摘要
In total, 20 multiparous Holstein-Friesian dairy cows received one of four diets in each of four periods of 28-day duration in a Latin square design to test the hypothesis that the inclusion of lucerne in the ration of high-yielding dairy cows would improve animal performance and milk fatty acid (FA) composition. All dietary treatments contained 0.55 : 0.45 forage to concentrates (dry matter (DM) basis), and within the forage component the proportion of lucerne (Medicago sativa), grass (Lolium perenne) and maize silage (Zea mays) was varied (DM basis): control (C)=0.4 : 0.6 grass : maize silage; L20=0.2 : 0.2 : 0.6 lucerne : grass : maize silage; L40=0.4 : 0.6 lucerne : maize silage; and L60=0.6 : 0.4 lucerne : maize silage. Diets were formulated to contain a similar CP and metabolisable protein content, with the reduction of soya bean meal and feed grade urea with increasing content of lucerne. Intake averaged 24.3 kg DM/day and was lowest in cows when fed L60 (P<0.01), but there was no effect of treatment on milk yield, milk fat or protein content, or live weight change, which averaged 40.9 kg/day, 41.0, 30.9 g/kg and 0.16 kg/day, respectively. Milk fat content of 18:2 c9 c12 and 18:3 c9 c12 c15 was increased (P<0.05) with increasing proportion of lucerne in the ration. Milk fat content of total polyunsaturated fatty acids was increased by 0.26 g/100 g in L60 compared with C. Plasma urea and β-hydroxybutyrate concentrations averaged 3.54 and 0.52 mmol/l, respectively, and were highest (P<0.001) in cows when fed L60 and lowest in C, but plasma glucose and total protein was not affected (P>0.05) by dietary treatment. Digestibility of DM, organic matter, CP and fibre decreased (P<0.01) with increasing content of lucerne in the diet, although fibre digestibility was similar in L40 and L60. It is concluded that first cut grass silage can be replaced with first cut lucerne silage without any detrimental effect on performance and an improvement in the milk FA profile, although intake and digestibility was lowest and plasma urea concentrations highest in cows when fed the highest level of inclusion of lucerne.
摘要译文
总共，在拉丁平方米的设计中，测试将苜蓿纳入高产奶牛的比例将提高动物性能和乳脂肪酸（FA）组成的假设所有膳食处理包括0 ：0浓缩物（干物质（DM）），在饲料组分中，苜蓿（Medicago sativa）的比例，草（黑麦草）和玉米青贮（Zea mays）变化（DM基）：对照（C）\x3d0 0rrr：玉米青贮饲料; L20 \x3d0 0 0 ucerne：grass：玉米青贮饲料L40 \x3d0 0 6卢塞恩：玉米青贮饲料和L60 \x3d0 0 ucerne：玉米青贮饲料配方含有相似的CP和可代谢的蛋白质含量，随着芸香苷含量的增加，大豆粉和饲料级尿素的减少量平均为24天DM /天，饲喂L60时，母牛最低（P 0 ，但对乳产量，乳脂肪或蛋白质含量或活体重变化没有影响，平均每天平均40天/天，41 30 / kg和0 kg/天。18：2 c9 c12和18：3 c9 c12 c15的乳脂肪含量增加（P 0 ，荔枝比例增加）L60中总多不饱和脂肪酸的乳脂肪含量与C Plasma尿素相比增加了0 g/ 100g，β-羟基丁酸酯浓度平均为3 和0mmol / l，分别饲喂L60和C最低（P 0 ），但血浆葡萄糖和总蛋白没有受到影响（P0 ），DM，有机质，CP和纤维减少（P 0 ，随着苜蓿在饮食中的含量增加，尽管L40和L60的纤维消化率相似可以得出结论，可以用第一次切割的苜蓿青贮饲料替代第一次青贮青贮饲料，对性能没有任何不利影响，并且改进了奶粉FA分布，虽然摄入和消化率最低，血浆尿素浓度最高，当喂养最高水平的琉璃苣
L. A. Sinclair [(a1)]; R. Edwards [(a1)]; K. A. Errington [(a1)]; A. M. Holdcroft [(a1)];M. Wright [(a1)].... Replacement of grass and maize silages with lucerne silage: effects on performance, milk fatty acid profile and digestibility in Holstein-Friesian dairy cows[J]. animal, 2015,9(12): 1970-1978