Cow Weight Research Articles

Simulating the productivity and profitability of a herd of beef-dairy crossbred breeding cows on New Zealand hill country with fixed feed supply

Beef-dairy crossbred cows (such as Angus-Friesian) have lighter mature cow weights while weaning heavier calves compared with cows in a typical self-replacing New Zealand Angus breed herd. The objective of this study was to quantify the potential profitability of farming an Angus-Friesian cow herd through modelling the potential changes in cattle numbers, feed demand, production, and beef enterprise economics. The Angus-Friesian cow herd was simulated as purchasing all replacement heifers and was modelled with different sire breeds (Angus or terminal such as Charolais or Simmental) and offspring sale policies (sold at weaning at six months of age or at 27 months of age). Total annual cattle feed demand was maintained at the same level for all modelled scenarios. Angus-Friesian herds had 8% to 79% higher beef enterprise cash operating surplus (COS) compared with the self-replacing Angus herd (COS = NZD 255/ha). For the Angus-Friesian herds, selling all offspring prime (direct to slaughter) at 27 months of age resulted in 20% to 59% higher COS than selling all offspring store (sold at weaning) at weaning at six months old. Utilising terminal breed sires with the Angus-Friesian herd resulted in 10% to 12% higher COS compared with using Angus sires when selling all offspring store at weaning, due to the heavier sale weights and resultant higher per head sale values. However, when selling all offspring prime at 27 months of age the utilisation of Angus sires resulted in 10% to 11% higher COS than using terminal sires, as the lighter weights and thus total feed demand was lower for offspring born to Angus sires allowing for a greater breeding cow numbers (and therefore numbers of offspring sold). Scenarios in which offspring were retained on-farm until 27 months of age increased total feed demand of cattle destined for sale, necessitating reductions in breeding cow numbers to as low as 60% of the base system level, which may inhibit farmers’ ability to manage pasture quality. Farmers considering a change to an Angus-Friesian crossbred herd of breeding cows can include the potential herd numbers, feed demand, production, and economic changes predicted in this analysis in their decision making, as well as the practicalities of the explored strategies for designing their farm system.

Creation of a breeding group of Hereford cows improved by bulls of canadian reproduction

The results of research on the creation of a breeding group of Hereford cows at the Novosibirsk Region breeding reproducer are presented. It was found that cows from the 3rd to 7th calves have the lowest coefficient of variability for live weight (from 1.9 to 2.7%), for milk yield - from 1.9 to 5.6%. The variation in height at hips (characterizing the manifestation of the type) was from 1.3-1.6%. Based on these indicators, a breeding group of 82 cows was selected and evaluated. The average live weight of the animals was 570.5 kg, which exceeds the standard of the breed by 50.5 kg or 9.7%, and corresponded to the elite-record class. The selection differential by live weight of cows of the whole herd and breeding group was 11 kg. Taking into account the coefficient of inheritance and the effect of selection on the first generation to achieve the indicators of the desirable type based on the cows of the breeding group will take 3.5 generations (10.5 years), respectively, for milk yield - 3.9 generations (4.5 years). More effective breeding achievement can be achieved in height at hips (1.1 generations and 3.3 years). Ten stud bulls selected for custom mating are homogeneous and rated elite-record class. They exceeded the breed standard by 151.5 kg (8.1%) in live weight at 3 years of age and by 115.3 kg (14.1%) at 5 years and older. They are characterized by a well-defined desirable type of constitution. Stud bulls obtained from the cross of the Canadian and Siberian selections with the complex index "B", according to the quality of progeny 104-105 recognized as improveers.

Genetic variation in PLAG1 is associated with early fertility in Australian Brahman cattle.

Variation in the genome region coding for PLAG1 has well-documented associations with skeletal growth and age at puberty in cattle. However, the influence of PLAG1 on other economically important traits such as cow stayability has not yet been explored. Here we investigate the effect of PLAG1 variation on early and later in life female fertility, as well as size and growth, in a well-phenotyped Australian Brahman herd. Yearly pregnancy and productivity records were collected from 2,839 genotyped Brahman cows and used to generate fertility, growth, and weight phenotypes. A variant on chromosome 14 in PLAG1 (NC_037341.1:g.23338890G>T, rs109815800) was previously determined to be a putative causative mutation associated with variation in cattle stature. The imputed PLAG1 genotype at this variant was isolated for each animal and the effect of PLAG1 genotype on each trait was estimated using linear modeling. Regardless of how heifer fertility was measured, there was a significant (P < 0.05) and desirable relationship between the additive effects of PLAG1 genotype and successful heifer fertility. Heifers with two copies of the alternate allele (TT) conceived earlier and had higher pregnancy and calving rates. However, the effects of PLAG1 genotype on fertility began to diminish as cows aged and did not significantly influence stayability at later ages. While there was no effect of genotype on growth, PLAG1 had a negative effect on mature cow weight (P < 0.01), where females with two copies of the alternate allele (TT) were significantly smaller than those with either one or none. Selection emphasis on improved Brahman heifer fertility will likely increase the frequency of the T allele of rs109815800, which may also increase herd profitability and long-term sustainability through improved reproductive efficiency and reduced mature cow size.

137 Application of Performance Metrics to Evaluate Cow Performance: A Collaboration of the Alabama Beef Cattle Improvement Association and the Alabama Cooperative Extension System

Abstract Beef cattle producers engaged in the Alabama Beef Cattle Improvement Association (BCIA) Commercial Record Keeping Program are encouraged to expand records for evaluation of whole herd performance. Collection of cow weight at calf weaning can be used as a metric to estimate cow performance for overall productivity. From 2019 to 2021, five beef cattle operations annually collected individual cow weight at calf weaning (n = 284 observations). Cow age was classified as 2 to 4 years old, 5 to 8 years old and 9 years and older. Cow weight was classified into three categories as small (1199 lb or less), moderate (1200 to 1499 lb) or large (1500 lb or greater). Average cow weight per category was small 1108 lb (n = 37), moderate 1353 lb (n = 180) and large 1605 lb (n = 67). Within each age range and size category, cow performance was measured by average calving interval, average calf adjusted weaning weight and percentage cow body weight weaned. For 2 to 4 years old, average calving interval was 18 days longer between small to moderate categories and 96 days longer between moderate to large categories. For 5 years of age and older, modest impact on average calving interval due to an increase in body weight was observed (3 to 7 days small to moderate; 19 to 8 days moderate to large). Across all ages, moderate impact on average calf adjusted weaning weight due to cow weight was reflected (19, 38, 43 lb. small to moderate; 37, 27, 37 lb. moderate to large). As cow age and weight increases, percentage of cow body weight weaned decreases (2 to 4 years 57%, 48%, 42%; 5 to 8 years 50%, 45% 40%; 9 years 47%, 44% 39%). In summary, measuring cow weight at calf weaning enhances genetic and management practices to illustrate and improve cow herd productivity.

Aplikasi Pengolahan Citra Digital Menentukan Bobot Sapi Dengan Metode Titik Berat Berbasis Android

Cattle is a consumption animal that is in great demand by Indonesians, its soft meat and delicious taste make beef one of the most expensive meats at the moment, cattle breeders are now starting to modernize and continue to develop their farms to make it easier to maintain and sell cattle, in this modern era there are many things that are facilitated by technology that makes it easier for people to do things, one of which is calculating the weight of a cow with an android application by entering an image of a cow that will be processed and will produce a value for the size and weight of the cow. The weight of the cow can be calculated using the Schoorl formula and the Modified/ Lambourne formula which requires variables of body length and chest circumference for calculation. To get bodyweight, it is necessary to measure chest circumference and body length which are measured manually. However, the reality in the field shows that to get the values for chest circumference and body length, manual measurements need to be carried out, and this is not easy to do because cows are difficult to condition. In the field itself, there is no practical and accurate tool to calculate chest circumference, body length, and weight of cows. Starting from this problem, gave rise to the idea of making a tool that can measure accurately and easily.

English

The objective of this study was to determine the environmental and genetic factors influencing mature cow weight (MCW) trait in Tswana cattle breed. Analyses of environmental and genetic effects for mature cow weight trait were performed using 19301 records of Tswana cows born between 1996 and 2010 from 610 dams and 137 sires in 54 contemporaries. Mature cow weight trait was analysed using repeatability model. The significant environmental effects for MCW were selection line, cow age and contemporary group. Heritability estimate for mature cow weight traits was 0.26&plusmn;0.03. Genetic correlations between growth traits and MCW ranged from 0.15&plusmn;0.17 between BWT and MCW to 0.84&plusmn;0.19 between YWT and MCW. Phenotypic correlations between growth traits and MCW ranged from 0.15&plusmn;0.04 between BWT and MCW to 0.31&plusmn;0.03 between EWT and MCW. The existence of significant genetic variability and moderate repeatability in MCW trait coupled with high genetic correlation between this trait and early growth traits suggest that caution should be exercised when selecting for growth traits to avoid undesirable resultant change in mature cow weight trait. Key words: Selection, cow weight, genetic correlations, heritability, repeatability model.

The use of 3-dimensional imaging of Holstein cows to estimate body weight and monitor the composition of body weight change throughout lactation

Three-dimensional (3D) imaging offers new possibilities in animal phenotyping. Here, we investigated how this technology can be used to study the morphological changes that occur in dairy cows over the course of a single lactation. First, we estimated the individual body weight (BW) of dairy cows using traits measured with 3D images. To improve the quality of prediction, we monitored body growth (via 3D imaging), gut fill (via individual dry matter intake), and body reserves (via body condition score) throughout lactation. A group of 16 Holstein cows-8 in their first lactation, 4 in their second lactation, and 4 in their third or higher lactation-was scanned in 3D once a month for an entire lactation. Values of morphological traits (e.g., chest depth or hip width) increased continuously with parity, but cows in their first lactation experienced the largest increase during the monitoring period. Values of partial volume, estimated from point of shoulder to pin bone, predicted BW with an error of 25.4 kg (R2 = 0.92), which was reduced to 14.3 kg when the individual effect of cows was added to the estimation model. The model was further improved by the addition of partial surface area (from point of shoulder to pin bone), hip width, chest depth, diagonal length, and heart girth, which increased the R2 of BW prediction to 0.94 and decreased root mean square error to 22.1 kg. The different slopes for individual cows were partly explained by body condition score and morphological traits, indicating that they may have reflected differences in body density among animals. Changes in BW over the course of lactation were mostly due to changes in growth, which accounted for around two-thirds of BW gain regardless of parity. Body reserves and gut fill had smaller but still notable effects on body composition, with a higher gain in body reserves and gut fill for cows in their first lactation compared with multiparous cows. This work demonstrated the potential for rapid and low-cost 3D imaging to facilitate the monitoring of several traits of high interest in dairy livestock farming.

Hubungan antara ukuran tubuh dan bobot badan pada induk sapi perah Friesian Holstein laktasi pertama

This study aims to determine the relationship between body size and bodyweight of the first lactating FH dairy cow. The research method used was linear regression analysis with 17 individuals at 27-29 months. The observed variables were body weight (BW), body length (BL), shoulder height (SH), and chest circumference (CC). The results showed that the correlation value between BW and BL was 0.6791 with the correlation regression equation Y = -724.63+7.68X1. SH and BW have a correlation value of 0.4043. CC with BW has a correlation value of 0.6863 with the regression equation Y = -733.455.90X1. The relationship between BL and SH has a correlation value of 0.2048. BL and CC have a correlation value of 0.4832. The conclusion of this study was that BW has a correlation of 67.91% to BL and 68.63% to CC of first lactating dairy cows, but does not have a correlation to SH. The more the BL and CC of the first lactating dairy cow increased, the more the weight of the dairy cow increased. BL does not have a correlation with SH and CC. SH has a 60.08% correlation with CC.

Genetic parameters for body weight and milk production of dairy Gyr herds.

The aim of this study was to estimate genetic parameters for cow weight at calving (CW) and cumulative 305-day milk yield (MY305) in dairy Gyr cattle by two-trait analysis. The study used 1,847 CW records, in which 418 females presented more than one measure, and 4,048 MY305 records, wherein 1068 females provided repeated measures, from 2,339 females belonging to three herds, which calved between 1986 and 2019. Variance components were estimated by the restricted maximum likelihood method (REML) using a two-trait animal model. The model included direct additive genetic, permanent environmental and residual effects as random effects and the fixed effects of contemporary group, formed by animals that had calved on the same farm year and season, and age of cow at calving as covariates (fitted as linear and quadratic effect). The heritability estimates for CW and MY305 were 0.21 ± 0.06 and 0.29 ± 0.04, respectively, and repeatability estimates were 0.49 ± 0.03 and 0.49 ± 0.02. The genetic correlation between CW and MY305 was positive and of low magnitude (0.33 ± 0.18), indicating that selection for MY305 will cause little genetic change in the weights of dairy Gyr animals. The genetic trends of breeding values of analyzed traits showed marked genetic gains in MY305, with little changes in CW of dairy Gyr cows over the years in the herds studied, which is an important result considering the production systems adopted in the tropics.

Genetic parameters, heterosis, and breed effects for body condition score and mature cow weight in beef cattle.

Understanding the genetic relationship between mature cow weight (MWT) and body condition score (BCS) is useful to implement selection programs focused on cow efficiency. The objectives of this study were to estimate genetic parameters, heterosis, and breed effects for MWT and BCS. In total, 25,035 and 24,522 overlapping records were available for MWT and BCS on 6,138 and 6,131 cows, respectively, from the Germplasm Evaluation program, a crossbred beef population at the U.S. Meat Animal Research Center. Pedigree was available for 48,013 individuals. Univariate animal models were used to estimate heritabilities for each trait by parity. Bivariate animal models were used to estimate genetic correlations between parities within a trait and between traits within parities. Bivariate repeatability animal models were used to estimate genetic correlations between traits across parities. Estimates of heritability for different parities ranged from 0.43 ± 0.05 to 0.55 ± 0.07 for MWT and from 0.12 ± 0.03 to 0.25 ± 0.04 for BCS and were lower with the repeatability model at 0.40 ± 0.02 and 0.11 ± 0.01 for MWT and BCS, respectively. Estimates of repeatability were high for MWT (0.67 ± 0.005) and low for BCS (0.22 ± 0.006). Estimates of genetic correlation for MWT and BCS between parities were, in general, high, especially between consecutive parities. Estimates of genetic correlation between MWT and BCS were positive and moderate, ranging from 0.32 ± 0.09 to 0.68 ± 0.14. The direct heterosis estimates were 21.56 ± 3.53kg (P ≤ 0.001) for MWT and 0.095 ± 0.034 (P ≤ 0.001) for BCS. Ordered by decreasing MWT, the breeds ranked Brahman, Charolais, Angus, Simmental, Salers, Hereford, Santa Gertrudis, Chiangus, Brangus, Red Angus, Shorthorn, Maine-Anjou, Gelbvieh, Beefmaster, Limousin, and Braunvieh. Ordered by decreasing BCS, the breeds ranked Brahman, Red Angus, Charolais, Angus, Hereford, Brangus, Beefmaster, Chiangus, Salers, Simmental, Maine-Anjou, Limousin, Santa Gertrudis, Shorthorn, Gelbvieh, and Braunvieh. Estimates of breed differences for MWT were also adjusted for BCS (AMWT), and in general, AMWT depicted smaller differences between breeds with some degree of re-ranking (r = 0.59). These results suggest that MWT and BCS are at least moderately genetically correlated and that they would respond favorably to selection. Estimates of breed differences and heterotic effects could be used to parameterize multibreed genetic evaluations for indicators of cow maintenance energy requirements.

Milk productivity and live weight of cows at ООО “PskovAgroInvest”

Currently, the food problem occupies an important place among the global problems of mankind. Despite a slight increase in food production, the level of nutrition of the population is not reaching optimal levels. This is especially true for Russia. One of the ways to solve this problem is the development of agriculture, in particular animal husbandry. Over the five analyzed years, there has been an increase in the level of milk production in cows of all ages. Milk yield, fat and protein content in the milk of cows of all ages significantly exceed the breed standard. The live weight of cows of all ages for all years also significantly exceeds the breed standard, in particular, full-aged cows are characterized by a weight varying in the range of 599–606 kg. The fat content in milk of cows during this period ranges within 3.70–3.85% with a breed standard of 3.7%, protein content – 3.07–3.26% with a 3.0% breed standard, that is, exceeds the standard for the entire period taken into account. It should also be noted that every year there is an increase in indicators, reaching a maximum in 2020. It should be noted that a number of cows have been in the list of the best in OOO “PskovAgroInvest” for a number of years, improving their milk yield with each lactation. So, from Travinka 1330 in 2018, 10,573 kg of milk with a fat and protein content of 3.63% and 3.12% were milked, and in 2020 – already 11,239 kg with a fat and protein content of 3.71% and 3.18%; from cow Torpedo 234 the corresponding figures for the same years amounted to 9340 kg, 3.75%, 3.06% and 10,504 kg, 3.74%, 3.18% respectively.

Structural Traits, Structural Indices and Body Weight Prediction of Arsi Cows

Structural measurements are indicators of animal performance, productivity and carcass characteristics. This study was conducted with the objectives of assessing structural measurements, developing body weight prediction and structural indices for cows of Arsi breed. The cows were purchased from highland and lowland agro-ecologies of Arsi and East Shoa zones of Oromia regional state, Ethiopia and kept in Adami Tulu Agricultural Research Center (ATARC) for the breed development purpose. Totally 222 cows were included in the structural traits measurement. Thirty four young heifers were also considered in the study. Twenty two structural traits were considered during observational survey. The structural index was calculated from the phenotypically correlated linear measurements. Structural traits were analyzed by T-test of SPSS version twenty four. The observed average values of height at wither, chest depth, heart girth, body length, pelvic width, cannon bone circumferences of the cows were 107, 55.62, 141.06, 117.82, 31.41 and 13.58cm, respectively. Heart girth (0.82), flank girth (0.73), hook circumferences (0.67), chest depth (0.65) and height at rump (0.64) were highly correlated (P&lt; 0.01) to body weight of the cows. Regression analysis indicated that hearth girth had the highest coefficient of determination for body weight of the cows and heifers. Accordingly, the simple linear equations were developed to predict the body weight of cows and heifers. Body weight of Arsi cow (y) = -221.005 + 3.1(heart girth) and Body weight of Arsi heifer (y) = -188.452 + 2.75 (heart girth). Based on this, the measuring chart tape can be developed to estimate the body weight of Arsi cows and heifers at field condition where there is no access to weighing scales.

Alternative measures of cow–calf efficiency for Afrikaner, Bonsmara, Nguni, Angus and Simmental sired calves

Context It is desirable to identify cows that produce higher weaning weights while consuming less feed in order to increase biological efficiency; however, there is no universally accepted metric for cow–calf efficiency. Aim Due to the common usage of ratios to express biological cow efficiency, despite their theoretical defects, these measures and alternatives to them were examined to understand better some of the complexities in improving cow efficiency. Methods The analyses were carried out using SAS. In model 1, 205-day calf weight/cow weight was used to define cow–calf efficiency and in model 3, 205-day calf weight per Large Stock Unit (LSU), which is a standard unit of energy consumed, was used to quantify efficiency. In models 2 and 4, 205-day calf weight was analysed using cow weight and Large Stock Unit, respectively, as covariates. Key results The use of ratios was biased in favour of the smaller Nguni cows. The Bonsmara and Angus sired calves attained 53% of the weight of their Nguni dams, and their weaning weight per Large Stock Unit was 169 ± 9 kg. However, Angus sired calves from Bonsmara dams were most efficient when efficiency was determined by analysis of covariance when cow weight and Large Stock Unit were used as covariates (162 ± 17 kg and 133 ± 22 kg), respectively. Conclusions The results indicate the difficulty in determining differences in cow–calf efficiency in the absence of a standard definition. The difference between output and input can be maximised, when traits are reported in consistent units like joules, financial currency, or carbon footprint. Implications This inconsistent definition of cow–calf efficiency makes its improvement challenging.

INFLUENCE OF LIVE WEIGHT, AGE OF FIRST INSEMINATION AND CALVING ON MILK PRODUCTIVITY OF COWS

The article examines the influence of live weight, age of first insemination and calving on the milk productivity of cows of the Ukrainian red-spotted dairy breed in the conditions of LLC "ATZT Myrne" of the Kitsman district of the Chernivtsi region. The milk productivity of first-born cows largely depends on their live weight, because it is an indicator of the general development and fattening of animals. The results of our research indicate the influence of live weight of animals on their milk productivity. When the live weight of animals at the first insemination increases from 300 to 450 kg, the yield increases by 699.3 kg, milk fat by 28.9 kg, and milk protein by 25.2 kg (P&lt;0.05, P&lt;0.01). The influence of live weight at the first insemination on fertility, the amount of milk fat and protein was 15.1-19.1 %. When studying the dependence of the milk productivity of first-borns of the Ukrainian red-spotted dairy breed on the age of their first insemination, it was established that the cows with the age of first insemination ranged from 16.1 to 18.0 months had the highest fertility, the amount of milk fat and protein. – 6875.8, 266.6, 227.1 kg, respectively (P&lt;0.05). The influence of the age of first insemination on fertility, the amount of milk fat and protein was 5.7-9.5 %. According to the results of own research, it was established that the live weight of first-born cows at the first calving affects their milk productivity. With an increase in live weight to 550 kg, their weight increases by 312.9 kg, milk fat by 11 kg, and protein by 10.8 kg. With an increase in live weight of more than 551 kg, the productivity of cows does not increase, but remains at a high level - 6682.7 kg, 257.1 and 220.1 kg, respectively. Correlation coefficients between live weight at the first calving of cows and their productive indicators were -0.072-0.113. A significant influence of the live weight of the firstborns at the first calving on their fertility, the amount of milk fat and protein (15.3-22.9 %) was established, which proves the need for intensive breeding of repair young. It has been established that the age of first calving of first-born cows affects their future milk productivity. Cows with the age of first calving in the range of 25.1-27.0 months had the highest hope, amount of milk fat and protein. – 6510.2, 252.3 and 217.0 kg, respectively (P&lt;0.05). First-borns with the age of first calving of 29.1–31.0 months were characterized by the lowest indicators of milk productivity. Their weight was 6017.2 kg, the amount of milk fat and protein was 234.7 and 198.6 kg, respectively (P&lt;0.05). The correlation coefficients between the age of the animals at the first calving and their milk productivity were in the range of -0.088–0.240. The influence of the age of the first calving on fertility, the amount of milk fat and protein was 20.7-23.6 %.

Effects of pasture season on the body temperature, steps-taken, and body weight of Japanese black cows

Effects of pasture season on the body temperature, steps-taken, and body weight of Japanese black cows

МАТЕМАТИЧЕСКИЕ ЗАВИСИМОСТИ ДЛЯ ОПРЕДЕЛЕНИЯ РАЗМЕРОВ КОРОВНИКА

When designing new livestock farms, it is important to introduce the proper space-planning solutions in cow barns and technological solutions for major production processes. This task requires the development of mathematical relationships. The study presents the mathematical relationships for determining the dimensions of a cow barn for loose cubicle housing of animals using three options for the location of cubicles (technological modules). Each mathematical relationship takes into account several factors. They include the number of cows in the group; parameters of the technological module depending on the live weight of cows (the dimensions of cubicles and alleys); selection of the width of a feed table, a manure removal channel and a cow traffic alley depending on the adopted technological solutions. Determining the overall barn size makes it easier to compare different options of spatial solutions for the loose cubicle housing in terms of financial costs and animal comfort. It also allows selecting an option best suited for specific farm conditions at the stage of preparing the design assignment (basis). The proposed relationships can be used in designing algorithms of dairy farms.

Estimation of body weight and body condition score in dairy cows by digital image analysis method

In this study the body weight (BW) and body condition score (BCS) of lactating cows was estimated by using conventional (CM) the digital image analysis methods (DIAM). BCS is an important factor to facilitate different practices of management in dairy cattle. A total of 204 Holstein cows live images were taken by remote shutter camera. Six body measurements such as heart girth (HG), wither height (WH), hip height (HH), body length (BL), front hip-width (FHW), and back hip-width (BHW) were used for the assessment of BW and BCS by CM and DIAM. The estimation of CBW using HG, FHW, and BL variables was effective (R2 = 0.75). However, all the body measurements were ineffective for body condition score by measurements (MBCS), (R2 = 0.06, conventional) and DBCS (R2 = 0.05, digital) estimation. The measurements of WH, HG, FHW, BHW, and BL were precise in DBW estimation (R2 = 0.77). No significant differences were found across the assessment methods (CM, DIAM) for body measurements. The intra-class reliability coefficient (ICC) of conventional and digital (MBW, DBW) measurements was “good” and “excellent” between conventional and digital estimations. This study indicates that DIAM is a reliable method for determining DBW and MBW, and can be interchanged effectively with CM.

Breed recognition and estimation of live weight of cattle based on methods of machine learning and computer vision

A method of measuring cattle parameters using neural network methods of image processing was proposed. To this end, several neural network models were used: a convolutional artificial neural network and a multilayer perceptron. The first is used to recognize a cow in a photograph and identify its breed followed by determining its body dimensions using the stereopsis method. The perceptron was used to estimate the cow's weight based on its breed and size information. Mask RCNN (Mask Regions with CNNs) convolutional network was chosen as an artificial neural network. To clarify information on the physical parameters of animals, a 3D camera (Intel RealSense D435i) was used. Images of cows taken from different angles were used to determine the parameters of their bodies using the photogrammetric method. The cow body dimensions were determined by analyzing animal images taken with synchronized cameras from different angles. First, a cow was identified in the photograph and its breed was determined using the Mask RCNN convolutional neural network. Next, the animal parameters were determined using the stereopsis method. The resulting breed and size data were fed to a predictive model to determine the estimated weight of the animal. When modeling, Ayrshire, Holstein, Jersey, Krasnaya Stepnaya breeds were considered as cow breeds to be recognized. The use of a pre-trained network with its subsequent training applying the SGD algorithm and Nvidia GeForce 2080 video card has made it possible to significantly speed up the learning process compared to training in a CPU. The results obtained confirm the effectiveness of the proposed method in solving practical problems.

Relative variability of phenotypic traits and indicators of milk productivity of cows

The research was conducted on cattle of Black-and-White breed (Holstein and Ukrainian Black-and-White dairy breed) at LLC “Veleten” Glukhiv district of Sumy region (n = 1956) and PJSC “Breeding Plant “Stepnoy” of Kamyansko-Dniprovsk district of Zaporizhzhia region (n = 1981). Based on retrospective data analysis (“Uniform-Agri” – program of dairy herd management) for the period from 2004 to 2017 it was studied the live weight of cows in growing period (newborns, 6, 12; 18 months, at first insemination and after the first calving), body measurements of heifers (height at shoulders, chest depth, chest width, chest girth behind the shoulder blades, oblique body length, width of hips, wrist girth) and traits of reproducibility (age at first insemination, age at first calving, duration of service period, insemination index, fertility index) and milk productivity of cows (milk yields for 305 days, fat and protein content in milk for the first, second and third lactation). Based on our previously obtained data by correlation analysis method it was studied the relative variability of phenotypic traits and indicators of dairy productivity of cows. It is established that the connections of live weight of cows during their rearing with traits of milk productivity were multidirectional and ranged from slightly improbable to moderately significant values. At the same time, in both farms, the most significant highly probable connection was noted between the live weight of animals at the age of 12 months and the milk yield of first-borns that indicates the possibility of selecting heifers at the specified age to provide them future high milk productivity. There was significant variability of the relationship between body measurements and the amount of milk yield of cows for the first, second and third lactation. However, cows of both farms, had direct connection, but a bit weaker in animals at PJSC “Breeding Plant “Stepnoy”. Positive correlation coefficients between indicators of exterior and milk yields of cows give reasons to claim the efficiency of indirect selection of heifers by body measurements. Rational management of dairy farming and high profits depend a lot on knowledge of regularities of correlative variability of productive traits of cows and indicators of reproductive capacity. It is established that the connections between the traits of milk productivity and reproductive capacity of animals were different and ranged from weak to medium and from reliable to improbable. The most significant highly reliable, however, with negative correlation coefficients were observed between milk yield of cows for all studied lactations and their age at the first insemination and the first calving

The current state of interbreed types of Ukrainian main dairy breeds

The research was carried out on domestic breeds of dairy cattle, namely the Ukrainian black-and-white dairy cattle with a total breeding stock population of 100778 and the Ukrainian red-and-white dairy cattle - 35270. The material was based on the structural formations (intrabreed types) - Southern (6528 heads in 12 herds), Central-eastern (49001 heads in 69 herds), Western (15746 heads in 19 herds), Polissya (27031 heads in 38 herds) and Sumy (2472 heads in 4 herds), they belong to the Ukrainian black-and-white dairy cattle, and the Central one (23822 heads in 41 herds), South-eastern (8431 heads in 16 herds), Prykarpattia (3017 heads in 3 herds) to the Ukrainian red-and-white dairy cattle. It is established that intergroup differentiation was observed on quantitative and qualitative indicators. Thus, the highest average hopes were observed in cows of the Central-eastern (7640 kg) and the South-eastern (7184 kg) types. In other structural formations, milk productivity ranged from 6012 kg to 6951 kg. Live weight of cows of the Western type is 553 kg, with low amplitude of other types (560 kg… 579 kg). The range of the main components of milk in the studied intrabreed types in terms of fat and protein content is 3,67%… 4,04% and 3,13%… 3,27%, respectively. In each intrabreed type there is a selection nucleus for selection of the best cows and obtaining valuable offspring from them, the analysis of which showed a tendency to increase the milk yield of lactating cows by an average of 457 kg and their live weight - by 11 kg. Also, the main components of milk have a fluctuating level, which does not depend on lactation and intrabreed types, which in turn may indicate inadequate selection for them. According to the analysis of the distribution of cows by calving, a high share of first-borns in the structure of types was noted, which ranges from 27,3% in the Western to 41,2% in the South-eastern types. Key words: breed, intra-breed type, milk productivity, live weight, breeding stock population, herd structure, age of first calving.