sheep production - sciencegrindsireland.com

SCIENCE GRINDS IRELAND STUDY NOTES: LEAVING CERT. HONS Ag. SCIENCE: SHEEP & LAMB PRODUCTION – DIGESTION – BEEF - EXPERIMENTS

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Sheep Production

Sheep meat consists of lamb slaughtered at 3-12 months

Sheep rearing is in exposed and mountain areas

lamb rearing in adjacent lowland areas

Grazing is on heather

Breed like Blackface Mountain are located in mountain areas usually in the west of Ireland

Wicklow Cheviot are in Wicklow area

Galway breed are in Galway and Roscommon

Other breeds that are in plains with good soils are Texel, Down breeds (Suffolk/Oxford) and

Crossbreeds (Halfbred and Greyface)

Mountain Breeding Strategy: same breed of ewe and ram are bred and the ewe lambs are sold or replace

flock and the ram lambs are fattened or sold. Ewes stay on the mountain for average 5 years and then

are sold to hill farmer for lambing and they are called “culled for age”, “draft” or “cast” ewe’s.

Hill Breeding Strategy: the draft or cast ewes are mated with a ram to give a cross breed lamb examples

Greyface and Halfbred.

Lowland Breeding Strategy: lambs are produced for slaughter.

Ram Breed: is purebred used for fast growth rate ex Suffolk, Oxford Down (early) and Texel (mid

season lamb)

Ewe Breed: Greyface and Halfbred in lowland areas

Sheep are polyoestrous: come in season repeatedly over a season usually Sep-Feb, with a 17 day cycle.

Gestation is 149 days.


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Synchronised Breeding:

• reduces mating and lambing period by 3 weeks

• reduces work load

• good for flock management

• Method:

1. sponges implanted with progesterone are placed into the ewe for 12-16 days

2. all sponges are removed simultaneously

3. ewes come into heat 2 days later

• ram: ewe ratio is reduced from 1:40 to 1:10

Breeding out of Season:

• producing lambs for the Easter market

• lambs must be born by December

• ewes are pregnant in July

• ewe comes in heat Sep the progesterone sponges are implanted for 2 weeks and when removed

the ewe is injected with PMSG (pregnant mare serum gonadotophin)

• ewes come into heat 2 days later

• ram:ewe ratio is reduced from 1:40 to 1:10

Mixed Grazing:

• common practice with cattle and sheep

• land must have adequate fertiliser and good grassland

• leads to an even of recycling of nutrients (sheep graze on cattle dung and sheep dung urine)

• increase in tillering

• a denser sward

• increased DM production

• sheep can eat the grass surrounding the dung pats of cattle

Wool Production

• shearing occurs in June

• quality is determined by fineness of the fibre, Merino ( Spain/Australia)

• merino wool is 15 micro width

• wool from Ireland and Britain is 40-50

• Bradford Count is the standard measure of wool quality


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Lamb Production

Selection for Breeding:

Ewe: good health, good feet and good conformation

Ram: good health, good feet, good conformation, performance tested by Dept of Agric

Lowland Lamb Production: Sequence

Jan/Feb lambing

occurs March-May

suckling to mother

creep

feeding

weaning

of lambs

June-August lamb grazes good quality grass by lamb

mating

ewe on poor quality land

Sep-Oct flushing occurs and ewe is put on good pasture

mating

ewe remains on land

Nov-Dec ewe is fed for maintenance

Dec-Jan steaming occurs


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Flushing:

• feeding ewe low plane nutrition after weaning then on high plane

nutrition for about a month before mating

• advantages are : more eggs released, more regular heat periods and

higher conception rate • it is continued after mating for 3-4

weeks

Mating:

• ratio is usually 1:40 and when oestrus is synchronised it is 1:10

• ram and ewe groups must be kept separate

• keep a record when each ewe is mated to predict the lambing date

• recording can be done by marker dye on the ram’s chest which

transfers to the ewe he mates with

• dye in a raddle attached to a harness also used or dye and

vegetable oil mixed to rams chest


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• ewes should be ear tagged

• change colour every 17 days during mating season

Flock Management during the Mating Season:

• good grazing and moderate stocking rate are used during the

mating season and also 3-4 weeks of pregnancy of a ewe

• ensures proper development of the embryo and attachment to

uterine wall due to good nutrition

• early-mid pregnancy, ewes are fed on low/moderate plane of

nutrition to maintain their weight

• first 2 months of pregnancy a ewe’s nutritional requirements are at

their greatest due to the quick growth rate of the embryo and

foetus

• ewes should be housed as lambing approaches

Steaming Up

• hay/silage with concentrates of protein (15%) together with a good

mix of mineral and vitamin mix

Chilled Lambs:

• use infra red lamp

• glucose injection

• fostering crate

Feeding:

• growth of lamb depends on health of the ewe

• early lambing 9Dec-Feb) requires ewes to be fed on hay or silage

and concentrates until spring grass is available

• for late lambing (March onwards) grass is fed

• ewes with twins should be fed concentrates

• lambs produced for Easter should be fed grass and concentrates


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Weaning:

• lambs sold before June suckle from their mother up to being sold

• other lambs then are weaned in June and separated from ewe for 7

days

• when weaning is complete, lambs can graze with ewes or be kept

separate

• lambs are kept on good quality pasture and ewes are kept on bare

pastures to prepare them for flushing

•

Housing:

• winter housing is needed for intensive sheep production and

prevents poaching and encourages early grass growth

• a collecting pen is for initial housing of the sheep and sorting out

the flock Page | 6

• storage pens are used to gather sheep to pare their feet to shear

their wool

• dipping unit to dip sheep into

Sheep Diseases:

Pregnancy Toxaemia inadequate nutrition

abortion occurs

feed on concentrates

Chilled lamb lack of colostrum

weakness

dry, warm and feed colostrum

Foot Rot bacterial infection by fusiform species

lameness


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clean feet and between toes, pare hooves

Clostridial Diseases soil borne clostridial bacteria

affects tissues and organs

vaccination 8 in 1

Maggots external parasite due to blue/green bottle fly

maggots hatch on

soiled area around

tail and feed on skin

and flesh area

becomes infected and

animal can die

dipping in insecticide,

clipping area and

worm control

Sheep Scab external parasite by mange mite

loss of wool, biting the area

dip all sheep, notify gardai of infected sheep


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Intestinal Worms


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Digestive Systems

Digestion serves to provide energy for living organisms. They need

energy to fulfil the following functions:

1. metabolism

2. exercise

3. produce waste products from food assimilated

4. excretion

5. produce heat

5 stages of digestion:

1. Ingestion: food enters the mouth

2. Digestion: physical break down of food using teeth and tongue,

chemical break down using salivary amylase

3. Absorption: enters bloodstream

4. Assimilation: nutrients from food used where needed

5. Egestion: getting rid of undigested food from the body

Digestive System:

Mouth: teeth and tongue break down food (mastication) and saliva

moistens and chemically breaks down food. Mucus lubricates the

food. Salivary amylase breaks down starch to maltose.

Peristalsis = rhythmic contractions of muscles along alimentary canal to

push food down to the stomach. Wavelike motions.

Stomach: Stores food and further digestion by churning it in the

stomach and stomach acid kills germs. Rabbits, horses and humans


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have monogastric stomachs/ In micro-organisms the large intestine

and the appendix server to ferment the food which digests cellulose.

Rabbit and Pig Stomachs:

o monogastric stomachs as they have only 1 o gastric juices are

secreted from the stomach walls

o This consists of HCL to kill germs and maintain an acid pH

of 3, pepsinogen to P

age | 9 form pepsin and rennin to digest milk.

o Gastrin is produced which circulates the food and helps

stomach to stimulate gastric juice

o Sphincters are at the entrance and exit of the stomach to

prevent a back flow of food and unexpected flow out of the

stomach


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Sheep

Ruminant Stomach:

o cattle and sheep have this stomach o is specialised to digest

cellulose o their stomach consists of 4 chambers o Rumen: is the

1st part-contains bacteria to digest cellulose o Reticulum:

(honeycomb) o further chewing of the food occurs next when

food is passed back to the mouth o the cud is then passed to the

3rd chamber o Omasum: food is pressed together to absorb water

and solid parts are passed on o Abomasum: gastric juices are

secreted and digestion occurs here


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Cellulose:

o normally most higher animals cannot digest cellulose o

exception: Hind-gut fermenters: rabbit and horse and ruminants

o pigs and humans cannot digest cellulose /roughage


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Small Intestine:

o Duodenum: pancreas secretes pancreatic juice into the

duodenum.

Contains: Trypsin to break down protein to peptides

Amylase: break down starch to maltose

Lipase: to break down lipids to fatty

acids and glycerol o Intestinal Juice: breaks

down sugar o Maltose/sucrose/lactose =

maltase/sucrose and lactase to glucose.

Page | 10 o Erepsin to break down protein to peptides to amino acids.

o Liver: produces bile to emulsify fats. Bile is produced in the liver.

It is stored then in the gall bladder. The liver serves to break down

excess proteins, detoxify poisons, store minerals and vitamins,

store glycogen and regulate the amount of fat in the body.

Absorption:

o Villi: finger like projections to increase the surface area for

absorption by diffusion or active transport of nutrients

Large Intestine:

o digestion of cellulose

o major part is the colon: reabsorbs water


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Experiment: Test the Chemicals in Food

Grind food up and test presence for fat, Vit C, Glucose and starch.

Experiment: Observe Gizzard of Chicken

Use giblets from a chicken and examine it. Draw a diagram of what you

see.

Experiment: Digestive System of a Rabbit

Dissent and examine the digestive system, draw a labelled diagram.


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Beef Production

Most beef breeds are the results of cross breeding with bulls and Friesian

cows

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Appearance Dairy Characteristics Beef Characteristics

General Wedge shape Block type

Head Long & narrow head

Thin elongated neck

Short & wide head

Short and thick neck

Shoulders Shoulder blades close together

Strong

Not fleshy

Wide apart shoulder

blades

Fleshy

Back Level

Level

Broad at all points

Hind Legs Not fleshy

Good feet

Long and wide

Strong

Evenly fleshy to the hocks

Good feet

Long and wide

Strong

Barrel Triangular shape

Narrows at the front

Deep from front legs to

the loin

Rectangular shape


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Suckler Calves: Feeding

• Maintenance feeding usually for 5-6 months of the year

• The remainder time the cow needs to be fed highly nutritious

food:

1. steaming up prior to calving

2. nutrition allows for good milk production to feed the

newborn

• Concentrates are usually fed just before and after calving

• Calf suckles from birth to weaning

Beef : Nutrition

• age at which an animal reaches maturity varies greatly and so the age at which they Page | 12 are slaughtered also varies

• if on all concentrate it can occur as early as 1 year: diet is maize

and they are housed all year round, very intensive farming:

Termed a high plane of nutrition

• in contrast in Ireland, the system is one mainly of grass, and the

age varies from 1.5 –


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2.0 years

• the weight of the beef animals when they have reached maturity

varies on their breed

• nutrition for Irish based beef animals is that of moderate quality

silage or hay for the winter months : this is a “store” period

meaning their frame grows but they don’t put on much weight

• this type of feeding programme results in “compensatory”

growth during the summer periods: an animal is well fed after a

time of restrictive feeding

• growth rates as a result are higher during the compensatory

period than during the winter months

• very economical as it keeps costs down

• quality of grass when it is left over the winter, result in high

quality

• animals left out “out wintered” for the whole year often do not

put on sufficient weight and are older before they reach their

slaughter weight

Beef: Body Development

• increase in fat from age 2 onwards

• deposited mostly in abdomen region

• age for fat depositing varies with age and once it deposits it is not

food practice to continue to feed after this as it wasted

• fat deposits occur in Hereford’s at age 1.5-2.0 and in Charolais at

2.3-2.5 years

• “conformation” refers to the shape of an animal and the fat

distribution

• breed is a major factor in shape: Continental breeds the best

(Charolais, Limousin and Simmental )

• dual purpose the next best and dairy the worst

• 2 criteria for slaughter: 1. conformation and 2. fatness


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Beef: Sex and development

• male bulls, castrated males (steers or bullocks) and female heifer

are used and so too are culled cows

• Bulls: have the fastest growth and development rate. Can be

violent. Little bull beef production in Ireland

• Steers: no testosterone. Lower in development as a result. Most

bulls in Ireland are castrated due to farming being mostly

outdoors and can interfere with breeding.

• Heifers: Lowest in development.

Farming Cycle for Calves:

• First Year: Summer:

1. calf should weigh about 80kg

2. leader-follower system

3. protect against diseases

4. spring born calves now called weanlings

• First Year: Winter:

1. weight should be 200kg

2. use high quality silage: DMD of 73% quality, if not must

use high quality feed to compensate

3. protect against disease

4. can be housed in open sheds with straw or slatted houses:

floor space of 1.4m2 and air space of 7m3

• Second Year: Summer

1. weight should be now 280kg

2. should be second in line of the leader-follower system

3. dose for parasites


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4. when being housed, a floor space of 2m2 is required and

10m3 of air space per animal

• Second Year: Winter

1. weight should now be 450kg

2. feed on good quality silage and concentrates

3. should reach the slaughter weight at the end of the winter

Grading at Slaughter:

• EUROP is used

• grading is on the basis of conformation and fatness

• grades for conformation range from E-P

• E is the best

• P is the worst

• grades for fatness from 1-5: 1= leanest 5= fattest

Purchasing Calves:

• best to buy from a farmer you know to ensure calf was fed

colostrum and how the calf was housed and fed and

transportation can be done swiftly and conveniently

• when purchasing from cattle marts look out for conformation and

health

• Conformation: wide shoulders and hindquarters and a deep barrel

• Health:

Eyes: bright

Ears: pricked

Nose: clean and no discharge


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Naval: clean and no swelling

Mouth: clean and no dribbling

Anus: clean, if soiled it is a sign of diarrhoea

Appearance: lively and alert

• once bought they should be allowed to house in a clean and

draught free house and have time and space to recover

• feed on water and glucose for the first 24 hours

• wean gradually onto milk for 3-4 days

Breeding Management:

• a spring-calving system is often used

• reproductive efficiency: is the number of calves that are weaned

per 100 cows

• diet is the most important factor to achieve a high rate of

efficiency: with a target of 90-100

• calving interval: should be kept close to 12 months to utilise

summer grass

• heat detection in females is common practice

• in smaller herds: AI and heat detection and servicing are used


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Diseases:

worms

TB

lungworm

blackleg

lice

redwater

grass tetany


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Experiment Summary

1. To test a leaf for starch

o kill a leaf in boiling water, place in a test tube add methylated spirits and heat

to remove chlorophyll

o remove the leaf and dip in cold water to

soften it

o add iodine

o if starch present the leaf turns blue/black

o if starch is not present the leaf remains

brown

2. To show light is necessary for photosynthesis

o destarch a potted plant by keeping it in the dark for 24hours

o put foil on a part of the leaf, sketch

o expose the plant to light for 4 hours

o then remove the leaf and the foil

o test the leaf for starch, the part of the leaf which was under the foil

remains brown, so no starch was present

o the part of the leaf that was left uncovered, goes blue/black, starch was present

3. To show carbon dioxide is necessary for photosynthesis

o destarch 2 potted plants : keep in the dark for 24 hours

o add soda lime on the soil of 1 plant and cover each plant with a plastic

bag

o expose each both plants to strong light for 4 hours

o remove a leaf from each plant


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o test the leaf for starch , the part of the leaf with the soda lime (no CO2)

remains brown so no starch was present

o the leaf of the plant without the soda lime (CO2) present, goes

blue/black so starch was present

4. To show chlorophyll is necessary for photosynthesis

o destarch a potted plant in the dark for 24 hours

o expose to strong light for 4 hours

o remove a leaf

o sketch

o test the leaf for starch: the area with no chlorophyll stays brown so no starch

o the leaf with starch present the chlorophyll goes blue/black

5. To compare the number of stomata on the upper and lower leaf

o apply clear nail varnish to the upper and lower leaf

o allow to dry and peel off the layers of varnish

o examine under a microscope and count the number of bumps (stomata)

o the lower surface has more than the upper surface

6. To show the factors necessary for germination

o test tube A: control: moist cotton wool, seeds, warm

o test tube B: dry cotton wool, seeds, warm

o test tube C: moist cotton wool, seeds, fridge

o test tube D: cotton wool, seeds, filled with water, layer of oil, warm place

o leave for 10 days

o no germination in B,C,D

o germination in A


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7. To show the effect of nutrient deficiency on plant growth

o 2 test tubes with seeds of equal size and in 1 test tube add a tablet with all the

nutrients

o in the other test tube leave out 1 nutrient

o cover both with foil and leave for 2 weeks

o top up nutrient solution

o test tube with all the nutrients grows well

o test tube without all, shows poor growth

o lacks nitrogen: lacks protein

o lacks phosphorous: poor root formation

o lacks potassium: poor protein formation

o lacks magnesium: can’t make chlorophyll

o lacks calcium: lack of cell wall production

o lacks iron: unable to make chlorophyll aeration tube: allows for

respiration

o tin foil: prevents any algae competing with seeds for food

8. To show that germinating seeds release energy

o 2 thermos flasks

o add live peas to one, insert a thermometer and plug with cotton wool

o add dead peas to the other, insert a thermometer and plug with cotton wool

o record the temperatures

o leave for one week

o flask with the live peas shows a rise in temperature

o flask with dead peas shows no change in temperature


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9. To demonstrate the rate of transpiration using a potometer

o fill the photometer under water and add the seedlings

o remove it from the water and keep the capillary tube in the water

o then remove the capillary tube and allow an air bubble to enter

o note the position of the air bubble

o place on a window sill for 3-4 hours and then note the position of the air bubble

which should have moved closer to the plant

o as water is lost through the leaves (transpiration), it was replaced by the water in

the podometer

10. To demonstrate transpiration in a plant using a bell jar

o get a well watered potted plant and cover the soil with plastic

o place a bell jar over the plant

o leave in the light for 3-4 hours and then note the condensation inside the jar

o test for water with cobalt chloride paper, water is lost from the surface of the

plant due to transpiration

11. To demonstrate the transpiration stream

o place celery in a beaker of dyed water for 1 hour, then remove and examine the

veins in the leaves

o cut across the celery and examine the xylem tubes and note their colour change

12. To demonstrate the range of pigments found in a grass plant

o grind up grass leaves, add acetone and filter

o add a drop of extract to chromatography paper o add solvent (acetone) in a covered jar o

place the end of the paper in the solvent and note the separation of pigments


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13. To demonstrate osmosis

o fill visking tubing with sugar solution and place this in a beaker of water

o leave for 20 minutes and note the result of the water moving up from the beaker

into the visking tubing

14. To demonstrate phototropism

o cover a seedling with some cardboard that has a hole cut out

o leave for 2-3 days and note the growth towards the light

15. To demonstrate geotropism

o add 2 beans to a glass jar filled with moist cotton wool

o put 1 bean upright and the other on it’s side

o leave for 1 week

o note how shoots grow up and roots grow down

16. To show the micro-propogation of plants

o add cells from a plant to a petri dish with nutrients and place in good light at

20-25 degrees o note how cells multiply and callus forms

o transfer the callus to a different medium to encourage the development of

roots and shoots and plant the small plants in the soil

17. To obtain and grow a culture of bacteria for the root nodules of a clover plant

o dig up a clover plant, clean and disinfect use inoculating loop to transfer

bacteria to an agar plate and incubate for a week

o note how colonies of Rhizobium bacteria grow


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18. To assess the hygienic quality of milk

o add 10 ml of milk to sterile test tubes A,B,C,D

o A: fresh pasteurised milk, B: fresh unpasteurised milk, C: sour pasteurised milk

and D: sour unpasteurised milk

o add 1ml Resazurin, stopper and incubate at 37 degrees for 10 mins

in water bath

o A: blue B: mauve C: pink D: white o blue is the best quality and

white is the poorest quality

19. To show the presence of bacteria in a sample of milk

o transfer milk samples to 5 separate sterile agar plates

o o A: fresh pasteurised B: fresh unpasteurised C: sour pasteurised, D:sour

unpasteurised and E: no milk

o seal each and incubate plates for 24-48 hours

o o bacterial colonies increases from plate A to D and no colonies on plate

E

20. To determine the soil texture by sedimentation

o get soil and add to a graduated cylinder, add water to make 100ml and cover,

invert a few times and allow to settle

o calculate the percentage of sand, silt and clay use a soil textural triangle

21. To determine the soil texture by feel

o use sandy and clay soil

o feel and note the texture, wet a little and note the texture, plasticity and

cohesiveness

o use a table with pre-determined information to decide textures sandy soil=

gritty and will not stick or roll clay will roll and is not gritty


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22. To demonstrate the drainage of different soil samples

o use 2 graduated cylinders and add a funnel with filter paper

o add equal amounts of soil to each and equal amounts of water

o measure the length of time it takes for the water to drain

o sandy soils have better drainage

23. To demonstrate soil capillarity

o fill one glass tube with sand and the other with clay

o plug the ends of each tube with cotton wool and immerse in a beaker of water

for a few hours

o observe the movement of water

o water moves up through the clay soil

o very little movement in the sand

sample

24. To demonstrate the role of earthworms in the soil

o set up a wormery using different types of soil

o add worms

o set up a a wormery with no worms, this will be the control

o observe the movement after one week: layers are mixed up, the leaves on the

surface are brought down by the worms and channels are produced by the

movement of the worms. There is no change in the control.

25. To determine the number of earthworms in soil

o use 1m2 area of grassland and remove all vegetation from it with a shears

o make up a solution of sudsy water and pour over that area, watch the earthworms

rise to the surface and count.


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26. To determine the organic matter and inorganic matter content of a soil

sample

o weigh a dried sample of soil and put in a crucible over a Bunsen burner and

watch the black smoke come out of the soil. This is the organic matter being burnt

off.

o Heat until the soil glows red.

o Reweigh the same soil sample. Any loss in weight equals the organic matter that

was burnt off.

Soil that remains is equal to the inorganic matter content.

% of organic matter content: loss of weight/ weight of sample x 100 o %

of

inorganic matter content: weight remaining/ weight of sample x 100

27. To determine the percentage dry matter and percentage water in a soil sample

o weigh a container and then weigh the same container with a sample of soil

o calculate the weight of the soil sample o place the sample in the oven at 100 degrees

and remove the sample and weigh again

o replace into the oven and remove and weigh it again, repeat until the

weight is constant

o calculate the percentage of water and the percentage of dry matter in the

sample

o % water: loss in weight/weight of sample x 100

o o % dry matter content: weight remaining/weight of sample x 100


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28. To determine the temperature of soil

o dig a hole in the soil in the ground and coat the bulb of a thermometer with many

layers of wax, then place the thermometer into the ground in the hole.

o Covering the bulb with wax prevents the atmospheric temperature from

affecting the temperature before the reading is taken.

o leave for 2-3 hours and remove and read the temperature

29. To determine the percentage of air in a soil sample

o measure the volume of an empty can and insert it into the ground and put soil

into it, remove the can with the soil in it from the ground

o add a known volume of water to a graduated cylinder and pour that water into

the soil sample until the can is full

o measure the amount of water added

o the volume of the water added is equal to the amount of air in the soil o

calculate the percentage of air in the soil, this should be about 25%

30. To determine the pH of a soil sample

o place a small amount of soil into a beaker

o add some water and stir and stand for 10 minutes

o insert the electrode of a pH meter into the soil solution and record the pH of it


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31. To demonstrate Cation Exchange Capacity

o get some soil with a high pH and place filter paper in a funnel and add the soil

into the filter paper

o slowly add potassium chloride reagent and test the leachate for calcium by

adding ammonium oxalate reagent

o white precipitate indicates a positive result o continue adding the potassium

chloride and testing the leachate and continue testing for calcium until the test

is negative

o soil colloids are transformed from being calcium dominated to potassium

dominated

32. To determine Soil Flocculation

o add some clay to water and shake

o divide the solution into 3 graduated cylinder and label A,B,C

o A=add calcium chloride or limewater

o B= add sodium hydroxide or sodium bicarbonate

o C= add water o mix and settle

o the soil flocculates in cylinder A and there is no flocculation in B or C

o calcium ions are required for flocculation to occur, calcium cations act like a

bridge between the soil particles and stick them together the soil clusters then sink

to the bottom of the cylinder


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33. To determine the lime requirement of soil

o get 6 small screw cap bottles

o add 10g of soil to each bottle and add calcium hydroxide to each bottle in varying

quantities, doubling up the amount

bottle 1= 0.0g . B2= 0.01g, B3= 0.02g, B4= 0.04g, B5=0.08g, B6= 0.16g of calcium

chloride

o add 25ml of water and 2 drops of chloroform to each bottle and close the bottles

then shake

o leave for 1 week after which, take the pH of each bottle using a pH meter

o X (reading from graph) x 100 (mol weight of calcium carbonate)x227

(converts g/10g to tonnes/ha) ÷ 74 (mol weight of calcium hydroxide)

o plot your graph of pH versus calcium hydroxide

34. To obtain a sample of soil for soil testing

o collect 2-25 soil samples from a field and avoid areas near troughs/.feeding

areas/ marsh and pathways

o collect in the shape of a W and place them all in one bag and send off for testing


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35. To investigate the presence of minerals in a soil sample

o place soil sample in a conical flask and add distilled water, put on a stopper and

shake

o then filter the contents of the flask and add a few drops of the correct reagent

to the filtrate and state the results

o Nitrogen= diphenylamine reagent blue indicates a positive result for it o

Calcium= ammonium oxalate reagent, white precipitate indicates a positive

result

o Phosphorus= ammonium molybdate reagent and yellow indicates a positive

result

o Sulphates= barium chloride and a white cloudiness indicates a positive result

o Chlorides= silver nitrate reagent and white precipitate indicates a positive

result

36. To determine the botanical composition of an area

o use a line transect and a quadrat and throw the quadrat randomly

o using a key, identify the different plant species and note the frequency of each

one and then estimate the percentage cover of each species


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37. To investigate the protein content in a sample of grass

o weigh the sample of grass and separate the leaf from the stem

o weigh each lot separately and calculate the leaf to stem ratio. The ratio is

proportional to the protein content of the grass

o at the leafy stage: grass contains more than 15% protein

o at the stemmy stage, the protein content then falls to less than 12%

o Or using the Kjeildahl method to detect the nitrogen content: protein contains

16% nitrogen and the % of protein is equal to the % of N x 100÷ 16

38. To investigate the productivity of an area of grassland

o measure an area of grassland, mow the area and weigh the amount of grass that

was cut and record it.

o repeat once a week for one year

o the grass growth curve should peak during the summer and gradually reduce to

December

39. To investigate the influence of an element nitrogen on grass growth

o mow an area of grass and mark out 5 1m2 areas

o add nitrogen to each area in increasing quantity of nitrogen which goes up by

25g

o Area 1= 0g, A 2= 25g, A3= 50g, A4= 75g and

A5= 100g of Nitrogen

o record the height of the grass in the 5 areas throughout the growing

season


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40. To determine the percentage of water soluble carbohydrates (WSC) in a

sample of grass

o dry a sample of grass and place in a plastic bag

o roll the bag to remove the air and place in a freezer until frozen

o remove from the freezer at this stage the cells have burst releasing the cell sap o

squeeze out a drop and place on a refractometer o obtain a reading along with 2

further readings from the other drops

calculate the mean reading and estimate the percentage of soluble carbohydrates

o knowing the carbohydrate content, then allows you to determine the amount of

additive required.

o grass greater than 3% does not need an additive at silage making, and dry weather increases

the WSC of grass

41. To identify the differences in silage quality

o observe a newly opened silage pit

o Lactic Acid: firm, green colour with sharp vinegar smell

o Butyric Acid: slimy, dark green and rancid smell

o Overheated: dry, brown colour with a sweet like smell

o squeeze the silage and record results: if 1 hand can squeeze silage= poor quality,

if liquid can be wrung out using 2 hands the quality is good and if the liquid cannot

be extracted the quality is very good

o pH: use a pH meter, if it is acidic pH < 5 (less than) then it lactic acid silage, if

pH is > 5 then it is butyric acid silage


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42. To determine the percentage of germination of a sample of seeds

o put 100 seeds on a seed tray with moist cotton wool, leave at room temperature

for 10-14 days and count the number of germinated seeds

(sprouted)

o Repeat and get the average and % germination o certified seeds should have a %

germination greater than 85%

43. To determine the percentage purity of a sample of barley seeds

o weigh out 100g seeds and sift remove any that are not barley repeat with 2 other

lots of seed and reweigh each sample and find the average.

o calculate the % purity of the sample of barley seeds

o certified seeds should have a % purity of more than 98%

44. To estimate the yield of a crop prior to harvesting

o locate a crop ready for harvesting and measure with a quadrat a 1m2 area, remove

the crop and the tops or seeds from the seed head

o weigh the root or the grain and record the result, repeat x3 and calculate the

average weight per area and the yield per hectare and state the correct expected

yield

o barley= winter: 7-8 ton/ha, spring: 5 ton/ha

o potatoes= first earlies: 40 ton/ha, main crop: 25-30 ton/ha

o sugarbeet= roots 40 ton/ha, tops: 25-30 ton/ha


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45. To demonstrate the presence of fat in a sample of food

o get 2 pieces of brown paper and rub food sample on one and water on the other

(control)

o allow to dry o first patch will have a translucent spot due to presence of fat with

no spot on the other paper

46. To demonstrate the presence of protein in a food sample (Biuret Test)

o add a food sample (grind and filter )to test tube A and water to test tube b

o add water to b and sodium hydroxide and copper sulphate to both test tubes,

shake gently

o test tube A = purple shows the protein present and B remains blue no protein

47. To demonstrate the presence of glucose

o add glucose to test tube A and water to tt B

o add Benedict’s solution to both and heat gently in a water bath

o A= brick red, positive test for glucose o B= blue colour, no glucose present

48. To demonstrate the presence of sucrose

o put some food on a refractometer and read the percentage sugar present

o add a drop of water on the refractometer as a control and note that the percentage

sugar present is 0


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49. To demonstrate the presence of Vit C o add orange juice to test tube A and water

to test tube B o add DCPIP to both tubes

o A= turns to the colour of the orange juice , DCPIP is a blue colour and goes

colourless in the presence of Vit C

o B= remains the blue colour

50. The percentage of water and solids in a milk sample o weigh the container and

weigh the milk sample in the container and calculate the weight of the milk sample

o place in the oven at 100 degrees until all the water

evaporates, repeat o calculate the loss in weight this equals the

water content o calculate the % water and solids in the sample

o % water= loss in weight÷ weight of sample x 100 o % of

solids = loss in weight ÷ weight of sample x 100 o milk= %

water of 87.5% and % solids of 12.5% o colostrum= % water

of 78% and % solids of 22%

51. To demonstrate the presence of mico-organisms in an animal foodstuffs

o get 2 sterile agar plates and leave open this is the control, flame the inoculating

loop and transfer a sample of food (milk/concentrates) to it and incubate upside

down

o leave for 24-48 hours

o Furry growth= fungus present

o dome shaped colonies=

bacteria

o control=clear


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52. To investigate the effect of salivary amylase on starch

o label and make up 2 test tubes A and B of starch solution (dissolve starch powder

in warm water)

o rinse your mouth with water then collect your saliva into the test tube A and put both test

tubes into a water bath at 37 degrees after 2 minutes remove and add iodine

o A= iodine remained brown, salivary amylase was present in the test tube and it

digested and broke down the starch

o B= no change, starch still present and iodine remains a blue-black colour

53. To demonstrate that food contains energy

o get some high energy food samples and put 100cm3 of water into a beaker and

note the temperature

o heat the food sample until it starts to burn o place the burning food under the

beaker of water and leave until the food completely burns out and note the final

temperature

o as heat is a form of energy, the increase in temperature is due to the energy

released from the food

sheep production - sciencegrindsireland.com

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