Application of acoustic Doppler current profiler combined with a scientific echo sounder for krill Euphausia pacifica density estimation

ABSTRACT:   An application of the acoustic Doppler current profiler (ADCP, 153.6 kHz) in combination with a scientific echo sounder (EK60, 38 and 200 kHz) was investigated to estimate the density of krill Euphausia pacifica . The acoustic backscattering strength from sound scattering layers was compared with biomass estimates from midwater trawls. Euphausia pacifica was targeted among mixed species populations in the sound scattering layer in the offshore Funka Bay area of Hokkaido, Japan. The frequency characteristics of acoustic backscattering by krill were calculated using a distorted wave Born approximation scattering model at three frequencies. Krill aggregations identified from the EK60 data were extracted as the mean volume backscattering strength difference between two frequencies. They were then used to identify similar aggregations in the ADCP data by matching observation times and depths for the two methods, which were applied simultaneously. Results from the comparison of the mean volume backscattering strength and the density calculated from the ADCP and EK60 showed that ADCP can be used to measure density and spatial–temporal distribution of krill aggregations. Current speed and direction at the study site were found to be 16.1 cm/s and 187.0°, respectively, and krill speed and direction (including the current component) were found to be 19.8 cm/s and 172.2°, respectively. Based on the ADCP data, the net speed and direction of the krill aggregations were found to be 5.9 cm/s and 128.0°, respectively.     

Single oral β-cryptoxanthin administration increases its serum concentration and enhances peripheral blood neutrophil function in Holstein cattle

We investigated the effect of oral administration of β-cryptoxanthin (β-CRX) on its serum concentration and peripheral neutrophil functions by the chemiluminescence (CL) response in Holstein cattle. A single oral administration of β-CRX was performed for serum β-CRX concentration (0, 0.05, 0.1, or 0.2 mg/kg body weight [BW]) and for peak CL response of peripheral neutrophils (0.2 mg/kg BW). The serum β-CRX concentration was peaked on 2 days after, similar to peak CL response on 3 days after β-CRX administration. Therefore, a single oral administration of β-CRX (0.2 mg/kg BW) induces higher serum concentration and concurrently enhances bactericidal ability of peripheral neutrophils in Holstein cattle.     

Glucagon‐related peptides and the regulation of food intake in chickens

The regulatory mechanisms underlying food intake in chickens have been a focus of research in recent decades to improve production efficiency when raising chickens. Lines of evidence have revealed that a number of brain‐gut peptides function as a neurotransmitter or peripheral satiety hormone in the regulation of food intake both in mammals and chickens. Glucagon, a 29 amino acid peptide hormone, has long been known to play important roles in maintaining glucose homeostasis in mammals and birds. However, the glucagon gene encodes various peptides that are produced by tissue‐specific proglucagon processing: glucagon is produced in the pancreas, whereas oxyntomodulin (OXM), glucagon‐like peptide (GLP)‐1 and GLP‐2 are produced in the intestine and brain. Better understanding of the roles of these peptides in the regulation of energy homeostasis has led to various physiological roles being proposed in mammals. For example, GLP‐1 functions as an anorexigenic neurotransmitter in the brain and as a postprandial satiety hormone in the peripheral circulation. There is evidence that OXM and GLP‐2 also induce anorexia in mammals. Therefore, it is possible that the brain‐gut peptides OXM, GLP‐1 and GLP‐2 play physiological roles in the regulation of food intake in chickens. More recently, a novel GLP and its specific receptor were identified in the chicken brain. This review summarizes current knowledge about the role of glucagon‐related peptides in the regulation of food intake in chickens.     

Impaired female fertility in tubulointerstitial antigen-like 1-deficient mice

Tubulointerstitial nephritis antigen-like 1 (Tinagl1, also known as adrenocortical zonation factor 1 [AZ-1] or lipocalin 7) is a matricellular protein. Previously, we demonstrated that Tinagl1 expression was restricted to extraembryonic regions during the postimplantation period and detected marked expression in mouse Reichert’s membranes. In uteri, Tinagl1 is markedly expressed in the decidual endometrium during the postimplantation period, suggesting that it plays a physical and physiological role in embryo development and/or decidualization of the uterine endometrium during pregnancy. In the present study, in order to determine the role of Tinagl1 during embryonic development and pregnancy, we generated Tinagl1-deficient mice. Although Tinagl1^–/– embryos were not lethal during development to term, homologous matings of Tinagl1^–/– females and Tinagl1^–/– males showed impaired fertility during pregnancy, including failure to carry pregnancy to term and perinatal lethality. To examine ovarian function, ovulation was induced with equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG); the number of ovulated oocytes did not differ between Tinagl1^–/– and Tinagl1^flox/flox. In vitro fertilization followed by embryo culture also demonstrated the normal developmental potential of Tinagl1-null embryos during the preimplantation period. Our results demonstrate that Tinagl1 deficiency affects female mice and results in subfertility phenotypes, and they suggest that although the potential of Tinagl1^–/– oocytes is normal, Tinagl1 is related to fertility in adult females but is not essential for either fertilization or preimplantation development in vitro.     

Influence of light intensity on feeding, growth, and early survival of leopard coral grouper (Plectropomus leopardus) larvae under mass-scale rearing conditions

This study investigated the effect of different light intensities on feeding, growth and survival of early stage leopard coral grouper Plectropomus leopardus larvae. Four different light intensities (0, 500, 1000 and 3000 lx) were used and larvae were kept under constant light conditions from 0 day after hatching (DAH) to 5 DAH. The larvae were fed a small S-type of Thai strain rotifers at a density of 20 individuals/mL from 2 DAH. The number of rotifers in larval digestive organ and total length of larvae were examined at 3 h intervals between 04:00 and 22:00 h on 3 DAH, and thereafter at 6 h intervals until the end of the experiment (5 DAH). Four experimental trials of the larval rearing were repeated using by 60 kL mass-scale rearing tanks. The results indicate that coral grouper larvae are visual feeders and their food intake increases with increasing light intensity. Food intake of larvae reared at 3000 lx was significantly higher than those reared at 0–1000 lx on 3 DAH despite being the first-feeding day (P < 0.01). On 4 DAH, total length of larvae reared at 3000 lx was significantly larger than those reared at the lower light intensities (0, 500 and 1000 lx), and thereafter light intensity significantly influenced larval feeding and growth until the end of the experiment. Survival on 5 DAH did not show a significant difference between light intensities, but survival rate at 3000 lx and 1000 lx had a tendency to be higher than those reared at the lower light intensities (0 and 500 lx). In contrast, larvae reared at 0 lx exhibited stagnant and/or negative growth. These results indicate that light intensity is significantly the factor affecting larval feeding, growth, and survival in coral grouper larvae under the rearing conditions.     

Changes in organosulfur compounds in garlic cloves during storage

We determined the changes in the contents of three gamma-glutamyl peptides and four sulfoxides in garlic cloves during storage at -3, 4, and 23 degrees C for 150 days using a validated high-performance liquid chromatography method that we reported recently. When garlic was stored at 4 degrees C for 150 days, marked conversion of the gamma-glutamyl peptides, gamma-L-glutamyl-S-allyl-L-cysteine and gamma-L-glutamyl-S-(trans-1-propenyl)-L-cysteine (GSPC), to sulfoxides, alliin and isoalliin, was observed. Interestingly, however, when garlic was stored at 23 degrees C, a decrease in GSPC and a marked increase in cycloalliin, rather than isoalliin, occurred. To elucidate in detail the mechanism involved, the conversion of isoalliin to cycloalliin in both buffer solutions (pH 4.6, 5.5, and 6.5) and garlic cloves at 25 and 35 degrees C was examined. Decreases in the concentration of isoalliin in both the solutions and the garlic cloves during storage followed first-order kinetics and coincided with the conversion of cycloalliin. Our data indicated that isoalliin produced enzymatically from GSPC is chemically converted to cycloalliin and that the cycloalliin content of garlic cloves increases during storage at higher temperature. These data may be useful for controlling the quality and biological activities of garlic and its preparations.     

不同添加剂对苜蓿青贮饲料品质的影响

利用糖蜜、甲酸、乳酸菌制剂和酶制剂分别或共同对 2种不同含水率的苜蓿进行了青贮调制试验 ,结果表明 :不同添加剂处理的苜蓿 1(含水率 71%～ 73% )和苜蓿 2 (含水率 6 2 %～ 6 4 % )青贮饲料的等级均为良好 ,且发酵品质均比对照组有所提高。糖蜜使苜蓿 1和苜蓿 2青贮饲料乳酸与总酸质量比分别提高 4 7%和 32 % ,NDF降解率分别提高 10 %和 2 2 % ;乳酸菌制剂降低了青贮饲料中乳酸含量 ,提高了乙酸含量 ,使NDF降解率分别比对照组提高 2 6 %和 18% ;酶制剂提高了动物的消化率 ;乳酸菌制剂和酶制剂共同作用使乳酸与总酸质量比分别降低了37%和 39% ,同时提高了动物消化率和青贮饲料的营养价值 ;甲酸处理使饲料中乙酸与总酸质量比分别降低了31%和 2 5 % ,NDF降解率分别提高了 19%和 14 % ,并在一定程度上抑制了蛋白质和氨基酸的分解。糖蜜有效抑制了苜蓿 1青贮饲料的二次发酵 ,但苜蓿 2青贮饲料的发酵品质显著优于苜蓿 1(P <0 0 5 )。     

Effects of feeding and animal performance on nitrogen, phosphorus and potassium excretion by Holstein cows

Thirty‐four Holstein dry cows and 16 lactating cows were used in balance trials to identify the effects of feeding and animal performance on nitrogen (N), phosphorus (P) and potassium (K) excretion by dairy cows, and to develop prediction models for these excreta. Orchard grass silage, corn silage, alfalfa silage or timothy hay were offered to dry cows. Orchard grass silage or alfalfa silage, and concentrates were offered to lactating cows. In the statistical analysis, the independent variables were bodyweight (kg), dry matter (DM) intake (kg/day), milk yield (for lactating cows only, kg/day), water intake (free water plus water in feed, kg/day), intake (g/day) of N, P and K and dietary contents (% of DM) of crude protein, P and K. The dependent variables were N, P and K excretion (g/day) in feces and urine. In both dry and lactating cows, intake of N, P and K had large effects on corresponding excretion. The results indicated that a decrease in the intake of N, P and K could decrease the corresponding excretion. Further research by path analysis showed that K intake positively affected urinary N excretion in dry cows indirectly, through water intake and urine volume.     

Development of X-ray computed tomography for live standing cattle

An X‐ray computed tomography (CT) system for live standing cattle was developed for studying the meat yield, carcass composition and so on. The gantry contained three X‐ray tubes and detectors that corresponded to each X‐ray tube. The system was able to operate while the animal remained standing. The scan area had a diameter of 900 mm. The Musculus longissimus and Musculus trapezius areas, and the back fat thickness in the CT image were evaluated and compared to the actual cross‐section of the carcass using eight cattle. The differences among the muscles, and the subcutaneous and intermuscular fat were easily recognized. The correlation coefficient between the CT image and the actual carcass photograph of the M. longissimus area and the back fat thickness was high (r = 0.84, r = 0.93, P < 0.01). The present study demonstrated that muscle, fat and bone can be clearly imaged from a live standing animal using X‐ray equipment.     

Quantitative structure—activity relationships of light-dependent herbicidal 4-pyridone-3-carboxanilide derivatives II. Substituent effects of anilide and pyridone moieties

The variations in the light-dependent herbicidal activity against Echinochloa oryzicola of a number of 4-pyridone-3-carboxanilides with various substituents on the anilide and pyridone rings have been examined by use of physicochemical substituent parameters and regression analysis. The effects of substituents of the anilide ring were such that the activity was related parabolically not only with the substituent hydrophobicity (π) but also with the steric bulk parameter (E_s) of the bulkier ortho substituent. The effect of substituents at the 1-position of the pyridone ring was analysed with steric(STERIMOL L and B₅) and electronic(γ₁) parameters. That of substituents at the 5-position of the pyridone ring was explained by a parabolic function of a steric (MR) parameter. Analyses of the activity of 105 analogs confirmed that our previous selection of a candidate compound in this series for field trials was indeed appropriate in terms of physicochemical substituent effects.