Revision Guide And Frequently Asked Questions

REVISION GUIDE AND
FREQUENTLY ASKED QUESTIONS
AGRICULTURAL SCIENCES
2017

Agricultural Sciences

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TABLE OF CONTENTS
Introduction Animal Nutrition Animal Production, Protection and Control Animal Reproduction Agric. Management and Marketing Basic Agricultural Genetics Tips And Frequently Asked Questions

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3 4-7 8-9 9-11 11- 12 12-20 21-30

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FOREWORD
The purpose of this manual is to assist grade 12 learners in preparation for their 2017 end of year examination preparation
The activities in this document are meant to be a guide and not to replace any study material/ text book.
The manual focuses on selected challenging content topics informed by experience of dedicated curriculum implementers and analysis of June results 2017
This manual is distributed free of charge as a learning support material to all Agricultural Sciences teachers and learners in Mpumalanga Province and is fully funded by Mpumalanga Department of Education
The guide is compiled from different sources. We hope that the guide will serve as a valuable and helpful resource for both teachers and learners

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PAPER 1
1 . Animal Nutrition :
A. Concepts  Ruminant: Animal with a complex/compound stomach [eg. Cattle, Sheep, Goats]  Non-ruminant (monogastric): Animal with a single/simple stomach [eg. Pigs, Poultry,
Horses]  Rumination: The process of bringing back the cud/bolus food into the mouth for re-
chewing, re-insalivation and re-swallowing.  Peristalsis: The movement of food through the alimentary canal / rhythmic contraction
and relaxation of muscles of the alimentary canal.  Retroperistalsis /regurgitation: The bringing back of food from the stomach to the
mouth cavity.  Chyme : The contents of the stomach  Chyle: The contents of the small intestines  Biological value (BV): The quality of proteins in the feed. B. Diagrams.
Possible diagrams. I. Alimentary canal for a pig Carefully take note of the main parts of the alimentary canal of a pig and locate their functions in the process of digestion.

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II. Alimentary canal for poultry Attempt to label all labeled parts and the functions of D, H and N.

III. Alimentary canal for cattle Identify all labeled parts and supply functions for C, D, L,

K

J

A

I

H G

B

F

Sphincter

C

D E

IV. Process of rumination

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This process is critical in ruminants. It ensures that food ingested is properly chewed and re-swallowed for chemical digestion to continue.

C. Calculations NB: In all calculations, don’t forget to use a calculator. I. Digestibility coefficient: Note the formula and the calculations for digestibility coefficient

Digestibility coefficient t= (Feed intake – moisture) – DM Excreted X 100 (Feed intake - moisture) OR
Digestibility coefficient = Dry matter intake – Dry matter of manure X 100 Dry matter intake

E.g. A cow eats 10kg of maize with a 10% moisture content and excreted 4kg of dry matter

= 9 kg – 4 kg 9 kg

X 100

= 5 kg 9 kg

X 1OO

= 500 kg 9 kg

= 55,6 % (56 % )

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ii. Nutritive ratio (NR) Note the following:  Know the Definition of Nutritive Ratio NR is defined as a ratio used to determine the protein content of feed for animals
 Know the formula of NR  Interpretation/implication of the Narrow and Wide ratios
NR = 1: % Non-nitrogen substances % Digestible Protein (DP)
OR %Total digestible nutrient (TDN) - %Digestible protein (DP) NR = 1:
% Digestible Protein (DP)
Calculate the NR— (a). Maize has a TDN of 80% and DP of 10% (b) Soya bean has a TDN of 72% and DP of 12% (c) Oats has a TDN of 95% and DP of 5%
NR =1: 80 - 10 10
= 1:70 10
= 1:7 (Wide NR) above 1:6 .Suitable for Maintenance( more carbohydrates and less proteins)
NB IF NR is 1:5 or less(Narrow NR) the feed is Suitable for growth , production and reproduction(MORE Proteins and Less carbohydrates). iii. Pearson square

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A Pearson square is used to balance rations. If for instance, a farmer has got Sorghum meal that contains 13% digestible protein (DP) and oilcake meal with digestible protein content of 23% . The farm animals kept require 17% digestible protein (DP), then the calculation for balancing the rations is done as follows:

Sorghum meal

13% 6 parts

17%

oil cake meal 4 parts

23%

2. Animal Production Protection and Control: A. Concepts i. Animal Production
 Intensive production system  Extensive production system  Subsistence farming  Commercial farming ii. Protection and Control  Internal parasites  External parasites  Plant poisoning B. Structures Handling facilities C. Life Cycles

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3. Animal Reproduction : A. Concepts
i. Primary and secondary reproductive organs (Male and Female) ii. Spermatogenesis : iii. Oogenesis/Ovigenesis iv. Ovulation v. Oestrus vi. Gestation/Pregnancy vii. Parturition viii. Lactation ix. Dystocia

D. Diagrams i. Female reproduction system Identify labels in the diagram below: A
B C
D

E

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ii. Spermatogenesis Take note of how the process unfolds in the testes

iii. Oogenesis

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