Establishment of trees on mixtures of pulverized fuel ash and Gypsum. Part II: Nutrition and trace elements

Nutrients and trace elements were determined in the foliage of nine tree species grown in mixtures of pulverized fuel ash (PFA) and gypsum. No serious macronutrient deficiencies were observed. Treatments with PFA consistently increased foliar levels of boron, potassium and molybdenum, and the poor performance of some tree species in pure PFA was attributed to boron toxicity. Gypsum hindered the uptake of boron when mixed with PFA, however, and co-disposal of the two wastes could be used to minimize problems associated with boron toxicity.     

A feasible method for humane slaughter of eel (Anguilla anguilla L.): electrical stunning in fresh water prior to gutting

It was observed that farmed eels could be rendered unconscious and insensible instantaneously by passing an electrical current through fresh water. The general epileptiform insult on the EEG was characterized by a tonic/clonic and an exhaustion phase. After stunning, the ECG (electro‐cardiogram) revealed fibrillation. The electrical stunning parameters were on average 194 ± 4 V and 0.636 ± 0.040 A/dm² for 1.6 ± 0.4 s. Within a confidence level of 95%%, taking into account the number of animals with a reliable EEG (n = 29), at least 93% of all eels are effectively stunned in fresh water by an average current of 0.636 ± 0.040 A/dm². The behaviour of groups of five eels, which were able to move freely in the water was observed before and after stunning with 50 V and 0.17 A/dm². After 3‐s stunning, two eels were turned upside down. They changed to a normal position after 10 and 13 s respectively. Subsequently, all eels were very active in swimming behaviour and stopped swimming after 75 s. When stunned for a longer duration, all eels were turned upside down and stopped breathing for a limited period of time. In the last experiment the eels were stunned in fresh water (500 μS) with a voltage of 200 V for approximately 1 s, which was followed by 50 V for 5 min. As soon as the stunning started the water was de‐oxygenated by flushing nitrogen to kill the eels by suffocation during the period of unconsciousness and insensitivity. The oxygen saturation decreased from 74 ± 10 to 23 ± 11% at 22 °C. After stunning no brain activity and no responses to pain stimuli were observed on the EEG. The heart rate increased (P < 0.05) after stunning, which was followed by a significant decrease. Only 1 out of 18 eels returned partially from upside down to a normal position 2 h after stunning; however, the eel did not respond to pain stimuli in behaviour. The developed stunning procedure can be recommended for humane slaughter of 50‐kg batches of eels.     

Effects of the dietary protein to energy ratio on growth,feed utilization and body composition in Macrobrachium nipponense

Oriental river prawn (Macrobrachium nipponense) has been widely cultured in Asian countries. However, its nutritional studies are very limited. In the present 8‐week study, we investigated the effects of dietary protein to energy ratio (P/E ratio) on the growth, feed utilization and body composition in juvenile M. nipponense (initial weight 0.302 ±0.03 g). Two‐factor experiment was designed and nine semi‐purified diets were formulated to contain three lipid levels (20, 80 and 140 g kg^?1) and three protein levels (330, 380 and 430 g kg^?1), producing P/E ratios from 16.5 to 23.4 mg KJ^?1 protein. The results indicated that the growth, survival rate and protein efficiency were dose dependently improved by the increased dietary lipid, but not dietary protein content. Increased dietary lipid content and/or protein content increased lipid accumulation in whole body, hepatopancreas and muscle, but did not change the feed intake and hepatopancreas weight. In conclusion, our present study indicated that M. nipponense is a species with relatively high‐energy requirement. It could utilize dietary lipid content up to 140 g kg^?1, while the dietary protein with more than 330 g kg^?1 would not promote growth and protein efficiency. Taken together, 330 g kg^?1 dietary protein and 140 g kg^?1 dietary lipid level with P/E ratio 16.49 could be optimum for M. nipponense.     

CNS mastitis: nothing to worry about?

In this paper, we analyzed a very large field data set on intramammary infections (IMI) and the associated somatic cell count (SCC) in dairy cows. The objective of the study was to analyze the impact of coagulase-negative staphylococci (CNS) IMI on cow SCC, both mean and variability, and on the potential of these infections to have a major impact on the bulk milk SCC (BMSCC). Data and milk samples for bacterial culture were collected by Quality Milk Production Services (QMPS) between 1992 and March of 2007. The QMPS program services dairy farms in New York State and other states in the Northeastern USA and operates in conjunction with Cornell University. Only records from cows where SCC and milk production data were available, and where only one organism was isolated from bacterial cultures of milk samples (or where culture was negative) were used for this analysis. A total of 352,614 records from 4200 whole herd mastitis screening sampling qualified for this study. Within herds an average of 15% (S.D. 12%) of cows sampled were infected with CNS, ranging between 0 and 100%. Average within herd prevalence of cows with a CNS IMI and an SCC over 200,000 cells/ml was 2% (S.D. 4%) with a minimum of 0% and a maximum of 50%. Results of linear mixed models showed three distinct populations of IMI statuses: negative cultures with the lowest SCC; CNS and Corynebacterium bovis with a moderate increase in SCC, and Streptococcus agalactiae, Streptococcus spp. and Staphylococcus aureus showing an important increase in SCC. Surprisingly, milk production was slightly but significantly higher in CNS infected cows compared to culture-negative cows, whereas it was strongly reduced in cows with a major pathogen IMI. The percentage contribution of CNS infections to the BMSCC was 17.9% in herds with a BMSCC less than 200,000 cells/ml. This value decreased to 11.9 and 7.9% in herds with bulk milk SCC between 200,000 and 400,000 and over 400,000 cells/ml, respectively. We concluded that very few herds with milk quality problems would have an important increase in BMSCC that could be mostly attributed to CNS infections. On the other hand, in herds with low BMSCC, CNS infections may be an important contributor to the total number of somatic cells in the bulk milk.     

Biochemical genetics of oxidative resistance to diazinon in the house fly

The genetics and biochemistry of oxidative resistance to diazinon were investigated in a diazinon-resistant strain of the house fly, Musca domestica L. The resistant strain was crossed with a multimarker susceptible strain and substrains containing portions of the resistant strain genome were prepared. Resistance, microsomal oxidase, and cytochrome P-450 spectral characteristics were then compared in the different strains. The major gene for resistance to diazinon is semidominant and is located on chromosome II, 13 crossing over units from the recessive mutant stubby wing. Additional resistance genes occur on chromosome II and on other chromosomes as well. Resistance to diazinon was introduced into a susceptible mutant-marked strain via genetic crossing over. Increases in parathion oxidase, total and P-450-specific N- and O-demethylase activity, and resistant strain type I binding spectrum were introduced along with resistance, indicating genes controlling these parameters and resistance are either identical or closely linked. No increase in activity of cytochrome P-450 itself was introduced into the mutant strain. Additional genes controlling the amount of cytochrome P-450 and several spectral changes characteristic of the resistant strains are apparently controlled by genes located at different loci on chromosome II. Resistance factors on other chromosomes are also present, but were not characterized.     

Evaluation of hemostatic defects secondary to vascular tumors in dogs: 11 cases (1983-1988)

Two populations of dogs with cutaneous hemangiomas and hemangiosarcomas were evaluated retrospectively. One population consisted of 96 dogs seen at the Veterinary Medical Teaching Hospital at the University of California, Davis. The second population consisted of 116 dogs that had skin biopsy specimens submitted to a private veterinary diagnostic laboratory for histologic diagnosis. Nine dogs from the teaching hospital and 2 dogs, from which samples had been submitted to the veterinary diagnostic laboratory, developed hemostatic defects in association with the tumors. Hemostatic defects included hemorrhage directly from the tumor, thrombocytopenia, hypofibrinogenemia, and findings associated with disseminated intravascular coagulation. Because bleeding during surgery can develop in animals with hemostatic defects, dogs with one or more tumors suspected of being vascular in origin should have platelet numbers and hemostatic analytes evaluated prior to surgery, especially if petechiae or ecchymoses are evident.     

Cultivation of Pen Shells: An Example with Atrina maura in Northwestern Mexico

Pen shells are economically important and most are threatened by overexploitation and habitat degradation. Cultivation represents an alternative for preserving the resource and increasing the production. Atrina maura was cultivated in a suspension system which was followed by a bottom phase. Samples of pen shells and tissues were collected monthly to measure absolute growth, shell height increase, and an adductor muscle index. After the trials, adults shell height was 195 ± 10 mm, total weight was 223 ± 28 g, and mean shell height increase was 0.81 cm/mo. Protective devices were vital to avoid predation by crabs and fish; survival was 90% in the suspension phase and 70% in the bottom phase. Variations in the muscle index were apparently related to reproduction, suggesting activity (partial spawning) from August 2008 to April 2009 in juveniles and a major spawning in adults during August 2009. Adductor muscles reached a mean of 21 g after 20 mo of cultivation, but muscle weights decreased significantly after reproduction (August to November 2009). Results indicated that A. maura is suitable for aquaculture and the cultivation system adopted here should be tested in pilot‐scale ventures. This system may work with other species of pen shells.     

Dietary plasticity in Arctic charr (Salvelinus alpinus) in response to long‐term environmental change

Corrigan LJ, Winfield IJ, Hoelzel AR, Lucas MC. Dietary plasticity in Arctic charr (Salvelinus alpinus) in response to long‐term environmental change.
Ecology of Freshwater Fish 2011: 20: 5–13. © 2010 John Wiley & Sons A/S Abstract –  In the face of widespread environmental change impacts, there is a need to better understand mechanisms promoting flexibility and resilience of ecosystem components to such change to inform strategies for conservation. Glacial relict species are especially vulnerable to such changes. We investigated the behavioural responses of a native, glacial relict species, Arctic charr (Salvelinus alpinus) to long‐term environmental changes. It was hypothesised that changes in feeding behaviour would occur as a key intermediary to reduction in habitat availability (through climate change and eutrophication) or competitive interactions [with introduced roach (Rutilus rutilus)]. Stomach content analysis was used to assess the diet of 199 charr caught from Windermere, United Kingdom, in the months of March, June, September and November 2003–2007. The results were compared to data from 1940 to 1951 prior to the environmental changes and revealed a marked increase in the contribution of benthic invertebrates in the present diet. Stable isotope analysis confirms the results of the stomach analysis, suggesting that the charr have switched their diet from zooplanktivory towards benthivory. We discuss the possibility that habitat modification and roach population expansion in Windermere have contributed to changes in charr diet. Complementary studies suggest that this diet shift is more likely to be a response to the increasing roach population than to habitat modification; however, further study in Windermere would be required to elucidate the exact mechanism. Long‐term data sets such as these provide information that is useful for determining the directivity of ecological change and the capability of species to respond to change.