Shigeru Ohtani

Effect of dried Bacillus subtilis culture on growth, body composition and hepatic lipogenic enzyme activity in female broiler chicks

To investigate the effect of dried Bacillus subtilis culture on growth, body composition and hepatic lipogenic enzyme activity, female broiler chicks were fed on either no additive (control) or dried B. subtilis-culture-supplemented commercial diets (215 g crude protein/kg, 12.85 MJ metabolizable energy/kg) at 10 or 20 g/kg diet for 28 d from 14 to 42 d of age. Body weight, and moisture, fat, protein and ash contents of the body were not influenced by the B. subtilis culture. Feed efficiency, N utilization, the ratio of abdominal fat or liver to body weight, acetyl-coenzyme A carboxylase (EC 6.4.1.2) activity, liver and serum cholesterol contents were significantly lower in treatment groups, while fatty acid synthetase activity and serum cholesterol concentration were not significantly different, compared with the control group. Liver triacylglycerol concentration was decreased in chicks given 20 g culture/kg diet, while serum and carcass triacylglycerol concentrations were significantly lower in treatment groups than in the control group. Serum phospholipid concentration was increased but carcass phospholipid concentration was decreased in chicks given 20 g B. subtilis/kg diet, while liver phospholipid concentration was not significantly influenced. The advantages of inclusion of B. subtilis to the broiler diet included improved feed efficiency, less abdominal fat, reduced triacylglycerol concentrations in the liver, serum and carcass and reduced cholesterol concentrations in the liver and carcass.

Effects of pantethine on lipogenesis and CO2 production in the isolated hepatocytes of the chick (Gallus domesticus)

1. Isolated hepatocytes from chicks were used to study the effects of pantethine supplementation to incubation medium on in vitro lipogenesis, CO2 production and beta-oxidation of fatty acid. 2. In vitro lipogenesis, determined by the incorporation of 1-[14C]acetate into total lipid and various lipid fractions, as depressed in concordance with the increase of pantethine concentration in the medium. 3. Incubation of isolated hepatocytes with pantethine resulted in a significant decrease (P < 0.01) in the activities of acetyl-CoA carboxylase and fatty acid synthetase. 4. The results suggest that in vitro fatty acid synthesis from 1-[14C]acetate was depressed and CO2 production was elevated in hepatocytes of chicks through pantethine addition to the medium at a low level.

Milk composition and flavor under different feeding systems: A survey of dairy farms

Understanding the influence of regional dietary factors on the flavors of milk and dairy products will provide consumers with more options and promote the conservation of regional resources and the original terroir. The objective of this study was to evaluate the influence of regional differences in feeding systems on the composition, fatty acid content, and flavor of pasteurized milk at the farm level. Nine dairy farms using grass silage (GS), 6 farms using maize silage (MS), and 4 farms using by-products (BP) as the characteristic feed components were chosen for this survey. Fresh milk was sampled once per month from September 2008 to February 2009 at each dairy farm. The percentages of GS, MS, and BP (soybean curd residue or brewers grain) in the feed were 32.4, 22.1, and 15.1%, respectively. The milk fat, protein, and lactose contents did not differ among the milks from farms with different feeding systems. Fatty acids with chain lengths of less than C16 and saturated fatty acids were present at higher concentrations in the milks from the GS and MS farms than in the milk from the BP farms; conversely, fatty acids with chain lengths greater than C18 and unsaturated fatty acids (UFA), including mono- (MUFA) and polyunsaturated fatty acids (PUFA), were present at higher concentrations in the milks from the BP farms than in the milks from the GS farms. No significant differences were detected in milk flavor, evaluated as sweetness, body, texture, aftertaste, and palatability, between the milks from the farms with different feeding systems. The proportion of BP in the cows diet was positively correlated with the concentrations of fatty acids with chain lengths greater than C18 and with UFA, MUFA, and PUFA. In contrast, the proportion of GS in the diet was positively associated with the levels of milk fat, protein, fatty acids with chain lengths less than C16, and SFA. The MUFA, PUFA, UFA, and fatty acids with chain lengths greater than C18 were not associated with any of the milk flavors. These results suggest the regional differences in feeding systems contribute to the differences in the fatty acid compositions of milk at the farm level. However, these differences do not influence the flavor of pasteurized milk. Thus, more specific feed profiles will be required to provide a specific regional flavor to pasteurized milk.

Nutrient sufficiency in beef cows grazing on a dwarf bamboo‐dominated forestland pasture in Japan

The nutritional status of cows grazing on a 120-ha public alpine forestland pasture dominated by the dwarf bamboo Sasa senanensis located in central Japan was evaluated over the course of 2 years. Data were collected during grazing seasons in three periods: early (June), mid- (August) and late (late September-early October) periods. During these periods, the number of experimental Japanese Black cows varied between three and six. With the exception of the dry matter (DM) intake in 2005 and the crude protein (CP) digestibility in 2006, the DM and CP intake and digestibility were lower in the mid- and late periods than in the early period for both years (P < 0.05). Metabolizable energy intake was slightly insufficient for the requirement of the cows in the late period of 2005; in the mid- and late periods of 2006, the metabolizable energy intake was 0.4 to 0.5 times the requirement. These results suggest that the energy intake of cows grazing on forestland pasture dominated by S. senanensis would not satisfy their requirements starting in the mid-period (August) grazing, even though the pasture had abundant herbage resources during these periods.

Effects of Diets on Lipogenesis and on Lipoprotein and Hormone-sensitive Lipases in Adipose and Mammary Tissues of Lactating Goats

泌乳中ヤギに給与する飼料の変換が,皮下脂肪および乳腺組織における,脂肪酸合成能と脂肪酸合成関連酵素の活性,ならびに皮下脂肪組織における,リポプロティンリパーゼとホルモン感受性リパーゼの活性におよぼす影響を検討した.泌乳中のヤギ5頭(日本ザーネン種,体重35～46kg)を,3頭と2頭の2群に分けて供試した.第1群(3頭)は粗飼料のみを3週間給与した後,濃厚飼料多給に変換し,3週間飼育した.第2群(2頭)は,第1群と逆の処理を行なった.いずれの群においても,飼料を変換する1時間前に採血を,また直前に生検によって皮下脂肪組織と乳腺組織を,それぞれ1～2g摘出した.血清中グルコース濃度は,粗飼料給与時より濃厚飼料多給時の方が高く,一方,血清中遊離型脂肪酸濃度は,粗飼料給与時において高い値を示した.皮下脂肪組織における,脂肪酸合成能および脂肪酸合成関連酵素とリポプロティンリパーゼの活性は,粗飼料給与時に比べて,濃厚飼料多給時の方が高い値を示した.一方,ホルモン感受性リパーゼ活性は粗飼料給与時の方が高かった.乳腺組織における脂肪酸合成能は皮下脂肪組織に比べ著しく高い値を示したが,飼料変換による顕著な影響は観察されなかった.これらの結果から,泌乳中の反芻家畜への濃厚飼料多給による乳脂肪生産の低下の原因の1つは,乳腺組識での脂肪酸合成能の低下というより,血流中の脂肪酸および乳脂肪合成のための前駆物質が皮下脂肪組織の方向に流れ,乳腺組織へのこれらの取込みが減少するためであろうと推察される.

Effect of Dietary Energy Increase with the Addition of Various Levels of Carbohydrate on Hepatic Lipogenesis in Growing Chicks

炭水化物の配合量を変化させることにより,飼料中のエネルギー含量を増減させたときの鶏ヒナの肝臓における脂質合成能および脂肪酸合成に関与しているいくつかの酵素活性を検討した.肝臓中のトリグリセリド含量はME3200kcal/kgの飼料を,また全コレステロール含量はME1900kcal/kgの飼料を給与したヒナにおいて高い値を示した(P<0.01).肝臓中のリン脂質含量および血清中のNEFA濃度は,いずれのME含量の飼料を給与しても大きな差はみられなかった.肝臓切片における脂肪酸合成能,肝臓中のNADP-リンゴ酸脱水素酵素およびクエン酸開裂酵素の活性は,飼料のMEを1900から3200kcal/kgまで増加するとそれに伴って増加したが(P<0.01),さらに増してME3600kcal/kgにすると低下した.

The Effect of Grazing on the Development of the Alimentary Tracts in the Young Calf

子牛の消化管発達に及ぼす生草主体の育成方法の影響を人工乳主体の育成方法と比較して検討した.ホルスタイン種雄子牛20頭を代用乳,人工乳,乾草で哺育•育成し,次の5群に分けた.A;10週齢屠殺,B1;13週齢屠殺,B2;11週齢より放牧,13週齢屠殺,C1;16週齢屠殺,C2;11週齢より放牧,16週齢屠殺.離乳は全群とも6週齢とした.B2,C2群の放牧時における生草採食量はクロモーゲン法により測定した.屠殺後,消化管を第一•二胃,第三胃,第四胃,腸に分割して臓器重量を測定し,第一•二胃,第四胃は併わせて容量も測定した.乾物摂取量合計には生草主体で放牧育成した子牛と人工乳主体で育成した子牛との間に差は認められなかったが,増体量にはかなりの差が認められた.屠殺前2週間時平均乾物摂取量には処理の差は認められず,体重の2.6～4.0%であった.また屠殺前2週間における乾物摂取量合計に対する人工乳の比率は処理により顕著な差異があった.空体重に対する臓器重量は第一•二胃で週齢•処理による影響は認められなかった.第三胃は週齢に伴いやや増加,第四胃ではやや減少の傾向であったが,有意差は認められず,処理による影響も顕著でなかった.腸では放牧子牛は週齢が進んでも変化しなかったが,人工乳•乾草給与子牛では減少し,処理による影響が認められた.第一•二胃,第四胃の容量には週齢•処理による影響は認められなかった.