Formation of exterior features in technological conditions of traditional keeping and feeding of Chinese Holstein cows

. By importing superior breeds, strengthening the breeding foundation, and showcasing the breeding and productivity potential, it is crucial to expand the output of animal products. Strengthening the foundation for cattle breeding and boosting cow output are crucial now in Uzbekistan. In the article, the appearance, development of characteristics, productivity and biological characteristics of Chinese Holstein cows in traditional technological storage and feeding conditions were studied. Farm storage methods, feeding types and standards, and Chinese Holstein cows were taken as an experimental object. Experiments were conducted on bulls with genotypes characteristic of different bull systems and cows of II-genetic-ecological generation. he feeding of Chinese Holstein cows during lactation consisted of 57.1-57.5% juicy feeds, 32.4% concentrate feeds, and 10.1-10.4% coarse feeds, which positively impacted their productivity. The importation of improved breeds to new habitats involves adaptation to varying natural-climatic, storage, and feeding conditions, which ultimately reveals their potential for productivity and breeding.


Introduction
It is important to increase the production of livestock products, to strengthen its breeding base by importing improved breeds, demonstrating the potential of breeding and productivity [1][2][3]. Today, in Uzbekistan, strengthening the cattle breeding base, increasing the breeding and productivity of cattle is of great importance [4][5][6].
Ensuring food security by increasing the production of livestock products in the country, wide introduction of modern methods of production, thereby creating an added value chain, developing cooperative relations, state support of the livestock industry and its branches, as well as modern information in this area in order to organize effective use of communication technologies and scientific achievements [4][5][6][7]. Decision PQ-120 of the President of the Republic of Uzbekistan dated 08.02.2022. It serves to a certain extent in the implementation of the tasks defined in the decisions on the program for the development of the livestock sector and its branches for 2022-2026 in the Republic of Uzbekistan and the regulatory and legal documents related to this activity [1][2][3]. In the following years, the breeding stock of improved Holstein, Swiss and Flegfix Simmental breed was imported by the farms from Germany, Holland, Austria, Slovenia, Poland, China and many other countries, bred in pure condition and effective results were achieved.

Materials and methods
The conventional technological practices of cattle keeping and feeding in farms have been prevalent in the collective farms of the republic for several decades. These methods involve tying the cattle within the buildings and releasing them in the fields, feeding them primarily with green grass during the summer season and roughage and juicy feed during the winter [7][8][9]. The cow shed, built with a concrete structure, has been designed to house 120 cows in four rows. The building spans 110 meters in length and 20 meters in width, and includes two feeding lanes that are wide enough to accommodate a tractor (220 cm). On both sides of the feeding lanes, four concrete feeding mangers have been installed with an upper width of 60 cm, a lower width of 40 cm, and a width of 160 cm for each individual cow's living space, which measures 190 cm [4][5][6][7]. Automatic drinking bowls are placed between each cow, and special manure channels (50 cm wide and 20 cm deep) have been constructed at the rear of the cow storage areas [5][6][7]10].
To facilitate milking, a milker aisle (100 cm wide) is left at the rear of each cowshed row. The cows are milked three times a day using special individual portable devices in their tied places, at 5-7 in the morning, 13-14 at noon, and 17-19 in the evening. The lighting inside the building is optimized according to the project, and four high and wide iron gates have been installed at the beginning and end of the tractor walkways [6][7][8][9]. These gates are closed in winter and opened in summer to regulate the temperature and ventilation inside the building.During the optimal periods of summer and winter days, it is important to allow the cows to graze and feed in open fields, which has a positive effect on their health and performance [7]. Areas for feeding under the canopy and distribution of feed in transport are organized in the open areas of the production. Cattle can eat feed under awnings (green grass in summer and roughage and juicy feed in winter) whenever they want and move and rest in open areas as they wish [6][7][8][9][10]. The feeding corridor measures 220 cm in width, the concrete mangers are 60 cm wide, and the feeding areas are covered with concrete and asphalt, with a width of 300 cm. Light type awnings protect cattle from solar radiation and air humidity, and large iron buckets are installed for watering the cows with cold water [5][6][7]. The production of open fields corresponds to one cow for every 20 m2, and a lick of table salt is placed in mangers in open areas. In summer, cows are bathed in a special 2.5% solution of "Ectovate 60%" anti-mite liquid once every 15 days. The technological methods of storage and disease control measures implemented in open fields have a positive impact on the behavior of cows and help protect them from diseases [4][5][6][7]9].

Results and discussion
It is known that the productivity genetic potential of cows is manifested depending on the rate and type of feeding. The factors that influence milk productivity of cows can be attributed to 55-60% of various factors. With this in mind, a feeding program and standard for Holstein cows were developed, which demonstrated a positive effect (Table 1). The feeding rations for cows in experimental groups were formulated based on their lactation phases, with specific attention given to cows during days 10-100 of lactation to maintain high milk yield from days 101-275 and gradual weaning during the last 30 days of lactation. In order to achieve higher milk yield, the cows were given a greater quantity of A.P. Kalashnikov than the generally accepted feeding rate, and long-term sedation measures were taken as a result (Table 2).   In accordance with established practices in developed countries, feeding rations for cows have been established based on the months and days of long-term lactation, taking into consideration the negative effects of rapidly changing the composition of the diet. These rations include farm-grown blue mass, hay, silage, and haylage, as well as commercially available concentrate feeds such as bran, meal, mixed feed, and bar. Notably, Dutch and German Holstein cows' breeding experiments use high "advance" feeding standards. During the weaning period of cows, juicy feeds constitute 53-59%, concentrate feeds make up 34-37%, and coarse feeds make up 12-14% of their diet (Table 3). Various measures were employed in the feeding of cows during the lactation period, such as increasing the ratio of satiety to maintain milk yield from days 101-275 of lactation compared to days 10-100 of lactation. During the last 30 days of lactation, satiety norms were reduced, and the amount of juicy feed was decreased while the amount of coarse feed was increased. The winter diet of Holstein dairy cows has a positive effect on increasing milk production, thanks to its nutritional content. Feeding rations for dairy cows in the summer period are also highly nutritious. Alfalfa grass was added to the summer ration to increase the amount of dry matter, and it was mixed with barda and distributed in a mixture, as per the specified feeding norm.
For every kilogram of concentrate given to cows, they produce 300 grams of milk. In the feeding plan, cows are provided with 60-63% of their diet in the form of blue grass and bar, and the remaining 33-38% is given in the form of concentrates.
The amount of feed given to dairy cows during winter and summer was calculated based on their consumption. As the calving periods of cows occurred during different seasons, their lactation periods coincided with either the winter or summer feeding periods. Accordingly, blue mass, silage, hay, straw, and concentrate feed were provided to the cows, as indicated in Table 4. The female bulls in the experimental groups received feed with the same nutritional value, as observed in their dry matter (5827-5836 kg), nutritional unit (5366-5371), exchangeable energy (58339-58437 Mj), and amount of digestible protein (671-690 kg). Although there was a difference in the amount of nutrients consumed during winter and summer, their nutrition was equivalent to the same amount. The feeding of Chinese Holstein cows during lactation consisted of 57.1-57.5% juicy feeds, 32.4% concentrate feeds, and 10.1-10.4% coarse feeds, which positively impacted their productivity. The importation of improved breeds to new habitats involves adaptation to varying natural-climatic, storage, and feeding conditions, which ultimately reveals their potential for productivity and breeding. To optimize the genotype-environment interaction, we examined the productivity and reproductive qualities of Chinese Holstein cows imported to the hot climate of Uzbekistan under traditional storage and feeding conditions. We studied the development of cows in different lactation ages, external characteristics, milk yield qualities, live weight, and manifestation of milk yield. The live weight changes of imported cows in Uzbekistan were comparable to those in other studies, with the live weight of cows in their first lactation ranging from 482.3-551.0 kg and the live weight of cows in their third or higher lactation ranging from 528.4-570.4 kg.
The growth rate of the live weight of Chinese Holstein cows was found to be the same under the hot climate and feeding conditions of Uzbekistan. In our study, we assessed the live weight of Chinese Holstein cows in the I-genetic-ecological generation and their daughters in the II-genetic-ecological generation during the I-lactation. We found that the development of the cows raised in the warm climate of Uzbekistan was comparable to that of their mothers. The average live weight of mothers during their first lactation was 484.5 kilograms, while their daughters' weight (n=16) was 476.1 ± 6.86 kilograms, showing a difference of 8.4 kilograms or 1.8%, which is not statistically significant. The live weight of some cows in the II-genetic-ecological generation ranged from 547 to 630 kilograms.
In addition, we evaluated the characteristics of the cows' exterior and identified the qualities typical of the breed by measuring the body dimensions of cows in the I-genetic-ecological generation during their III-lactation and cows in the II-genetic-ecological generation during their I-lactation, as shown in Table 5. Table 5. Body measurements of Chinese Holstein cows, cm.

Body measurements
Cows of the I-geneticecological generation in the III-lactation (n-11) Cows of II-geneticecological generation in Ilactation (n-10)

Conclusions
The results of the study indicate that Chinese Holstein cows demonstrated consistent productivity characteristics in both summer and winter feeding under highly nutritious juice and concentrate-based diets. Moreover, they exhibited normal physiological conditions even after adapting to the hot climate conditions in Uzbekistan. Additionally, their offspring in the II-genetic-ecological generation displayed high productivity and adaptability to the conditions, thereby forming a breeding reproductive farm. By maintaining Chinese Holstein cattle under traditional storage and feeding conditions, it is possible to fully utilize their productivity genetic potential, especially in the I-II geneticecological generation.
It was reported that Chinese Holstein cows imported to Uzbekistan showed high productivity and adaptability to the hot climate and feeding conditions. The live weight growth rate of the cows was similar to that in other studies, and the live weight of cows in their first and higher lactations was comparable to those in other regions. The study also found that the development of cows raised in Uzbekistan was comparable to that of their mothers, and the daughters in the II-genetic-ecological generation showed high productivity potential. Overall, the study suggests that Chinese Holstein cows can be successfully maintained and bred in Uzbekistan under traditional storage and feeding conditions.