Takehiro Nishida

Effect of peppermint feeding on the digestibility, ruminal fermentation and protozoa

Feeding herbs to dairy cattle may effect rumen fermentation and digestibility due to the herbs’ physiological or pharmacological functions. Thus, in the present study, peppermint was tested for its effects upon digestibility and rumen fermentation. Digestion trials and an investigation of rumen fluid were conducted by four rumen-cannulated Holstein steers having or not having been fed peppermint. When peppermint was fed to the steers, the digestibility of nutrients tended to be higher than that of the control. Ammonia-nitrogen concentrations were higher in the control steers than in the peppermint-fed steers (P<0.01). Numbers of Entodinum, Isotrica, and Diplodium were decreased significantly by the ingestion of peppermint (P<0.05). The total numbers of protozoa were significantly decreased by peppermint ingestion (P<0.05). Based on these results, it can be concluded that peppermint has a great potential as a natural manipulator of rumen fermentation by depressing ammonia-nitrogen concentration or numbers of protozoa.

The effect of temperature on survival of pathogenic bacteria in biogas plants

The paper deals with the hygienic advantages of sanitation to treat dairy manure in full-scale biogas plants. The slurry samples were collected from two thermophilic biogas plants (55°C) and two mesophilic biogas plants (38°C) in Hokkaido Japan. A detectable number of Coli-aerogenes group and Enterococcus in the slurries after anaerobic digestion (AD) could not be found in either thermophilic biogas plants. However, in both mesophilic biogas plants the viable numbers of Coli-aerogenes group and Enterococcus were detected in the slurries even after anaerobic digestion. The mean decimation reduction time (T(90) ) values of the Coli-aerogenes group and Enterococcus in the slurries during mesophilic digestion were 13.3 days and 16.7 days, respectively.

Effect of variety, stages of maturity and botanical fractions on phosphorous concentration and in situ degradability characteristics of phosphorous of whole crop rice silage

Abstract The effect of seven varieties of whole crop rice harvested and ensiled each at four stages of maturity was investigated for P content, in situ degradability and ruminal availability of P in a 7×4 factorial experiment. Rice (Akichikara, Fukuhibiki, Habataki, Hamasari, Kusanami, Tamakei 96 and Yumetoiro) were grown at Saitama, Japan and harvested in 1998 on 10, 22, 34 and 45 days after flowering. Variety and maturity affected (P 0.05) to in situ parameters and effective degradability of P, which suggests that the data on washing loss of P may be used to estimate P degradability of forages in the rumen. In conclusion, variety, stages of maturity and botanical fraction of WCRS affected significantly on P content and availability of P of WCRS in the rumen. Most of the phosphorous in WCRS solubilized immediately in the rumen. The results also indicate that the excretion of P of WCRS from different categories of ruminants is likely to be minimal.

Potential of anaerobic digestate of dairy manure in suppressing soil-borne plant disease

Frequent use of pesticides to control soil-borne plant disease leads to environmental pollution and the development of pesticide resistance in phytopathogens. Soil amendment is considered to have the potential of suppressing plant disease because of its biological properties. However, information on anaerobic digestate is limited. In this study, potential of antagonistic activities of anaerobic digestate against phytopathogens were investigated by detecting the amounts of antagonistic bacteria (Bacillus and Pseudomonas) in anaerobic digestates of dairy manure. The results showed that anaerobic digestion increased the total amounts of Bacillus and Pseudomonas in digestate. Bacillus suppressed growth of phytopathogens, while Pseudomonas did not show any antagonistic activities. These results indicated that Bacillus was an effective antagonistic bacterium in digestate against phytopathogens. Furthermore, two selected isolates, B11 (Bacillus subtilis) and B59 (Bacillus licheniformis), were applied in field experiments and showed significant reduction in percent infection of potato late blight (Phytophthora infestans). These results demonstrate the benefits of digestate in suppressing soil-borne plant diseases caused by antagonistic bacteria.

Effect of substituting soybean meal with euglena (Euglena gracilis) on methane emission and nitrogen efficiency in sheep

Abstract This study evaluated methane (CH 4) emission, intake, digestibility, and nitrogen efficiency in sheep fed diets containing replacement levels (0%, 33%, 50%, and 67% of soybean meal with euglena). In this experiment, four Corriedale wether sheep with an initial body weight of 53.8 ± 4.6 were arranged in a 4 × 4 Latin square design. This experiment lasted 84 days, divided into four experimental periods. Each period lasted 21 days, which consists of 14 days of adaptation to the diets, 5 days to collect samples, and 2 days to collect gas emission from sheep. Methane emission expressed as L/kg DM intake or g/kg DM intake reduced by up to 37% and the energy loss via CH 4 (% of GE intake) reduced by up to 34%. No differences (p > 0.05) were observed in DM and OM intake and whole tract apparent DM digestibility due to substitution of soybean meal with euglena. The total CP loss reduced significantly (linear, p < 0.001) and CP efficiency increased linearly (p = 0.03) with increasing concentration of euglena. As a result, nitrogen balance and average daily weight gain remained unchanged despite higher nitrogen concentration in soybean supplemented group. In conclusion, substitution of soybean meal with euglena reduced methane emission without affecting the performance of animals.

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.

Effect of Prepartum Feeding Level of Hay on Blood Mineral Composition of Periparturient Cows and Newborn Calves

Eight periparturient Holstein cows were fed 90% hay and 10% concentrate or 50% hay and 50% concentrate on a DM basis to meet maintenance plus last 2 months of gestation level of TDN for 12 weeks before parturition. The cows almost consumed the given feed before parturition. Blood hemoglobin and plasma inorganic P of cows fed a high ratio of hay were lower than that in cows fed a high ratio of concentrate, but plasma Fe of cows fed a high ratio of hay were lower. At parturition, plasma inorganic P of cows fed a high ratio of hay and concentrate were 2.8 and 4.2mg/100ml. There were no significant differences in blood hematocrit, hemoglobin and plasma minerals of calves at d 1 of age between treatments.

Neutron activation analysis of lanthanides (La, Sm and Yb) as a particule marker, and estimation of paddage rates

消化管通過速度測定の指標物質として用いられる希土類元素(La,Sm,Yb)を放射化分析法により測定し,標準物質による検量線作成におよぼす糞マトリクスの影響を調査した.また子牛にYb標識飼料を給与し,経時的に採取した糞中濃度を測定し,通過速度を算出するとともに,原子吸光法での値と比較した.中性子照射後30時間以内に希土類元素を測定した場合,糞マトリクスの影響が強く現れたが,それ以降の測定では影響は小さく,これは糞マトリクスに存在する短半減期元素(24Na)によるものと推察された.糞中Yb濃度からtwo-compartment modelにより通過速度を算出するとき,糞マトリクスの影響を考慮した検量線を用いた場合のk1,k2,TT値は考慮しないものに比べ小さい値となり,逆にTMRTは有意(p<0.05)に大きい値となった,またYb濃度を原子吸光法で算出した場合,k1,k2値は放射化分析法での値より小さく(それぞれp<0.001,p<0.10),TMRTは大きい値となった(P<0.01).これはYbを原子吸光法で測定すると,放射化分析法よりやや低い値となることによるものと思われた.