Sheep Production - Woolwise

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WOOL 412-512: Sheep Production

Revision Notes

WOOL-412-512 was originally issued in 2008. It was created with funding provided by the Sheep CRC supported by AWET. Funded by WET and MLA the in 2013 the original version of this module was merged with ANPR-420-520 Sheep Meat Production and Marketing.

ANPR-420-520 is still available on this site. The two modules were merged because there was considerable overlap between the two modules and also in recognition of the increasing importance of sheep meat as part of a traditional wool production enterprise.

Topic 1: Profile of the Australian Sheep Industry

This topic will introduce the key factors that characterise the Australian sheep industry including the environments in which wool is produced, the different enterprises responsible for wool production and their relative contributions to the industry, historical and current trends in sheep population and wool production and state and regional differences in sheep and wool production.

On completion should be able to:

articulate your understanding of the Australian environments in which wool production is undertaken, specifically rainfall patterns and how these influence pasture growth and composition;
describe the range of Australian wool-producing enterprises, including the difference between specialist woolgrowers and mixed enterprises, the determinants of farm income from wool, the major production costs and the variation that exists in farm productivity and profitability between individual farms within a district; and
use your understanding of the productivity of the Australian wool-growing industry in terms of product quantity and quality, including state and regional differences as well as features of the national sheep population (genotypes, spatial distribution and age structure) to analyse information and justify informed decisions.

Topic 2: Fleece Weight and its Component Traits and Fibre Diameter

This topic will give you an understanding of the factors that contribute to fleece weight and yield and how the contribution of each differs within and between fleeces as well as discussing how some of the component traits are measured.

On completion you should be able to:

describe and quantify the relationships between fleece weight, washing yield and the non-fibre components of the fleece
explain the relationship between clean fleece weight and its component traits
describe the sources of variation and within-fleece gradients in the fibre and non-fibre components of the fleece
justify the merits of the mid-side region of the fleece for flock testing purposes
identify non-genetic factors that may introduce bias into selection decisions based on fleece weight and its component traits
demonstrate and understanding of fibre diameter and the economic importance of fibre diameter
explain and calculate the difference between the standard deviation of diameter and the coefficient of variation of diameter
define the relationship between mean diameter, diameter variation and “coarse edge” or “prickle

Topic 3: Staple Strength, Style, Handle and Curvature

This topic will discuss the economic importance of and sources of variation staple strength, style; handle and curvature.

On completion of this topic you should be able to:

measure staple strength and describe its economic importance
explain the sources of variation in staple strength within a mob of sheep
describe localised vs generalised fibre weakness as determinants of staple strength
define and quantify the relationship between staple strength and each of minimum diameter, along-staple diameter variation, rate of change in diameter, fibre length variation and intrinsic fibre strength
relate raw wool style including the main component traits to economic importance
explain the influence of fibre diameter and fibre crimp on wool handle
describe fibre curvature and the value of curvature

Topic 4: Contamination – Dark and Medullated Fibres and Vegetable Matter

On completion of this lecture you should be able to:

discuss the relevance of dark and medullated fibre contamination in wool
document the main origins of dark and medullated fibres and the economic implications
justify practices implemented to prevent or control occurrences of dark and medullated fibres and the opportunities for improvement
document the causes of Vegetable Contamination (VM)
calculate how VM is measured
describe the effect of VM on wool processing
describe the economic importance of VM
list and describe the plant species causing VM problems
illustrate your understanding of the strategies which can be employed to reduce VM
plan management strategies in a sheep management system to reduce VM problems in wool.

Topic 5: Managing Weaners and Breeding Ewes for Wool Production

On completion of this topic you should be able to:

demonstrate a clear appreciation of the extent of the impact of age, season, pregnancy and interactions with nutrition on liveweight and fibre growth
explain how hormonal mechanisms contribute to the effects of age, pregnancy and lactation on wool
describe and justify management strategies that can be used to minimise the impact of age, pregnancy and lactation on wool growth and quality
compare and contrast management choices that can be made to modulate wool production and quality in young and/or pregnant sheep

Topic 6: Lamb and Mutton Markets

The lamb industry in the 21st century is a modern, versatile and ‘trendy’ industry that has undergone major changes in the last decade to provide consumers with a quality product that offers versatility, value for money and an enjoyable eating experience.

On completion of this topic you should be able to:

Understand the significance of the Australian sheepmeat industry;
Improve your knowledge and skills in producing lambs and sheep to market specifications;
Incorporate new knowledge and skills into your sheepmeat production system;
Understand the reasons why Australia has a live sheep trade with other countries and why at various times this is controversial;
Recognise customer requirements dictate the existence of the trade in parallel with the export carcase trade; and
Gain an understanding of the management factors that will improve returns from lamb and sheep skins.

Topic 7: Methods for Meeting Lamb Market Specifications and Marketing

On completion of this topic you should be able to:

Improve your knowledge and skills in producing lambs and sheep to market specifications;
Have skills in describing live weight and fat score of the live animal and how they meet a market specification;
Be able to calculate dressing percentage of sheep and lambs; and
Understand how improving quality assurance in production systems increases the number of sheep and lambs meeting market specifications.

Topic 8: Feeder Lambs and Lean Meat Yield

On completion of this topic you should be able to:

Explain why feeder lamb systems are being developed;
Recognise the benefits of breeding feeder lambs;
Be aware of the benefits for specialist lamb finishers;
Understand the benefits of breeder/finisher alliances and appreciate the difficulties in developing alliances;
Know the different specifications required for a grass and feedlot finished system;
Know what lean meat yield is and why it is important; and
Know how lean meat yield is measured.

Topic 9: Managing Lean Meat Yield

At the end of this module the learner will be able to:

Understand the relationship between lean meat yield and the profitability of prime lamb businesses;
Learn the practical measures that the sheep industry uses to assess lean meat yield; and
Learn more about the application of genetics and management of growth through nutrition to manage a lamb enterprise to comply more closely with market specifications.

Topic 10: Sheep meat eating quality

On completion of this topic you should be able to:

Understand the importance of the SMEQ research program in developing tools to provide consistent sheep meat products; and
Understand the factors influencing sheep meat eating quality and how manipulating these factors can improve sheep meat eating quality.

Topic 11: Industry services for Sheep Genetics

On completion of this topic you should be able to:

Understand and describe the way in which Sheep Genetics has improved sheepmeat production;
Understand the relevance of genetic correlation to ASBVs;
Be able to separate environmental from genetic effects; and
Understand the measures of accuracy for ASBVs and FBVs

Topic 12: Genetics of Fleece Weight and Fibre Diameter

On completion of this topic you should be able to:

apply knowledge of the repeatability and heritability of a range of economically-important production traits, as well as the genetic correlations between some of these traits;
describe the economic importance of fleece weight and fibre diameter and explain why these two traits should be given high priority within breeding objectives;
explain the potential for identifying individual bloodlines to achieve genetic improvement in fleece weight and fibre diameter, even though these two traits are genetically antagonistic at the bloodline level;
explain the potential for identifying individual animals within a flock to deliver genetic improvement in fleece weight and fibre diameter, even though these two traits are genetically antagonistic at the within-flock level;
describe the value of performance records, pedigree information, adjustments for environmental ‘penalties’ and index selection in improving the accuracy of selection; and
describe the Trangie QPLU$ selection.

Topic 13: Genetics of Disease Resistance

On completion of this topic you should be able to:

identify sheep diseases of importance to the Australian sheep flock that can be controlled by genetic means and define measures of resistance to these diseases;
describe the heritability of resistance to some major sheep diseases in Australia: nematode parasites, flystrike, fleece rot and footrot;
describe the genetic relationships among disease resistance traits and between the disease resistance traits and production traits;
understand the considerations involved in incorporating disease resistance traits into a breeding objective;
describe the potential to use variation in disease resistance between strains and bloodlines within the Merino breed and between breeds; and
explain the potential benefits of using SNP markers and genomic selection to breed disease resistant sheep.

Topic 14: Optimising Paternal and Maternal Genetics

At the end of this topic you should be able to:

demonstrate a thorough understanding of the factors that impact on selection of terminal sires for a prime lamb flock;
identify the factors that need to be considered when setting a breeding objective; and
utilise Sheep Genetics (SG) and LAMBPLAN information to select a terminal sire for use in a given prime lamb production flock.

Topic 15: Managing Breeding

At the end of this topic you should:

understand the important components of reproduction and to appreciate the potential that exists to improve reproductive performance;
identify the relative merits of various genetic and animal management strategies in improving the reproduction rate of the flock;
appreciate the importance of nutrition as a major determinant of reproductive performance and to recognise that “management” means “lifetime management”;
understand the role that technology has in improving the productivity of genetically elite ewes and rams and to assess the potential for further improvement; and
appreciate the significance of what increases in reproductive performance mean in terms of the economic value of the national flock.

Topic 16: Sheep health: Key concepts, economic impact, bacterial and viral diseases

On completion of this topic you should be able to:

describe the major disease challenges faced by sheep during their lifecycle and the reasons why these challenges occur when they do;
discuss the impact of disease on sheep productivity and underlying mechanisms for this; and
describe and the most important bacterial and viral diseases of sheep and their control.

Topic 17: Sheep health: Internal parasites

On completion of this topic you should be able to:

describe the prevalence and importance of gastro-intestinal parasitic disease of sheep;
understand the effects of gastrointestinal nematode and liver fluke infection on sheep and wool production;
understand the principles of control of gastro-intestinal nematode and liver fluke infection.
sheep production in southern Victoria; and
appreciate the different approaches to pasture and grazing management used by sheep producers.

Topic 18: Sheep health: External parasites

On completion of this topic you should be able to:

describe the prevalence and importance of external parasitic disease of sheep;
define the effect on wool production of blowfly strike and body lice infestation; and
understand the principles of control of blowfly strike and body lice infestation.

Topic 19: Nutrition for Sheep Production

On completion of this topic you should be able to:

list the key components of diets for sheep;
understand the importance of the rumen and its microbes in digesting feed components;
list the key end-products of digestion of dietary materials in the rumen;
list the principal sources of metabolisable energy and amino acids available to the sheep tissues;
define protein quality (amino acid composition) and the factors affecting protein requirements for growth and milk production in sheep;
understand the factors affecting maintenance/production energy requirements of younger and older sheep;
understand the importance of nutrition for ewes in the pre-mating period and during pregnancy and lactation; and
outline the nutritional requirements of pasture-fed and feedlot lambs.

Topic 20: Mineral Nutrition

On completion of this topic you should be able to:

articulate the macro-and micro-minerals of importance in sheep production;
describe the major roles of each mineral associated with nutritional disorders of sheep;
explain how the animal, plant and soil factors alter mineral requirements of sheep;
explain which minerals are most likely to limit wool production in grazing or grain-supplemented sheep and justify your explanationcalculate and explain the characteristics of the animal response curve to tissue mineral supply;
explore alternative hypotheses when analysing whether or not mineral deficiencies or toxicities are likely to be affecting sheep production;
articulate why mineral supplementation is likely to be justified economically;
justify your recommendations for practical solutions to overcoming identified mineral deficiencies or toxicities.

Topic 21: Dry Year Management and Supplementary Feeding

By completing this topic, you should have an understanding of the following aspects of drought management and supplementary feeding. You should be able to:

discuss planning and managing sheep production in expected and unexpected dry periods;
justify your selection of strategies for the sheep producer in times of drought;
explain your design and implementation of a program of supplementary feeding
discuss animal welfare and productivity;
evaluate using crop residues for animal production; and
apply your knowledge to practical aspects of supplementary feeding – what nutrients are needed and when to start feeding, selecting the most appropriate supplement, how much to feed, feeding methods and when to stop.

Topic 22: Sheep Production in Semi-arid Rangelands

On completion of this topic you should be able to:

describe the diverse nature of the rangelands utilised for sheep production;
analyse and discuss the impact of grazing pressure on botanical stability of rangeland communities;
justify the need to manage the total grazing pressure exerted by sheep and other competing herbivores within the rangelands environment;
explain the importance of maintaining the botanical stability of specific rangelands communities and the role of various management tools; and
describe the differences that exist between various rangelands communities in their response to grazing pressure and other systems of manipulating botanical composition.

Topic 23: Sheep Production in Mediterranean Environments

On completion of this lecture you should be able to for Mediterranean climatic regions in Australia:

understand the distribution and characteristics;
be aware of the pasture growth characteristics;
whole-farm considerations of key farming systems;
feed sources for sheep other than pastures, in particular those associated with crop residues; and
wool growth.

Topic 24: Wool Production from Perennial and Annual Pastures

On completion of this topic you should be able to:

understand the dynamics of annual pastures and the implications for sheep production;
understand the influence of stocking rate on the productivity of annual pastures and on the sheep grazing them;
understand the potential value for grazing strategies such as autumn deferment, intensive spring;
grazing and strip grazing to accommodate the seasonality of annual pastures used for wool production;
understand the influence of stocking rate on wool production per head and per hectare;
understand the role of native and introduced perennial grass species in sheep production in Northern NSW;
understand the focus given to stocking rate and fertiliser application rate for perennial pastures used for sheep production in southern Victoria; and
appreciate the different approaches to pasture and grazing management used by sheep producers.

Topic 25: Husbandry Calendars, Precision Sheep Management and Benchmarking

On completion of this topic you should be able to:

define what drives profitability in sheep enterprises;
use the key principals that will enable prioritisation and organisation of management events in order to achieve the most profitable compromise for a farm; and
describe the role of technologies that allow precision sheep management.

Topic 26: Pregnancy and lambing management

On completion of this topic you should be able to:

understand how real time ultrasound scanning fits into an annual flock reproduction program;
understand different aspects of lambing management;
understand the range of predators that influence lamb survival;
understand the differences between primary and secondary predation;
have the skills to identify different reasons why lambs die from birth to two weeks of age; and
understand target fat scores and nutritional needs through pregnancy.

Topic 27: Managing Finishing

At the end of this topic students will be able to:

understand why protein and energy requirements change during life of the lamb;
explain the difference between supplementation, substitution and complementation when feeding lambs;
describe non-nutritional issues that affect lamb performance and their management; and
discuss finishing options for lambs used in the Australian lamb industry.

Topic 28: Grazing Management

On completion of this topic you should be able to:

demonstrate a thorough understanding of grazing management concepts and principles;
discuss relevant literature relating to grazing management;
access and utilise recent research and extension efforts describing sustainable grazing systems;
understand terms and definitions used for describing different grazing methods/systems including benefits and limitations to these systems; and
discuss the influence of grazing management on livestock production.

Topic 29: Dual Purpose Sheep Enterprises

At the end of this topic you should be able to:

demonstrate a thorough understanding of the factors that influence productivity and profit in dual purpose sheep enterprises;
discuss the impacts of management decisions relating to lambing date and stocking rate, breed mixes and genetics, proportions of wool and meat and product marketing; and
access and utilise recent research and extension material describing dual purpose sheep production systems.

Topic 30: Greenvale – Case Study

At the end of this topic you should be able to:

demonstrate a thorough understanding of the factors that impact on profitable production of a sheep enterprise on sandy soils; and
discuss the impacts of management practices relating to problems encountered and overcome, animal health, pest management, grazing systems, production levels and genetic merit.

Topic 31: Warrane – Case Study

At the end of this topic you should be able to:

demonstrate a thorough understanding of the factors that impact on profitable production of a sheep enterprise in the New England; and
discuss the impacts of management practices relating to problems encountered and overcome, animal health, pest management, grazing systems, production levels and genetic merit.