Bisection of bovine morulae and blastocysts from superovulated Danish dairy cows

Sixtyfour compacted morulae and blastocysts were bisected with a microscalpel. The majority of the demi-embryos (n = 122) were reinserted into separate zona pellucidae (ZP) before non-surgical transfer to 113 synchronized recipients, as singles (n = 98) (DE-S) or in pairs (n = 30) (DE-P). Thirty non-manipulated embryos (E) were transferred during the same period and served as controls. Pregnancies were diagnosed by rectal palpation 4-7 weeks after transfer. The pregnancy rates for DE-S, DE-P and E were 32%, 53% and 40%, respectively (P greater than 0.05). A substantial number of abortions were recorded between 50 and 250 days of pregnancy among the recipients with DE-S. The fetal survival rate for DE-S was reduced to 21% and significantly lower (p less than 0.05) than the survival rates of DE-P (43%) and E (40%). The quality of DE and the presence of ZP did not significantly influence the results. No conclusive reasons for the fetal loss could be found but different possibilities are discussed.     

Effects of Dietary Vitamin C on Maturation and Egg Quality of Cod Gadus morhua L.

The effects of dietary vitamin C on maturation and egg quality of cod Gadus morhua L. have been investigated. The broodstock groups were fed three different levels of vitamin C mixed into a commercial dry pellet. The experimental feeding started three months prior to the spawning season. Naturally spawned eggs were collected and analyzed with regard to viability, biochemical composition and physical characteristics. Differences in free amino acid profile, egg strength and neutral buoyancy were found, whereas no effects on vital parameters, such as fertilization rate and survival rate, were detected.     

Temporal sensitivity ofAlternaria solani to foliar fungicides

Alternaria solani Sorauer (Ellis) is a causal agent of early blight of potato (Solanum tuberosum L.). Sensitivity to chlorothalonil, triphenyl tin hydroxide (TPTH), and mancozeb was determined for field isolatesof A. solani in 1998 and 1999. Specifically, the relative sensitivity ofA. solani to foliar fungicides in field populations collected from several commercial fields was evaluated over the course of two growing seasons. Sensitivity to these foliar fungicides was determined with anin vitro spore-germination assay method. The fungicide concentration that inhibited conidial germination by 50% (EC₅₀) was estimated for each isolate. Sensitivity ofA. solani isolates to TPTH and mancozeb varied little during the growing season, possibly because there were few TPTH and mancozeb applications made to the fields studied. At several locations, however, repeated exposure ofA. solani populations to chlorothalonil resulted in considerable variability in sensitivity, frequently causing isolates to have decreased sensitivity to this fungicide at the end of the growing season. In five of seven fields, isolates of A.solani collected at the end of the season were significantly less sensitive to chlorothalonil than isolates collected at the beginning of the season.     

Sangre selection studies: I. Selection and comparative trials

Seventeen clonal selections of Sangre were made from a tuber-unit seed lot planted at the San Luis Valley Research Center in 1982. Seven selections had typical vine size and 10 had larger vine size than the standard cultivar. Progeny of each selection were increased and observed in 1983. During the three-year interval from 1984–1986 comparative performance trials were conducted. All clones selected for larger vines were significantly taller and later maturing than the standard. Clones 10 and 11 also had significantly greater total yields and clones 10, 11, and 14 had significantly greater U.S. No. 1 yields. Tuber shape of these clones was comparable to the standard. Results indicate that improvement may be made in the Sangre cultivar through clonal selection.     

Cleaning heavy metal contaminated soil with soluble humic substances instead of synthetic polycarboxylic acids

Abstract

Soils contaminated with heavy metals constitute a serious and widespread ecological problem but to clean such soils requires strong chemicals such as polycarboxylates; frequently ethylenediaminetetraacetic acid and nitrilotriacetic acid are used. However, these compounds are synthetic and toxic and their replacement by natural products such as soluble humic substances as washing agents for cleaning heavy metal polluted soils would be environmentally very attractive. In fact, such a replacement seems possible at least on cadmium and copper contaminated soil inasmuch as humic substances, depending on the concentration, were found to extract up to 45% and 54% of total cadmium and copper from a highly contaminated calcareous soil. Even though higher amounts of the two metals were extracted by ethylenediaminetetraacetic acid and nitrilotriacetic acid, the humic substances undoubtedly extracted the most reactive fractions. However, the humic substances extracted only 4% of total lead and 17% of total nickel, whereas the percentages for the synthetic polycarboxylates were about 30% for nickel and lead. Ethylenediaminetetraacetic acid and nitrilotriacetic acid may therefore be replaced by humic substances as washing agents for cadmium, copper and maybe nickel contaminated soils, whereas they seem unsuited for cleaning lead contaminated soils, at least if the soils are as calcareous as the soil tested.     

Future Cereal Starch Bioengineering: Cereal Ancestors Encounter Gene Technology and Designer Enzymes

The importance of cereal starch production worldwide cannot be overrated. However, the qualities and resulting values of existing raw and processed starch do not fully meet future demands for environmentally friendly production of renewable, advanced biomaterials, functional foods, and biomedical additives. New approaches for starch bioengineering are needed. In this review, we discuss cereal starch from a combined universal bioresource point of view. The combination of new biotechniques and clean technology methods can be implemented to replace, for example, chemical modification. The recently released cereal genomes and the exploding advancement in whole genome sequencing now pave the road for identifying new genes to be exploited to generate a multitude of completely new starch functionalities directly in the cereal grain, converting cereal crops to production plants. Newly released genome data from cereal ancestors can potentially allow for the reintroduction of cereal traits including, for example, health‐promoting carbohydrates that may have been lost during domestication. Raw materials produced in this manner can be processed by clean enzyme‐assisted techniques or thermal treatment in combination to further functionalize or stabilize the starch polymers. Importantly, such products can be multifunctional in the sense of combined food/material or food/pharma purposes, for example, edible plastics, shape memory materials, and cycloamylose carriers and stabilizers for diverse bioactives.     

Modelling the effects of dietary methionine level and form on postprandial plasma essential amino acid profiles in rainbow trout (Oncorhynchus mykiss)

Aquafeed formulation is susceptible to affect amino acid (AA) availability for metabolic functions. Statistical models were applied to quantify the effect of dietary methionine level (from 6.01 to 16.17 g kg^?1 dry matter) and form (free, coated or bound) on postprandial concentrations of plasma essential amino acid (EAA) in rainbow trout. Twelve diets were formulated with pea and soya protein concentrate or fish meal as the main protein ingredients and were supplemented or not with increasing amount of either crystalline or agar‐coated methionine. Fish were acclimatized to one of the 12 diets for 6 weeks before postprandial plasma sampling (six sampling points up to 36 h, seven fish each time), further analysed for EAA content. Using generalized additive models, we show that (i) dietary methionine level and form explained 74% postprandial methionine plasma variations and that (ii) the methionine dietary form and plasma concentrations significantly affected the plasma concentrations of the other EAAs. Finally, linear model revealed a positive relationship (R² > 0.9) between plasma concentrations of the three branched‐chain AAs under the present experimental conditions. The results obtained add new information on the dietary effects on EAAs in the plasma availability and the interactions between them.     

Population genetic structure of lumpfish along the Norwegian coast: aquaculture implications

The potential for genetic contamination of stocks arising from translocation and subsequent release or escape of translocated and/or genetically mixed stocks may be a significant risk to wild populations. In this context, we undertook a population genetic survey of stocks of lumpfish (Cyclopterus lumpus) along the Norwegian coast to establish the existing genetic population structure, which will aid the development of policy of the species’ use as cleaner fish in salmonid aquaculture. This was done by using 14 microsatellite loci and 287 specimens collected at five fishing grounds, covering most of the Norwegian coastline from south to north, with additional 18 samples of first-generation reared fish from a fish farm outside Tromsø (North Norway). Overall, there was no indication of significant spatial genetic structuring or of positive correlation between geographic and genetic distance among the wild lumpfish samples. These results suggest that, should translocated individuals escape from aquaculture in Norway, this will probably have little to no impact on the genetic composition of the local fish population.