Irvin Ramer and his family manage 200 acres of pasture in Todd County, using 140 of those and a well-planned rotation to achieve nearly 12 months of grazing for their 80 Jersey dairy cows. Their Green Acres Farm was one of the first Certified Organic by the Kentucky Department of Agriculture and Organic Valley's longest-standing organic dairy farm in Kentucky. Irvin is also the first Certified Organic egg producer in Kentucky for Handsome Brook Farm. Their farm is participating in a UK/UT research project to determine what forage mixtures are best for organic dairy farmers.
Dr. Silvia Abel-Caines, Staff Ruminant Nutritionist for Organic Valley / CROPP, partnered with Chris Teutsch, Forage Specialist from UK’s Education and Research Center in Princeton, to share their expertise with nearly 30 participants from Kentucky and Tennessee.
Dr. Abel-Caines led the group through a discussion about the specialized nature of ruminant animals (like cows) to produce wholesome products (like milk) from fiber that is not digestible by any other species. Dr. Abel Caines demonstrated how the rumen works to ferment the food the animal consumes, allowing the animal to regurgitate it, chew it back, and then extract all the nutrients from there.
She explains when high amounts of grain are introduced into the cow's diet, the pH in the rumen drops, creating a more acidic environment. The change in pH affects the population of bacteria in the rumen: starch-digesting bacteria increase, and beneficial fiber-digesting bacteria decrease, resulting in a negative impact on the animal’s health.
Conversely, a grass-fed animal consumes microbes present in the grass; the cow chews the grass; and then the rumen microbes—bacteria, fungi, protozoa— transform that into healthier fatty acid.
“The quality of the milk that cow is producing has direct connection with the quality of the grasses and forage and pasture that she’s consuming,” Dr. Abel-Caines remarked.
The diversity of the grasses and legumes growing in the paddock has a direct correlation with the cow’s health and nutritional needs. If the average grasses of the paddock…fescue, orchard grass, timothy, rye grass…are all the cow has for forage, it will need additional nutrients, like protein. Legumes, like alfalfa and clover, provide more protein to the diet of the cow.
A walk through the pastures of Green Acres Farm allowed us to learn more about Mr. Ramer’s forage mixes of Freedom clover with annual ryegrass and sorghum-sudangrass with turnips. Additional foundational forages include new fescue, chicory, red and white clovers, alfalfa, and bluegrass in the cattle’s permanent pasture. Rotational research paddocks include crab grass and lespedeza for summer.
“Being organic… for me, clover is a must!” stated Mr. Ramer, emphasizing the protein benefit to the cows as well as its nitrogen-fixing bacteria contributing to soil health. Sunnhemp is another consideration mentioned for leguminous forage, as well as a cowpea/sorghum mix.
Dr. Teutsch stressed that it takes years for nitrogen to build up and requires the integration of livestock in the pasture as an important part of the nitrogen cycle.
Annual ryegrass, a cool season grass with strong spring production, is temperature-limited by the time June’s heat arrives, and therefore requires a late summer/early fall planting.
Crabgrass, on the other hand, is a warm season perennial and is highly digestible (especially in comparison with other warm season annuals) and can provide 10-14% protein in early season pastures. As a prolific re-seeder in Ramer’s paddock mixed with clover, it will need to be reclaimed without removing or damaging the critical clover growth, by pasture dragging and rolling in late spring to stimulate growth.
Providing the high-quality of these diverse mixes all year long can be challenging, but Dr. Teutsch offered advice for yielding quality silage
“Cut as vegetative as possible,” Teutsch stressed, referring to harvesting forage in or before the "boot" stage, the plant’s transition from the vegetative to the reproductive stage.
The stage of maturity is the #1 factor for quality silage. Forage quality generally declines with increasing length of the interval between harvests of stored forages or with longer rest periods in rotational grazing. Maturity of legumes and cool-season grasses can be assessed by determining the reproductive stage of growth. For warm-season grasses, however, weeks of regrowth are a better indicator of maturity because flowering may begin shortly after regrowth begins.
Making that decision to maximize quality requires the farmer’s concession that the yield will be less than if the plant is allowed to mature farther. It also may require intensive demands for harvest, such as sorghum-sudangrass, which must be cut and crimped one day and then bailed the very next day before molds set in and quality declines.
Another demand for quality pasture includes monitoring soil fertility w/ a soil test every couple of years, taken 3-4” deep in no- or shallow-till systems. The deeper you test, Teutsch cautions, the nutrients could present lower than the root uptake. Forage soil testing should include nitrogen and potassium.
Learning to assess your average pasture height, density, and dry matter is also a necessary skill to develop for forage management. Learning to use a grazing stick can help to simplify measuring pasture yield, allocating pasture to animals, and tracking productivity changes. Tips include advice to truly randomize the 10 samples taken across the field and avoid biased selection of only the richest, healthiest pasture; learning to train the eye while keeping accurate and regular pasture logs; and grazing to no less than 2-3” for forage regrowth.
Diversifying and improving forage is essential but not the only consideration for grass-fed dairy cows. Considering, Dr. Abel-Caines explained, that a 1200lb cow has the capacity to consume 3.5% of its body weight in dry matter daily and requires 2-3% to give milk, maintain her body condition, and reproduce. The dry matter from grain must be replaced with hay and pasture. This is no small task when one considers that nine pounds of grain at 13% moisture is close to eight pounds of dry matter. Consider replacing that eight pounds with forages that have moisture levels of 80 to 90%. It takes close to 100 actual pounds more of hay or pasture to replace the nine pounds of grain that is no longer being fed!
Irvin Ramer’s cows are completely grass-fed, with supplemental mineralization only, and therefore receive no grain in their diet. They are milked only once per day, which helps to control lactations and better manage their supply during periods when pasture quality is low or stored supply is minimal.
Part of this is due to the selection of species, like Mr. Ramer’s Jerseys, Dr. Abel-Cines explained, which maintain condition, milk production, and reproduction on forage. These cattle types are typically smaller-framed and have lower dry matter intake and nutrient requirements than Holsteins, which are designed and bred primarily for high yield.
“Crossbreeding is ideal,” Dr. Abel-Caines added, referencing the Holstein genetics developed through selection by grass-based producers in New Zealand.
Transitioning a grain-based herd to an exclusively or primarily grass-fed diet requires planning and patience, as cows need to go through two lactations to adjust.
“These cows must have a transition from their diet of dry, fermented feed since their rumen bacteria are not accustomed to the high protein of a diversified grass pasture.” Dr. Abel-Caines explained. “By flash grazing – allowing them 1-2hrs on healthy pasture – the first week, and then gradually increasing the length of time for ~3 weeks, gives their system time to adjust.
The final stop of the day was a shift from organic dairy to organic pastured laying hens, for which Mr. Ramer uses a forage selection of perennial rye, bluegrass, and clover that helps primarily with erosion prevention and sod formation under the feet of his 2,400 Isa Brown chickens.