Nutritive Value of Four Soybean Products in Diets for Atlantic Salmon (Salmo salar,L.)

Abstract

Four processed soybean products were evaluated as protein sources for Atlantic salmon: solvent-extracted soybean meal (SBM44), dehulled and solvent-extracted soybean meal (SBM50), dehulled full-fat soybean meal (FFSBM) and soybean concentrate (SBC). The soybean products replaced high-quality fish meal at levels corresponding to 0, 14, 28, 42 and 56% soybean protein of total protein.

Dietary inclusion of SBC, at the expense of fish meal, did not affect weight gain, carcass lipids, fecal excretion of nutrients or fecal dry matter content significantly. The nutritive value of the SBC protein appeared comparable to that of the fish meal. The three other soybean products impaired performance increasingly with increasing levels of inclusion, indicating lower nutritive value than for the fish meal. The favourable results seen with SBC indicated a great potential of soybean to become an important protein source for Atlantic salmon through improved processing.     

Attract,reward and disrupt: responses of pests and natural enemies to combinations of habitat manipulation and semiochemicals in organic apple

The widespread use of pesticides along with the simplification of the landscape has had undesirable effects on agroecosystems, such as the loss of biodiversity and the associated ecosystem service biological control. How current production systems can be remodelled to allow for a re-establishment of biological pest control, while preserving productivity, is a major challenge. Here, we tested whether a combination of tools could augment or synergize biological control of insect pests in apple (Malus domestica), comprised of a tortricid pest complex, a geometrid pest complex and the rosy apple aphid. The tools aimed at disrupting mating behaviour of multiple pest species (multispecies mating disruption, “Disrupt”, MMD), attracting natural enemies (a blend of herbivory-induced volatiles, “Attract”, A), or providing refuge and rewards for a diverse insect community (perennial flower strip, “Reward”, R) over a 3-year period. Suction samples were consistently richer in generalist predators but not in parasitoids when multiple tools including MMD?+?A?+?R or MMD?+?A were employed. In addition, lepidopteran pest levels were significantly lower in these plots than in MMD or MMD?+?R at the end of the 3-year experiment. This was, however, not reflected in survival of artificially established aphid colonies. Our data indicates that multiple, complementary tools can greatly enhance natural enemy level, but also that long-term implementation is needed to fully realize the augmentatory or synergistic potential of complementary components and restore biological control as an ecosystem service of practical relevance.

     

Predicting the solubility of Cd,Cu, Pb and Zn in uncontaminated Croatian soils under different land uses by applying established regression models

Soil pH, soil organic matter (SOM), dissolved organic carbon (DOC) and total trace metal concentration (M_(tot)) control the solubility of metals in the soil. Several regression models have included these soil chemical variables for the prediction of metal solubility and free metal ion (FMI) concentrations in contaminated soils. We hypothesize that models developed on contaminated soils (after optimization of the coefficients) can be used on samples from uncontaminated sites. Soil samples were collected from unpolluted agricultural and forest soils located in Eastern Croatia and extracted with water to determine the concentrations of Cd, Cu, Pb and Zn. We used these data to test the applicability of three regression models on existing conditions under different land uses. The same predictors issued in the three models and the same regression coefficients were utilized in the present study. The results showed a good correlation between the observed and predicted values of metal solubility. However, the models overestimate the total solution concentration (M_(sol)) and the concentrations of free metal ions (FMI) in solution, and therefore the same regression coefficients were optimized to fit our own observations. This was found to be very successful. The results showed that pH and DOC played a very important role in controlling metal solubility, while SOM and CEC were somewhat less significant. The impact of total soil concentration of metals (M_(tot)) was rather minor. However, we feel that to carry out good predictions of M_(sol) and FMI, the M_(tot) is needed in such regression models.     

Blood parameters in Swedish dairy herds with high or low incidence of displaced abomasum or ketosis

Sixty dairy herds were studied to investigate the association between long-term incidence of displaced abomasum and clinical ketosis and body condition score and blood profiles, including parameters estimating energy metabolism and hepatic lipidosis in the periparturient period and early lactation. Blood samples were taken around parturition and in early lactation from cows without apparent clinical symptoms of metabolic disorders. A difference in metabolism between high and low incidence herds was shown post-partum by a lower metabolic index (the revised Quantitative Insulin Sensitivity Check Index, RQUICKI), and tendencies for higher concentrations of glucose, insulin and non-esterified fatty acids in the high incidence herds. High incidence herds had more cows and produced on average 1400kg energy-corrected milk per cow per year more than the low incidence herds. No differences were found in parameters reflecting liver cell damage. In the first 3weeks post-partum the RQUICKI was a more sensitive marker of herds with a high incidence of displaced abomasum and clinical ketosis than any of the individual parameters, but further research is needed before practical applications of the RQUICKI can be foreseen.     

Decreased mononuclear cell response to mitogens in artificially reared neonatal pigs.

The influence of two rearing methods for neonatal pigs on mononuclear cell responses to mitogens was studied. Littermate pigs were reared artificially or on the sow. Artificially reared pigs displayed a leukocytosis (P less than 0.05) characterized by an increase (P less than 0.05) in mature and immature neutrophils. Skin-test responses to intradermal injections of phytohemagglutinin were less (P less than 0.05) in artificially reared pigs than in sow-reared controls. Lymphocyte proliferative responses to mitogenic stimulation were approximately 50% lower (P less than 0.05) in artificially reared pigs than in sow-reared pigs. These data suggest that artificial rearing lowers in vivo and in vitro lymphocyte responses in neonatal pigs.     

Clostridium difficile associated with acute colitis in mature horses treated with antibiotics

Clostridium (C.) difficile, or its cytoxin, was demonstrated in faecal samples from 10 of 25 (40%) mature horses investigated with acute colitis treated primarily with antibiotics for disorders other than diarrhoea. C. difficile was not found in faecal samples from 140 horses without signs of enteric disorders, from 21 nondiarrhoeic horses treated with antibiotics, nor from 22 horses with colitis untreated with antibiotics. Except for C. difficile neither Salmonella nor any other investigated intestinal pathogen was isolated in any of the diarrhoeic horses. The findings strongly support some earlier reports that C. difficile is associated with acute colitis in mature horses treated with antibiotics. Of the 10 horses, 4 proved positive for C. difficile both in culture and in the cytotoxin test, 4 in culture only and 2 only in the cytotoxin test. Eight of 10 horses positive for C. difficile were or had recently been hospitalised, indicating that C. difficile may be a nosocomial infection in horses. All horses positive for C. difficile were treated with beta-lactam antibiotics.