Training Lambs to be Weed-eaters

1
Training Lambs to be Weed-eaters

• Experiments on the efficiency of Ovis airies for
  use in the biological control of Brachypodium
  sylvaticum- a non-native bunchgrass
• Ryan Scholz-
• Junior Animal Sciences/ Bioresource Research
• Dr. Howard Meyers-
• Professor OSU Dept. Animal Sciences
• Dr. Deborah Clark-
• Sr. Instructor OSU Biology Program

2
Control

• Grazing
• Observations at OSU indicate grazing is effective
• Studies are underway to investigate this
• H. H. Meyer
• Relatively low palatability?
• Nutrition Tests
• Endophyte Tests

Grazed
Un-Grazed
3
(No Transcript)
4
Planned Studies

• Pasture Training
• Lambs to be grazed with mothers on B. sylvaticum
• Bummer Lamb Training
• Bummer lambs to be fed B. sylvaticum
• Seed Viability
• Nutritional Analysis

5
Pasture Training Study
6
Hypothesis

• Lambs grazed on B. sylvaticum with their mothers
  prior to weaning will have an increased affinity
  for B. sylvaticum as adults when compared to
  unexposed sheep.

7
Experimental Design

• Pre-Trial Training
• Treatment- Grazed on B. sylvaticum
• Control- Grazed on standard pasture
• All lambs grazing for 3 week training period
• First 2 weeks with ewes
• Last week weaned

8
Experimental Design

• Confinement Feeding Trial- wethers
• Offered fresh cut B. sylvaticum after overnight
  fast
• To determine the relative preference for B.
  sylvaticum after training
• Pasture Grazing Trial- ewes
• Grazed on a series of plots containing B.
  sylvaticum
• To measure
• Relative preference in a pasture setting
• Continued preference over extended period of time

9
Confinement Feeding Trial

• Procedure
• Lambs removed from field at 400pm and
  individually penned
• 250g B. sylvaticum placed in each feeder at
  1000am
• Allowed to eat for 30 minutes
• Removed from pens
• Leftover and wasted B. sylvaticum collected and
  weighed
• Repeated following morning
• Conducted immediately following training and
  again one month later

10
Data- Trial 1

• Treatment

• Control

100.0g B. sylvaticum
11
Data- Trial 2

• Treatment

• Control

250.0g B. sylvaticum
12
Analysis
Treatment

• Shows training to be effective
• Treatment lambs ate more
• Observations indicated treatment lambs to be less
  timid when eating
• Some conditioning occurred with control
• Likely situational conditioning

Control
13
Pasture Grazing Trial

• Procedure
• Lambs grazed on series of 100m2 plots containing
  B. sylvaticum
• Four 1m2 clippings taken before and after grazing
• Determine biomass composition
• Determine amount biomass removed
• Grazing patterns will be recorded using
  time-lapse video surveillance system
• Forage consumption and grazing patterns analyzed
  using forage maps

14
Data
15
Analysis

• Final Analysis not complete
• Observations indicate training to be effective
• Treatment lambs consumed more B. sylvaticum
• Treatment lambs spent more time grazing
• Trial cut short due to uncontrollable
  circumstances

16
Further Planned Research

• Yearling trial
• Ewe lambs will be kept
• Pasture trial will be repeated with same lambs
  next summer
• Determine the continued preference over extended
  time
• Study replication

17
Bummer Lamb Study
18
Hypothesis

• Orphan lambs which are fed milk replacer
  containing B. sylvaticum will have an increased
  affinity for B. sylvaticum as adults when
  compared to unexposed sheep.

19
Experimental Design

• Breeding/ lambing
• 25 ewes given luteinizing hormone for estrus
  synchronization, and bred
• Labor induced using hormone treatment
• Lamb Care
• Lambs divided into control and experimental
  groups
• Experimental lambs receive milk replacer with B.
  sylvaticum juice
• Confinement feeding trial
• Lambs will undergo same confinement feeding trial
  as pasture raised lambs.

20
Seed Viability Study
21
Hypothesis

• B. sylvaticum seeds digested and later deposited
  by Ovis airies will have a significantly
  diminished ability to germinate.

22
Experimental Design

• To determine the risk of further spread of B.
  sylvaticum through seeds deposited by sheep used
  for control.
• Two Trials
• Forage Diet
• Sheep on forage diet to achieve similar ruminal
  micro biotic content as grazing sheep
• Concentrate Diet
• To facilitate easy and accurate recovery of seeds
  from feces

23
Experimental Design

• Ripe seeds collected and dried to 10 moisture
• B. sylcaticum
• Loliium multiflorum (control)
• 5 gram samples weighed to 1/10000g accuracy and
  sealed in Dacron digestion bags
• Samples inserted into rumen cannulas and allowed
  to digest for 72h, 48h, 24h, 12h
• Control sample placed in water for 30m

24
Experimental Design

• After removal from rumen
• Samples washed thoroughly
• Dried to 10 moisture
• Weighed to 1/10000g accuracy
• Germinated in 25C/15C chamber

25
Data

• Average sample weight loss

26
(No Transcript)
27
Further Research

• Concentrate Diet Trial
• Replication of Dacron bag procedure
• 15g seed introduced directly into rumen
• Recovered from feces
• Further investigation into mode of digestion
• Neutral/Acid Detergent Fiber tests
• Determine amount of carbohydrates digested

28
Nutritional Analysis
29
Purpose

• Proximate Nutritional analysis
• Samples collected throughout growth season
• Allow grazing periods to be planned to maximize
• Control of B. sylvaticum
• Nutritional benefits to sheep

30
Questions