Possible factors influencing the immunoglobulin G concentration in swine colostrum

The immunoglobulin (Ig) G concentration in swine colostrum was determined by the single radial immunodiffusion method, using 157 samples collected from farm-raised sows in the Yamaguchi Prefecture of Japan during 1976 and 1977. The mean IgG value was 53.03 mg/ml, and the maximum and minimum values were 101.39 mg/ml and 11.74 mg/ml, respectively. The amount of IgG varied greatly among sows. To clarify the possible factors influencing the amount of IgG in colostrum, the following items were surveyed: season, district, breed, age of sows, number of parturitions, udder section from which samples were collected, kind of feed, vaccinations of swine erysipelas live-organism vaccine, hog cholera live-virus vaccine, Japanese encephalitis live-virus vaccine, tramsmissible gastroenteritis liver-virus vaccine, type of farming, and number of sows raised on a farm. Relationships between the amount of IgG in colostrum and each of these 13 items were analyzed. Seemingly, strong correlations with the amounts if IgG in colostrum were found with five items (district, number of parturitions, kind of feed, type of farming, and number of sows). To the contrary, five items (age, udder section, and vaccinations of swine erysipelas live-organism vaccine, hog cholera live-virus vaccine, and Japanese encephalitis live-virus vaccine) had poor correlations. Other items had moderate correlations. The multiple correlation coefficient obtained was 0.5499.     

Evaluation of Cold Tolerance in NERICAs Compared with Japanese Standard Rice Varieties at the Reproductive Stage

New Rice for Africa (NERICA) is a general name for interspecific rice varieties derived from a cross between the high‐yielding Asian rice (Oryza sativa L.) between locally adapted African rice (Oryza glaberrima Steud.). Eight NERICAs were evaluated for cold tolerance (CT) at the reproductive stage and compared with their O. sativa parents and three Japanese standard rice varieties over 3 years. Cold tolerance was evaluated based on the filled grain ratio (FGR) after cold water irrigation. The FGR was greatly reduced by cold water irrigation. NERICA 1, 2 and 7 had higher FGR (51.9–57.9 %), while NERICA 6, 15 and 16 had lower FGR (6.2–14.5 %). NERICA 1, 2 and 7 were less affected by cold stress, with a 31 % mean reduction in FGR, while NERICA 6, 15 and 16 were greatly affected, with their FGRs being reduced by more than 80 %. NERICA 3 and 4 were moderately affected by cold stress, with about 45 % reduction rate in FGR. FGR significantly influenced the grain weights of the varieties with strong positive correlations (r = 0.83–0.91; P < 0.001), and thus, similar trends in grain weights were observed. Grain weights were reduced by 61.7–96.4 % under cold stress. NERICA 1, 2 and 7 showed significantly better performance than NERICA 3 and 4, while NERICA 6, 15 and 16 performed poorly under cold water irrigation. The Japanese varieties Koshihikari (very tolerant) and Ozora (moderately tolerant) were more affected by cold water irrigation than NERICA 1, 2 and 7. On the basis of the mean reduction rate (%) in FGR under cold stress, the varieties were classified as follows: NERICA 1, 2 and 7 as tolerant; NERICA 3 and 4 as moderately tolerant; and NERICA 6, 15 and 16 as susceptible to cold stress. However, NERICA 7 grain yields were lower under cold stress due to both greatly reduced number of panicles per plant and number of spikelets per panicle. Therefore, NERICA 1 and 2 are suitable candidates for production in the highland regions of East Africa and should be promoted for production.     

Presence and ontogeny of intestinal and pancreatic phospholipase A2-like proteins in the Red Sea bream,Pagrus major. An immunocytochemical study

We have studied the location and the ontogeny of the digestive enzyme, phospholipase A₂ (PLA₂) immunohistochemically in the adult and larvae/juvenile of the red sea breamPagrus major by using an antiserum against theNaja naja venom PLA₂. The antiserum reacts with at least one enzyme among the PLA₂s purified from the fish hepatopancreas or intestine. Although the reactivities were comparatively low, it labelled zymogen granules of the pancreatic acinar cells and secretory materials of certain epithelial cells in the depths of epithelial crypts in the pyloric caeca of the adult. The immunoreactivities of PLA₂s were investigated in the viscera of larvae and juveniles of the 0 to 85^th day after hatch. In the larvae of the 13^th day, accumulation of PLA₂-positive zymogen granules in the pancreatic acinar cells were first recognized by the immunostaining. The intensity of the labelling subsequently became stronger and dramatically increased between the 20^th and 30^th day. This increase appeared to be one of the physiological changes associated with the transition to a new benthic life as juveniles. Lack of PLA₂ in the pancreas before the 13^th day may suggest the possibility that larvae utilized exogenous PLA₂, inherent in their prey, to digest the phospholipids. On the other hand, no reactivity was found in the intestine until the 85^th day.     

Photoperiod influences the growth, food intake, feed efficiency and digestibility of red sea bream (Pagrus major)

Two consecutive trials were conducted to investigate the effects of photoperiod manipulation on growth rate, food intake and feed conversion efficiency (Trial 1), and the digestibility of nutrients and energy (Trial 2) in red sea bream, Pagrus major (body weight 19–120 g). Fish were exposed to four photoperiods (6L:6D, 12L:12D, 16L:8D and 24L:0D) with light intensity 1500 lx on the water surface. The fish were fed with a commercial diet to apparent satiation. In Trial 2, 0.5% chromic oxide (Cr₂O₃) was used as an inert marker. Significantly higher weight gain and specific growth rates were observed in fish exposed to a 24L:0D photoperiod followed by 16L:8D, 6L:6D and 12L:12D photoperiods (P < 0.05). Food intake and feed conversion efficiency (FCE) were also significantly higher in fish exposed to 24L:0D followed by 16L:8D, 6L:6D and 12L:12D photoperiods (P < 0.05). Fish exposed to 24L:0D and 16L:8D photoperiods showed significantly higher lipid and energy digestibility than those exposed to a 12L:12D photoperiod (P < 0.05). The results demonstrated that the enhancement of growth performances under 16L:8D and 24L:0D photoperiods were attributed to improved appetite, greater food intake and higher feed conversion efficiency as well as higher digestibility.     

Size-related factors causing individual variation in seasonal reproductive success of fluvial male Dolly Varden (Salvelinus malma)

Abstract– Reproductive activities of individually identified fluvial Dolly Varden ( Salvelinus malma ) were observed during a breeding season in a small stream. Males and females both established dominance hierarchies based on body size. Females spawned from late October to late November, with no apparent peak, and larger females spawned earlier than small ones. Males competed for access to females by adopting two types of mating tactics: pairing and sneaking. The tactic used depended on the male's position in the dominance hierarchy of the breeding group. Seasonal reproductive activity and mating success of males were positively correlated with body size, with only the largest male monopolizing most of the mating opportunities, and the small males were rarely successful in mating. Smaller males, however, lost as much weight as large males during the breeding season. Females preferred the largest male in the breeding group as a mate, while males courted females of any size. It is suggested that the polygynous mating pattern is a consequence of size-related differences in competitive ability among males, and the degree of monopolization is affected by both the temporal distribution and the spawning tactics of the females.     

Cytokinin oxidase regulates rice grain production

Most agriculturally important traits are regulated by genes known as quantitative trait loci (QTLs) derived from natural allelic variations. We here show that a QTL that increases grain productivity in rice, Gn1a, is a gene for cytokinin oxidase/dehydrogenase (OsCKX2), an enzyme that degrades the phytohormone cytokinin. Reduced expression of OsCKX2 causes cytokinin accumulation in inflorescence meristems and increases the number of reproductive organs, resulting in enhanced grain yield. QTL pyramiding to combine loci for grain number and plant height in the same genetic background generated lines exhibiting both beneficial traits. These results provide a strategy for tailormade crop improvement.     

The influence of age and body mass index on relative accuracy of energy intake among Japanese adults

OBJECTIVE: To examine relationships between the ratio of energy intake to basal metabolic rate (EI/BMR) and age and body mass index (BMI) among Japanese adults. DESIGN: Energy intake was assessed by 4-day semi-weighed diet records in each of four seasons (16 days in total). The EI/BMR ratio was calculated from reported energy intake and estimated basal metabolic rate as an indicator of reporting accuracy. SETTING: Residents in three areas in Japan, namely Osaka (urban), Nagano (rural inland) and Tottori (rural coastal). SUBJECTS: One hundred and eighty-three healthy Japanese men and women aged > or =30 years. RESULTS: The oldest age group (> or =60 years) had higher EI/BMR values than the youngest age group (30-39 years) in both sexes (1.74 vs. 1.37 for men; 1.65 vs. 1.43 for women). In multiple regression analyses, age correlated positively (partial correlation coefficient, beta = 0.012, P < 0.001 for men; beta = 0.011, P < 0.001 for women) and BMI correlated negatively (beta = -0.031, P < 0.001 for men; beta = -0.025, P < 0.01 for women) with EI/BMR. CONCLUSION: Age and BMI may influence the relative accuracy of energy intake among Japanese adults.