Methodology for assessing milk productivity and milk quality of cows

Milk yield for 305 days or a shortened lactation is calculated by summing up the monthly milk yields for the first 10 or fewer months.

Milk yield for a completed lactation is determined by summing up the monthly milk yields of a cow for all months of lactation.

The fat and protein content in the milk of a cow is determined once a month.

The average fat and protein content in a cow's milk for lactation is determined by dividing the sum of one-percent milk by fat or protein by the sum of milk yields for lactation.

The amount of one-percent milk by fat and protein per month is calculated by multiplying the monthly milk yield by the fat or protein content in the cow's milk in that month of lactation.

The quantity (production) of milk fat and milk protein is determined by dividing the amount of one-percent milk by fat or protein by 100.

The average daily milk yield for a month is determined by dividing the monthly milk yield by the number of days in that month.

Table 4 – Indicators for recording and evaluating the dairy productivity of cows

For 305 days or a shortened lactation number 1 2 3 4 5 6 7 8 9 10 11 12 milk by milk in milk, %

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 protein

Task 10. Based on the data of average daily milk yields, plot and analyze the lactation curves of Holstein and Ayrshire cows.

Methodology. To plot a lactation curve (a graphic representation of the change in daily milk yields over the course of lactation), find the intersection points of the horizontals from the ordinate axis "average daily milk yield" and the verticals from the abscissa axis "month of lactation" according to the data from task 1 and connect them with a smooth line.

1 2 3 4 5 6 7 8 9 10

Figure 1 – Lactation curves of Holstein and Ayrshire cows milk yield curve of a Holstein cow milk yield curve of an Ayrshire cow.

Task 11. Master the methods of calculating the mass of standard (credited) milk.

Methodology. To determine the monetary revenue for sold dairy products, calculate the mass of standard milk and multiply it by the selling price.

When selling milk of natural fat content, its standard mass is determined by the formula:

When selling cream, the mass of standard milk is determined by the formula:

When selling milk in liters, the mass of standard milk is determined by the formula:

Жб where Mб – mass of standard (base fat content) milk, kg;

Mф – mass of milk of actual fat content, kg;

Жб – base fat content of milk, % (for Krasnodar Krai Жб = 3.4 %);

Сл – mass of sold cream, kg;

Жо – fat content of skim milk, % (from 0.05 to 0.1 %);

1.03 – average density of milk, g/cm³.

Task 12. Get acquainted with the methodology of bonitation (evaluation) of replacement heifers, pregnant heifers, and cows of dairy and dairy-beef breeds.

Methodology. Bonitation is the determination of the breeding and productive qualities of animals for the purpose of assigning them an evaluation class and determining their purpose for further use.

According to the Procedure and conditions for conducting the bonitation of breeding cattle of dairy and dairy-beef productivity (Order of the Ministry of Agriculture No. 379, 2010), bonitation is carried out annually, during the year; summary reports on the results of the bonitation are compiled as of January 1st with an analysis of the following issues:

a) number of evaluated cattle and its distribution by breed purity, class, purpose, and genealogical groups;

b) characteristics of the herd and individual cows of the breeding core by live weight, exterior, expression of exterior and body type, milk production, reproductive capacity, and development of young stock;

c) age and live weight of heifers at first insemination;

d) results of performance testing of young bulls;

e) results of the evaluation of bulls (sires) by offspring quality;

j) fulfillment of the breeding and selection work plan.

Determining the class of animals by a complex of traits is carried out:

– for replacement young bulls: by exterior and body type, live weight, origin;

– for bulls (sires): by the exterior and body type of daughters and breeding value;

– for cows – by milk yield, fat and protein content in milk, exterior and body type, live weight, duration of service period, productive longevity;

– for replacement heifers and pregnant heifers – by origin, exterior and body type, live weight.

During bonitation, the evaluation of the exterior and body type of replacement heifers and pregnant heifers is carried out on a 10-point scale.

Table 5 – Evaluation of replacement heifers and pregnant heifers by exterior and body type

General appearance and development. Harmonious development with a well-expressed breed type. All body parts without pronounced deviations of more than 3 points. The skeleton is strong but not coarse. Light head and limbs. Absence of excessive musculature on the thighs and withers.

Head and neck, chest, withers, back, loin, mid-section, hindquarters. The head is lean. The neck is of sufficient length with a clear hollow along the esophagus. The chest is deep, but not wide.

The withers are not wide and well-defined. The back is straight with slightly protruding spinous processes of the thoracic vertebrae. The ribs are wide and set far apart. The shoulder blade fits tightly against the rib cage. The loin is straight, short, and wide. The sacrum is long, wide, and slightly sloped backwards. The hip joints are located slightly lower than the hooks, but higher than the pin bones. The tail is long and thin, with the root located at the level of the hooks. The skin is thin, elastic, and—

Limbs and hooves. The limbs are strong, but neither thin nor coarse. The metatarsus, as well as the forearm and pastern, are set vertically. The average angle of the hind limb bend in the area of the hock joint is no more than 3. The carpal and hock joints are well-defined and lean. The front wall is inclined to the floor plane at an angle of approximately 45°, the rear wall is high, and the sole is even. 4 Total score no more than 10

To assess the live weight of replacement heifers and bred heifers, the minimum requirements of the breed standard are taken into account.

Table 6 – Minimum requirements for live weight of replacement heifers,

Live weight, kg Breeds 10 11 12 13 14 15 16 17 18 24 1st 2nd 3rd calv. mo mo mo mo mo mo mo mo mo mo calv. calv. and st. Black-

250 270 290 310 330 345 360 375 390 440 490 530 560 Pied Hol-

260 280 300 320 340 355 370 385 400 450 500 540 580

230 250 270 290 310 325 340 355 370 420 480 520 560 Pied Red

When assessing replacement heifers and bred heifers, the total point score is reduced for:

• III and IV generation – by 3 points (in case it is impossible to classify them as purebred).

When bonitating cows, the conformation is assessed based on a complex of traits (on a 100-point scale in the 2nd–3rd month of lactation).

The mid-section of the body is relatively long in relation to the height of the animal, giving the body volume, strength, and power. The shoulder blade is long and deep, positioned evenly relative to the rib cage and withers. The rib cage is deep and wide with good curvature of the front ribs. The base of the chest is wide with sufficient distance between the limbs. The chest volume is large; full in the area of the subscapular hollows and the elbow joint. The back is straight and strong. The mid-section has a barrel-like shape. The ribs are long, deep, and wide, set at a sufficient distance to ensure the leanness of the body. The sacrum is long and wide. The hooks are wide, clearly protruding, but not sticking out. The pin bones are widely spaced and lean. The hip joints are positioned high in the center between the hooks and pin bones.

Expression of dairy type (100 / 15): Body shape is angular, without signs of weakness or coarseness. The head is lean; eyes are large and bright, ears are mobile. The neck is long and thin. The withers are well-defined, wedge-shaped. The spine is lean, clearly defined with protruding vertebrae. The ribs are elastic, widely spaced with a wide intercostal space; bones are wide, flat, and long. Attention is paid to the slope of the ribs. The flank is deep, clearly defined. The hooks and pin bones are widely spaced, providing sufficient space for the udder and its attachment. Leg bones are even, strong but not coarse. The udder is voluminous, cup-shaped without edema, firmly attached, and collapses well after milking. The skin is loose, thin, and mobile. The coat is thin and shiny.

Hooves are short, well-rounded with a deep rear wall and an even sole, toes slightly spread.

Pasterns are strong, medium length, flexible; front legs are straight and widely set with upright hooves.

Hind legs are almost perpendicular from the hock to the pastern when viewed from the side, and straight and widely set when viewed from behind.

• Hock joints are clearly defined, well-shaped, not coarse, and lean.
• Bones are even, strong, durable, with well-marked tendons.

The udder is symmetrical, long, wide, and deep; slightly divided into quarters from the sides. The floor of the udder is horizontal. The central suspensory ligament is strong, clearly distinguished, dividing the udder into halves. The udder is conveniently located above the hock joints.

The udder structure is soft, pliable, elastic, and collapses well after milking. The front quarters of the udder are strong and smoothly connected to the body; long, of uniform width, and well-balanced.

The rear quarters of the udder are attached tightly, deep, equally wide from top to bottom of the udder, and slightly rounded in the lower part. They are well-balanced and located above the hock joint at the same level as the front quarters.

Teats are uniform in size, moderate in length and diameter, cylindrical in shape, and vertically positioned in the center of each quarter when viewed from the side and slightly inward when viewed from the rear, with moderate spacing between them. Milk veins are long, winding, and branched.

General appearance 100 20 The expression of the breed type is evaluated in accordance with approved breed models. In general, the animals are massive, have well-developed musculature, but possess feminine traits and are strong. Physique – height is tall, including moderate leg length with an elongated skeletal trunk. The head is relatively lean, proportional to the body; the muzzle is broad with large nostrils; the jaws are strong, eyes are large; the forehead is slightly concave and broad, the bridge of the nose is straight; ears are medium-sized and mobile. The neck is long and relatively thin, transitioning smoothly into the shoulder girdle; the throat, dewlap, and brisket are well-defined. The front part of the body has a strong constitution, reflecting the strength and refinement of a dairy breed. The withers are well-defined, wedge-shaped, with the spinous processes of the vertebrae forming a slight elevation in the shoulder area. The shoulder blades and shoulder joint are attached tightly and evenly in relation to the chest line and withers, transitioning smoothly into the line of the body and neck. The chest is deep with sufficient width between the front legs. The spine is clearly defined with protruding vertebrae. The ribs are elastic, widely spaced, and the bones are wide, flat, and long, creating ample space for the udder and its attachment. The flank is deep and clearly defined. The sides are deep. The back is straight. The loin is broad and level. The rump is long, broad, and nearly level, blending well with the loin. The hip bones (hooks) are broad, well-defined but not protruding, and located slightly higher than the pin bones. The pin bones are widely spaced, lean, and free of fat and muscle tissue. The hip joints are high and widely positioned in the center between the hip bones and pin bones. The thighs are moderately concave from both the sides and the rear, widely set, providing sufficient space for the udder and its rear attachment. The tail head is located nearly level with the back line and is not coarse. The tail is thin. The front legs are of medium length, straight, and widely spaced. The rear legs are nearly perpendicular from the hock to the pastern when viewed from the side and straight when viewed from the rear. The hocks are clearly defined, lean, and not coarse. The pasterns are strong, of medium length, and flexible. The hooves are short and well-rounded with a high heel and a level sole. The udder is voluminous, firmly attached, well-balanced, and cup-shaped with moderate spacing between the teats. The skin is loose, thin, and pliable. The hair is fine and glossy Total 100 100

The overall assessment of cows based on conformation and body type is determined by the formula:

OS = (OT × 0.1) + (MT × 0.15) + (N × 0.15) + (V × 0.40) + (OV × 0.20), where OS is the overall score in points;

When evaluating conformation and body type, the expression of the breed type, the conformity of body parts to the dairy type, the size of the udder, its shape, and its suitability for machine milking are taken into account. A cow can receive a maximum of 15 points for conformation and body type.

Points for live weight are given to the cow based on the results of meeting minimum requirements – a maximum of 5 points.

Table 8 – Evaluation of cows based on a complex of traits

Traits Points 1 2 3 1. Milk productivity for the best lactation, total 70

Milk yield for the best lactation, total 60 including: as a percentage of the breed's minimum requirements:

Every 0.1% excess of minimum butterfat requirements

Every 0.05% excess of minimum protein content in milk is assessed with 1 point 2. Conformation and body type, total 15 including: excellent (90 points or more) 15 good plus (80–84 points) 9 satisfactory (65–74 points) 3 3. Live weight (kg), total 5 including: meets minimum requirements 5 live weight is 95–99% of minimum requirements 3 4. Service period duration (days), total 5 including: up to 90 days 5

121 and more 1 5. Productive longevity (calvings), total 5

6 and more 5 Sum of points 100

For milk productivity – milk yield for the best lactation, a cow can receive 60 points and an additional 4 for exceeding the butterfat standard, and 6 points for exceeding the standard for protein content in milk.

Table 9 shows the milk productivity standard requirements for cows of various breeds.

A cow can receive 5 points each for the minimum (90 days or less) duration of the service period and maximum longevity (6 years or more).

Based on the total score received by the cow for all traits, an evaluation class is assigned. Table 9 – Minimum requirements for milk productivity of cows by breed

Quantity per 305 days of lactation, kg

3500 3800 4200 3.7 3.0 129 140 155 105 114 126 pied Holstein-

4500 5000 5500 3.6 3.0 166 185 203 135 150 165 Red-and-White 3200 3500 4000 3.8 3.0 121 133 148 96 105 120 Red Steppe

3000 3500 3800 3.7 3.1 111 129 141 93 109 118 Kuban type Ayrshire

3300 3600 3900 4.1 3.3 135 148 160 109 119 129

Table 10 – Class assignment based on the number of points scored by producers, points Elite – record 80 and above 40 and above Elite 79–70 39–35 Class I 69–60 34–30 Class II 59–50 29–25

Task 13. To become familiar with the main elements of dairy cattle technology.

Methodology. The main task of modern technology for keeping and using livestock is: increasing animal productivity, improving milk quality, increasing labor productivity, and reducing the cost of produced goods.

In dairy farming, two housing methods are used: tie-stall and loose housing. With tie-stall housing, cows are kept in stalls on tethers, usually using bedding and providing the cows with exercise. With loose housing, uniform groups of 50 cows are placed in separate sections. Loose housing typically utilizes free-stall systems with slatted floors. This has become widespread.

Herd management and rearing of replacement young stock

The efficiency of dairy farming directly depends on the selected housing system for the animals. In practice, stall, stall-camp, pasture-camp, and stall-pasture systems are used. At the same time, milk production is organized either using tie-stall technology with milking into buckets or a pipeline, or using the more promising loose-housing technology with milking in a milking parlor.

For herd reproduction, artificial insemination is used. Heifers are inseminated at the age of 15–18 months, when their live weight reaches 70% of the weight of adult cows. The period for inseminating cows after calving should be no more than 80 days, and the calving itself is carried out in the maternity ward.

• Heifer insemination age — 15–18 months
• Heifer weight at insemination — 70% of adult cow weight
• Insemination interval after calving — up to 80 days
• First colostrum feeding — within 1 hour after birth

Newborn calves require individual care. For the first 10–15 days, they are kept in individual "Evers" cages, after which they are moved to individual hutches, where they stay until 2 months of age. Heifers in the milk-feeding period are moved to group pens, the size of which is increased as the animals grow.

Recommended parameters for individual "Evers" cages for calves:

• length — 120 cm;
• width — 45 cm;
• height — 100 cm;
• leg height from the floor — 20–45 cm.

Recommended herd sizes for heifers in group pens by age:

• up to 6 months — 20–25 heads;
• from 6 to 9 months — 40–50 heads;
• from 9 to 12 months — 100–120 heads;
• from 12 to 18 months — 120–150 heads.

In sections for replacement heifers, animals are kept in loose housing groups of 40–50 heads. Young stock is fed two to three times a day with a mono-diet or a balanced feed mixture. Exercise begins from 10–15 days of age: initially for 20 minutes, gradually increasing the time to 2–4 hours. In summer, heifers are kept in outdoor pens under a canopy.

Dividing the herd into groups depends on the total headcount. The main criteria for division are physiological status, age, and current productivity level. By age, animals are divided into first-calf heifers, second-calf cows, and mature individuals from the third calving onward. Physiological status involves segregating fresh cows during the first 10 days of lactation, cows in the ascending stage from day 10 to 100, cows in the descending stage from day 101 until the dry period, as well as dry cows at 39 and 21 days before calving.

Feeding standards and milking control

For accurate productivity monitoring, test milkings are conducted every 10 days. Based on the data obtained, the average daily milk yield of the group is calculated and the nutrition ration is adjusted for the next ten-day period. This approach prevents feed wastage and maintains animal health.

Concentrated feed distribution is divided into 5–6 times per day. At one time, a cow is fed no more than 2.5 kg of concentrates. The standard is calculated based on a ratio of 400 g of concentrated feed per 1 liter of milk.

Daily ration for a high-yielding cow (yield 7000–8000 kg per lactation, live weight 600 kg, daily yield 40 kg):

Daily ration for pregnant dry cows:

The milking process is organized using machinery in specialized milking parlors. To assess production efficiency and maintain technical records at the dairy complex, the facility's operational parameters are regularly analyzed. Special attention is paid to time studies and the sequence of all machine milking operations.

Key indicators for regular technical monitoring on the farm:

• total number of cows at the complex, breed raised, and breeding method used;
• on-farm specialization and principles of forming technological groups;
• housing conditions for lactating and dry cows, including the design and layout of stalls;
• feed storage technology and preparation for feeding;
• feeding regime for lactating and dry cows, including the frequency and sequence of feed distribution;
• level of mechanization of primary processes, sanitary condition of premises and territory;
• daily schedule, annual yield per cow, milk fat content per lactation, and average daily yield per lactating cow;
• sequence and duration of machine milking technological operations.

Appendix 1 to Topic 1. Options for Task 9 of Topic 1 No. Name Lactation months var cow, Pokariinv. No. indicators 1 2 3 4 5 6 7 8 9 10 11 12 ant and breed 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 yield, kg 531 641 653 625 580 573 555 505 415 398 230 205

2160, % fat 3.4 3.4 3.5 3.5 3.6 3.6 3.6 3.7 3.7 3.8 3.8 3.8

% protein 2.9 2.9 3.0 3.1 3.1 3.0 3.1 3.2 3.0 3.1 3.0 3.1 1.16 yield, kg 511 525 614 505 500 440 389 321 230

18745 % fat 3.8 3.8 3.9 3.8 4.1 4.1 4.7 4.2 4.4

% protein 3.6 3.6 3.6 3.7 3.7 3.8 3.8 3.7 3.8 yield, kg 559 588 625 514 494 496 467 427 217 197 150

157 % fat 3.3 3.4 3.4 3.5 3.6 3.6 3.8 3.8 3.9 3.9 3.9

% protein 2.8 2.9 2.8 2.9 3.0 3.0 3.1 3.1 3.2 3.2 3.3 2.17 yield, kg 535 470 448 445 458 385 290 296 225 251 210