# Presentation: 424569

## 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

- Time

- TNC

**Sunup**

**Sundown**

**Day**

**Night**

## Variety Differences in TNC.

- TNC

**Sunup**

**Sundown**

- Variety Differences in TNC.

## Relative Quality and Intake3-cuttings alfalfa, Kimberly, ID

|  | PM | AM |
| --- | --- | --- |
| NDF,      % | 39.6 | 41.1 |
| ADF,      % | 30.3 | 31.3 |
| CP,        % | 22.4 | 22.3 |
| NO3-N,  ppm |    730 |   810 |
| RFV |    154 |   148 |
| RFQ |    157 |   150 |
| TNC,       % |        5.32 |       4.19 |
| DMI         g | 3000 | 2300 |

## Cattle Preferences

## Preference Testing

- Forage species
- Fescue, p/a ryegrass, orchard grass, bromegrass oat hay, etc.
- Corn, switch grass, sudangrass.
- Legumes:  alfalfa, several clovers
- Animal species
- Ruminants – cattle, sheep, goats
- 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 |  |
| IDAHO | 88 | 83 | <0.01 |
| WISCONSIN | 93 | 92 |  0.28 |

## 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 | Time on Pasture |  |
| --- | --- | --- |
|  | 7 am to 7 am | 3 pm to 3  pm |
|  Winter | 1.4 | 1.6 |
|  Spring | 1.2 | 2.5 |

## Ensiled Materials

## Protein  Degradation & Ensiling

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

## When Do I Cut?

- TNC

**Sunup**

**Sundown**

**When Do I Cut?**

## Impact on 1⁄2 of Crop on Western US Alfalfa and Dairy Industry

**5% increased forage  value =  $100,000,000+**
**Reducted NDF: $2.40-3.40/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
-  <  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