Posted: September 7th, 2016

Measuring feed intake in sheep

Measuring feed intake in sheep

Introduction

Literature review
• Variation intake,
• Factors affecting intake
o Animal, forage, environment etc.
• Effect of intake
o Animal, digestion, emission, rumen, etc.
Material and method
Body weight
• Sample: Live body weight
• Time: Day 1, 8, 15, and 18 of each period.
• Materials: Scale located at Gogerddan.
• Analysis performed: Calculation of growth performance
Intake
• Sample: Weigh feed offered and refusals (if any). Amount of feed offered based on energy requirements based on individual BW.
• Time: Daily throughout the experiment.
• Materials: Scale located at Gogerddan.
• Analysis performed: Calculation of dry matter and nutrients intake.
Feed analyses
• Sample: 300 g of feed.
• Time: Weekly (every Monday).
• Subsamples:
 Dry matter
o Sample: 200 g of feed.
o Processing: Grind sample to 2 mm, and oven dry at 55C for 48 h.
o Materials: Mill located at Gogerddan. Oven from the lab in IBERS.
o Analysis performed: Dry matter of 12 samples (1 per week)

 Composition (NDF, ADF and CP)
o Sample: 100 g of feed (composited for every experimental period).
o Processing: Grind sample to 2 mm, and oven dry at 55C for 48 h.
o Materials: Mill located at Gogerddan. Analytic system from the lab in IBERS.
o Analysis performed: Composition of 3 samples (1 per period)
Rumen fluid
• Sample: 100 mL of ruminal liquid.
• Time: Immediately before feeding (0 h), 2 and 4 h post-feeding, on day 17 of each period.
• Processing:
 Collect ruminal content from the ruminal cannula.
 Filtrate content trough 250 µm pore size nylon mesh.
• Subsamples:
 pH
o Sample: The original 100 mL of ruminal fluid.
o Processing:
 Immerse pH probe into the ruminal liquid.
o Materials: Portable pH probe.
 VFA
o Sample: 4 mL in 15 mL falcon tube.
o Processing:
 Pipette 4 mL into a previously labelled 15 mL falcon tube containing 1 ml 20% V/V orphophosphoric acid with 4 mM 4 ethyl butyric acid.
 Store at room temperature.
o Materials: 5 mL Pipette, falcon tubes, solution of 20% V/V orphophosphoric acid with 4 mM 4 ethyl butyric acid.
o Analysis performed: VFA quantification on 54 samples (6 sheep, 3 sampling times over 3 periods).
 Ammonia
o Sample: 1 mL in a 2 mL Eppendorf tube.
o Processing:
 Pipette 1 mL into a previously labelled 2 mL Eppendorf tube containing 0.25 ml of 25% W/V trichloroacetic acid (TCA).
 Store at room temperature.
o Materials: 1 mL Pipette, 2 mL Eppendorf tubes, solution of 25% W/V TCA.
o Analysis performed: Ammonia quantification on 54 samples (6 sheep, 3 sampling times over 3 periods).
 Protozoa
o Sample: 0.5 mL in 1.5 mL Eppendorf tube.
o Processing:
 Pipette 0.5 mL into a previously labelled 1.5 mL Eppendorf tube containing 0.5 mL of saline formaldehyde 9.25% in NaCl 0.9% solution and dyed by adding a drop of methylene blue.
 Store at room temperature.
o Materials: 1 mL Pipette, 1.5 Eppendorf tubes, solution of saline formaldehyde 9.25% in NaCl 0.9% solution and dyed by adding a drop of methylene blue.
o Analysis performed: Protozoa count on 54 samples (6 sheep, 3 sampling times over 3 periods).
Faeces and urine
• Sample: Total amount of faeces and urine.
• Time: From d 15 to d 18 of each period.
• Processing:
 House sheep in metabolic crates.
 Collect faeces and urine separately.
 The container used to collect the urine will have approximately 100 ml of 10% sulphuric acid.
 Filtrate urine trough 250 µm pore size nylon mesh.
 Weigh faeces and urine collected
• Subsamples:
 Nutrient digestibility
o Sample: 20% and 10% of the total faces and urine collected in a 24-h period, respectively, composited per animal over every experimental period.
o Processing:
 Collect subsamples of faeces and urine into previously labelled containers.
 Composite samples of each animal over each experimental period.
 Store at –20°C.
o Materials: Vessels to weigh the subsamples, plastic bags to store faeces, and plastic vessels to store the urine.
o Analysis performed: Nutrient digestibility on 18 samples (6 sheep over 3 periods)
Behaviour
• Sample: Feeding behaviour.
• Time: From 10 min before to 1 h after each feeding, on day 16 each period.
• Processing:
 Sheep will be fitted with a head harness that will incorporate a sound recording device and a 3-axis accelerometer.
 A wall mounted camera will record movements of the head.
 Video recorder, sound recorder and accelerometer will be activated at least 10 min before offering the food, and will be turned off at least 1 h after.
 After the sampling period, all devices will be transported to the office where data will be downloaded to a computer to be analysed.
• Materials: Head harness, sound and video recording devices, accelerometers, timer to synchronize data recording devices.
• Analysis performed: Movement and sound analysis compared to visual observation on 36 h of data (1 h per sheep, 6 sheep, during 2 feeding times, over 3 periods).