Description
Although necessary to maintain milk production in late lactation when grass is scarce, dependency on imported concentrate has negative environmental credentials; diversifying native feeds i.e., perennial ryegrass, using biorefinery, to produce high quality by-products may be a solution (Sanders et al., 2020). To validate these suggestions, a study was undertaken on dairy cows during the winter period; 60% of a perennial ryegrass silage diet was replaced with perennial ryegrass (PRG) press cake in treatment cows (GSPC; n=20), while a perennial ryegrass silage diet was offered to control cows (GS; n=20). Cows substituted with press cake produced 9.1 and 10.5 % more milk solids (kg), and fat and protein corrected milk (kg), respectively, compared to their GS herd mates (P < 0.05). The GSPC cows also produced 6.5% more methane than GS cows (P<0.05). This was primarily driven by a higher group average dry matter intake in GSPC cows (15.6 kg) compared with GS cows (15.1 kg). Although cows offered press cake had a higher group average dry matter intake, they were not significantly heavier than cows offered a silage based diet, and they tended (P=0.05) to have a lower body condition score (BCS). Cows substituted with press cake produced 3.8% more methane per kg dry matter intake and 13.0% more methane per kg body weight (P=0.01), respectively. Feeding PRG press cake to late lactation dairy cows did not improve environmental credentials, as there was a greater methane output compared to cows offered a grass silage based diet. Although PRG press cake significantly improved milk solids yield, when methane was expressed per kg milk solids output was similar for treatment and control cows.
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
The Partial Replacement of Perennial Ryegrass Silage with Ensiled Biorefined Perennial Ryegrass Press Cake, and its Impact on Productivity of Late Lactation Dairy Cows
Although necessary to maintain milk production in late lactation when grass is scarce, dependency on imported concentrate has negative environmental credentials; diversifying native feeds i.e., perennial ryegrass, using biorefinery, to produce high quality by-products may be a solution (Sanders et al., 2020). To validate these suggestions, a study was undertaken on dairy cows during the winter period; 60% of a perennial ryegrass silage diet was replaced with perennial ryegrass (PRG) press cake in treatment cows (GSPC; n=20), while a perennial ryegrass silage diet was offered to control cows (GS; n=20). Cows substituted with press cake produced 9.1 and 10.5 % more milk solids (kg), and fat and protein corrected milk (kg), respectively, compared to their GS herd mates (P < 0.05). The GSPC cows also produced 6.5% more methane than GS cows (P<0.05). This was primarily driven by a higher group average dry matter intake in GSPC cows (15.6 kg) compared with GS cows (15.1 kg). Although cows offered press cake had a higher group average dry matter intake, they were not significantly heavier than cows offered a silage based diet, and they tended (P=0.05) to have a lower body condition score (BCS). Cows substituted with press cake produced 3.8% more methane per kg dry matter intake and 13.0% more methane per kg body weight (P=0.01), respectively. Feeding PRG press cake to late lactation dairy cows did not improve environmental credentials, as there was a greater methane output compared to cows offered a grass silage based diet. Although PRG press cake significantly improved milk solids yield, when methane was expressed per kg milk solids output was similar for treatment and control cows.
