Diurnal Changes in Forage Quality Affects Animal Preference, Intake, Performance Hank Mayland, Dave Mertens and Bret Taylor USDA-ARS Kimberly, ID; Madison, WI; Dubois, ID Pablo Gregorini, Universidad Nacional de La Plata, Argentina Joe Burns, Dwight Fisher, Tony Ciavarella, Kevin Smith, Glenn Shewmaker, Tom Griggs Dec 2005

PM-Cut Hay Is it For Me ?

Diurnal Cycling of TNC  1. In forages  2. Animal preference PM-AM cut hay  3. Animal production PM-AM cut hay  4. Animal production: strip grazed pasture  5. Economic response to PM-cut hay  6. Other benefits

Photosynthesis = CO 2 + H 2 O chlorophyll O 2 + Sugar Time TNC SunupSundown DayNight

Time TNC SunupSundown Variety Differences in TNC.

Relative Quality and Intake 3-cuttings alfalfa, Kimberly, ID PMAM NDF, % ADF, % CP, % NO 3 -N, ppm RFV RFQ TNC, % DMI g

Cattle Preferences

Preference Testing  Forage species Fescue, p/a ryegrass, orchard grass, bromegrass oat hay, etc. Fescue, p/a ryegrass, orchard grass, bromegrass oat hay, etc. Corn, switch grass, sudangrass. Corn, switch grass, sudangrass. Legumes: alfalfa, several clovers Legumes: alfalfa, several clovers  Animal species Ruminants – cattle, sheep, goats Ruminants – cattle, sheep, goats Non Ruminants – horses, rabbits Non Ruminants – horses, rabbits

Preference for PM/AM-cut Hay  Cattle, sheep, goats, horses, rabbits sense hays differing by 0.5% sugar concentrations

Dairy Cow Lactation

Milk Production Hay Source Milk Yield, lbs/d P TMR with PM-cut alfalfa TMR with AM-cut alfalfa IDAHO8883<0.01 WISCONSIN

Sheep Growth

Growth Study  Lambs at USSES being conditioned for fall breeding were fed TMRs containing 50% PM- or AM-cut alfalfa.  Lambs adapted more quickly to the PM- than AM- TMR by consuming more of the stem material.  No overall difference in DMI, feed efficiency, or weight gains.

Pasture – Strip Grazing

Heifer Weight Gains (lbs/d) in 24 h Strip Graze System Season Season Time on Pasture 7 am to 7 am 3 pm to 3 pm Winter Winter Spring Spring1.22.5

Ensiled Materials

Protein Degradation & Ensiling  Alfalfa and red clover (Owens et al) TNC increased throughout the day TNC increased throughout the day Silage pH decreased and starch increased with cutting time Silage pH decreased and starch increased with cutting time Success in ensiling forages like alfalfa Success in ensiling forages like alfalfa

Time TNC SunupSundown When Do I Cut?

Impact on ½ of Crop on Western US Alfalfa and Dairy Industry  5% increased forage value = $100,000,000+  Reducted NDF: $ /ton for each 1% = $44 to 62 m annually.  Increased RFQ: $0.90/ton for each 1% = $127 m annually.  Increased milk production 5% at $13/cwt = $276 m annually.

Benefits of Feeding Afternoon vs. Morning Cut Forage  > Rate of passage  > DM intake and digestibility  > Efficiency of forage utilization  > Efficiency of protein utilization  > Increased energy intake for production < Ammonia excreted < Ammonia excreted < Manure excreted < Manure excreted

Summary  Sugars increase during day in plants  Herbivores can detect sweeter forage  Expect 5%+ increased milk production in western U.S.

Isn’t it astonishing that all these secrets have been preserved for so many years just so that we could discover them. Orville Wright, 17 Dec. 1903