Effect of Maize Stover Silage based Total Mixed Ration on Milk Yield and Composition of Cross Breed (Boran X Friesian) Dairy Cow

This study was conducted at Holetta agricultural research center, Ethiopia with the major objectives to evaluate the effect of silage made from late maturing dual purpose maize crop on intake digestibility, milk yield and composition of dairy cows. A total of eight mid lactating F1 (Boran X Friesian) dairy cows with similar milk yield (9.1 ± 0.91 kg/d) but differing in parity (ranges one to four) were selected and randomly assigned in to one of the four dietary treatments (T1=Natural pasture hay ad libitum + 0.5 kg concentrate mixture (CM) per liter of milk production; T2=TMR-1 (70% MSS: 30% CM) ;T3=TMR -2(60% MSS: 40% CM) and T4=TMR-3 (50% MSS: 50% CM) in a double 4X4 Latin square design. The cows fed T1 and T4 diet had similar DM, OM and NDF intakes (P>0.05) which is significantly higher over cows receiving the remaining treatments (P<0.05). On the other hand CP was significantly higher (P<0.05) inT4 while the ADF intake was significantly higher (P<0.05) in T1 compared to the other treatments. In addition to this, dietary treatments varied (P<0.001) in terms of their apparent DM, OM and CP digestibility, with cows on T3 showed considerably higher (P<0.05) digestibility for DM, OM and CP than cows on the control diet. Similarly T4 had shown higher CP digestibility (P<0.05) compared to the control group. However, the NDF and ADF digestibility were not affected by dietary treatments. Silage based total mixed ration improved daily milk yield with the higher (P<0.01) milk being recorded for cows receiving T4 (10.2 litter/day). Dietary treatment had no effect (P>0.05) on milk composition. Feeding maize stover silage harvested at late maturity to crossbred cows resulted better daily milk yield; however, further study is required on the economics aspect before the diet is recommended for wider use under field conditions in Ethiopia.

本研究于埃塞俄比亚霍莱塔农业研究中心（Holetta Agricultural Research Center）开展，核心目标为评估晚熟兼用型玉米作物制作的青贮饲料对奶牛采食量、消化率、产奶量及乳成分的影响。本研究共选取8头泌乳中期的F1代（波尔牛×弗里生牛）杂交奶牛，其初始产奶量一致（9.1±0.91 kg/d），但胎次存在差异（范围为1至4胎），采用双4×4拉丁方试验设计，将其随机分配至4组日粮处理组：T1组为自由采食天然牧草干草+每升产奶量饲喂0.5 kg浓缩混合料（CM）；T2组为全混合日粮1（TMR-1，70%玉米青贮秸秆（MSS）:30%浓缩混合料（CM））；T3组为全混合日粮2（TMR-2，60%玉米青贮秸秆（MSS）:40%浓缩混合料（CM））；T4组为全混合日粮3（TMR-3，50%玉米青贮秸秆（MSS）:50%浓缩混合料（CM））。采食T1与T4组日粮的奶牛，其干物质（DM）、有机物（OM）及中性洗涤纤维（NDF）采食量无显著差异（P>0.05），且显著高于其余各组（P<0.05）。相较而言，T4组的粗蛋白质（CP）采食量显著更高（P<0.05），而T1组的酸性洗涤纤维（ADF）采食量显著高于其余处理组（P<0.05）。此外，不同日粮处理对奶牛的表观干物质、有机物及粗蛋白质消化率存在极显著影响（P<0.001）：其中T3组奶牛的干物质、有机物及粗蛋白质消化率显著高于对照组（P<0.05）；同理，T4组的粗蛋白质消化率也显著高于对照组（P<0.05）。但中性洗涤纤维与酸性洗涤纤维的消化率未受日粮处理的显著影响。基于青贮饲料的全混合日粮可提升日产奶量，其中T4组奶牛的产奶量最高，达10.2升/日（P<0.01）。日粮处理对乳成分无显著影响（P>0.05）。给杂交奶牛饲喂晚熟期收获的玉米秸秆青贮饲料可获得更优的日产奶量，但在将该日粮推广应用于埃塞俄比亚田间生产前，仍需开展相关经济学方面的进一步研究。