolerant. During severe drought, overstory chestnut oak and understory dogwood, red maple and chestnut oak displayed osmotic adjustment (-0.12 to -0.20 MPa) in the dry treatment relative to the wet treatment. (No osmotic adjustment was evident in understory red maple and chestnut oak during the previous wet year.) Osmotic potential at full turgor was generally correlated with leaf water potential, with both declining over the growing season, especially in species that displayed osmotic adjustment. However, osmotic adjustment was not restricted to species considered dehydration tolerant; for example, dogwood typically maintained high Psi(pio) and displayed osmotic adjustment to drought, but had the highest mortality rates of the species studied. Understory saplings tended to have higher Psi(pio) than overstory trees when water availability was high, but Psi(pio) of understory trees declined to values observed for overstory trees during severe drought. We conclude that Psi(pio) varies among deciduous hardwood species and is dependent on canopy position and soil water potential in the rooting zone.     

The experimental production of big liver and spleen disease in broiler breeder hens

SUMMARY Big liver and spleen disease (BLS) was reproduced experimentally by intravenous (IV) and oral (PO) administration of BLS inocula to susceptible broiler breeder hens 34 to 36 weeks of age. Serological and pathological signs of BLS similar to those seen in the natural disease occurred in inoculated and in-contact birds. Splenomegaly was the earliest and often the only necropsy finding, with hepatomegaly and kidney enlargement occurring in some birds later in the course of the disease. After IV administration, serum antigen was detected between 2 and 4 weeks, and antibody between 3 and 5 weeks. After PO administration, antigen was detected between 2 and 4 weeks, and antibody between 3 and 6 weeks. Antibody persisted in all birds to the end of the experiment (6 weeks), and horizontal transmission probably occurred since in-contact birds developed BLS. Liver probably contained the highest concentration of BLS agent because it had the highest infectivity.