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Sheil T.S.,Alltech European Bioscience Center | Wall D.P.,Crops | Culleton N.,Crops | Murphy J.,Crops | And 2 more authors.
Journal of Agricultural Science

Increasing phosphorus (P) fertilizer use efficiency in grassland is desirable, since uncertainty exists over the reserves of finite phosphate rock and its future availability. This necessitates revaluation of the current P fertilizer recommendations for grassland to examine the potential to increase fertilizer P efficiency. The present paper reports results from a long-term grassland P experiment (17 years) on two sites in which annual P fertilizer application rates were 0, 15, 30 and 45 kg P/ha/year. The effect of P fertilizer rate on herbage production and mineral concentration in herbage were investigated in addition to the soil test P (Morgan's) trends and P balance over the duration of the experiment for each rate of P fertilizer. The results showed that the P response to herbage yield and P concentration was similar on both sites. The response of herbage yield to P fertilizer was limited to harvests early in the growing season. The P concentration in herbage was lower in mid-season than in spring or autumn. Annual P fertilizer applications > 30 kg P/ha/year were required to maintain soil P levels at their initial levels over the duration of the experiment. © 2015 Cambridge University Press. Source

Slowinska M.,Polish Academy of Sciences | Jankowski J.,University of Warmia and Mazury | Dietrich G.J.,Polish Academy of Sciences | Karol H.,Polish Academy of Sciences | And 5 more authors.
Poultry Science

The effects of Se supplementation and its organic or inorganic form on semen quantitative parameters (ejaculate volume, sperm concentration, and total number of sperm) and biochemical parameters of seminal plasma (protein concentration, acid phosphatase activity, superoxide dismutase activity, and total antioxidant capacity) were investigated over a 25- wk reproductive season. Additionally, DNA fragmentation and motility characteristics of turkey spermatozoa were measured. The parameters of turkey semen in relation to yellow semen syndrome were also determined. Twenty-four males (Big 6) were divided into 3 experimental groups differing in form of Se supplementation (no Se supplementation, 0.3 mg/kg of inorganic Se from sodium selenite and 0.3 mg/kg of organic Se from Sel-Plex, Alltech Inc., Nicholasville, KY). Dietary Se supplementation enhanced the sperm concentration and total number of sperm and did not influence the antioxidative properties of turkey seminal plasma and most biochemical parameters. Only seminal plasma acid phosphatase activity was increased in turkeys fed inorganic Se. The main sperm DNA fragmentation parameters were not affected by dietary Se. The highest percentage of motile spermatozoa (85%) was recorded for the semen of turkeys fed organic Se. Values of the biochemical parameters (acid phosphatase, superoxide dismutase, total antioxidant capacity) of seminal plasma increased during the reproductive season. Yellow semen was characterized by increased biochemical parameters and decreased spermatozoa motility characteristics. However, the percentage of motile spermatozoa did not differ between white and yellow semen. Organic Se seemed to be the preferred form of diet supplementation in comparison with inorganic Se. Biochemical parameters of semen and spermatozoa motility parameters appear to be useful for evaluating the effect of age on semen quality. Monitoring the DNA fragmentation of spermatozoa at the end of the reproductive season could be a useful tool for monitoring turkey semen quality. Increased superoxide dismutase activity can be used as an indicator of yellow semen. A decline in the quality of yellow semen can be related to a decrease in the spermatozoa motility parameters of turkeys. © 2011 Poultry Science Association Inc. Source

Fay B.J.,Alltech European Bioscience Center | Corrigan A.,Alltech European Bioscience Center | Murphy R.A.,Alltech European Bioscience Center
Applied Soil Ecology

This study focused on identifying the short-term effects of mechanical drainage on the structure and diversity of fungal and bacterial communities in soil. Mechanical drainage is a widely used agricultural practice which allows for the management of surface and sub-surface water. It is vital for improving land productivity and reclaiming marginal land. The use of mechanical drainage is known to have several impacts on the physico-chemical components of soil; however, little is known about its effect on the soil microbiome. In the present study, 454 pyrosequencing of the 18S and 16S rRNA gene regions was used to evaluate differences in fungal and bacterial communities in soil samples taken pre and two months post drainage from an extensively managed grassland in Co., Meath, Ireland. Mechanical drainage was found to have no significant impact on soil pH or on soil carbon and nitrogen levels, however a statistically significant reduction in moisture content was recorded (c. 7%). Analysis of metagenetic data showed that Basidiomycota was the largest classifiable fungal phylum accounting for 16% of all sequences. The predominant bacterial phyla identified in all samples were Proteobacteria, Bacteroidetes and Acidobacteria with average relative abundances of 23%, 26% and 27% respectively. Overall fungal and bacterial community structure and diversity remained unchanged in response to mechanical drainage but two fungal phyla, Chytridiomycota and Blastocladiomycota, showed a significant increase in relative abundance in response to drainage. These findings contribute to our overall understanding of how mechanical drainage impacts the soil microbiome. © 2016 Elsevier B.V. Source

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