Technology of meat and wool sheep breeding and basics of breeding work

The development of the sheep farming industry in Russia is possible through the management of meat-wool sheep production. The increase in the number of meat sheep breeds in private and individual farms serves as an indicator of the industry's demand in the country.

Along with commercial livestock, it is necessary to select and breed animals with a high level of genetic potential, for which it is important to restore and create new breeding centers and stud farms. In the Krasnodar Territory, a breeding center farm has been preserved, which is distinguished by the improvement of meat-wool breeds. The Kuban type of Lincoln and Southern Meat, under conditions of year-round stall housing, can serve as an example for the creation of new sheep breeding enterprises.

Purpose of the lesson. To become familiar with the technology of meat-wool sheep farming. To study the types of productivity and methods of evaluating the productive and breeding qualities of sheep.

Task 1. To become familiar with the main elements of the technology of meat-wool sheep farming at the "SKNIIZh" experimental production farm.

Methodology. The technology of meat-wool sheep farming is largely determined by the housing system of the sheep. Three main systems are used in sheep farming:

• year-round pasture – sheep are on pasture all year round;
• stall-pasture – in the winter period, sheep are kept in sheds, in summer on pasture;
• stall – sheep are kept on the farm all year round.

The sheep flock is divided into bands. Bands are formed annually, taking into account the breed affiliation of the animals, their age, sex, and classing grade. Bands of young animals are formed after weaning from their mothers.

Size of the band:

Winter (February – March) or spring (April – May) lambing is used. Lambs are traditionally weaned from ewes at the age of 4–5 months, with early weaning at 2 months. With winter lambing, the weaning of lambs occurs at the end of spring – early summer during the time of good grass growth on pastures. Spring lambing allows for easier labor in animal care.

Lambing of ewes occurs in the maternity ward. The ewe that has lambed along with its lamb is kept for 1–2 days in individual "lambing pens". Then they are transferred to group pens (groups of up to 5 ewes with lambs) for 4–5 days, and subsequently, "sakmans" (groups of 10 to 200 ewes with lambs) are formed.

When raising lambs, it is important to ensure the timely feeding of colostrum (15–20 minutes after birth) and to monitor the milk production of the ewes. Supplementary feeding of lambs begins from the age of 10–15 days in feeders, where they are trained to eat high-quality legume hay and concentrates.

Feeding of sheep should be carried out taking into account the requirements for nutrients. When kept on pasture, sheep can be on good pastures without concentrate supplements.

Sheep are grazed for 10 hours a day with a 2-hour break during the daytime. When using poor pastures, sheep are supplemented with roughage and succulent feed with the addition of minerals. It is advisable to feed sheep in portions every 2–3 hours. It is better to use complete feed mixtures.

To obtain milk, sheep of semi-fine-wool meat-wool breeds are used after the lambs are weaned.

Milking of sheep is carried out manually or by machine. In machine milking, preventative shearing of wool around the udder is performed. Stationary or mobile milking units (single and double row) are used for milking sheep.

Under conditions of intensive sheep farming technology, the shed-base method of raising lambs is used. It involves grazing ewes in early spring without lambs on nearby pastures.

• During the ewes' grazing, the lambs are kept in pens or sheds on deep bedding, which protects them from colds and contributes to better growth and development.
• To feed the lambs with the ewes' milk, they are returned to the lambs 2–3 times a day for 2–3 hours.
• Lambs left in the sheds get used to eating plant feed faster and subsequently tolerate weaning without complications.

Task 2. Describe the meat-wool sheep farming technology at the "Rassvet" farm of SKNIIZh. Methodology. The description of meat-wool sheep farming technology is carried out according to the following outline:

• Breeds of sheep raised on the farm
• Methods of housing for ewes and sires
• Conducting ewe lambing
• Raising lambs
• Feeding the sheep
• Milking the ewes

Task 3. Become familiar with wool groups, type, and histological structure of wool fibers. Methodology. One of the important types of products obtained from sheep is wool. There are 4 groups of wool:

1. I – uniform fine, obtained from sheep of fine-wool breeds;
2. II – uniform semi-fine, obtained from sheep of semi-fine-wool breeds;
3. III – non-uniform semi-coarse, obtained from sheep of semi-coarse-wool breeds;
4. IV – non-uniform coarse, obtained from sheep of coarse-wool breeds.

Wool is represented by various types of wool fibers: the finest (diameter 15–25 µm), short (length 5–10 cm) crimped down fiber.

The quality of sheep's wool directly determines the profitability of a livestock farm. To maximize profit when selling raw materials, it is necessary to accurately assess fiber properties, as well as to follow the rules for sorting and packaging the fleece. The technological value of the raw material depends on the ratio of fiber types in the wool cover and their physical characteristics.

Physical and technological properties and structure of sheep's wool

The wool cover of sheep consists of fibers of various types that differ in structure and thickness. Down fibers are the finest; they consist only of cuticle and cortical layers. Transition hair has a diameter of 25.1 to 60 µm with a length of 10–30 cm; it is distinguished by the presence of an intermittent medulla. Guard hair is the thickest fiber with a diameter of 60 to 180 µm with a solid medullary layer; its varieties include dry and dead hair, kemp, and sensory kemp.

The technological properties of wool determine the direction of its further processing. Fiber length divides wool into worsted and woolen types. Fiber crimp can be desirable (semicircular) or undesirable (high, compressed, looped, and elongated). Tensile strength and hygroscopicity of the raw material are also important physical properties.

• Standard wool humidity — 17 %
• Maximum moisture absorption — up to 50 %
• Density in fine-wool sheep — 70–100 fibers per 1 mm²
• Worsted wool length — from 5 cm
• Woolen wool length — less than 5 cm
• Weight of an English pound for classification — 453.6 g

To assess fineness, the Bradford classification is used in global practice. It indicates the number of yarn hanks 512 meters long that can be obtained from one English pound (453.6 g) of clean scoured fiber. Wool with a quality count of 60 and higher is classified as fine, and with a count of 58 and coarser — as semi-fine.

Organization of shearing, classification, and preparation of wool for sale

The type of raw material obtained depends on the season of work. During spring shearing, the wool is removed as a single sheet — the fleece, which is held together by suint and slanted "stray" fibers. Summer and autumn shearing result in piece wool, as the fibers break into separate parts. For these operations, either electric clippers with animal restraint on tables or the high-speed "sitting" position shearing method is used.

The shearing campaign requires a clear sequence of organizational stages:

1. Determining the optimal timing and frequency of shearing throughout the year.
2. Creating a schedule for bringing flocks to the shearing station.
3. Preparing workstations for shearers, and classification and packaging equipment.
4. Performing shearing using the chosen method.
5. Organizing veterinary care for animals after shearing.

According to GOST 30702-2000, non-uniform sheep's wool is divided into four groups, while autumn and lamb wool of all groups are divided into six categories. Inferior grades and defects must be separated from the main fleece. These include yellowed wool (having lost color at the tip or base of the staple), base (contaminated with excrement), and felt (densely matted pieces). Brand marks (areas with paint) and sorting waste with coarse hair are also removed.

Based on color, the main fleece wool is divided into five main categories. This allows for more precise matching of batches for the textile industry. Length standards for fleece and yellowed wool are strictly regulated.

Sorted raw materials are pressed into bales weighing from 70–80 to 80–95 kg depending on the wool type and press model. The product must be stored in dry, covered facilities on wooden shelving to prevent contact with the floor. Transportation is allowed only in packaged form with a consignment note, settlement documents, specifications, and a veterinary certificate. The final stage of batch evaluation is determining the yield of clean (scoured) wool.

Methodology. Sheared sheep wool, in addition to yolk and wool fibers, contains foreign impurities – dust, sand, feed residues, seeds weed plants, bedding, manure, urine, and other impurities. Therefore, the weight of the wool does not characterize the true productivity of the livestock animal, the indicator of which is the weight of the most valuable part of the fleece – wool fibers. The weight of natural wool with all its components is commonly called physical (original) weight. The portion of wool after its washing and the removal of yolk and impurities is called washed (clean) weight. The weight of washed wool expressed as a percentage of the original wool weight is called the washed wool yield or rendeman, taxat, which is expressed as a percentage.

Washed wool yield (WWY) is an important indicator characterizing the actual wool productivity of sheep. It depends on the breed, individual characteristics of the animals, sex, age, feeding and management conditions, and natural-climatic factors. In fine-wooled animals, WWY can range from 35–45%, in dry-steppe merinos up to 70–75%, in Australian merinos and the majority of domestic fine-wooled breeds 45–55%, and in coarse-wooled sheep 60–70%.

Washed wool yield can be determined by the following methods:

Expert – organoleptic, performed without the use of any devices or instruments, but with the help of sensory organs – vision and touch.

Laboratory – using wool washing in soap-soda solutions and drying in drying ovens.

Calculating the clean wool yield by multiplying the weight of the pressed sample by a special coefficient: for uniform wool – 0.41535, for mixed wool – 0.4025.

The percentage of clean wool yield can be determined by drying the washed wool sample in a drying oven (at t = 100°C) to an absolutely dry weight.

Conditioning, i.e., all operations related to drying wool and calculating its conditioned weight, are carried out using conditioning apparatuses, hydraulic devices, drying ovens, and thermostats.

After establishing a constant dry weight, the percentage of washed fiber yield is determined, taking into account the standard conditioning humidity of 17% for fine and semi-fine wool.

Where Q is the percentage of washed fiber yield, %

Y is the constant dry weight of the sample, g

A is the initial weight of the sample in its unwashed form, g

Example. The constant dry weight of a fine wool sample is 72.7 g, the weight of the unwashed sample is 200 g, the percentage of washed fiber yield is:

Task 10. Familiarize yourself with the methodology of sheep appraisal (bonitierung) for various breeds.

The main appraisal of sheep is usually conducted once at the age of one year in the spring before shearing. This is standard practice in fine-wooled, semi-fine-wooled, and also coarse-wooled sheep farming.

Romanov sheep are preliminarily appraised at 5–6 months after the down fibers have turned gray, and finally at 8–9 months after shearing, when their main breed characteristics are fully expressed.

In astrakhan (karakul) breeding, the main appraisal is considered to be that of lambs at the age of 1–2 days. At this time, they are evaluated by pelt type, shape and size of the curl, color, and character of the wool cover.

In sheep breeding practice, two types of appraisal are used – individual and class-based. In individual appraisal, the animal must have an inventory number, and the results of its evaluation are recorded in a logbook with subsequent entry into the pedigree card.

In class-based appraisal, the sheep is evaluated by main economically useful traits without recording in a logbook, and based on the total score, it is assigned to a specific class. Commercial sheep on commodity farms are subject to class-based appraisal. The selection of sheep based on class-based appraisal is called group selection.

For sheep of each breed, a desired type (breed standard) is determined. During appraisal, animals that meet the requirements of the desired type are assigned to class 1, while the rest are assigned to lower classes.

For fine-wooled sheep, standards and minimum requirements for live weight, wool clip, and staple length are established, which serve as the basis for their classification.

There is a standard for wool-type sheep breeds, a standard for wool-meat sheep breeds, and a standard for meat-wool sheep breeds (these are described in the appraisal instructions).

Standards serve as the main criterion for evaluating and dividing sheep into classes. To record the results of evaluating individual traits and properties of an animal during appraisal, conventional symbols are used, which make up the appraisal key.

S M D I Tk U Zh Ts K E Os Ob SP R Nnsh Nmsh Vchsh Zhm Okl

T M D I Tk K E VM Os Ob Zh Ts B SP R P U Zhm Mp Nnsh Nmsh Vmsh OKl

Records are kept for each livestock animal: breed, type, skin fold development, density, length, fineness, crimp, uniformity of the fleece and staple, quantity and quality of yolk, and live weight. Characteristics of constitution and exterior, coverage, and a general assessment are also recorded. Standardized abbreviations and special codes are used for these indicators, allowing the results of the animal appraisal to be processed on a computer using the "SELEX" program.

In preparation for the appraisal, a check of the animals' identification numbers is conducted, and recording journals are prepared, into which the sheep to be evaluated are entered in advance, in ascending order, along with their date and year of birth and their origin. The necessary equipment is prepared – ear-notching pliers, tags and their corresponding pliers, scales for determining the live weight of the sheep, and a necessary supply of panels for setting up the sorting chute and enclosures.

Accurate animal record-keeping is the basis of breeding work in sheep farming. To conduct the appraisal, a special working sorting chute is equipped, with scales installed at the end. Animals are marked with individual numbers or class signs using tattooing, plastic or electronic tags, buttons, ear-notching, microchipping, or branding numbers onto horns.

• Width of the appraisal sorting chute — 40–50 cm
• Length of the appraisal sorting chute — 6–8 m
• Depth of the ear notch — at least 1 cm
• Timing for marking elite lambs — 2nd–3rd day of life

Rules for individual and class marking

An individual number is assigned to an animal for precise pedigree record-keeping, while class marks indicate the level of productivity based on the appraisal results. For purebred sheep, class signs are applied to the right ear; for crossbreds, to the left. Notches are made with special pliers to a depth of at least 1 cm; otherwise, the wounds will heal quickly and the mark will become illegible.

An individual number in a flock is not assigned to all animals sequentially. There are strict rules for selecting groups for individual marking. These groups include animals that represent the highest breeding value.

• Lambs from elite ewes (in purebred flocks) and selected ewes (in crossbred flocks). On the 2nd–3rd day after birth, a tattoo with the dam's number is applied to their left ear, under which the young animal remains until one year of age.
• All ewes classified as elite during the appraisal, the selected group, and in some farms, Class I as well.
• All ewe lambs and ram lambs intended for sale as breeding stock.
• Ewes selected for progeny testing of sires, as well as all offspring from these ewes.

During critical periods in the flock, temporary group marking with easily washable "Ovcevod" (Sheep-breeder) paint is used. During lambing, the ewe and her newborn lambs are marked with the same number on the side so that the families do not get mixed up. During artificial or natural insemination, covered ewes are marked with paint on the poll or at the base of the tail.