Terler Georg, Winter Manuel, Resch Reinhard, Rohrer Hannes, Fasching Christian, Mandl Michael, Sweeney Joseph, McDonnell Kevin, Steinwidder Andreas
Institute for Livestock Research, Agricultural Research and Education Centre Raumberg-Gumpenstein, Irdning-Donnersbachtal, Austria.
Institute for Organic Farming and Livestock Diversity, Agricultural Research and Education Centre Raumberg-Gumpenstein, Irdning-Donnersbachtal, Austria.
Arch Anim Nutr. 2025 Feb;79(1):46-58. doi: 10.1080/1745039X.2025.2473590. Epub 2025 Apr 3.
Press cake silage (PCS) is a by-product of biorefining, which can substitute unprocessed grass or grass-clover silage (GCS) in ruminant feeding. The aim of this study was to examine the effect of including re-ensiled PCS from GCS in dairy cows' diet on feed intake, milk production and composition, feed conversion, apparent total tract digestibility (ATTD) as well as feed sorting and rumination behaviour compared to a control ration. Three total mixed rations (TMR) were tested in this experiment differing in PCS and GCS proportion in forage: 0% PCS and 50% GCS (CON), 25% PCS and 25% GCS (PCS25) and 50% PCS and 0% GCS (PCS50). The study was designed as a cross-over trial with six Holstein Friesian and nine Simmental cows (average 624 ± 68 kg body weight and 60 ± 20 days in milk at the start of the trial). The experiment consisted of three experimental runs, each lasting for 35 days with a 14 days adaptation phase and a 21 days measurement period. Diets were fed as TMR containing 37% grass silage, 26% concentrates and differing proportions of PCS or GCS depending on experimental group (37% GCS in CON, 18.5% PCS and 18.5% GCS in PCS25, 37% PCS in PCS50). Dry matter intake of dairy cows was higher in the PCS25 compared to the PCS50 group with both groups being not different from the CON treatment. Energy-corrected milk (ECM) production was lowest in the PCS50 group but did not differ significantly between treatments. Milk composition was also similar in all three treatments, except for milk urea content, which was lower in the PCS50 group. Moreover, ATTD of crude protein and ruminal nitrogen balance as well as phosphorus intake and the phosphorus effort for production of 1 kg ECM decreased with rising PCS inclusion in the diet. In contrast, no differences between treatments were found for dry matter, crude protein and energy effort for ECM production as well as for feed sorting and rumination behaviour. In conclusion, replacing GCS by re-ensiled PCS in TMR-diets did not affect ECM production and feed conversion of dairy cows while increasing the utilisation of crude protein and phosphorus. Therefore, re-ensiled PCS can substitute GCS in dairy cows' TMR-diets. However, the long-term effects of decreased phosphorus intake and ATTD of crude protein in cows fed PCS-rich diets should be examined in future studies.
压榨饼青贮饲料（PCS）是生物精炼的副产品，可替代反刍动物饲料中未加工的青草或青草 - 三叶草青贮饲料（GCS）。本研究的目的是检验与对照日粮相比，在奶牛日粮中添加由GCS重新青贮制成的PCS对采食量、产奶量及乳成分、饲料转化率、表观全肠道消化率（ATTD）以及饲料挑选和反刍行为的影响。本试验测试了三种全混合日粮（TMR），其草料中PCS和GCS的比例不同：0% PCS和50% GCS（CON）、25% PCS和25% GCS（PCS25）以及50% PCS和0% GCS（PCS50）。该研究设计为交叉试验，选用6头荷斯坦 - 弗里生奶牛和9头西门塔尔奶牛（试验开始时平均体重624±68千克，产奶60±20天）。试验包括三个试验期，每个试验期持续35天——14天适应期和21天测量期。日粮以TMR形式投喂，其中包含37%的青贮草料、26%的精饲料，且根据实验组不同含有不同比例的PCS或GCS（CON组含37% GCS，PCS25组含18.5% PCS和18.5% GCS，PCS50组含37% PCS）。与PCS50组相比，PCS25组奶牛的干物质采食量更高，且这两组与CON组处理无差异。PCS50组的能量校正乳（ECM）产量最低，但各处理组间无显著差异。除了PCS50组的乳尿素含量较低外，三种处理的乳成分也相似。此外，随着日粮中PCS添加量的增加，粗蛋白的ATTD、瘤胃氮平衡以及磷摄入量和生产1千克ECM所需的磷量均下降。相比之下，各处理组在生产ECM的干物质、粗蛋白和能量消耗以及饲料挑选和反刍行为方面没有差异。总之，在TMR日粮中用重新青贮的PCS替代GCS不会影响奶牛的ECM产量和饲料转化率，同时提高了粗蛋白和磷的利用率。因此，重新青贮的PCS可以替代奶牛TMR日粮中的GCS。然而，未来的研究应考察采食富含PCS日粮的奶牛磷摄入量降低和粗蛋白ATTD降低的长期影响。
