Oddy V H, Gooden J M, Annison E F
Aust J Biol Sci. 1984;37(5-6):375-88. doi: 10.1071/bi9840375.
The contribution of leg muscle, pregnant uterine tissue and lactating mammary gland to overall energy utilization was determined in Merino ewes. Ewes were offered one of three diets based on chaffed oaten hay (7.9 MJ metabolizable energy per kilogram dry matter); chaffed lucerne hay (8.6 MJ/kg); or a 50:50 (w/w) mixture of chaffed oaten and lucerne hays (8.2 MJ/kg). Measurements were made during five different physiological states: dry (non-pregnant), at 94 and 125 days after mating, and at 20 and 50 days after lambing. Tissue energy use was calculated from oxygen uptake and carbon dioxide output obtained from measurement of blood flow and arteriovenous difference. Whole-body energy use was calculated from carbon dioxide energy rate. Energy use by leg muscle was 144 +/- 8 (mean +/- s.e.) kJ kg-1 day-1, and unrelated to metabolizable energy intake, but leg energy use increased with ewe body weight. On the basis that leg muscle was representative of all muscle, total muscle energy use accounted for 26 +/- 4% of whole-body energy expenditure in dry ewes. Uterine energy use per unit weight was respectively 348 +/- 53 and 254 +/- 23 kJ kg-1 day-1 at 94 and 125 days after mating. Milk production was highly correlated with weight of secretory tissue, and with blood flow to the mammary gland. The ratio of blood flow to milk produced was 473:1 in ewes producing from 200 to 1000 ml of milk per day. The mammary gland used energy to produce milk with an efficiency of 0.90 +/- 0.01, a value close to the theoretical estimate of 0.89. On the basis that metabolic rate does not increase during lactation, the efficiency of use of metabolizable energy for milk production was 0.51 +/- 0.05. Examination of energy use by different tissues indicated that energy use by muscle was related to weight, but energy use by remaining tissues (whole body less muscle, uterus and mammary gland) was related to metabolizable energy intake. The results reveal an increase in energy use by the remaining tissue in lactating ewes (8500 +/- 569 kJ/day) compared with dry (5634 +/- 216 kJ/day) and pregnant ewes (5815 +/- 393 kJ/day).
在美利奴母羊中测定了腿部肌肉、妊娠子宫组织和泌乳乳腺对整体能量利用的贡献。母羊被提供三种日粮之一，分别基于铡碎的燕麦干草（每千克干物质含7.9兆焦可代谢能量）、铡碎的苜蓿干草（8.6兆焦/千克）或铡碎的燕麦和苜蓿干草按50:50（重量/重量）混合的日粮（8.2兆焦/千克）。在五个不同生理状态下进行测量：干奶期（未怀孕）、配种后94天和125天以及产羔后20天和50天。组织能量利用根据从血流量和动静脉差异测量中获得的氧气摄取量和二氧化碳排出量来计算。全身能量利用根据二氧化碳能量率来计算。腿部肌肉的能量利用为144±8（平均值±标准误）千焦·千克⁻¹·天⁻¹，与可代谢能量摄入量无关，但腿部能量利用随母羊体重增加而增加。基于腿部肌肉代表所有肌肉这一假设，干奶期母羊中总肌肉能量利用占全身能量消耗的26±4%。配种后94天和125天，子宫单位重量的能量利用分别为348±53和254±23千焦·千克⁻¹·天⁻¹。产奶量与分泌组织重量以及乳腺血流量高度相关。每天产奶量在200至1000毫升之间的母羊，血流量与产奶量的比率为473:1。乳腺利用能量产奶的效率为0.90±0.01，该值接近理论估计值0.89。基于泌乳期间代谢率不增加这一假设，可代谢能量用于产奶的效率为0.51±0.05。对不同组织能量利用的研究表明，肌肉的能量利用与体重有关，但其余组织（全身减去肌肉、子宫和乳腺）的能量利用与可代谢能量摄入量有关。结果显示，与干奶期（5634±216千焦/天）和怀孕母羊（5815±393千焦/天）相比，泌乳母羊中其余组织的能量利用增加（8500±569千焦/天）。
