Sensitivity of Crops to Increased Ultraviolet Radiation in Northern Growing Conditions

Crops growing at high latitudes are adapted to low intensities of solar ultraviolet B radiation (UV-B). As a result of destruction of stratospheric ozone layer especially at the Polar Regions of the globe, the intensity of UV-B is projected to increase at high latitudes. In order to find out the consequences of increased UV-B on crops, the sensitivity of different varieties of barley, wheat, oats, clover, timothy, meadow fescue, tall fescue and potato was tested in Jokioinen, Finland. The experiment was conducted in the field, under natural light, with a continuous 30 % increase in UV-B. Both increased UV-B and the control with slightly increased UV-A radiation affected the number of lateral shoots in cereals, and the specific leaf area and the content of phenolic substances in grasses. The effects varied according to plant variety and time of growing season. However, no visible damage, nor changes in biomass and yield production were found in any of the crops. Long-term effects on, e.g. genetic stability and germination of crop seed remain to be studied.     

Quality and production trait genetics of farmed European whitefish, Coregonus lavaretus

We present here phenotypic and genetic parameters for the major quality and production traits of farmed European whitefish. A total of 70 families were produced by mating each of 45 sires to an average of 1.6 dams and each of the 52 dams to an average of 1.3 sires. A total of 2,100 individuals were recorded for survival, and 507 individuals for growth and quality-related traits. The 4 major results were as follows: first, all traits exhibited nonzero heritabilities except for fillet gaping and fillet protein%. The heritabilities for the production traits were harvest weight (0.42 ± 0.10), gutted weight (0.40 ± 0.10), fillet weight (0.36 ± 0.09), maturity score (0.27 ± 0.11, on liability scale), survival (0.19 ± 0.05, on liability scale), carcass% (0.14 ± 0.07), and fillet% (0.11 ± 0.06). The heritabilities for the quality traits were condition factor (0.49 ± 0.10), fillet lipid% (0.37 ± 0.10), muscle texture (0.30 ± 0.09), Distell lipid reading (0.26 ± 0.09), fillet lightness (0.16 ± 0.07), fillet gaping (0.04 ± 0.06), and fillet protein% (0.04 ± 0.06). Second, the quality traits that were significantly genetically correlated with each other were all related to lipid deposition. Increasing fillet lipid% (an undesired change in whitefish) was genetically related to desired lighter fillet color [genetic correlation (r(G)) = 0.70 ± 0.22] and to undesired greater condition factor (0.39 ± 0.17). None of the other genetic correlations between condition factor, fillet lipid%, muscle texture, fillet lightness, fillet gaping, and fillet protein% were significant. Third, BW and gutted weight were genetically related to the quality traits that were genetically related to lipid deposition. Increasing harvest weight was genetically related to high fillet lipid% (r(G) = 0.59 ± 0.14), lighter fillet color (0.61 ± 0.25), and to greater condition factor (0.60 ± 0.12). All other genetic correlations of harvest weights with the quality traits were nonsignificant, indicating that rapid growth was not genetically related to gaping and softer flesh. Fourth, none of the genetic correlations of carcass%, fillet%, maturity, and survival with the quality traits were significant, implying weak genetic integration between the traits. Yet, marginally significant genetic correlations were found for fillet lipid% with maturity score (r(G) = -0.46 ± 0.24) and survival (0.36 ± 0.19). These results provide the genetic basis for assessing the potential to improve product quality via selective breeding.     

Effect of sowing date and increasing sowing rates on plant density and yield of winter oilseed rape (Brassica napus L.) under Nordic climate conditions

Abstract

A five-year investigation on overwintering of winter oilseed rape (Brassica napus L.) cv. Wotan has been carried out in Estonia. Sowing in August was conducted four times at weekly intervals. Seeding rates of 100, 150, and 200 plants m^?2, at which respectively 47, 71, and 98 plants overwintered, gave different densities at harvest. A lower plant density (47 plants m^?2) produced yields just as high as those with higher density (98 plants m^?2). The optimal sowing date was mid August, which gave on average 98 plants m^?2 with various plant densities. Those plants also gave higher yield (1748 kg ha^?1), compared with the plots sown early or later in August.     

Effect of low temperature on feed intake, growth rate and body composition of juvenile Baltic salmon

Feed intake, specific growth rate and changes in body composition were studied in juvenile (140-170 g) Baltic salmon, Salmo salar, reared at three temperatures (2, 4 and 6 °C) under continuous light conditions. Feed intake increased from 20.4 kJ kg-1 day-1 at 2 °C to 63.8 kJ kg-1 day-1 at 6 °C, and growth rate increased from 0.10% day-1 to 0.37% day-1 over the same temperature interval. The estimated lower temperature limits for feeding and growth were approximately 0.35 °C and 0.6 °C, respectively. Amongst fish reared at 2 °C the majority (86%) of the weight gain consisted of water and protein, and these fish deposited very little lipid. Lipid deposition increased amongst the groups of fish held at the higher temperatures, and amongst the salmon reared at 6 °C lipid accounted for 43% of the body energy gain.     

Indirect estimation of stomach volume of rainbow trout Oncorhynchus mykiss (Walbaum)

The main hypothesis of this study was that if stomach volume is correlated with food intake it can be estimated without laborious and destructive direct measurement. Rainbow trout, Oncorhynchus mykiss (Walbaum), ca. 500–1300 g, were starved for 1, 4, 8 or 16 days at 15°C after which they were fed in excess with dry pellets containing known amounts of X‐ray‐dense markers. Immediately after feeding the fish were killed, X rayed and weighed. Then the stomach was dissected, its contents removed and weighed, and stomach volume was measured. X‐ray plates were developed and feed intake was estimated based on the amount of marker. All measured variables correlated positively with stomach volume. The best fit for linear regression models was obtained for fish starved for 4 days, where stomach content (dry mass) explained 94%, food intake (based on X‐ray measurement) 77% and fish mass 62% of the variation in stomach volume. However, as stomach content measurement can be a lethal, or at least very stressful, event for the fish, the accuracy of food intake measurement (X‐ray) could be increased using multiple regression. In multiple linear regressions, R²‐values varied between 0.79 (16‐day starvation) and 0.91 (1‐day starvation) with food intake and fish mass as explanatory variables for stomach volume. These results indicate that the stomach volume in rainbow trout can be estimated satisfactorily using indirect methods, which are not detrimental to the fish, although feeding history may affect the accuracy of the estimates.     

Feed intake, growth rate and body composition of juvenile Baltic salmon exposed to different constant temperatures

Feed intake, specific growth rate and changes in body composition of age 1+ and 2+ Baltic salmon, Salmo salar L, were studied for fish held under constant temperature conditions. The 1+ fish (60 g) were reared for 6 weeks at 11, 15, 17, 19 or 23 °C and 2+ fish (250 g) were held at 15 °C. Feed intake of 1+ salmon increased from 176 kJ kg-1 day-1 at 11 °C to 275 kJ kg-1 day-1 at 17 °C and decreased to 229 kJ kg-1 day-1 at 23 °C. Specific growth rate increased from 1.18% day-1 at 11 °C to 1.59% day-1 at 15 °C and decreased to 0.56% day-1 at 23 °C. Optimum temperatures for feed intake and growth were estimated at 17.8 °C and 15.6 °C, respectively, and estimated upper thermal limits for feeding and growth were 29.0 °C and 24.1 °C, respectively. Models for feed intake and growth rate in relation to temperature and fish size are presented. The utilization efficiency of ingested energy decreased from 57% at 11 °C to 22% at 23 °C. For all groups of 1+ fish, most (approximately 86%) of the weight gain consisted of water. Lipid deposition accounted for about 52% of the body energy gain irrespective of rearing temperature.     

Inclusion of barley fibre and barley protein in a total mixed ration for growing dairy bulls

Abstract

A 2×2 factorial design with 32 dairy bulls was used to study the effects of partial replacement of a starchy concentrate with a fibrous concentrate and replacement of rapeseed meal with barley protein as protein supplement on performance of bulls with ad libitum access to a total mixed ration feeding. The two energy supplements were flattened barley (B) and a mixture (1:1 on dry matter (DM) basis) of flattened barley and barley fibre (BF). These were fed with either rapeseed meal or barley protein so that the crude protein content of rations was 162 g kg^?1 DM. Replacing half of the barley grain with barley fibre increased (P<0.01) the average DM intake (9.3 kg d^?1 versus 9.9 kg d^?1), but had no effect on the average live weight gain (1.27 kg d^?1). There seemed to be only a minor difference between rapeseed meal and barley protein as protein supplements on animal performance.     

Norway spruce (<Emphasis Type="Italic">Picea abies</Emphasis> L.) regeneration and growth of understory trees under single-tree selection silviculture in Finland

This study presents empirical data on regeneration and growth of understory trees and constructs simple models for predicting these characteristics at various stand structure and post-thinning standing volume levels. The field experiment was established on a grass/herb mineral soil site in central Finland. Regeneration and understory tree growth data were collected from 24 Norway spruce (Picea abies L.)-dominated mixed substands. Seedlings with heights from 5 to 130 cm were measured in 1996 and 2007. In addition, the annual height growth of Norway spruce seedlings was measured in 2007. The spatial pattern of the substands varied from clustered to regular with a decreasing standing volume. Stand complexity was uniform across the range of standing volume. In the 2007 survey, the amount of Norway spruce regeneration increased from approximately 400 to 5,000 seedlings ha⁻¹ when the post-thinning standing volume level was reduced from 230 to 90 m³ ha⁻¹, respectively. Nearly no seedlings were found when the standing volume was over 300 m³ ha⁻¹. The annual diameter increment in Norway spruce understory (dbh < 5 cm) trees decreased, on the average, from 2.3 to 0.3 mm with an increase in the standing volume level from 90 to 340 m³ ha⁻¹, respectively; their height growth showed also a decreasing trend when the standing volume increased. The results indicated that a post-thinning standing volume lower than 150 m³ ha⁻¹ with a regular overstory spatial structure provides a suitable environment for regeneration and growth of Norway spruce understory trees in the studied forest type.     

Quantification of alkylresorcinol metabolites in plasma by high-performance liquid chromatography with coulometric electrode array detection

This study presents the optimization and validation of a rapid protocol for quantifying alkyresorcinol (AR) metabolites 3,5-dihydroxybenzoic acid (DHBA) and 3-(3,5-dihydroxyphenyl)-1-propanoic acid (DHPPA) in plasma, using high-performance liquid chromatography (HPLC) coupled with a coulometric electrode array detector. Syringic acid (SyrA) serves as the internal standard. The new method is simple and could be used in large epidemiological studies. The summed AR metabolite concentrations measured in plasma correlate significantly with the summed urinary AR metabolite concentrations (R = 0.613; p < 0.001) and with the summed intact AR (C17:0-C25:0) concentrations in plasma (R = 0.686; p < 0.001). Additional investigation is needed to clarify whether the two plasma AR metabolites are useful as biomarkers of whole-grain intake and helpful in the exploration of the association between whole-grain cereal intake and human diseases.