Effect of food amount and temperature on growth rate and aerobic scope of juvenile chum salmon

Offshore migration of Pacific salmon Oncorhynchus spp. is partly triggered by increasing body size and high motility in the early stages of life. The survival of juvenile salmon may depend on their growth rate during the first few months in the sea, and this factor partly regulates the dynamics of adult populations. Here, we assessed the effects of water temperature and food availability on the growth of juvenile chum salmon O. keta. In addition, by combining the measurements of metabolic performance for growth and activity (Absolute Aerobic Scope: AAS) with a bioenergetics model, we estimated the energy allocation for different activities in the juveniles. Under high temperatures (14 °C), juveniles reared at low food levels (1% body weight) allocated less than half their energy for growth than those reared at high food levels (4% body weight). These findings suggest that high temperature and low food level constrain the growth of juveniles, providing an insight into the effect of the recent increase in warm and low-nutrient water masses on survival of juveniles and catches of adult chum salmon on the Pacific side of Honshu Island, Japan.

     

Anthracnose of <Emphasis Type="Italic">Enkianthus campanulatus</Emphasis> and <Emphasis Type="Italic">Rhynchosia acuminatifolia</Emphasis> caused by <Emphasis Type="Italic">Colletotrichum gloeosporioides</Emphasis> (new occurrence)

In 2003–2004, anthracnoses of Enkianthus campanulatus and Rhynchosia acuminatifolia were found for the first time in Kanagawa Prefecture and Tokyo in Japan. These pathogens were identified as Colletotrichum gloeosporioides based on their pathogenicity, morphology and ribosomal DNA spacer sequences. Results were presented at the annual meeting of The Phytopathological Society of Japan in 2004.     

Organic phosphorus in upland soil

The nature and behaviour of soil organic phosphorus has been studied in many places of the world, especially in Iowa, U.S.A., and Quebec, Canada.     

Heading behaviour in Japan of Turkish populations of cocksfoot,Dactylis glomerata L.

Summary Ninety-nine populations of cocksfoot collected throughout Turkey were examined for heading behaviour at Sapporo, Japan. In some populations, all the plants produced heads in the year of sowing or in the aftermath of the next year. Much of the Turkish populations, even from the mountainous regions with severe winters, is also distinct in heading behaviour in autumn from the north European types, which fail to head in the year of sowing. This behaviour is related to winter temperatures of the place of origin, with the milder winter tending to result in a higher heading rate. Date of heading is also influenced by the climatic factors of the habitat, especially by the length of the growing period between winter and summer dormancies. Turkish populations provided useful material for the study of flowering habit.     

Prevalence of Giardia intestinalis infection in household cats of Tohoku district in Japan

Fecal samples obtained from 600 household cats (244 males and 356 females) kept in 3 prefectures of Tohoku district in Japan were examined for Giardia intestinalis antigen, using a commercial enzyme-linked immunosorbent assay (ELISA) kit. G. intestinalis antigen was detected in 40% of the fecal specimens. The factors such as the age, life style or environmental condition of cats could be significantly related to the positive rate of G. intestinalis antigen. In contrast, the investigative district, appearance of feces, sex, breed or origin produced no significant difference in the positive rate. The present results suggest that G. intestinalis infection is widely spread in household cats of Tohoku district.     

Effect of isotonic and hypotonic lactated ringer's solutions with dextrose intravenously administered to dehydrated heifers

To determine the effects of rapid infusion of essential fluids in a volume of hypotonic lactated Ringer's solution, the central venous pressure (CVP) and acid-base equilibrium were investigated in to mildly dehydrated heifers. Mild dehydration was induced in 9 Holstein heifers by withholding food and water until 7.0+/-5.7% of plasma volume had been lost. The heifers were randomly assigned to the ILG (lactated Ringer's + 5% dextrose), HLG (1/2 lactated Ringer's + 2.2% dextrose) or HRG (1/2 Ringer's + 2.5% dextrose) groups with 3 heifers in each group. Heifers received 30 ml/kg of one of the fluids, at a flow rate of 20 ml/kg/hr. The rapid intravenous (IV) infusions of HLG and HRG used in this study were found to be safe and effective in increasing plasma volume without increasing CVP, even though the infusion was given to the jugular vein at a dosage of 30 ml/kg. However, ILG infusion induced progressive increases in CVP, reaching 9.0+/-2.0 mmHg. No clinical signs, such as moist rales on auscultation, moist cough, jugular vein congestion, ophthalmoptosis, salivation or arrhythmia, were observed throughout the fluid infusion. The relative changes in base excess (rBE) for the ILG and HRG groups were significantly decreased until the end of fluid infusion. As for the HLG group, rBE slightly decreased until the end of the fluid infusion. Then the values significantly increased and exceeded the pre-infusion value at the end of the experiment. While IV infusion of HLG inhibited acidification caused by dilution, HRG infusion induced diluted acidification. It is suggested that HLG infusion should be examined as a treatment for cattle with dehydration and moderate metabolic acidosis, since rapid infusion of HLG may be more beneficial for rehydrating cattle with metabolic acidosis than current treatment.     

Detection of Salmonella in spent hens and eggs associated with foodborne infections

About 16,000 spent hens from 23 farms in the northern area of Japan were purchased in 1996, 1997, 1998, and 1999 to isolate Salmonella in two poultry processing plants. Salmonella was detected in 12 of 23 farms (52.2%). In particular, the serotypes Enteritidis and Infantis were detected in four and three farms, respectively. The prevalence rates in the hens' ceca, immature eggs, and the yolk of mature eggs in oviducts were 14%, 7.2%, and 6.8%, respectively. A total of 23 serotypes were detected. The major serotypes of the strains were Enteritidis, Corvallis, Typhimurium, and Infantis, but most of the strains were untypable. In the same area during 1992 to 1996, Salmonella was detected in eggs associated with four outbreaks of Salmonella Enteritidis infection and one outbreak of Salmonella Infantis infection. The ratio of contamination was approximately 1%, and the level was estimated to be 93 MPN(most probable number)/100 g in one outbreak. In farms that produced the eggs associated with all of the five outbreaks of Salmonella, the serotype Enteritidis or Infantis was isolated from hens. Farms where Salmonella was not detected were not related to any of the outbreaks.     

Effect of cellulase supplementation in low-crude protein diets on performance, nitrogen excretion, fat deposition, hepatic lipogenic and lipolytic enzyme activity in broilers

1. Two experiments were conducted to investigate the effect of dietary enzyme supplementation of a low-protein diet on performance, nitrogen excretion, fat deposition, hepatic lipogenic and lipolytic enzyme activity in 7-21- (Experiment 1) and 21-42-d-old (Experiment 2) male broiler chicks. 2. Chicks were given diets containing 210 g (Experiment 1) or 170 g (Experiment 2) crude protein (CP)/kg (Control), amino acid-fortified diets 190 g (Experiment 1) and 150 g (Experiment 2) CP/kg (Low-protein), and a low-protein diet supplemented with 1000 U/kg of cellulase. 3. In Experiment 1, growth performance and abdominal fat deposition were not affected by dietary treatments, and birds given low-protein diets excreted less nitrogen. The activities of hepatic lipogenic and lipolytic enzymes were not different among the three dietary groups. 4. In Experiment 2, the dietary treatment did not affect growth performance or abdominal fat weight. Nitrogen excretion was significantly lower in chicks given the 150 g/kg CP diet than those on the 170 g/kg CP diet; however, nitrogen retention was no different among the treatments. Dietary CP and enzyme supplementation did not significantly affect hepatic enzyme activities. 5. These results suggest that CP content in the broiler diet can be reduced by 20 g/kg without lowering performance by the supplementation of crystalline amino acids, and can reduce nitrogen excretion by about 25%. Cellulase supplementation of a low-CP diet slightly lowered abdominal fat deposition; however, it did not significantly affect hepatic lipogenic and lipolytic enzyme activity.