アミノ酸添加低タンパク質飼料への乾燥ミカンジュース粕の配合が豚の発育，背脂肪厚，肉色，窒素排せつ量および糞の臭気物質に及ぼす影響

　乾燥ミカンジュース粕を配合したアミノ酸添加低タンパク質(以下低CP)飼料を体重80kgからの肥育後期豚に給与した場合の発育，背脂肪厚，肉色，窒素排せつ量および糞の臭気物質を検討した。飼料は標準的CP飼料(以下標準CP区，CP15.6％)，アミノ酸添加低CP飼料(以下低CP区，CP11.9％)，乾燥ミカンジュース粕を10％および20％配合したアミノ酸添加低CP飼料(以下低CPミカン10％区，CP11.7％および低CPミカン20％区，CP11.5％)を調製し，供試豚に給与した。

1.1日増体量は標準CP区，低CP区および低CPミカン10％区の間では差はなく，低CPミカン20％区は他の区に比べ有意に低下した(p<0.05)。背脂肪厚および肉色は区間に差は認められなかった。

2.両ミカン区の糞中窒素排せつ量は標準CP区に比べてやや増加したが，尿中窒素排せつ量は大きく低下した。

3.両ミカン区の糞からは，D-リモネンの揮発が認められた。低級脂肪酸の揮発量は，低CPミカン20％区で増加する傾向が認められた。

　従って，乾燥ミカンジュース粕を10％配合したアミノ酸添加低CP飼料を肥育後期豚へ給与すると，標準CP区と比較して発育成績，背脂肪厚および肉色は同等で，尿中および総窒素排せつ量が大幅に低減できることが明らかとなった。

〔キーワード：乾燥ミカンジュース粕，低タンパク質飼料，肥育後期豚，窒素排せつ量，低級脂肪酸〕

Effects of Feeding an Amino Acid-supplemented Lower Protein Diet Containing Dried Orange Juice Pulp on Growth Performance, Back Fat Thickness, Meat Color, Nitrogen Excretion and Fecal Odor Material in Finishing Pigs.

YAMAGUCHI Shoichiro, Akemi YAMAMOTO, Tetuya MURAKAMI, Minoru ITOH, Shu FURUYA(Fukuoka Agricultural Reserch Center, Chikushino, Fukuoka 818-8549, Japan) Bull. Fukuoka Agric. Res. Cent. 24: 88-93 (2005)

An experiment was conducted to determine the effects of supplementing a reduced crude protein (CP) diet with dried orange juice pulp on the growth performance, back fat thickness, meat color, nitorogen excretion and fecal odor material in finishing pigs (80 to 105kg). The experimental diets were prepared as follows : a standard CP diet (standard CP diet, CP15.6%), a low CP, amino-acid supplemented diet (low CP diet, CP11.9%), low CP,　amino-acid supplemented diets containing 10% or 20% of dried orange juice pulp (low orange 10% diet, CP11.7% and low orange 20% diet, CP11.5%), respectively. The experimental pigs fed in a group setting and kept with ad libitum feeding and drinking.

1.The average daily gains for the standard CP, the low CP, the low orange 10% and the low orange 20% diet were 923, 959, 960 and 674g, respectively. The low orange 20% diet was significantly lower than the other diets (p<0.05). The average back fat thickness and meat color were not significantly different across the diets.

2.Fecal nitrogen excretion for the low orange 10% and the low orange 20% diet was a little higher compared to the standard CP diet. Urinary and total nitrogen excretion for the low orange 10% and the low orange 20% diet were much lower than those for the standard CP diet.

3.d-Limonene was detected in the emission gas from feces for the low orange 10% and the low orange 20% diet. Lower fatty acid emission for the low orange 20% was higher than the other diets.

These results suggested that a diet containing 10% of dried orange juice pulp to an amino acid-supplemented lower CP diet can reduce urinary and total nitrogen excretion without any detrimental effects on growth performance and meat color in finishing pigs.