Abstract #91
Section: Forages and Pastures (orals)
Session: Forages and Pastures 1
Format: Oral
Day/Time: Monday 12:00 PM–12:15 PM
Location: Room 233
Session: Forages and Pastures 1
Format: Oral
Day/Time: Monday 12:00 PM–12:15 PM
Location: Room 233
# 91
Establishment of perennial forages with annual sudangrass or sorghum-sudangrass hybrids improved forage yields and in vitro total-tract NDF digestibility.
S. Thevakumaran1, C. Matteau2, B. Baurhoo1,2, P. Seguin1, A. Mustafa*1, 1McGill University, Sainte-Anne-de-Bellevue, QC, Canada, 2Belisle Solution Nutrition Inc, Saint-Mathias-sur-Richelieu, QC, Canada.
Key Words: dairy cow, forage, fiber digestibility
Establishment of perennial forages with annual sudangrass or sorghum-sudangrass hybrids improved forage yields and in vitro total-tract NDF digestibility.
S. Thevakumaran1, C. Matteau2, B. Baurhoo1,2, P. Seguin1, A. Mustafa*1, 1McGill University, Sainte-Anne-de-Bellevue, QC, Canada, 2Belisle Solution Nutrition Inc, Saint-Mathias-sur-Richelieu, QC, Canada.
The objective of this study was to evaluate the effects of underseeding a mixture of perennial forages (alfalfa, clover and tall fescue; control) with different annual companion forages on forage yields, chemical composition and total-tract NDF digestibility (TTNDFD) using DaisyII incubator. Treatments included the control seeded alone or with a companion forage [Sudangrass (SG), Sudangrass brown midrib (BMR) gene 12 (BSG), Sorghum-Sudangrass BMR gene 6 (BSSG) or oat]. Experimental plots (7 replicates / treatment) were harvested at d 60 (1st cut) and d 90 (2nd cut) at the bud stage of alfalfa. Forage indigestible NDF (iNDF) was calculated by in vitro incubation at 240 h whereas potentially degradable NDF (pdNDF) was calculated by subtracting iNDF from total NDF. Digestion rate (kd) of pdNDF was estimated by in vitro incubation at 24, 30 and 48 h. Data were analyzed as repeated measures using the MIXED procedure of SAS with fixed effects of treatment, cut and treatment x cut interaction. Total forage yields (cuts 1 and 2; DM basis) were higher (P < 0.001) with SG (6.56 T/ha), BSG (5.50 T/ha) and BSSG (5.37 T/ha) compared with control (2.82 T/ha). Oat produced higher forage yield in the first cut only. In presence of companion crops, yields of individual perennial forages and weeds were reduced (P < 0.001). Companion crop yield was lowest (P < 0.001) with oat (3.49 T/ha), intermediate with BSG (4.72 T/ha) and highest with SG (5.86 T/ha) or BSSG (5.89 T/ha). Companion forages reduced (P < 0.001) CP and ADL but increased (P < 0.001) NDF and ADF concentrations of harvested forages. In vitro TTNDFD followed the order (P < 0.001): BSG and BSSG (average 59.2%) > SG (55.7%) > control (49.9%) > oat (46.0%). Evidently, iNDF values were lower (P < 0.001) with SG, BSG and BSSG (average 21.0%) than control (35.6%) and oat (34.0%). First cuts had lower (P < 0.001) TTNDFD but higher (P < 0.001) kd than second cuts. In conclusion, seeding perennial forages with annual companion forages (SG, BSG, or BSSG) may improve forage yields and fiber digestibility in dairy cows.
Key Words: dairy cow, forage, fiber digestibility
