Using alternative forages to help maximize milk production
CLINTONVILLE – With numerous alfalfa fields experiencing winter kill in recent years, many dairy producers are turning to alternative forages to provide the crude protein, (CP) neutral detergent fiber (NDF) and total digestible nutrients (TDN) needed by their herds.
Dr. Matt Akins, UW-Madison Extension dairy nutrition specialist, provided the latest research to 48 dairy farmers and others in the agricultural industry on how to use alternative forages as a primary feed source.
Akins presented his findings during the opening session of the 58th annual UW-Extension Cow College program Jan. 7 at the Fox Valley Technical College Regional Center.
He discussed the various alternative forage options that include cereal grain forages like oats, rye or triticale planted in spring or late summer, fall planting of winter rye, triticle or wheat. Other options include cool season annuals like Italian ryegrass and warm-season annuals like corn, sorghum, sudan grass or a mix of sorghum and sudan grass.
Forage quality importance
Akins cautions that producers must be aware of the quality of the alternative forages being used in their dairy rations.
“Send samples to a lab for testing,” he advised. “Quality can vary depending on weather, cutting maturity and variety.”
Forage should be fed to groups of animals based on quality. “Low fiber/highest digestibility forages should be fed to the highest producing cows, forages with moderate fiber and digestibility are best fed to lower producing cows or young heifers and forages high in fiber with low digestibility are best fed to dry cows and pregnant heifers,” Akins stressed.
He reported on the results of alternative forage test plots that featured rye silage, Italian rye grass and a sorghum-sudan grass mix.
“The rye silage had 12% CP; 45% NDF; 71% NDFD; and 70% TDN. Numbers for the Italian ryegrass were 14.5%; 50%; 62% and 62%. The sorghum-sudan grass mix tested 14.5% CP; 50% NDF; 70% NDFD and 64% TDN,” Akins related.
He also emphasized the importance of measuring forage inventories so producers can accurate plan their feeding schedule.
“A 12-foot by 250-foot bag of ryelage contains 180 tons of DM, with a 10% shrink leaving 162 tons of DM. Feeding 200 lactating cows 6 pounds of DM per day, per cow will consume 1,200 pounds of DM per day, and provide feed for 270 days,” he said.
Akins suggested that multiple harvests, generally two in the Midwest, can produce forages with higher NDFD and protein. “A single harvest of moderate quality forage can maximize yield,” he added.
Feeding cereal grain forage should be based on quality, according to Akins. “A typical feeding rate for cereal grains is 10- to 30-percent of the forage ration,” he explained.
He noted that sorghum forages are better for drier soil conditions. “They often have a higher NDF content, and can replace corn silage. Sorghum-sudan forages are useful replacements for alfalfa or corn silage.”
Akins advised producers to be aware of the potential for toxicity including nitrates from drought or frosted sorghum forages and cereal grain forages with high nitrogen content. “Prussic acid (hydrogen cyanide) can be found on frosted sorghum,” he cautioned.
Jarrod Blackburn, Vita Plus Dairy Nutrition specialist suggested ways to maximize milk components using dairy nutrition and feeding strategies to boost profitability.
He spoke about alfalfa quality, forage quality and the NDF-fiber quality in the ration. “All three are important but are not necessarily the same thing,” he said.
He stressed that alfalfa should be persistent, have a high yield, be disease resistant, protect against leaf loss and feature harvest loss reduction. “Retention of alfalfa protein is of high value in corn silage diets and reduces supplemental crude protein costs.”
Ration NDF-fiber quality is related to the rate of NDF digestion, NDF passage and the effect of NDF source on dry matter intake. “Caloric supply drives milk production with the goal to reduce milk production variance,” he stressed.
High quality forages
Blackburn list these parameters for quality forages:
- Alfalfa (40% NDF; 20% uNDF240; NDF kd 6.5%/h)
- Straw (65% NDF; 30% uNDF240; NDF kd 1.55/h)
- Corn silage (40% NDF; 12% uNDF240; NDF kd 4.5%/h)
- BMR (40%NDF; 7% uNDF240; NDF kd 5%/h)
“High quality alfalfa is made at the proper maturity (uNDF 16-17%, 170-180 RFQ), made at the proper moisture - 60%, stored properly by being covered and sealed with adequate drainage and reaches the proper fermentation, with no butyric acid,” Blackburn said.
He stressed that high quality Italian rye grass should have a maturity of 3-7% uNDF, a 170-210 RFQ, and a moisture content of 65%, with storage and fermentation the same as alfalfa.
He warned that variation in dry matter can have a negative effect on milk production, nutrient balance, cow health, and contribute to lost income.
“The foundation of a dairy ration starts with quality forage,” Blackburn stressed. “Quality forages help maximize protein efficiency and reduce the need for purchased feed. They also minimizes butterfat suppression while maximizing income. Storing quality forage properly minimizes shrinkage and maximizes forage usability.”