Project Number: 5090-12630-006-022-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Aug 1, 2019
End Date: Jul 31, 2022
Our specific objectives include: 1) finalization of feed-delivery and data collection/management systems for 63 Calan Gates installed in 2017, but not yet in operational for research; 2) assess different strategies for incorporating round-bale grass silages into blended total mixed rations for dairy cows and heifers; 3) evaluate strategies to substitute annual grass silages for corn silage in dairy rations; and 4) assess the persistence and quality of intensively managed perennial cool-season grasses for use in dairy diets throughout central Wisconsin.
Objective 1. A 63-gate Calan feeding system was installed at Marshfield in 2017, but the development of a truck-mounted feed-delivery system to facilitate placement of diets within individual feeding stations has not been completed. While this project is nearing completion, it has not been tested, nor have standard operating procedures been developed. Our goal is to complete this effort, and develop standardized procedures for feed delivery, such that individual daily animal intakes can be measured to meet research goals. Objective 2. Small and mid-sized dairies have expanded the use of baled-silage techniques over the last decade, in part because of the reduced costs of required equipment and storage facilities. However, these silages are normally made in long-stem form, which can be problematic for incorporation into blended total mixed rations. Our goal is to evaluate strategies that ease the blending of grass silages into blended diets by: i) use of pre-cutting mechanisms available on many balers; ii) adjustment of shredding systems and shear-plate placement within mixer wagons; and iii) use of regrowth harvests of perennial-cool-season grasses that usually do not elongate (remain vegetative) after removal of the initial harvest. Objective 3. Forage sorghum and sorghum-sudangrass varieties are available currently that carry the brown midrib mutation that imparts traits of lower concentrations of lignin coupled with greater digestibility of forage fiber. Our goal is to investigate increased opportunities to substitute these forages for corn silage, while maintaining acceptable production from lactating cows. In addition, two potential production problems that must be resolved are prevention of lodging and attaining dry matter concentrations (> 30%) that limit undesirable fermentations and production of silage effluent. Objective 4. Perennial cool-season grasses are attractive in central Wisconsin because they persist better on heavy soils than alfalfa, and the nitrogen and other nutrients obtained from dairy-manure applications can be used to support forage production, and reduce the costs of purchased fertilizer inputs. More information is needed regarding persistence of these forages (orchardgrass, endophyte-free tall fescue, meadow fescue) under production systems utilizing multiple applications of manure. In addition, assessment of total-tract and in-vitro measurements of fiber digestibility are needed, particularly in response to various management and harvest strategies.