scholarly journals Morphological assessment of the ewe udder in different breeds and their productivity

2021 ◽  
pp. 18-26
Author(s):  
A. P. Kitaeva ◽  
◽  
V. M. Mamedova ◽  
Keyword(s):  
Mammary Gland ◽  
Weight Gain ◽  
Milk Production ◽  
Milk Yield ◽  
Live Weight ◽  
Morphological Properties ◽  
Lactation Period ◽  
Sheep Breeding ◽  
Morphological Assessment ◽  
Selection Of

Dairy productivity of sheep is extremely important for rearing lambs, although insufficient attention is paid to the milking of sheep during selection and selection of sheep during mating. The milk yield of ewes is determined by measuring expressed, sucked milk, or by weight gain of lambs for a certain period of life. But in sheep breeding the greatest application is to determine this indicator by the increase in live weight of lambs in the first 20 days of life. This is due to the fact that in the first month of lactation, the ewes' mammary gland synthesizes the largest amount of milk, and lambs are fed exclusively on mother's milk for up to 20 days after birth. The milk yielding capacity of ewes depends on many factors, including the breed characteristics of the morpho-functional properties of their udder. Studies had been carried out on the morphological properties of the udder of ewes of such breedsas Tsigai, Merinolandschaf and Dorper. Some differences were noted in the linear assessment of their udder and the amount of milk obtained from them (milk yield). It was found that Merinolandschaf ewes exceed their peers of Tsigai and Dorper breeds by 2.6 cm or 17.5% (P <0.95) and 4.3 cm or 32.8%, respectively (P˃0.99), udder girth - by 3.9 cm or 11.9% (P˃0.99) and 7.3 cm or 24.8% (P˃0.999). The length of teats in Dorper ewes is greater than in Tsigai ewes by 0.47 cm or 23.1%, and in the Merinolandschaf - by 0.2 cm or 8.7% (P <0.95). Ewes with male lambs in their offspring were more milk-producing than ewes with female lambs. This advantage was in ewes of Tsigai breed 2.2 kg or 9.5% (P≤ 0.95), Merinolandschaf - 2.0 kg or 10.2% (P≥ 0.95), Dorper - 1.5 kg or 7.51% (P≥0.95) During the lactation period of 180 days more milk was obtained from ewes of Tsigai breed than from ewes of the Merinolandschaf breed by 1.8 kg or 16.9% (P≤ 0.95), and from the Dorper breed - by 19.17 kg or 16.9% (P≥ 0.999). Thus, for milk production the most desirable of the studied breeds are Tsigai and Merinolandschaf breeds.

Some production traits and phenotypic relationships betweenudder and production traits of Hair goats

2016 ◽  
Author(s):  
Okan Atay ◽  
Özdal Gokdal
Keyword(s):  
Milk Production ◽  
Milk Yield ◽  
Live Weight ◽  
Lactation Period ◽  
Production Traits ◽  
Mean Values ◽  
Lactation Length ◽  
Animal Material ◽  
Daily Milk Yield ◽  
Production Characteristics

The study was conducted to determine the production characteristics and to find out the phenotypic relationships between udder and milk production traits in Hair goats. A total of 403 Hair Goats under extensive conditions of Çine town of Aydin province of Turkey were constituted the animal material of the study. The live weights of all goats were recorded just before breeding season. Milk was measured in every month according to the basis of morning or evening milking in a day to estimation of milk yields. Live weights of kids were recorded monthly intervals. Measurements for udder characteristics were determined for two times at 30th and at 180th of the lactation period. Average lactation length, lactation milk yield and daily milk yield of goats were 192.4 days, 139.1 kg and 0.7 kg, respectively. The live weights at birth, 30th, 60th, 90th and 120th days of goat kids were 3.1, 8.6, 13.9, 19.1 and 24.5 kg, respectively. Mean values of withers height, body length and live weight of goats were measured as 73.2 cm, 71.3 cm and 54.5 kg, respectively. Udder and teat characteristics of goats were found positively correlated with milk production characteristics both 30th and 180th days of the lactation period. It can be concluded that Hair goats in extensive conditions had a substantial level of milk yield and their kids had sufficient levels of live weight gains. Furthermore, the udder measurements at the beginning of the lactation could be used for identifying the differences among does.

A simple model of lactation curves for milk yield, food requirement and body weight

1979 ◽  
Vol 28 (1) ◽  
pp. 55-63 ◽  
Author(s):  
P. D. P. Wood
Keyword(s):  
Weight Gain ◽  
Milk Production ◽  
Milk Yield ◽  
Live Weight ◽  
Energy Output ◽  
Algebraic Models ◽  
Live Weight Gain ◽  
Food Requirement ◽  
Potential Demand ◽  
Desk Calculator

ABSTRACTSimple algebraic models of milk yield, live-weight change and food requirement are developed for use in a programmable desk calculator. The unit of time used is a week and of energy a megajoule. An algebraic equation for milk production is used to define potential energy output. An expression using live-weight gain describes the demand for energy for the recovery of weight lost and the requirements of pregnancy. The use of appropriate conversion factors enables the necessary dietary input to be calculated. The model also takes account of restricted feeding by allocating dietary energy to milk production and live-weight gain in proportion to their potential demand. Ten decisions relating to milk yield, live-weight loss and live-weight gain are required by the model.

scholarly journals Some production traits of indigenous Hair goats bred under extensive conditions in Turkey. 1st communication: reproduction, milk yield and hair production traits of does

2008 ◽  
Vol 51 (5) ◽  
pp. 498-506 ◽  
Author(s):  
H. Deger Oral Toplu ◽  
A. Altinel
Keyword(s):  
Milk Production ◽  
Litter Size ◽  
Milk Yield ◽  
Birth Rate ◽  
Live Weight ◽  
Lactation Period ◽  
Production Traits ◽  
Milk Production Traits ◽  
Lactation Length ◽  
Staple Length

Abstract. This study was conducted to investigate the reproductive performance, milk yield, hair production, fleece characteristics and body weight after shearing of Hair goats (Anatolian Black Goats), bred under extensive conditions in Turkey. The material of the study was formed a total data of 456 Hair goats, which were between 2 and 7 years of age bred in the period of two years. Conception rate, infertility rate, abortion rate, kidding rate, single birth rate, twin birth rate, the percentage of kids born according to mated does and litter size were 97.81 %, 2.19 %, 3.59 %, 94.30 %, 97.91 %, 2.09 %, 96.27 % and 1.02, respectively. Lactation length, milk yield in lactation period, milking period and milk yield in milking period of goats were determined as 232.29 days, 100.92 kg, 132.09 days and 43.14 kg, respectively. Hair production, fibre diameter and staple length of Hair goats in the study were determined as 381.00 g, 76.70 micrones and 13.63 cm, respectively. It was found that the effects of production year and farm on the reproductive traits given by percentage weren’t statistically significant, whereas the difference among production years for litter size was significant. It was found that the effect of production year on milk production traits except for lactation length and on the hair production; the effect of farm factor on the hair production, staple length and live weigth after shearing; the effect of age on the milk production traits, hair production traits and live weight after shearing; the effect of live weight on the hair production were statistically significant (p<0.05).

Utilization of energy for maintenance and production in dairy cows given protected tallow during early lactation

1978 ◽  
Vol 91 (1) ◽  
pp. 151-159 ◽  
Author(s):  
P. E. Brumby ◽  
J. E. Storry ◽  
J. A. Bines ◽  
Rosemary J. Fulford
Keyword(s):  
Fatty Acid ◽  
Weight Gain ◽  
Total Energy ◽  
Milk Production ◽  
Milk Yield ◽  
Crude Protein ◽  
Live Weight ◽  
Energy Yield ◽  
Net Energy ◽  
Curvilinear Effect

SummaryDuring the first 13 weeks of lactation, four groups of seven cows were given hay and a basal concentrate mix containing 0, 1·7, 3·3 or 5·0 kg/day of a protected lipid supplement (320 g long-chain fatty acid/kg D.M.). The proportion of hay to total concentrate was maintained at 25:75 and cows were fed to appetite.The total amount of energy digested corrected for endogenous loss (DEc) was partitioned into crude protein energy (CPEc), fatty-acid energy (FAEc), ‘carbohydrate’ (non-protein non-fatty acid) energy (CEC) and non-fatty-acid energy (NFAEc = CPEc + CEc).Partial efficiency of milk production and live-weight gain was curvilinearly related to FAEc, maximum efficiency occurring at about 30 MJ/day of FAEc.Net energy utilized was significantly related to DE0c for both of the periods considered, Weeks 2–6 and weeks 7–13. In addition, a curvilinear effect of the ratio of fatty acid energy to non-fatty-acid energy was established. At fixed intakes of digestibl energy, net energy utilized was maximal for ratios of FAEc/NFAEc of 0·14 and 0·18 for weeks 2–6 and 7–13 respectively.Milk yield was significantly related to DEc for weeks 1–6 and 7–13; milk energy yield was significantly related to DEc for weeks 7–13. The multiple regression relationships between milk yield or milk energy yield and CPEc, FAEc and CEc gave a negative effect of crude protein, possibly indicating that the proportion of total energy supplied as crude protein (18–26% of DEc) was above the optimum requirement.At fixed intakes of digestible energy, outputs of milk and milk energy were maximal at ratios of FAEc/NFAEc of 0·16 and 0·15 for weeks 1–6 and 7–13 respectively. The inclusion of a curvilinear effect of total energy (DEc2) gave some indication that utilization of energy for milk production for weeks 7–13 diminished at the highest digestible energy intakes whilst energy utilized for live-weight gain increased.

MODERN CONDITION AND PROSPECTS OF DEVELOPMENT OF THE UKRAINIAN WHITEHEAD BREED

2016 ◽  
Vol 52 ◽  
pp. 194-202
Author(s):  
S. L. Voitenko ◽  
L. V. Vishnevsky
Keyword(s):  
Milk Yield ◽  
Milk Fat ◽  
Objective Assessment ◽  
Live Weight ◽  
Fat Content ◽  
Early Age ◽  
Average Value ◽  
The Future ◽  
Efficiency Of Selection ◽  
Selection Of

The article shows the state of Ukrainian Whiteheaded cattle, which includes distribution of cattle, the number of animals belonging to respective bloodlines, evaluation of young animals with live weight in the process of growing and milk production of cows during the first lactation. It reflects the historic development of the breed when it was colonism whiteheaded cattle, which turned into the original breed, undergone a significant expansion in livestock and increase of productivity, decreased in the number, was as basis for creation of Ukrainian Black-and-White dairy breed and now bred only in one breeding farm. Visual estimation of animal exterior showed good development of cows and calves and their belonging to the dairy type. In the vast majority the cows of the herd have a black suit, a white head with " glasses" around the eyes, white belly, udder, lower legs and brush of the tail. The youngsters aren’t consolidated by the exterior, and among them there are animals which are not typical for Ukrainian Whiteheaded breed. The young animals have some lag in live weight behind the breed standard [12] to 7 months’ age with exceeding of this trait in certain periods quite significantly in the future. It was established that selection of heifers on live weight will be effective at the early age (1-5 months), given the coefficient of variation of live weight – 22,63-30,21% and will not have a significant influence in the future. Milk yields of first-calf heifers vary considerably depending on the origin. The milk yield of first-calf heifers in the herd was 4238,5 kg on average, the heifers belonging to Mart 171 and Ozon 417 bloodlines had the best milk performance – 4483,1 and 4254,9 kg accordingly. The most aligned milk yield during the first lactation was in the cows belonging to Ozon 417 bloodline, the limits of the trait are 4128,5-4327,4 kg with the average value by the line 4254,9 kg. In contrast, the first-calf heifers of Ryezvyi 33 bloodline with average milk yield 4048,9 kg had limits of the trait 2199,3-4736,1 kg. Even greater range in cows’ milk yield during the first lactation R= 4939 kg (limits 1687 – 6626 kg) is characterized for the herd in general, it shows, on the one hand, the possibility of qualitative improvement of cows’ productivity due to selection on the investigated trait and lack of selection in the herd on the other hand. It was established that daughters of bull Chardash belonging to Ryezvyi 33 bloodline produced 4736,1 kg of milk for 305 days of the first lactation with fat content 3,6%, whereas Zlak’s descendants of the same line were characterized by the lowest milk yield for the first completed lactation – 2199,3 kg with fat content 3,7% and the average value by the line – 4048,9 kg of milk, fat content 3,6%. Similar variability of first-calf heifers’ milk yields, depending on the origin, is typical for other bloodlines of Ukrainian Whiteheaded breed. To increase milk productivity of Ukrainian Whiteheaded cows is recommended to repeat successful combinations of parental forms, and to preserve the breed – to carry out an objective assessment of animals by a range of traits, given the efficiency of selection of heifers on live weight at early age.

СОВЕРШЕНСТВОВАНИЕ СТАД СКОТА СИММЕНТАЛЬСКОЙ ПОРОДЫ ПО МОЛОЧНОЙ И МЯСНОЙ ПРОДУКТИВНОСТИ

2020 ◽  
Author(s):  
N.V. SIVKIN ◽  
N.V. STREKOZOV ◽  
V.I. CHINAROV
Keyword(s):  
Milk Yield ◽  
Live Weight ◽  
Breeding Value ◽  
Early Age ◽  
Group I ◽  
Breeding Herd ◽  
Simmental Cattle ◽  
Meat Productivity ◽  
Selection Of ◽  
Meat Type

В симментальской породе предусматривается разведение скота, сбалансировано сочетающего молочную и мясную продуктивность. Однако в практике совершенствования племенных стад в подборах быков доминируют улучшатели удоя, что во многом предопределяет результаты селекции и продуктивный тип животных. Объектом нашего исследования стало стадо чистопородного симментальского скота в условиях стойловой системы беспривязного и привязного содержания коров. Для изучения эффективности использования быков-производителей разного племенного достоинства сформировали 2 опытные группы: I состояла из бычков, полученных от отцов с племенной ценностью (ПЦ) по удою 100 кг и более, а во II с ПЦ от 0 до 100 кг молока. Симментальские бычки, отобранные для контрольного убоя, достигали весовых кондиций 500 кг и более в 17,5 мес при среднесуточном приросте 911 г. При использовании на маточном поголовье быков-производителей с улучшающим эффектом по удою 100 кг и более, их сыновья (I группа), на фоне более высоких суточных приростов (на 30 г) и раннем возрасте достижения живой массы 500 кг (на 18 дней) имели массу и выход туши на 21,4 кг и 2,7 ниже, чем у бычков II группы. При формировании молочно-мясного типа быки-производители с умеренной племенной ценностью по удою обеспечивали получение потомства, сочетающего молочную и мясную продуктивность в экономически значимых пропорциях.The Simmental breed provides for the breeding of cattle that combines milk and meat productivity in a balanced proportion. However, in the practice of improving breeding herds, the selection of bulls is dominated by milk yield improvers, which largely determines the results of selection and the productive type of animals. The object of our research was a breeding herd of purebred Simmental cattle in variety feeding and housing practices. To study the effectiveness of using bulls-producers of different breeding values, 2 experimental groups were formed: I consisted of bulls received from fathers with a breeding value (BV) of milk yield 100 kg or more, and II with a BV from 0 to 100 kg of milk. Simmental bulls selected for control slaughter reached weight standards of 500 kg or more in 17.5 months with an average daily increase of 911 g. When used on breeding of bulls with an improving effect on the yield of 100 kg or more, their sons (group I), against the background of higher daily gains (30 g) and an early age of reaching a live weight of 500 kg (18 days), had a mass and carcass yield of 21.4 kg and 2.7 lower than that of group II bulls. When forming a dairy-meat type, producing bulls with a moderate breeding value for milk yield provided for the production of offspring that combined dairy and meat productivity in economically significant proportions.

A comparison of the Charolais, British Friesian and Hereford breeds as sires of crossbred singlesuckled calves for beef production

1973 ◽  
Vol 17 (3) ◽  
pp. 267-273 ◽  
Author(s):  
R. E. Haycock ◽  
D. A. Stewart
Keyword(s):  
Weight Gain ◽  
Birth Weight ◽  
Live Weight ◽  
The Other ◽  
Cattle Production ◽  
Significant Relationships ◽  
Grazing Period ◽  
Beef Cattle Production ◽  
Breed Crosses ◽  
Selection Of

SUMMARYIn three successive years cows from an Aberdeen Angus cross Shorthorn herd were mated to pedigree Charolais, British Friesian and Hereford bulls. A comparison of the progeny of the three breeds of sire under controlled conditions was therefore possible using a random selection of dams for mating, and identical rearing of the calves. Results for live-weight gain of the suckled progeny were analysed and showed superiority of the Charolais breed over the other two when used in this form of beef cattle production.For birth weights and daily live-weight gains, particularly during the grazing period, the Charolais cross progeny showed superiority over the other two. There was a consistent although not always statistically significant tendency for these differences between the breed crosses to occur in the male calves only, the females showing little difference between breeds. The data also showed highly significant relationships between gestation period and birth weight, both within and between breed crosses.

A comparison of starchy and fibrous concentrates for milk production, energy utilization and hay intake by Friesian cows

1987 ◽  
Vol 109 (2) ◽  
pp. 375-386 ◽  
Author(s):  
J. D. Sutton ◽  
J. A. Bines ◽  
S. V. Morant ◽  
D. J. Napper ◽  
D. J. Givens
Keyword(s):  
Milk Production ◽  
Milk Yield ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Energy Utilization ◽  
Energy Yield ◽  
Carbohydrate Source ◽  
Lactating Cows ◽  
Concentrate Inclusion ◽  
Friesian Cows

SummaryTwenty-four Friesian cows were allocated to one of four diets for weeks 3–14 of lactation following 2 weeks on a common diet. The diets (kg air-dry feed/day) were 7–2 kg hay and 10·8 kg either starchy or fibrous concentrates (60S and 60F) or 3·5 kg hay and 14·0 kg either starchy or fibrous concentrates (80S and 80F). Rumen samples were taken by stomach tube in weeks 10 and 12 of lactation and the digestibility of the diets was measured with four cows per treatment during weeks 13 and 14. The digestibility of the same feeds was also measured in sheep at maintenance.The principal carbohydrate constituents of the concentrates were barley, wheat and cassava in the starchy concentrates and citrus pulp, sugar-beet pulp and wheat feed in the fibrous concentrates. The concentrates were designed to have similar concentrations of metabolizable energy (ME) and the diets were planned to provide similar intakes of digestible energy and crude protein.Milk yield and composition were very similar for treatments 60S and 60F. With the higher proportion of starchy concentrates (80S), milk yield was about 20% greater than on 60S, fat concentration fell severely but protein and lactose concentrations were unaffected. With the higher proportion of fibrous concentrates (80F), milk yield and the protein and lactose concentration were similar to values on 60F but fat concentration was lower, though not nearly so low as on 80S. Milk energy yield was reduced by the higher proportion of concentrates but was unaffected by type of carbohydrates. Live-weight changes were small.In both the sheep, consuming at maintenance, and the lactating cows consuming at about 3 times maintenance, digestibility of dry matter, organic matter and energy was higher with the higher concentrate diets but was unaffected by type of concentrate. The digestibility of fibre was greater with the fibrous concentrates but the effect of level of concentrate inclusion was inconsistent. Digestibility coefficients were consistently lower for the lactating cows than for the sheep.The proportion of acetic acid in the rumen volatile fatty acids in the cows was higher and the proportion of propionic acid was lower with the fibrous concentrates. The differences were much greater with the higher proportion of concentrates.During weeks 15–22 of lactation the cows were reallocated to concentrate treatments and given hay ad libitum. Hay intake was about 1 kg/day higher with the fibrous concentrates but the difference was not significant. Hay intake fell by about 0·6 kg/kg concentrate intake for both concentrate types. No significant differences in milk yield or composition were established, probably because of incomplete adaptation even after 8 weeks.It is concluded that at concentrate intakes of about 10 kg/day, the source of carbohydrate in the concentrates has little effect on milk production when the concentrates are of similar ME concentration. However, at higher levels of concentrate inclusion, although the diets may have similar ME concentrations, important differences in the yields of fat, protein and lactose occur due to carbohydrate source and these can be related to differences in rumen fermentation.

The effects of plane of nutrition and diet type on metabolic hormone concentrations, growth and milk production in high genetic merit dairy herd replacements

2000 ◽  
Vol 70 (2) ◽  
pp. 349-362 ◽  
Author(s):  
A.F. Carson ◽  
A.R.G. Wylie ◽  
J.D.G. McEvoy ◽  
M. McCoy ◽  
L.E.R. Dawson
Keyword(s):  
Weight Gain ◽  
Milk Production ◽  
Live Weight ◽  
Live Weight Gain ◽  
Genetic Merit ◽  
Grass Silage ◽  
Nutrition And Diet ◽  
Condition Score ◽  
Metabolic Hormone ◽  
Diet Type

AbstractSeventy high genetic merit Holstein heifers were used in two experiments to investigate (1) the effects of plane of nutrition and diet type during the pre-pubertal period and (2) the effects of plane of nutrition during the post-pubertal period on metabolic hormone concentrations, growth and milk production. In experiment 1, treatment 1 and 2 heifers were given food to achieve a live-weight gain of 0·70 and 0·95 kg/day from 3 to 10 months of age on a grass silage based diet, while treatment 3 heifers were given food to achieve 0·95 kg/day on a barley straw/concentrate diet. During the pre-pubertal period, heifers reared on treatment 1 had significantly higher growth hormone(GH) concentrations (ng/ml per 1 h) than heifers reared on treatment 2 (P < 0·01) and had significantly lower insulin concentrations than heifers reared on treatment 3 (P < 0·01). Heifers reared on treatment 1 had significantly lower insulin-like growth factor 1 (IGF-1) concentrations than those reared on treatment 3 (P < 0·01). At 10 months of age heifers reared on treatment 1 were of lower condition score (P < 0·01) than those on treatment 2 and had a smaller heart girth diameter (P < 0·01) than those on treatments 2 and 3. During the first lactation, milk yield and composition produced by the heifers was not significantly affected by treatment. In experiment 2, treatment A heifers were given, from 14 to 24 months of age, a low plane of nutrition to allow a live-weight gain of 0·65 kg/day on a grass silage and grass based diet during the winter and summer periods respectively. Treatment B heifers were kept on a high plane of nutrition to allow a live-weight gain of 0·90 kg/day on the same forage along with concentrate supplementation. During the rearing period, GH and IGF-1 concentrations were not significantly affected by treatment. Treatment A heifers weighed less before calving (P < 0·05), had a lower condition score (P < 0·01), and had a smaller heart girth diameter (P < 0·01) than those on treatment B. During the first 10 weeks of lactation, heifers on treatment A had a higher silage dry matter intake and lost less weight (P < 0·05) than those on treatment B, however, by 20 weeks of lactation these effects had disappeared. Milk yield and composition during the first lactation were not significantly affected by treatment. Overall, the findings of experiments 1 and 2 did not show any beneficial effects of higher weights at first calving in high genetic merit Holsteins and therefore indicate that accelerated growth in the pre- or post-pubertal period may not be required.

scholarly journals Characteristics of the productive-economic indicators of cows of Yaroslavl breed of different genotypes

2020 ◽  
pp. 43-52
Author(s):  
N. Kosyachenko ◽  
Marina Abramova ◽  
M. Lapina
Keyword(s):  
Protein Content ◽  
Milk Production ◽  
Milk Yield ◽  
Milk Fat ◽  
Live Weight ◽  
Practical Significance ◽  
Holstein Breed ◽  
Blood Fraction ◽  
The Impact ◽  
The Relationship

Abstract. Aim. The study of the influence of crossbriding on the growth and development of heifers and subsequent productive and reproductive qualities of cows on the first lactation. Methods. Using statistical methods, correlation analysis and ANOVA for evaluated genetic indicators of economic-valuable traits of dairy cattle. In particular was studied live weight of heifers from birth to 18 months, first insemination age and first fecundation age, live weight at fecundation, frequency of insemination, first calving age, days open, live weight at first lactation, milk yield for 305 days (kg), fat (%, kg) and protein (%, kg) in milk. Results. Relationship between productive indicators and the genotype of the animal is established. When assessing the strength of the influence of the factor «blood on the Holstein breed» it was found that the greatest impact can be traced at the age of 6 and 18 months, and is respectively 12.7 % and 17.1 %.The reproductive qualities of the first-calf cows decreased with the increase percent of blood in the Holstein breed. Evaluation of the impact of crossbreeding on milk production at first lactation has revealed significant strong influence on milk yield for 305 days of first lactation, and related signs the amount of milk fat and protein. According to qualitative indicators, the low influence of the Holstein blood fraction was found, while to a greater extent on the fat content than on the protein content in milk. Evaluation of phenotypic and genotypic correlations of milk yield and quality components of milk revealed average negative phenotypic and low negative genotypic correlation in all groups. The exception was in heifers of Yaroslavl breed with percent of Holstein blood less than 50 %, in which the relationship of yield x protein was positive. The relationship between milk yield and fat and protein content in milk has the opposite moderate character and strength. Practical significance. Studies was established that breeding of animals of Holstein and Yaroslavl breeds in one herd allows to receive an optimum ratio of milk production with optimal percentage fat and protein. For this herd among animals of the improved genotypes of the Yaroslavl breed, the use of genotypes with a percent of blood in the Holstein breed from 75.1 % to 87.6 % is optimal, which should be taken into account when selecting bulls to the breeding program.

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