時田 昇臣

We investigated the intake and digestibility of different reed canarygrass (RCG) growth stages by sheep. RCG was cultivated in an experimental field and harvested at the first and second cuts at each pre-blooming stage. Feeding behavior was monitored on adult female sheep, fed 3 kg each of fresh RCG three times daily. While the crude protein content and dry matter digestibility of RCG were significantly higher in leaf than in stem tissue of both first and second cut in harvesting times, neutral and acid detergent fiber contents were higher in stem than in leaf. The dry matter intake of RCG at the second cut (296.1g) was significantly higher than at the first cut (214.1 g). The eating time for consumption of RCG on dry matter at the second cut (54.9 min) was shorter than at the first cut (69.4 min). Consequently, at the second cut, the rate of biting (54.6 bites/min) was lower than at the first cut (64.8 bites/min). Bite size, expressed as dry matter intake per bite, ranged from 0.05 g at first cut to 0.10 g at second cut.

ヤマザクラPrunus jamasakuraの結実期に,果実の色彩と栄養価そして鳥類による果実の持ち去りとの関係について調べた.果実の成熟過程は,果実の色によって,緑,赤緑,赤,黒の4段階に分けた.鳥類が持ち去った果実は,主に赤い果実と黒い果実であり,鳥類は特に黒い果実を選ぶ傾向がみられた.緑と赤緑の果実は赤や黒の果実よりも小さく,糖成分(フルクトース,グルコース,スクロース)の含有量とエネルギー量が少なかった.赤い果実と黒い果実を比較すると,大きさに差はないが,糖含有量とエネルギー量に差がみられた.黒い果実は,赤い果実よりも糖含有量がおよそ4.6%,エネルギー量がおよそ0.4kJ多かった.果実の持ち去りは主にムクドリSturnus cineraceusとヒヨドリHypsipetes amaurotisによるものであり,この2種では飛来のパターンが異なっていた.ムクドリの飛来数はヤマザクラの結実期間中に変動し,ヤマザクラの樹上に赤と黒の果実が同時についている時期(二色の果実表示期間)に増えた.一方,ヒヨドリの飛来数には変動がみられなかった.これらの結果は,ヤマザクラが二色の果実表示によって鳥類の一部の種をひきつけていること,そして,熟果に糖を蓄積することでエサとしての価値を高め,飛来した鳥に熟果を持ち去らせていることを示唆するものである.

The behavior of frugivorous birds during the removal of fruit from Swida controversa was investigated to compare the relationships between measures of fruit maturation and quantitative fruit removal behavior of birds. Bird exclusion devices were used on some branches to allow comparison of the traits of removed and un-removed fruits. Nine bird species visited S. controversa, but only four removed fruit, and each bird species removed a different number of fruits per visit. Only 11.5% of a branch's fruits were removed by birds. Birds removed only larger, blacker, more mature fruits, suggesting birds were effective seed dispersers. © The Ornithological Society of Japan 2012.

Chemical composition, energy content and in vitro dry matter digestibility of new leaves of three dwarf bamboo species were analysed in the Tanzawa Mountains. The three dwarf bamboo species were Pleioblastus chino, Sasamorpha borealis and Sasa hayatae. These species are almost exclusive winter food resources for sika deer because of their evergreen leaves. Protein content of newleaves of the three species ranged from 11.8% to 16.4% with the greatest content in Pleioblastus chino and the least one in the Sasamorpha borealis. The content of neutral and acid detergent fibers did not show large difference among the three species, but that of acid detergent lignin was higher in Sasamorpha borealis than in Pleioblastus chino. In vitro dry matter digestibility of Sasamorpha borealis was higher than that of Sasa hayataea, but these values were under 31.0% each. The gross energy of new leaves in this experiment ranged from 17.9kJ/g to 19.4kJ/g. These results indicate that the nutritive value of the three dwarf bamboo species in the Tanzawa mountains is insufficient for sika deer as a winter food resource because of their high content of neutral detergent fiber and low digestibility.

2009.

2009.

Digestive efficiency and nutrient and energy consumption of the dugong (Dugong dugon) were determined during 1 year, using one male and one female captive animals fed eelgrass (Zostera marina) at the Toba Aquarium. The quantity of urine excreted was also estimated to evaluate ingestion of metabolic energy (ME), by measuring creatinine concentration of spot samples taken from the female. Estimated consumption rate of eelgrass was low at 0.82-0.99% dry matter (DM) of bodyweight, which was closely associated with its high nutritive value and digestibility as shown by 74% total digestible nutrients and 14.6% digestible crude protein on a DM basis. Consumption of gross energy and digestible energy averaged 10.4 Mcal per day and 9.6 Mcal per day, respectively. The female individual consumed 8.64 Mcal per day ME, calculated from urination of 26.2 l per day and estimated from urinary creatinine concentration and an equation for urinary creatinine excretion and bodyweight.

Tuberous roots of yacon (Smallanthus sonchifolius) accumulate about 10%, on a fresh weight basis, of inulin-type fructooligosacharides (FOSs), known as a food ingredient with various healthy beriefits. However have a great difficulty to ensure these benefits because FOSs with a lower degree of polymerization (DP) decreased remarkably, and fructose increased when the tuberous roots were stored after harvesting oven under previously recommended storage conditions of low temperature with high humidity. In the present study, to elucidate the involvement of FOS-metabolizing enzymes in FOS reduction during storage at 90% relative humidity and 8 degrees C, we extracted a crude protein from yacon tuberous roots and measured the activities of invertase (beta-fructofuranosidase, EC 3.2.1.26), sucrose:sucrose 1-fructosyltransferase (1-SST, EC 2.4.1.99), fructan:fructan 1-fructosyltransferase (1-FFT, EC 2.4. 1.100), and fructan 1-exohydrolase (1-FEH, EC 3.2.1.80). The enzyme activities acting on invertase and 1-SST, were weakened after storage for a month. In addition, the activity of 1-FFT acting such as 1-kestose (GF(2)) and 1-nystose (GF(3)) was higher than that of 1 -FFT. These results suggest that the continuos decline in FOSs of low DP during storage was dependent mainly on the 1-FEH activity. On the other hand,FOSs with a DP of >= 9 only slightly decreased in stored yacon tuberous roots during storage, though distinct, was observed in vitro toward a high-DP inulin-type substrate, indicating that highly polymerized FOSs content was unlikely to be closely connectedwith the 1-FEH activity.

An experiment was conducted to investigate amino acid composition of three tropical legumes (Cooper (Glycine wightii), Tinaroo (Neonotonia wighiii) and Siratro (Macroptilium atropurpureum) at two different stages (pre-blooming and blooming stages). Chemical composition and totally 16 amino acids of these plants were analysed for comparison of their composition among species at different growing stages and characterizing the amino acid pattern of these legumes. Crude protein content of the plants ranged from 16% to 27% on a dry matter basis. The total amount of 16 amino acids analyzed in this experiment was highest at 89.7 mg/16 g N in Cooper at pre-blooming and lowest at 80.9 mg/16 g N in Glycine at blooming stage. Total amount of amino acids in each legume species tended to slightly decrease with their maturity but no statistical difference was found. The percentage or aspartic acid, glutamic acid and proline in the total amount of amino acids was dominant at 9% to 13%, and that of methionine was less than 1.6%. In this experiment it was concluded that three tropical legumes were rich in crude protein content and characterized by 16 different amino acids with lower sulfur-containing amino acid as methionine.

2005.

2004.

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2001.

コシジロウミツバメ(Oceanodroma leucorhoa)を用いて,翼長,最大尾長,最小尾長,フショ長,嘴高,嘴長の外部計測値と体重から,栄養状態の推定する指標を作成した.6個所の外部計測値から主成分分析によって抽出された第一主成分得点を計算することによって,全体の体サイズを表す指標とした.第一主成分得点を独立変数,体重の3乗根を従属変数とし,単回帰分析を行い,回帰直線から残差を栄養状態の指標とした.本研究では,この指標を余剰栄養指標(residual body condition index)と呼ぶ,コシジロウミツバメを用いて,余剰栄養指標の有効性を実測された脂肪蓄積量と比較することで検討した,コシジロウミツバメを全身麻酔下で殺した後,死体からエチルエーテルによって蓄積脂肪を抽出した.余剰栄養指標は,脂肪量の3乗根の57.4%を説明することが可能であった.したがった,体重と外部形態の測定を行うだけで,野外で繁殖するコシジロウミツバメについて,鳥を犠牲にすることなくまた容易に,栄養状態を推定することが可能となった.

1996.

1995.

1987.

1987.

1981.