Chemical stratification in the Seneca/Oswego rivers (NY)

The occurrence and characteristics of chemically-based density stratification in portions of the Seneca and Oswego Rivers, downstream of ion-polluted Onondaga Lake, are described for seven different days in the summer and fall of 1978 and 1981, which covered a wide range of river flows. The results indicate that chemically-based density stratification occurs routinely in the Seneca River downstream of the lake inflow, in response to a continuous chemically-based density difference between the two systems of 0.0015 to 0.0030 g cm^?3. The persistence of the phenomenon, and therefore the longitudinal range over which the river stratification occurred, was dependent on the velocity of river flow and the magnitude of the density gradient that bordered the upper river water and the lower released lake water. During the low flows common to summer the stratification extended approximately 14 km downstream to a dam, and 3 km upstream, of the lake outlet — river junction. Vertical mixing between the stratified layers increased as the flow in the Seneca River increased, and as the vertical density gradient decreased. A dimensionless group, $$\frac{D}{{V\left( {\frac{\rho }{{\Delta _\rho /\Delta _z }}} \right)}}$$ where: D = apparent vertical diffusion (m² hr^?1), V = average velocity of the overlying river flow (m hr^?1 ), p = density at the interface between the stratified layers (g cm^?3), and Ap/Az = density gradient between the stratified layers (g cm^?3 m^?1), was found to be constant for summer low flow conditions for a 6.5 km length of the Seneca River, thus quantifying the interaction between vertical mixing and the included influences for that portion of the river. The occurrence of chemical stratification in the river had dramatic implications on the corresponding distribution of dissolved oxygen (DO). The isolation of the organically enriched lake water in the lower layer enhanced the depletion of DO there, which resulted in the development of substantial (> 4.0 mg 1^?1 ) DO stratification downstream of the discharge from the lake during summer low flow periods.     

The first molecular detection of Clostridium perfringens from pneumonic cases associated with foot and mouth disease in cattle and buffalo in Egypt

Tropical Animal Health and Production - Panting syndrome and respiratory infection have been recorded in complicated cases of foot and mouth disease (FMD) in cattle. However, investigations on the...     

Relationship Between Dietary Protein Source and Feeding Frequency During Feeding Nile Tilapia,Oreochromis niloticus (L.) Cultured in Concrete Tanks

ABSTRACT

A 24-week feeding trial was conducted in concrete tanks with Nile tilapia, Oreochromis niloticus (L.) with an average initial weight and length of 50.87 ± 6.03 g and 14.4 ± 0.45 cm, respectively, to examine the effect of two protein sources and two feeding frequencies on growth performance, production traits, and body composition. Twelve 4 m³ concrete tanks (2 × 2 × 1.25 m, long, width, and height) were each stocked with 100 fish and fed diets containing either fish meal protein or soybean meal protein at two feeding frequency of two times daily or four times daily (2 × 2 × 3 factorial experiment). The results revealed that there was no significant effect of dietary protein sources on growth rate, whereas there was a significant increase in growth rate with increasing feeding frequency (P < 0.05). The same trend was also observed for mean body weight (g), production rate (kg/m3), specific growth rate (SGR % day^?1). The best final mean body weight (g), specific growth rate (SGR % day^?1), and production rate (kg/m3) were recorded in groups of fish fed with feeding frequency four times daily. Whole fish moisture, protein, fat, and ash contents were significantly influenced (P ≤ 0.05) by protein sources and feeding frequency, except protein not influenced with feeding frequency. Energy was significantly (P < 0.05) influenced by feeding frequency, but not by dietary protein sources. Economic evaluation indicated that soybean meal (Diet B) at four times feeding daily was the most cost-effective and affordable feed strategy for farmers. We conclude that a soybean diet fed four times daily is recommended for adult Nile tilapia reared in concrete tanks.     

Tissue responses to fractional transient heating with sinusoidal heat flux condition on skin surface

A fractional model of Bioheat equation for describing quantitatively the thermal responses of skin tissue under sinusoidal heat flux conditions on skin surface is given. Laplace transform technique is used to obtain the solution in a closed form. The resulting formulation is applied to one‐dimensional application to investigate the temperature distribution in skin with instantaneous surface heating for different cases. According to the numerical results and its graphs, conclusion about the fractional bioheat transfer equation has been constructed. Sensitivity analysis is performed to explore the thermal effects of various control parameters on tissue temperature. The comparisons are made with the results obtained in the case of the absence of time‐fractional order. © 2016 Japanese Society of Animal Science     

Pregnancy stage and number of fetuses may influence maternal plasma leptin in ewes

Maternal plasma leptin is elevated in ewes during pregnancy. The authors studied whether there was any relation between maternal plasma leptin and insulin concentrations, the number of fetuses and the circulating and faecal levels of gestagens. At the end of the breeding season in January the ovarian activity of Prolific Merino ewes was induced/synchronised with gestagen + eCG treatment. Ewes were inseminated artificially (AI) by laparoscopy. Blood and faecal samples were collected before AI (day 0) and again 41, 81 and 101 days later. The plasma levels of leptin (pL), insulin and progesterone (pP4), and the faecal P4 metabolite (P4-met) content were determined. The day 0 level of pL was significantly higher in pregnant (n = 24) than in non-pregnant ewes (n = 32). By day 41 the pL of pregnant animals had doubled, it showed a further moderate increase on day 81, and decreased slightly thereafter. During pregnancy pP4 and faecal P4-met rose continuously and were positively correlated at all stages. The mean levels of pL and pP4 and the faecal content of P4-met were lower in ewes bearing single (n = 12) than in those with 2 (n = 6) or 3-5 fetuses (n = 6). Analysis of variance demonstrated significant differences according to the number of fetuses in the pL and pP4, but not in P4-met (p = 0.042, 0.044, and 0.051, respectively). Leptin showed positive correlation with insulin before the AI but not during pregnancy. On days 41 and 81 pL showed a slight positive correlation with P4 and P4-met, which decreased slightly by day 101. This study shows that although leptinaemia is affected by the number of fetuses and the level of P4, pregnancy stage is a more important regulator than these additional factors.     

Evaluation of Cluster Bean Meal Cyamposis fefrugonoloba as a Dietary Protein Source for Common Carp Cyprinus carpio L.

Abstract— A12-wk feeding experiment was conducted to study the feasibility of utilizing cluster bean seed meal (CBM) as a replacement for fishmeal in the diets for common carp Cyprnus carpio fingerlings. The replacement levels of cluster bean meal protein in the diets were 25, 50, 75, and 100% of the total fishmeal protein. All diets were isonitrogenous at 33.1% crude protein and isocaloric at 4.8 Kcal/g. There were significant differences in the final individual weights, weight gains, specific growth rates (SGR %/d), feed conversion ratios (FCR), feed efficiency ratio (FER), protein efficiency ratios (PER), and feed intake among fish group ( P × 0.05). Common carp fed the diet containing 50% (CBM) exhibited comparable growth to those fed a fishmeal-based diet. Digestibility of protein, energy and lipid decreased with increasing levels of CBM above 50% of total fishmeal replacement in the diet. Incorporation of CBM in diets significantly affected the dry matter, protein, and energy of whole fish body. These results suggest that CBM can replace 50% of the fishmeal in diet for common carp.     

Soil properties,but not plant nutrients (N,P, K) interact with chemically induced resistance against powdery mildew in barley

Chemically induced resistance is a promising method of plant protection against diseases, which can be triggered by systemically acting chemical inducers such as BTH (benzo(1, 2, 3)thiadiazole‐carbothioic‐acid‐S‐methylester). BTH is commercially distributed as a 50 % formulation, called Bion®. The uncertain success of Bion® application in controlling infection by powdery mildew is a major obstacle in using induced resistance for plant protection in agriculture. This study aimed to investigate the effect of soil properties, selected macronutrients (N, P, and K), and addition of organic matter on induced resistance and to identify possible factors responsible for the high variability of BTH effect under field conditions. A pot experiment under open‐air conditions was set up using the pathosystem Hordeum vulgare cv. Ingrid / Blumeria graminis f. sp. hordei race A6. The different soils strongly affected the resistance of barley plants against powdery mildew after BTH treatment. The infection of barley by powdery mildew was lower than on all other soils when grown on an acid forest soil which was limed up to pH 4.9, even after BTH treatment. A reproducible induction of pathogen resistance by BTH was shown only on a mineral soil (Kleinlinden) with a negligible C content. Application of N, P, and K did not consistently affect the induction of resistance by BTH. The addition of green manure and compost led to an enhanced variability of resistance induction on the soil “Kleinlinden”. Possible effects of soil microflora on resistance induction are discussed.     

Humoral antibody responses to different H5N1 and H5N2 vaccination regimes: implications for the development of autogenously based vaccines

Whereas H5N1 vaccine and several H5N2 vaccines are commercially available and are used to control H5N1 outbreaks in some endemic countries, infections hit many vaccinated flocks. The following study was conducted to compare the efficacy of such vaccines and to assess their potential induction of antibodies against the haemagglutinin of local H5N1 isolate after single vaccination. The possible beneficiary effect of booster dose at different intervals was screened for both H5N1 vaccine as well as a selected H5N2 candidate. Differences in the serological immune response among native and cross breeds were also screened. No significant variations were detected between available commercial H5N1 and H5N2 vaccines after single vaccination. Two vaccination shots using H5N1 but not H5N2 vaccine were found to be superior to a single vaccination scheme, where chicks developed more conceivable antibody titers than in single vaccination program. There was considerable variation among chicken lines in the immune response to H5N1 vaccine: native breeds possessed the highest antibody titers as compared to other breeds.     

Effect of probiotic supplementation and genotype on growth performance,carcass traits,hematological parameters and immunity of growing rabbits under hot environmental conditions

The effect of dietary inclusion of probiotics and genetic groups on rabbit performance under hot environmental conditions was studied. A total of 80 rabbits aged 8 weeks were distributed into a completely randomized design in a 4 × 3 factorial arrangement, including four genetic groups and three concentrations of dietary probiotic (0, 200 and 400 g/t feed). The utilized probiotic contained 4 × 10⁹ colony‐forming units/g of Bacillus subtilis. Jabali local breed (J), imported Spanish V‐line (V) and their crossbreds (¼J¾V and ¾J¼V) were included in the current study. Final weight and body weight gain were not significantly affected by dietary probiotic levels or genetic group. The feed conversion ratio was better for purebreds than that of crossbreds. A significant improvement in percentage of dressed carcass, mid and hind parts was recorded for rabbits fed a diet containing 400 g probiotic/t feed compared with those fed a basal diet or low probiotic level. Probiotic supplementation had a significant decrease in serum cholesterol. Rabbits given 400 g probiotic/t feed had higher hemoglobin, red blood cells and platelets. Adding 400 g probiotic/t feed to rabbit's diet significantly (P ≤ 0.05) improved cell‐mediated immunity compared to the other treatments 48 h post‐injection.