Ikwuegbu O A, Sutton J D
Br J Nutr. 1982 Sep;48(2):365-75. doi: 10.1079/bjn19820120.
The effects of three levels of linseed oil (LSO) supplementation of a basal diet on rumen digestion and flow of nutrients to the proximal duodenum of three mature sheep provided with permanent rumen and duodenal re-entrant cannulas were studied. 2. A basal diet of 200 g hay and 400 g concentrates daily, providing approximately 7.0 MJ digestible energy and 13 g N/d, was given alone or with supplements of 13, 26, or 40 ml LSO/d in two equal portions of 06.00 and 18.00 hours. The flow of duodenal digesta was measured by spot-sampling using chromic oxide paper as the marker. Bacterial protein synthesis (BPS) was measured by the diaminopimelic acid technique. 3. Addition of LSO reduced the digestion of energy and organic matter, particularly acid-detergent fibre, in the stomach. Digestion in the intestines increased but at the higher levels of supplementation this failed to compensate completely for the reduction in rumen digestion. Total volatile fatty acid concentrations were not affected but molar proportions of acetate and butyrate were decreased by approximately 18 and 61% respectively while the molar proportion of propionate was increased twofold by the highest concentration of oil. The higher concentrations of LSO virtually eliminated protozoa from the rumen. 4. The second increment of LSO (26 ml/d) produced the highest duodenal flow of total N and bacterial N and the highest efficiency of BPS. The highest concentration of oil (40 ml/d) was without effect. Rumen and duodenal ammonia concentrations and plasma urea concentrations tended to be reduced by the higher concentrations of LSO. 5. It is argued that the results support suggestions made elsewhere that free oils reduce the efficiency of BPS but that they also reduce the numbers of protozoa which can cause an increase in efficiency of BPS. The net effect of free oil supplementation on BPS is thus likely to be variable and difficult to predict.
研究了在基础日粮中添加三个水平的亚麻籽油（LSO）对三只装有永久性瘤胃和十二指肠再入式插管的成年绵羊瘤胃消化及养分向十二指肠近端流动的影响。2. 基础日粮为每日200克干草和400克精饲料，提供约7.0兆焦可消化能量和13克氮/天，单独饲喂或在06:00和18:00分两次等量添加13、26或40毫升LSO/天。使用氧化铬纸作为标记物通过点样法测定十二指肠食糜流量。采用二氨基庚二酸技术测定细菌蛋白质合成（BPS）。3. 添加LSO降低了能量和有机物的消化率，尤其是酸性洗涤纤维在胃中的消化率。肠道消化率增加，但在较高添加水平下，这未能完全弥补瘤胃消化率的降低。总挥发性脂肪酸浓度不受影响，但乙酸和丁酸的摩尔比例分别降低了约18%和61%，而丙酸的摩尔比例在最高油浓度下增加了两倍。较高浓度的LSO几乎使瘤胃中原生动物消失。4. LSO的第二次增量（26毫升/天）使十二指肠总氮和细菌氮的流量最高，BPS效率也最高。最高油浓度（40毫升/天）没有效果。较高浓度的LSO使瘤胃和十二指肠氨浓度以及血浆尿素浓度趋于降低。5. 有人认为，这些结果支持了其他地方提出的观点，即游离油会降低BPS的效率，但它们也会减少原生动物数量，而原生动物数量减少会导致BPS效率提高。因此，添加游离油对BPS的净影响可能是可变的，难以预测。
