유우배합사료(乳牛配合飼料)의 단미사료(單味飼料) 입자 크기와 이용성에 관한 연구 = THE PHYSICAL FORM OF GRAIN IN BALANCED DIET AND ITS UTILIZATION BY FARM ANIMAL

국문 초록 (Abstract)

우리나라는 해마다 乳牛配合飼料 51만M/T의 상당히 많은 部門을 1.41mm크기의 粒子보다 크게 粉碎하여 供給하고 있다. 本 試驗에서는 穀類의 粒子 크기가 큰 原料를 混合한 乳牛用 配合飼料를 5種의 크기別로 分類한 後 in vitro nylon bag 乾物消化率과, 乳牛의 黃으로 排出 損失되는 澱粉質 粒子의 量을 調査한 後 市價로 換算하고 적당한 粒子의 크기를 硏究한 것이다.
市販 乳牛用 配合飼料의 11%에 해당하는 量이 1.41mm 粒子크기 原料로 構成되어 있었으며, 1.0mm 以上의 크기는 25%이었고, 0.5mm 以下의 粒子는 42%로 가장 많았다.
in vitro nylon bag 醱酵方法에 의한 各 醱酵時間別 乾物消化率을 보면, 4時間 醱酵時의 0.71∼1.0mm 粒子가 가낭 높았고, 48時間의 경우에는 0.5∼0.71mm 粒子가 높았고 72時間에는 0.71∼1.0mm粒子가 가장 높아, 점차 醱酵時間이 길어짐에 따라서 粒子가 큰 쪽의 消化率이 높은 傾向을 나타냈다. 5種의 粒子크기別로 分類하여 72時間 消化시킨 후 不消化 乾物을 同一한 方法으로 5種의 粒子크기로 再次 分類한 結果 1.41mm 以上의 粒子는 14%가 增加되었으나 0.5mm 以下 粒子는 상대적으로 17.51%가 減少되었다.
放牧中인 乳牛의 ??을 任意로 採取한 後 澱粉質粒子量을 調査한 결과, 1.0mm 以上의 粒子는 0.112∼0.43% 分布로써 平均 0.307%이었다. 1日 乳牛 1頭가 配合飼料를 2,3 및 6kg씩 給與받을 경우에 最下 7천3백90만원부터 11억6천여만원이 每年 損失된 셈이다.
本 硏究에서 얻은 最善의 粒子크기는 0.5∼0.71mm와 그 以下의 크기가 적당하다고 보며, 1.0∼1.41mm 粒子는 좀더 깊이 硏究해 볼 課題이며, 1.41mm以上의 粒子는 損失을 가져온다고 생각된다.

다국어 초록 (Multilingual Abstract)

Annual demand for dairy cattle concentrate ration amounts to 510,000M/T in Korea. In griding graints and other ingredients of balanced ration a large proportion of particles exceeding 1.41 mm in diameter were found. Particles of different sizes were digested by the in vitro nylon bag technique for estimating dry matter digestibilities during six fermentation periods of various durations. Starchy particles from random fecal samples, collected from grazing dairy cattle, were washed, counted and weighed.
In this trial 11 per cent of the balanced ration had a particle size exceeding 1.41mm in diameter, 25 per cent of the total feed particle size was larger than 1.0mm and 42 percent was finer than 0.5mm.
Five sieved samples of balanced ration were tested for dry matter digestibility using the in vitro nylon bag technique. After 72 hours fermentation the undigested material was sieved using 4 different sieve sizes. Distribution of particle sizes of undigested material were altered, increasing large particles and decreasing small particles proportionately. Particle size 0.71-1.0mm gave the highest digestibility after 4 hours fermentation, after 10-24 hours fermentation particle size 0.5mm was the highest, after 48 hours fermentation particle size 0.5-0.71mm was the highest and after 72 hours fermentation the digestibility of particle 0.71-1.0mm was the highest. Thus as length of fermentation period increased large particles were digested.
Starch granules in feces excreted by grazing dairy cattle were separated using a 1.0mm sieve. The distribution of granule partcles ranged from 0.112-0.430 per cent, with an average of 0.307 percent. When balanced ration was fed at the rates of 2, 3, and 6kg per head daily from 478-7509M/T of starchy particles of ration were estimated as lost annualy through feces of dairy cattle in Korea. If these amounts were converted into cost price of balanced ration the losses would be from 73,900,000-1,160,000,000 won.
The optimum particle sizes were found to be 0.5-0.71mm including a certain amount of particle finer than 0.5 mm. Particle sizes larger than 1.41mm appear to be unsuitable as many starchy particles were found in the feces. Particle sizes 1.0-1.41mm have still to be studied.