Pearl millet (Pennisetum glaucum (L.) R.) is an important crop for rainfed production systems and can play a significant role as a feed source for ruminants owing to its high yield and drought tolerance. It is well-established that the maturity stage can influence the chemical composition as well as the nutritional value of crops traditionally used for silage production, although quantitative evidence that this occurs with pearl millet under rainfed conditions is lacking. The current research assessed the agronomic characteristics, ensilability, intake and digestibility of a Brazilian pearl millet cultivar (IPA BULK1-BF) harvested at four different growth stages. Forage was harvested at 35, 50, 65 and 80 days after sowing and ensiled under laboratory and farm conditions. Apparent digestibility of the silages was determined using 24 male lambs. The results showed that dry matter (DM) and panicle and stem proportions increased with the advancement maturity. The silage evaluations showed that DM, total and non-fibrous carbohydrates and lignin concentrations increased, while crude protein, ADF and in vitro DM digestibility decreased with the increase in plant maturity. Additionally, the fermentation characteristics were improved with the increasing maturity. The digestion study showed that intake of DM and N as well as digestibility of DM and fibre fractions decreased, while lignin intake increased. The results obtained for the production of dry and digestible DM, the ratio of plant fractions and fermentation parameters indicate the possibility of harvesting pearl millet forage after 50 days after sowing for silage production in the Brazilian semi-arid region.

中文翻译：

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不同生育期珍珠粟品种的性能、农艺性状、青贮性及营养价值

珍珠粟（狼尾草(L.) R.) 是雨育生产系统的重要作物，由于其高产和耐旱性，可以作为反刍动物的饲料来源发挥重要作用。成熟阶段可以影响传统上用于青贮饲料生产的作物的化学成分和营养价值，这是公认的，尽管缺乏数量证据表明这种情况在雨养条件下发生在珍珠粟上。目前的研究评估了在四个不同生长阶段收获的巴西珍珠粟品种 (IPA BULK1-BF) 的农艺特性、青贮性、采食量和消化率。在播种后 35、50、65 和 80 天收获草料，并在实验室和农场条件下青贮。青贮饲料的表观消化率是用 24 只公羔羊测定的。结果表明，随着成熟度的提前，干物质（DM）和穗、茎比例增加。青贮评价表明，干物质、总和非纤维碳水化合物和木质素浓度增加，而粗蛋白、ADF 和体外干物质消化率随着植物成熟度的增加而降低。此外，随着成熟度的增加，发酵特性得到改善。消化研究表明，干物质和氮的摄入量以及干物质和纤维部分的消化率下降，而木质素的摄入量增加。生产干燥和可消化干物质、植物组分比例和发酵参数的结果表明，在巴西半干旱地区播种 50 天后收获用于青贮饲料生产的珍珠粟的可能性。