AGRIC SCIENCES GR12 MEMO JUNE 2023_English.pdf

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE GRADE 12 JUNE 2023 AGRICULTURAL SCIENCES MARKING GUIDELINE MARKS: 150 This question paper consists of 12 pages.

Downloaded from hlayiso.com 2 AGRICULTURAL SCIENCES (EC/JUNE 2023) SECTION A QUESTION 1 1.1 1.1.1 B ✓✓ 1.1.2 C ✓✓ 1.1.3 C ✓✓ 1.1.4 B ✓✓ 1.1.5 C ✓✓ 1.1.6 D ✓✓ 1.1.7 A ✓✓ 1.1.8 B ✓✓ 1.1.9 C ✓✓ 1.1.10 D ✓✓ (10 x 2) (20) 1.2 1.2.1 None ✓✓ 1.2.2 B only ✓✓ 1.2.3 Both A and B ✓✓ 1.2.4 A only ✓✓ 1.2.5 A only ✓✓ (5 x 2) (10) 1.3 1.3.1 Assimilation ✓✓ 1.3.2 Sustainable medication ✓✓ 1.3.3 Ovigenesis/Oogenesis ✓✓ 1.3.4 Superovulation ✓✓ 1.3.5 Cryptorchidism ✓✓ (5 x 2) (10) 1.4 1.4.1 Maintenance ration ✓ 1.4.2 Vaccination/immunisation ✓ 1.4.3 Pheromones ✓ 1.4.4 Leydig ✓ 1.4.5 Cloning ✓ (5 x 1) (5) TOTAL SECTION A: 45 Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/JUNE 2023) AGRICULTURAL SCIENCES 3 SECTION B QUESTION 2: ANIMAL NUTRITION 2.1 The alimentary canal of a farm animal 2.1.1 Identification of parts • D – Omasum ✓ • F – Rectum ✓ (2) 2.1.2 Classification of the alimentary canal of the farm animal Ruminant ✓ (1) 2.1.3 Justification • Has complex/compound stomach ✓ • Has rumen/reticulum/omasum/abomasum ✓ (Any 1 x 1) (1) 2.1.4 Identification of letters: (a) F ✓ (1) (b) A ✓ (1) (c) G ✓ (1) 2.1.5 Part of the fowl performing same function as abomasum Pro-ventriculus ✓ (1) 2.2 Vitamin or mineral deficiencies 2.2.1 Osteomalacia – Vitamin D/phosphorus/calcium ✓ (1) 2.2.2 Night blindness – Vitamin A/retinol ✓ (1) 2.2.3 Goitre – Iodine ✓ (1) 2.2.4 Anaemia – Iron/copper/vitamin B6 ✓ (1) Copyright reserved Please turn over

Downloaded from hlayiso.com 4 AGRICULTURAL SCIENCES (EC/JUNE 2023) 2.3 Calculation of digestibility coefficient of hay 2.3.1 85 • DM of hay = x 19 kg = 16,15 kg ✓ 100 DM feed intake (kg) – DM manure (kg) • DC = x 100 ✓ DM feed intake (kg) 16,15 kg – 2,5 kg • DC = x 100 ✓ 16,15 kg • DC = 84,5 ✓ % ✓ (5) 2.3.2 TWO methods to improve digestibility of hay • Cutting/grinding ✓ • Pelleting ✓ • Crushing ✓ • Soaking/adding molasses ✓ • Supplementing with NPN ✓ (Any 2 x 1) (2) 2.4 Ratio formulation for farm animals 2.4.1 Calculation of nutritive ration of FEED A TDN (%) – DP (%) NR = 1 : ✓ DP (%) 90% – 10% NR = 1 : ✓ 10% NR = 1 : 8 ✓ (3) 2.4.2 The feed most suitable for growing lambs FEED B ✓ (1) 2.4.3 Justification • Has more proteins / FEED B has 20% of DP and FEED A has 10% DP ✓ • Narrow NR ✓ • The NR is less than 1 : 6 ✓ (Any 1 x 1) (1) 2.5 Energy value of feeds 2.5.1 TWO important aspects of Net Energy • Maintenance ✓ • Production/work/lactation/reproduction ✓ (2 x 1) (2) 2.5.2 TWO purposes for calculating energy value of feed • Formulation of animal ration ✓ • Determine animal diet ✓ • Determine feeding standards for animals ✓ (Any 2 x 1) (2) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/JUNE 2023) AGRICULTURAL SCIENCES 5 2.6 Formulation of the ration 2.6.1 Pearson’s square method calculation Ratio for sorghum meal to sunflower oilcake meal (4) 2.6.2 The percentage of sunflower oil cake meal in the mixture • 30 + 3 = 33 ✓ 3 • x 100 ✓ 33 • 9,09% ✓ (3) [35] Copyright reserved Please turn over

Downloaded from hlayiso.com 6 AGRICULTURAL SCIENCES (EC/JUNE 2023) QUESTION 3: ANIMAL PRODUCTION, PROTECTION AND CONTROL 3.1 The production systems 3.1.1 Identification of animal production systems PICTURE A – Extensive ✓ PICTURE B – Intensive ✓ (2) 3.1.2 Justification: PICTURE A (Extensive) • Low stocking rate/low density/few animals in a large area ✓ • Less capital invested / no proper shelter / kraal made with stones ✓ • Animals fend for themselves ✓ (Any 1 x 1) (1) PICTURE B (Intensive) • High stocking rate/high density/many animals in a small area ✓ • More capital invested / proper cement shelter ✓ • Animals are fed by the farmer ✓ (Any 1 x 1) (1) 3.1.3 Differentiation Subsistence farming system • Farming on a very small scale in order to feed the family and sell the surplus ✓ (1) Commercial farming system • Farming on a large/medium scale to sell the produce and make a profit ✓ (1) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/JUNE 2023) AGRICULTURAL SCIENCES 7 3.2 Graph Average growth rate of beef and poultry at different temperatures 100 90 80 Average growth rate (%) 70 60 50 40 30 20 10 0 10 20 30 40 50 Temperature (°C) BEEF POULTRY 3.2.1 Criteria for marking • Correct heading ✓ • Type of graph ✓ • X-axis – correctly calibrated with label (Temperature) ✓ • Y-axis – correctly calibrated with label (Average growth rate) ✓ • Correct units: Percentage and degrees (% and °C) ✓ • Accuracy (80% and more in plotting) ✓ (6 x 1) (6) 3.2.2 The trend between beef and poultry at different temperature Poultry: Growth rate decreases at too low or too high temperatures ✓ (1) Beef: Growth rate responds better at lower/higher temperatures than poultry ✓ (1) 3.2.3 ONE method to protect poultry against extreme cold weather • Use of heaters ✓ • Air conditioners ✓ • Poultry house curtains ✓ • Insulation of roof and floor/bedding ✓ (Any 1 x 1) (1) Copyright reserved Please turn over

Downloaded from hlayiso.com 8 AGRICULTURAL SCIENCES (EC/JUNE 2023) 3.3 The picture of a pig 3.3.1 Identification of the equipment Plywood board ✓ (1) 3.3.2 TWO reasons for handling pigs • Vaccination ✓ • Dehorning ✓ • Dosing ✓ • Milking ✓ • Marking ✓ • Marketing ✓ (Any 2 x 1) (2) 3.4 Animal diseases A – Ringworm ✓ (1) B – Protozoa ✓ (1) C – Mastitis ✓ (1) D – Bacteria ✓ (1) E – Virus ✓ (1) F – Aggression / froth in the mouth / running and biting everything / circling / paralysis of lower jaw and tongue ✓ (1) 3.5 Parasites 3.5.1 Classification of the parasite External parasite/exoparasites/ectoparasites ✓ (1) 3.5.2 Reason Mites are found on less hairy parts of the skin ✓ (1) 3.5.3 THREE examples of external parasites except mites and ticks • Nasal worms ✓ • Blue flies/blowflies ✓ • Lice ✓ (3 x 1) (3) 3.6 Life cycle of parasites 3.6.1 The parasite Liver flukes/Trematodes/Flukes/Fasciola epatica ✓ (1) 3.6.2 The intermediate host Snail/Slug ✓ (1) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/JUNE 2023) AGRICULTURAL SCIENCES 9 3.6.3 TWO pasture management measures of controlling internal parasite • Rotational grazing ✓ • Resting of infected pastures ✓ • Allowing animals that are resistant to specific internal parasites ✓ • Avoid wet places ✓ • Use of zero grazing ✓ • Removal of manure/hygienic measures ✓ (Any 2 x 1) (2) 3.7 TWO examples of metallic salt poisoning • Salt poisoning ✓ • Urea poisoning ✓ (2) [35] Copyright reserved Please turn over

Downloaded from hlayiso.com 10 AGRICULTURAL SCIENCES (EC/JUNE 2023) QUESTION 4: ANIMAL REPRODUCTION 4.1 The reproductive system of a bull 4.1.1 Identification of parts • A – Seminal vesicles ✓ • C – Urethra ✓ • F – Epididymis ✓ (3) 4.1.2 The process Spermatogenesis ✓ (1) 4.1.3 Match of the functions (a) E ✓ (1) (b) L✓ (1) (c) J✓ (1) 4.1.4 TWO congenital defects • Hypoplasia ✓ • Cryptorchidism ✓ • Hermaphroditism ✓ (Any 2 x 1) (2) 4.1.5 Reason why scrotum is outside the body To regulate the temperature ✓ (1) 4.2 Identification of the electronic or mechanical devises (a) Tail-chalking/Tail-painting ✓ (1) (b) Pedometer ✓ (1) (c) Kamar heatmount detector/heatmount detector ✓ (1) 4.3 Oestrus cycle 4.3.1 The reproductive process Oestrus cycle ✓ (1 x 1) (1) 4.3.2 Identification of phases of oestrus cycle PHASE B – Pro oestrus ✓ PHASE C – Met oestrus ✓ (2 x 1) (2) 4.3.3 TWO hormones • Oestrogen ✓ • Luteinising Hormone/LH ✓ (2 x 1) (2) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/JUNE 2023) AGRICULTURAL SCIENCES 11 4.3.4 TWO visible sexual behaviours displayed by bulls. • Resting the bull’s chin on the cow’s rump ✓ • Flehmen response/Bull extends its head and curl upper lip ✓ • Bull follows/excited about the cow on oestrus ✓ • Bulls smelling and licking external genitalia and urine of the cow ✓ • Pawing on the ground and snorting by the bull ✓ • Bellowing and tongue lapping ✓ • Bull will try to protect/guard the female on oestrus ✓ (Any 2 x 1) (2) 4.4 Embryo transfer/transplant 4.4.1 Identification of the reproductive technique Embryo transfer/transplant ✓ (1) 4.4.2 The stages of embryo transfer/transplant • C✓ • A✓ • D✓ • E✓ • B✓ (5 x 1) (5) 4.4.3 TWO methods of collecting semen • Artificial vagina ✓ • Electro-ejaculator ✓ (2) 4.5 Stages of parturition 4.5.1 The stage of parturition Expulsion of foetus/ejection of foetus/delivery ✓ (1) 4.5.2 Identification of the birth position Anterior ✓ (1) 4.5.3 TWO signs of parturition • Vulva softens and become swollen ✓ • Cervix secretes sticky mucus ✓ • Cervix dilates ✓ • Cow urinates and defaecates frequently ✓ • Swollen udder that is dripping milk ✓ • Belly droops ✓ • Cow isolates itself ✓ • Cow stops eating ✓ • Cow shows signs of distress and discomfort ✓ • Cow becomes restless ✓ (Any 2 x 1) (2) Copyright reserved Please turn over

Downloaded from hlayiso.com 12 AGRICULTURAL SCIENCES (EC/JUNE 2023) 4.6 The milk production cycle 4.6.1 The name of the graph Lactation curve ✓ (1) 4.6.2 Identification of the range of weeks 4 to 6 weeks ✓ (1) 4.6.3 Name of the hormone Prolactin ✓ (1) [35] TOTAL SECTION B: 105 GRAND TOTAL: 150 Copyright reserved Please turn over