Fuminori Terada

Factors affecting methane production and mitigation in ruminants

Methane (CH(4)) is the second most important greenhouse gas (GHG) and that emitted from enteric fermentation in livestock is the single largest source of emissions in Japan. Many factors influence ruminant CH(4) production, including level of intake, type and quality of feeds and environmental temperature. The objectives of this review are to identify the factors affecting CH(4) production in ruminants, to examine technologies for the mitigation of CH(4) emissions from ruminants, and to identify areas requiring further research. The following equation for CH(4) prediction was formulated using only dry matter intake (DMI) and has been adopted in Japan to estimate emissions from ruminant livestock for the National GHG Inventory Report: Y = -17.766 + 42.793X - 0.849X(2), where Y is CH(4) production (L/day) and X is DMI (kg/day). Technologies for the mitigation of CH(4) emissions from ruminants include increasing productivity by improving nutritional management, the manipulation of ruminal fermentation by changing feed composition, the addition of CH(4) inhibitors, and defaunation. Considering the importance of ruminant livestock, it is essential to establish economically feasible ways of reducing ruminant CH(4) production while improving productivity; it is therefore critical to conduct a full system analysis to select the best combination of approaches or new technologies to be applied under long-term field conditions.

Effects of feeding Italian ryegrass with corn on rumen environment, nutrient digestibility, methane emission, and energy and nitrogen utilization at two intake levels by goats

This study was conducted to investigate the effects of corn addition to Italian ryegrass (IRG) (Lolium multiflorum Lam.) on rumen environment, nutrient digestibility, methane production and energy and nitrogen utilization by goats at two intake levels. Eight castrated Japanese goats were employed in two sequential digestion and metabolism trials. The goats were divided into two groups, offered two diets: Diet 1 consisted of 85% Italian ryegrass pellet (IRG) and 15% soybean meal; and Diet 2 consisted of 42.5% IRG, 7.5% soybean meal and 50% corn. The two intake levels were, high (1.6 times) and low (0.9 times) maintenance requirement of total digestible nutrient (TDN). Rumen ammonia nitrogen (NH3N) level of Diet 1 was lower (p 0.05) in energy losses as methane (CH4) and heat production between the diets. Urinary energy loss (UE) as a proportion of digestible energy (DE) was higher (p 0.05) for Diet 2. The N loss/unit of N intake was significantly lower (p<0.001) at the high level of intake although it had higher total N losses. Thus, supplementation of IRG diet with corn increased retained energy and retained N through reducing the energy and N losses. The high level of intake reduced the proportion of nutrient losses through feces, urine and methane. Supplementation of IRG with corn and soybean meal at the higher level of intake improved the efficiency of utilization of IRG and increased energy and nitrogen retention. # 2000 Elsevier Science B.V. All rights reserved.

Effect of cellooligosaccharide or synbiotic feeding on growth performance, fecal condition and hormone concentrations in Holstein calves

We investigated the effect of cellooligosaccharide (CE) or a combination of dextran and Lactobacillus casei ssp. casei strain JCM1134(T) (synbiotic; SB) feeding on growth performance, fecal condition and hormone concentrations in Holstein calves. Fifty-two female Holstein calves were randomly assigned to three treatment groups: CE feeding group (n = 16), SB feeding group (n = 18), and control group (n = 18). Body weight at 90 days of age, as well as daily body weight gain (DG) and feed efficiency after weaning to 90 days of age were greater (P < 0.05) in the CE feeding group than in the control group. The total fecal score tended to be lower (P < 0.1) in the SB feeding group than in the control group. Plasma insulin concentration was higher (P < 0.05) in the CE feeding group than in the control group at 90 days of age. Our results indicate that CE feeding improved DG and feed efficiency in calves. On the other hand, there was less effect on growth performance and fecal Escherichia coli counts in calves fed SB.

Clostridium pabulibutyricum sp. nov., a butyric-acid-producing organism isolated from high-moisture grass silage

A Gram-stain-variable, strictly anaerobic, rod-shaped, catalase-negative and endospore-forming bacterial strain, designated MJC39T, was isolated from grass silage preserved in Hokkaido, Japan. Growth occurred at 20-42 °C, pH 5.0-7.0 and NaCl concentrations up to 2 % (w/v). The isolated strain MJC39T produced butyric acid in peptone yeast extract medium with glucose. The DNA G+C content of strain MJC39T was 34.4±0.2 mol%. The major cellular fatty acids (>10 %) were C14 : 0, C16 : 0 and summed feature 3 (including C16 : 1ω7c/C16 : 1ω6c). No respiratory quinones were detected. The polar lipids of strain MJC39T were phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, one unidentified lipid, one unidentified aminolipid, two unidentified glycolipids, one unidentified phospholipid, one unidentified aminoglycolipid and one unidentified phosphoaminoglycolipid. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain MJC39T was a member of the genus Clostridium and is closely related to Clostridium tyrobutyricum JCM 11008T (95.8 % similarity) and Clostridium algifaecis MB9-7T (95.5 % similarity). Based on the genotypic, phenotypic and chemotaxonomic characteristics, strain MJC39T represents a novel species of the genus Clostridium, for which the name Clostridium pabulibutyricum sp. nov. is proposed. The type strain is MJC39T (=JCM 31506T=DSM 103944T).

An improved dry ash procedure for the detection of titanium dioxide in cattle feces.

We improved the dry ash procedure for detecting titanium dioxide (TiO2 ) in cattle feces containing chromium oxide [corrected] (Cr(2)O(3) ). First, the effect of amount of sodium sulfate (Na2 SO4 ) on the recovery of TiO2 from cattle feces that contained Cr2 O3 was evaluated. Average recovery of TiO2 at the 2.5 g Na2 SO4 level was significantly higher (P < 0.0001) than that at 0.75 g Na2 SO4 . Second, the effect of Cr2 O3 concentration on the recovery of TiO2 of cattle feces by using two levels of Na2 SO4 addition was examined. The recovery of TiO2 decreased with the increase in the amount of Cr2 O3 at the 0.75 g Na2 SO4 level but was consistently high at 2.5 g Na2 SO4 . Third, the recovery of Cr2 O3 from cattle feces was checked. The recoveries of TiO2 and Cr2 O3 were high enough at the 2.5 g Na2 SO4 level. Fourth, the improved dry ash procedure (5 mL of concentrated H2 SO4 and 2.5 g of Na2 SO4 were used for sample digestion) was compared to the wet ash procedure. Average recovery of TiO2 by the improved dry ash procedure was significantly higher (P = 0.0077) than that by the wet ash procedure. Thus, the improved dry ash procedure can be used for TiO2 analysis in cattle feces containing Cr2 O3 .

Effects of growth and dietary crude protein level until first insemination on milk production during first lactation in Holstein heifers.

To decrease the age at first calving in Holsteins, the effects of average daily body weight gain (ADG) and crude protein (CP) level until first insemination on growth performance and milk production were examined. The MM group had a target ADG of 0.75 kg and received a diet with a CP level of 14%. The HM and HH groups had a target ADG of 1 kg; both these groups received a diet with CP levels 14% and 16%, respectively. The ADG in the HM and HH groups was 1.1 kg, whereas in the MM group it was 0.97 kg (P < 0.01). The HM and HH groups showed no differences in withers height at body weight 350 kg. The ages at first calving in MM, HM and HH groups were 23.1, 21.0 and 21.8 months, respectively. The HM and HH groups had lower milk yield at day 305 than the MM group (P < 0.01). These results suggest that growth performance until first insemination should be maintained at an ADG of 0.97 kg or less with a CP level of approximately 14%, to shorten time until first insemination and prevent the decrease of milk yield.

Comparison of the Equations for Predicting nitrogen Excretion in Fattening Steers

肉用肥育牛の窒素排泄は窒素汚染の原因の一つと考えられているため,それを削減する方法を探ることは重要な課題である.本研究では,肥育去勢牛の糞尿による窒素排泄量を予測する数学式を作成,評価し,さらにその式を用いたシミュレーションによって窒素排泄量の削減の可能性を調べることを曲とした.2つの新しい式,Nf+u=Ns-CPg/6.25およびNf+u=a(Ns-Nr)+b+Nf+u(b)とすでに報告されているNf+u=16.74×DMI+8.54×CP+0.108×W-154.3を比較した.ただし,Nf+uは窒素排泄量(g/日),Nsは摂取窒素量(g/日),Nf+u(b)は内因性窒素排泄量(g/日), Nrは窒素要求量(g/日),CPgは増体のためのタンパク質要求量(g/日),DMI, CPおよびWはそれぞれ乾物摂取量(kg/日),粗タンパク質含量(乾物中%),体重(kg)である.CPg, NrおよびNf+u(b)は日本飼養標準を用いて推定し,回帰係数aとbは式を解くことによって求めた.新しい式は,23頭の黒毛和種と45頭の承ルスタイン種去勢牛の窒素出納実験の結果を用いて,作成•評価した. 1日当たりの増体量(DG; kg/日),粗タンパク質含量(CP; %)および代謝率(q)をそれぞれ独立に変化させることによって,肥育期間中の総窒素摂取量に対する総窒素排泄量(I1)および肥育期間中の総窒素蓄積量に対する総窒素排泄量(I2)の2つの環境負荷指標に対するこれらの要因の影響をシミュレートした.その結果,DGの増加はI1とI2の減少をもたらしCPの減少とqの増加はI2の減少をもたらすことが示された.また, I1に対するCPとqの効果は,用いる式によって異なることがうかがえた.

Effects of Proportion of Forage in the Diet on the Dry Matter Intake of Holstein Dry Cows During Last 9 Weeks of Pregnancy

経産ホルスタイン種乾乳牛8頭(体重:672.1±95.1kg,産次:4.1±1.7産)を用いて,分娩予定13週前から分娩までイタリアンライグラス1番草の乾草ウエハーと配合飼料の比率が9:1(H区,n=3,1頭除外)または5:5(C区,n=4)となるように混合して給与し,乾物摂取量(DMI)を測定した.飼料は,可消化養分総量(TDN)でホルスタイン種の維持要求量にホルスタイン種の胎子1頭増給分を満たすものとした.H区では分娩4週前以降に残飼が観察され,分娩が近づくに従ってその量が大きく増加し,乾物給与量に対するDMIの割合は分娩1週前に低くなる傾向(P<0.10)がみられた.C区では,全頭が給与飼料を全量採食した.仮に,本試験のH区におけるDMIを,分娩前各週における限界乾物摂取量とすると,分娩前4週間における乾乳牛のエネルギー要求量を満たす飼料中TDN含量は63.1%と計算される.

Effects of Energy Level on Plasma Hormones and Metabolites During the Last Two Months of Pregnancy in Holstein Dairy Cows

ホルスタイン種経産妊娠牛26頭を用いて,乳牛の妊娠末期におけるエネルギー摂取量が血中代謝産物およびホルモン濃度に及ぼす影響について検討した.イタリアンライグラス2番乾草またはサイレージ,および配合飼料を可消化養分総量(TDN)でホルスタイン種母体の維持要求量(M区),または維持要求量に胎子1頭分を増給(MP区)するものとした飼養試験を,妊娠28週目から行った.妊娠30週から40週まで2週に1度頸静脈および尾動脈から,それぞれ採食前に採血し,代謝産物濃度およびホルモン濃度の変化について検討した.M区の血漿インスリン濃度は,妊娠32週以降はMP区より有意に低く,妊娠36週以降は妊娠の進行に従って低下する傾向を示した.血漿グルコース濃度は,有意な差は観察されなかった.M区の遊離脂肪酸(FFA)濃度は,試験期間中は常にMP区より高い傾向にあり,妊娠40週目に上昇した.MP区では,妊娠38週まではほとんど変化はみられなかったが,分娩直前の40週に急激に上昇した.妊娠34週目以降におけるM区の各妊娠ステージでは,TDN摂取量が低くなるに従って,インスリン濃度は低く,グルカゴン濃度は高く,インスリンとグルカゴンのモル比率は低くなり,グルカゴン作用が優勢となっていた.以上の結果から,妊娠に必要なエネルギーを増給せず,維持量のみで妊娠末期を飼養した乳牛ではインスリンおよびグルカゴン濃度が低く,FFA濃度が高いことから体脂肪の動員が確認された.

Evaluation of the Nutritive Value of Steamed Japanese Beech and Steamed Japanese

17kg/cm2で15分間蒸煮処理したブナとコナラの栄養価を,子山羊を用いた飼養試験と出納試験を実施して検討した.1) イタリアンライグラス(IRG)乾草を48%(飼料乾物中)含む飼料,2) 蒸煮処理ブナを45%含む飼料,および3)蒸煮処理コナラを47%含む飼料を給与する3処理区を設けた.日本在来種去勢雄山羊12頭(試験開始時,平均22週齢,平均体重11.0kg)を用い,1区あたり4頭ずつ割り当てて,飼養試験を実施した.飼料の給与は,どの山羊にも代謝体重あたり等量の制限給餌とした.飼養試験に引き続き,全糞尿採取による出納試験を実施した.その結果,飼養試験期間中の乾物摂取量,1日増体量および飼料要求率について,3区の間に有意な差は認められなかった.消化試験成績から,間接法で求めた可消化養分総量の含量(乾物中)は,IRG乾草が54%,蒸煮処理ブナが43%,蒸煮処理コナラが47%であった.以上の結果から,蒸煮処理ブナと蒸煮処理コナラは,反芻動物によってエネルギー源として利用され,蒸煮処理ブナは稲わら,蒸煮処理コナラは野草類に相当するエネルギー価を有すると判断された.