Biomass allocation to resource acquisition compartments is affected by tree density manipulation in European Beech after three decades

This study reports on an investigation of fine root and foliage productivity in forest stands dominated by European beech (Fagus sylvatica L.) and exposed to contrasting intensities of mature forest harvesting. The main aim of this study was to consider the long-term effects of canopy manipulation on resource acquisition biomass compartments in beech. We made use of an experiment established in 1989, when five different light availability treatments were started in plots within a uniform forest stand, ranging from no reduction in tree density to full mature forest removal. We measured fine root standing stock in the 0–30 cm soil layer by coring in 2013 and then followed annual fine root production (in-growth cores) and foliage production (litter baskets) in 2013–2015. We found that the plot where the tree density was reduced by 30% had the lowest foliage and the highest fine root production. In 2013, this plot had the highest fine root turnover rate (0.8 year−1), while this indicator of fine root dynamics was much lower in the other four treatments (around 0.3 year−1). We also found that the annual fine root production represented around two thirds of annual foliage growth on the mass basis in all treatments. While our findings support the maintenance of source and sink balance in woody plants, we also found a long-lasting effect of tree density manipulation on investment into resource acquisition compartments in beech forests

Influence of the protein content of boar seminal plasma on spermatozoa viability, motility and acrosome integrity in diluted semen stored for 3 days

The aim of the present study was to investigate the influence of the protein content of seminal plasma on the motility, viability and acrosome integrity of spermatozoa in extended semen stored for 3 days. A total of 32 semen samples (from four boars) with high (4 mg/ml) and 32 semen samples (from four boars) with low (2 mg/ml) protein content were investigated. The semen samples were diluted by BTS at a ratio of 1:4, and stored for 72 h at 17oC. The percentages of live sperm (LS), live sperm with damaged acrosome (LDA) and total sperm with damaged acrosome (TDA) were detected by flow cytometry. Sperm progressive motility (PM) was detected using CASA. After 72 h of storage, the percentage of LS and PM was significantly (P lt 0.01) higher, and the LDA and TDA were significantly (P lt 0.01) lower in samples with high protein content than in the samples with low protein content (LS = 66 vs. 44%, PM = 64 vs. 48%, LDA = 15 vs. 21% and TDA = 29 vs. 45%, respectively). When comparing the difference between 0 and 72 h of storage, the percentage decrease in LS and PM, while increase in LDA and TDA were significantly higher in the samples with low (LS: 75 to 44%; PM: 68 to 48%; LDA: 11 to 21% and TDA: 23 to 45%) than in the samples with high protein content (LS: 78 to 66%; PM: 70 to 64%; LDA: 9 to 15% and TDA: 17 to 29%). We concluded that protein content in seminal plasma has a significant influence on progressive motility, viability and acrosome integrity in diluted semen stored for 3 days

Reproduktivna efikasnost visoko-mlečnih krava posle telenja

The aim of this work was to determine incidence of calving and postcalving reproduction disorders and their effect on the major parameters of cows reproductive efficiency at dairy farm in the R. Serbia. Total number of 1835 high-milking dairy cows (av. milk production >8500L/305d of lactation) records has been reviewed during one year period, at the large dairy farm in area of Vojvodina (R. Serbia). Normal calving and puerperal period without health problems was observed at 583 cows (27,6%), while different abnormalities during and after calving were recorded in 1252 cows (72,4%). The highest percentages of registered peripartal disorders were dystocia and endometritis (62% and 64%, respectively), affecting almost the same percentage of cows. Peripartal disorders had statistically significant influence (P lt 0.05) on the increase of number of services/conception (3,5 vs. 2,7, reproductive disorders vs. healthy cows, respectively), prolongation of the interval from first postpartal insemination till conception (110 vs. 57 days, reproductive disorders vs. healthy cows, respectively), and increase of days open period (214 vs. 146 days, reproductive disorders vs. healthy cows, respectively). This results have confirmed increased incidence of reproduction disorders during calving and postcalving period that significantly reduces reproductive efficiency in high milking dairy cows after parturition.Istraživanja u mnogim zemljama, tokom poslednjih decenija, pokazuju permanentan pad reproduktivne efikasnosti krava visoke mlečnosti. Cilj ovog rada je da se utvrdi da li i u kojoj meri, peripartalni poremećaji imaju uticaja na osnovne parametre reproduktivne efikasnosti krava u našim proizvodnim uslovima. Istraživanjem je obuhvaćeno ukupno 1835 krava, tokom jedne godine, na jednoj velikoj farmi sa visokom proizvodnjom mleka (prosečna proizvodnja >8500L/305 dana laktacije) u regionu Vojvodine (Republika Srbija). Od ukupnog broja ispitivanih krava, telenje je prošlo bez poremećaja kod 583 krave (27,6%), a različiti poremećaji tokom i posle telenja su ustanovljeni kod 1.252 krave (72,4%). Najčešće ustanovljeni peripartalni poremećaji kod visoko mlečnih krava su teško teljenje (62%) i endometritis (64%). Peripartalni poremećaji imaju statistički značajan uticaj (P lt 0,05) na povećanje indeksa osemenjavanja (3,5 prema 2,7), produženje intervala od prvog do fertilnog osemenjavanja (57 prema 110 dana), kao i na produženje trajanja servis perioda (146 prema 214 dana), u poređenju sa kravama bez poremećaja. Dobijeni rezultati pokazuju da na farmama visoko mlečnih krava povišena učestalost peripartalnih reproduktivnih poremećaja koji značajno utiču na smanjenje reproduktivne efikasnosti krava nakon partusa

Effect of proteine content in boar seminal plasma on the sperm motility in diluted semen stored for 3 days

Recently, it was frequently demonstrated that fertility of sows after artificially inseminated is lower than after mating. This is associated with a reduced fertilization capacity of overdiluted insemination doses. The aim of this study was to investigate the sperm motility in the semen samples, forming from the ejaculates with high or low protein content, stored in vitro on 17 degrees C for 3 days. Progressive motility was significantly higher (p lt 0.01) in the ejaculates with high, compared to the ejaculates with low protein content (82% vs. 76%). After 3 days of storage, in the1:4 dilution proportion, the average progressive motility was significantly (p lt 0.01) decreased in relation to this value in native semen from the boars with high (82% to 64%), as well from the boars with low protein content in seminal plasma (76% to 48%). However, the average diluted semen progressive motility was significantly greater (p lt 0.01) in the boars with high (64%), compared to the boars with low protein content in seminal plasma (48%). The number of good diluted semen samples (>= 65% progressive motility), was also significantly (p lt 0.01) greater in the boars with high (41%), compared to the boars with low protein content in seminal plasma (12%). These results show that seminal plasma proteins play an important role in maintaining the sperm progressive motility of diluted semen in vitro stored for 3 days

Investigations of mature Scots pine stands in wind-throw areas in Norway spruce forests in Western Rhodopes

We investigated the current health condition (defoliation), state of natural regeneration, and mycoflora and phytopathogen-caused attacks in Scots pine forests (Pinus sylvestris L.) planted in the 1960s in areas affected by wind disturbances in the West Rhodope Mountains in Bulgaria. Some damage types (resin outflow and anthropogenic damage) were present to a low extent in the research plots (S – Selishte and PK – Pobit Kamak). Some were missing completely (damage by deer and other animals, the presence of lignicolous fungi and abiotic damage). The most important results of this study were the following: i) the occurrence of the bark beetle pest Tomicus minor Hartig (Coleoptera, Scolytinae) was recorded on average in 4.6 (S) and 2.3 (PK) of fallen shoots under the tree crown within 1 m diameter around the stem; ii) significant damage to tree crowns due to the loss of assimilation organs in Scots pine trees (28% – S and 39% – PK, respectively) was several times higher than that recorded in Norway spruce (Picea abies L.) (10%); iii) tree species composition resulting from natural regeneration showed 95–100% proportion of Norway spruce despite the predominance of Scots pine in the maternal stand. These observations might provide evidence of unsuitable environmental conditions in the studied localities for pine forests on the southern range of the natural P. sylvestris occurrence. Forest management in similar ecological and climatic conditions should aim at significant diversification of the forest stand structure by utilizing tree species suitable for the given ecosystems

Citoplazmatske kapi spermatozoida nerastova – abnormalnost ili fiziološka pojava?

Reprodukcija svinja danas predstavlja osetljivo polje delovanja veterinarske službe koje značajno utiče na profitabilnost svinjarske proizvodnje. Bez obzira na ovu činjenicu, neki standardni pregledi razređenog semena nerastova kroz duži vremenski period predstavljaju nezamenljiv način kontrole kvaliteta dobijenog ejakulata. Cito-morfološki pregled izvodi se u svrhu procene učestalosti pojavljivanja abnormalno građenih spermatozoida. Citoplazmaske kapi javljaju se na srednjem delu spermatozoida, a po mestu lokacije, dele se na proksimalne i distalne. Distalne citoplazmatske kapi ukazuju na nezrelost spermatozoida, rano uvođenje mladih nerastova u reproduktivnu eksploataciju, prekomerno iskorišćavanje priplodnjaka ili pak posledično pojavljivanje ovakvih spermatozoida kao odgovor na ambijentalne oscilacije ili druge zdravstvene probleme vezane za nerasta. Ovaj rad predstavlja istraživanje koje je sprovedeno na nerastovima (n=30), durok i landras rasne pripadnosti. Eksperimentalna grupa životinja dobijala je peroralno zajedno sa kompletnom smešom za ishranu, dodatak preparata sa antioksidativnim potencijalom. Za potrebe bojenja spermatozoida korišćena je modifikovana metoda ‚‚u jednom koraku” (Mortimer, 1994; Jovičin i sar., 2012). Primena dvofaktorske ANOVE za ponovljena merenja pokazala je da nema statistički značajne razlike između kontrolne i eksperimentalne grupe nerastova u nalazima citoplazmatskih kapi spermatozoida (%) (F(7, 112)= 1,65, p= 0,13) u odabranim vremenskim tačkama. Iako nije zabeležena statistički značajna razlika, ovakav rezultat, odnosno konstanta u broju ovakvih spermatozoida nerastova označava i ujednačenost uslova pod kojim je ekseriment sproveden.Zbornik radov