Hydrocarbon grown yeast as the protein source of diet for dairy beef production

炭化水素資化酵母の乳用雄子牛肥育における飼料価値

Mimura Ko

Yoshimoto Tsutaru

Mitani Katsunosuke

広島大学水畜産学部紀要

Journal of the Faculty of Fisheries and Animal Husbandry, Hiroshima University

炭化水素資化酵母(以下酵母と称する)，いわゆる石油蛋白の蛋白質飼料源としての重要性は， その生産物の食品としての安全性とは別に，なお将来にわたり研究を要する課題と思われる.

これについての数多くの報告にもかかわらず，牛については公表されたものがほとんどなく，一方濃厚飼料多給方式の乳用雄子牛肥育は，近い将来わが国の牛肉生産の主力となるものと思われるので，鐘渕化学工業KK開発本部提供の酵母を用い，次の実験を行った.

7～15日令のホルスタイン種雄子牛6頭を附属農場に導入し，2区に区分し，試験区の3頭には，代用乳・人工乳期および育成・肥育期にわたり，魚粕・大豆粕などを酵母で完全に代替した飼料を給与した.

平均483日令でと殺・解体試験を行ったが，試験の結果は次の通りである.
1) 3か月令までの発育には，両区に有意の差がなかった.飼料消費量にも差がなかった.したがって，代用乳・人工乳に酵母を添加する場合も，メチオエンなどの添加を必要としないようである.
2) 6か月令で去勢し，約16月令まで肥育したが，その発育はホル協('62)の雄牛標準発育値の上限に近かった.濃厚飼料消費量にも差が全くなかった.
3) と体の肉質検査・格付の結果は，酵母区がよい傾向であったが，有意とは考えられない.
4) 供試牛は全期間ほぼ健康で推移し，酵母給与による栄養障害発生の徴候は，と殺時の内臓検査，と殺前日の尿・血液検査の結果からは認められなかった.ただしNo.4牛は途中へい死したが，急性鼓脹症によるものと診断された.
5) 以上の結果は，酵母が乳用雄子牛用飼料中の魚粕などに十分代替できることを示すものと思われるが，将来さらに検討するつもりである.

1. Six calves were selected and nursed with milk replacer and calf stater from 7-15 days of age to 3 months of age. Three calves were given formula feeds which contained hydrocarbon grown yeast as a substitution for fish soluble, fish meal and soybean meal; the others were given control feeds.

2. After 3 months of age the calves had been raised in stanchion stalls and another formula feed for raising and fattening had been given, in which one for control and another diet contained hydrocarbon brown yeast for yeast group.

3. Cattle were slaughtered on January 17th, 1973. Average ages were about 483 days old.

4. The results are as follow:
1) There is no any different tendency of growth between the two groups.
2) Available evidence showed that hydrocarbon grown yeast may be substituted for fish meal and soybean meal. For example, average daily gain and feed efficiency were quite similar from 3 months of age to the finishing stage.
3) Carcass characteristics and carcass grades in cattle of the yeast group were a little higher than those of the control group. But it is most probably not significant.
4) The cattle investigated had been in good health throughout the experiment. While No. 4 cattle which had been fed on hydrocarbon grown yeast died at 14 months of age. The cause of death was diagnosed by the office veterinarian as acute bloat, without any connection to the yeast.

Animal husbandry [ 640 ]

eng

広島大学水畜産学部

[ISSN] 0440-8756

[NCID] AN00213563

[NAID] 40018463831