大麦とアンモニア処理もみ殻による乳用雄子牛の肥育について

Utilization of Ammoniated Rice Hulls as a Roughage in Barley-Beef Production

Mitani Katsunosuke

Tanimoto Hitoshi

Yoshimoto Tsutaru

Otani Isao

広島大学水畜産学部紀要

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

アンモニア処理もみ殻(ARH)の飼料価値について検討し,あわせてARHを唯一の粗飼料源としたオールインワン飼料の開発が可能か否かを検討するため,乳用雄子牛6頭を使用し,肥育試験と消化試験を行なった。試験は肥育期(238日)と仕上期(84日)に分け,それぞれTrial 1および2とした。

Trial 1は,開放追込式牛舎で群飼とし,粉砕大麦,ARHおよび添加剤をそれぞれ,80%,14.4%,56%配合したオールインワン飼料(Ration I)を自由採食させた。

Trial 1の終了後,ただちに全頭をスタンチョンに繋留し,Ration Iを引き続き給与した群(大麦区)と大麦をトウモロコシに切替えた群(トウモロコシ区)の2群に,平均体重が等しくなるよう3頭ずつ区分けし,Trial 2を実施した。14日間の飼料切替の後14日間の予備飼育をし,56日間の肥育試験を行なった。

Trial 2の試験終了前に4日間採糞し,消化試験を行なった。それらの結果は次の通りである。
(1) Trial 1の238日間の6頭の平均増体量は241㎏,1日当り増体量は1.01㎏であった。
(2) Tria1 2では,トウモロコシ区の3頭に下痢が発生したため,増体成績は明らかに大麦区より劣った。しかし,枝肉量では両区に差はなかった。
(3) 大麦区およびトウモロコシ区の摂食飼料の消化率(%)は,それぞれ,乾物;71.3, 56.2,粗蛋白質;77.4, 50.6,粗脂肪;75.8, 71.7,粗繊維;17.3, 0, NFE;83.5, 68.6であった。
(4) Trial 1および2においてRation 1を給与した3頭の322日間の増体量は324kgであり,1日当り増体量は1.00kg,肥育終了時体重は584㎏であった。また,肥育期間中の飼料摂取量は1日1頭当り9.45㎏となり,1㎏増体に要したDCP量,TDN量はそれぞれ,0.86㎏, 5.69㎏であった。
(5) 試験開始後22週頃より,各牛とも1～2回の鼓脹症の発生とそれにともなう発育の停滞が見られたが,その治癒とともに,増体も代償的に回復した。各牛にルーメンパラケラトーシスが認められたが,肝のう瘍は認められなかった。

以上の結果から,粉砕大麦,ARHおよび添加剤の単純な配合でも,体重584kg,1日当り増体量1.0㎏の成績は可能であるが,鼓脹症およびルーメンパラケラトーシスの予防についてさらに研究が必要と思われる。

Two feeding trials were conducted to estimate the value of ammoniated rice hulls (ARH) as a roughage in barley-beef production.

In trial 1, six Holstein steers averaging 265 kg. were fed 80% barley ration for 238 days. This ration (Ration I) contained ground barley, ARH and premix; 80.0%, 14.4% and 5.6%, respectively. The steers were group-fed, twice daily, on an ad libitum basis. In trial 2, the steers were raised in stanchion stalls, immediately after trial 1, and were divided into two groups of three each on a basis of weight. The steers of one group were fed Ration I, and the other ones Ration II containing 80% ground corn, which was substituted for barley in Ration I. This trial was conducted to determine the feeding value and digestion coefficients of both rations.

A 28-day preliminary period to allow the steers to adjust to ground corn was followed by a 56-day experimental period. The rations were fed ad libitum with water available at all times by a water-cup.
The results collected were as follows:
1) Average weight gain and daily gain for 238 days were respectively 241 kg. and 1.01 kg. in trial 1.
2) Steers fed Ration I gained more than those fed Ration II, which elicited diarrhea. In spite of this, carcass weights were remarkedly similar in both steers fed Ration I and Ration II.
3) Digestion coefficients of Ration I and Ration II were respectively as follows: dry matter; 71.3%, 56.2%, crude protein; 77.4%, 50.6%, crude fat; 75.8%, 71.7%, crude fiber; 17.3%, 0%, NFE; 83.5%, 68.6%.
4) Fattening performance data of steers fed Ration I for 322 days through two trials were as follows: average final weight, daily gain and daily feed intake were respectively 584 kg., 1.00 kg. and 9.45 kg., and the amount of DCP and TDN per kg. of gain were respectively 0.86 kg. and 5.69 kg..
5) After fattening for a 22-week period, steers sometimes suffered from bloat, so that body weight gain and feed intake decreased. However, the tendency of compensatry growth was observed in all steers, after recovery from this digestive disturbance. Rumens of all steers were generally parakeratotic, however, no incidence of livers abscessation were found.
From the above results, it was found that dairy beef steers fed diet containing ground barley, ARH and premix reached successfully a final 584 kg. wt. with 1.00 kg. daily gain except for cases of bloat and rumenparakeratosis.
It is necessary to carry out still further experiments so as to find the means to prevent these digestive disturvances.

Animal husbandry [ 640 ]

jpn

広島大学水畜産学部

[ISSN] 0440-8756

[NCID] AN00213563

[NAID] 40003288855