E- Global Congress Hosted online from Dubai, U. A. E., E - Conference. Date: 30th May, 2023 Website: https://eglobalcongress.com/index.php/egc ISSN (E): 2836-3612 7 | P a g e CHANGES IN AGE DYNAMICS OF LIVE WEIGHT OF CHICKS BELONGING TO THE CROSS LOHMANN BROWN-CLASSIC AND LOHMANN SANDY Alimbaev B.K. Doctoral student of Karakalpakstan Institute of Agriculture and Agrotechnologies Annotation Changes in live weight-age dynamics of chicks belonging to the «Lohmann brown-classic» and «Lohmann sandy» crosses from the 1st day to the 80th week were studied, analyzed according to absolute growth indicators, and conclusions were given. Keywords. Cross, live weight, absolute growth, age dynamics INTRODUCTION Until the years of independence, poultry products were mainly brought to our country from abroad, but today, after gaining independence, the need for poultry products is sufficiently provided by the entrepreneurs of our country. The system of production of chicken meat and egg products for the consumption of our people is further developing on the shelves of our domestic markets. Poultry is one of the priority branches of the livestock sector, it is worth mentioning that the demand for poultry eggs and meat is high, and the product is inexpensive. In recent years, attention to poultry farming, mainly meat and eggs, has increased in our country. On the direct initiative of our government, a number of benefits were granted to the network. We are happy to say that our government has adopted the decision of our President No. PQ-4015 of November 13, 2018 on “Additional measures for the further development of poultry farming” and the President of Uzbekistan's decision of June 14, 2021 Decisions No. PQ-5146 “On additional measures aimed at the development of poultry farming and strengthening of the network's feed base” serve as a priority basis for the future development of this sector. In accordance with these decisions, priority tasks for the development of the poultry industry in order to provide all-round support for the further development of poultry farming in the Republic, to introduce advanced technologies and innovative developments in the sector, to expand the processing of poultry https://eglobalcongress.com/index.php/egc E- Global Congress Hosted online from Dubai, U. A. E., E - Conference. Date: 30th May, 2023 Website: https://eglobalcongress.com/index.php/egc ISSN (E): 2836-3612 8 | P a g e products, and to increase their types and export volume have been defined. Now it is planned to establish poultry clusters in all regions covering poultry breeding, its processing, final product preparation and its delivery to the consumer. The purpose of the study. Poultry breeding in farm conditions is to determine the live weight and absolute growth parameters of birds belonging to the prospective “Lomann Brown-Classic” and “Lomann Sendi” crosses in the dynamics of their age. Tasks of research. Live weight parameters of chicks obtained from promising “Lomann Brown-Classic” and “Lomann Sandy” crosses were determined depending on the dynamics of age, keeping, care, and feeding. Research object. The live weight of the birds obtained from the prospective “Lomann Brown Classic” and “Lomann Sendi” crosses kept at the “Nurummat Kurbanov” farm, Ellikal'a District, Republic of Karakalpakstan. Research subject. It is a study of the influence of the level of feeding on the growth, development, and differentiation of birds belonging to different crosses. Research methods. Zootechnical, biological and statistical. Research results. Today, the provision of protein-rich poultry products is promising, and the implementation of chicken crosses with the involvement of low-cost technologies in the rapid breeding of chickens based on templates remains one of the urgent issues. Step-by-step reforms in the development of poultry farming are having a positive effect. It is one of the important tasks to fully satisfy the demand of the population of our country for chicken eggs and meat. In order to ensure food safety and stabilize it to a certain extent, long-term programs and projects have been developed in our country, and specific tasks have been defined in this regard. Due to the consistent implementation of state programs in this field, reforms in poultry farming, a solution to the food problem in our country will be found to some extent. https://eglobalcongress.com/index.php/egc E- Global Congress Hosted online from Dubai, U. A. E., E - Conference. Date: 30th May, 2023 Website: https://eglobalcongress.com/index.php/egc ISSN (E): 2836-3612 9 | P a g e Studying the growth and development patterns of different breeds of poultry is of great economic value, the reason is to know the periods of rapid growth, the poultry is to a certain extent exposed to external factors and breeding activities. shows the effect of z. All biological characteristics of birds are determined by heredity, but the extent and quality of their manifestation is related to the conditions of keeping in the course of individual development. There are still conflicting interpretations and details of the concepts of growth and development of the avian organism, because many studies in these processes require clarification. [1; 287-b]; according to his opinion, the development process of the organism is presented as a set of quantitative and qualitative changes in the cells of tissues and organs that occur as a result of the constant interaction of the organism and the environment. [2; 331-334-b]; according to his data, he explains growth as one of the important factors of formation and concludes that development is the accumulation of quantitative changes that lead to the emergence of qualitatively new differentiations. The rapid increase in live weight of chickens depends on several factors, first of all, it depends on the feed ration. It is observed that the live weight of chicks increases rapidly if the feed composition is balanced with nutritious substances. By adding macro- and micro-elements, vitamins and enzymes to the ration, research works are being carried out by the scientists of the field to increase the satiety of the ration and, at the same time, to reduce the cost of feed. Experiment The results of determining the live weight of “4-line” “Lohmann brown-classic” and “Lohmann sandy” chicken crosses in the dynamics of age at the farm “Nurummat Qurbanov” located in the Ellikkala district of the Republic of Karakalpakstan are presented in Table 1 below. The data of Table 1 shows that the growth and development of the chicks of both crosses in the experiment was not uniform over the weeks. “Lohmann brown- classic” cross has a live weight of 266,7 grams at the age of 4 weeks, while “Lohmann sandy” cross has 248,7 grams, that is, “Lohmann brown-classic” cross has a live weight of 18 compared to “Lohmann sandy” live weight. gram prevailed. Live weight of chicks increased to 61,6 grams in the 12th week, 62,3 grams in the 16th week, and 51,3 grams in the 20th week. In the dynamics of the https://eglobalcongress.com/index.php/egc E- Global Congress Hosted online from Dubai, U. A. E., E - Conference. Date: 30th May, 2023 Website: https://eglobalcongress.com/index.php/egc ISSN (E): 2836-3612 10 | P a g e age of the chicks, it is necessary to protect them from any external influences, not distribute the feed uniformly, and ensure that the supply chain of the feed is long, especially in the first four weeks. “Lohmann brown-classic” chickens at the age of 80 weeks had a live weight of 1893,9±16,47, and compared to the 1st day period, they had 1854,7 grams of absolute growth, while "Lohmann sandy" in crossbred chickens, this indicator was 1649,9 grams. Table 1 Changes in the live weight of chicks in the age dynamics of the experimental Lohmann brown-classic and Lohmann sandy crosses, grams. Age, day and week Crosses Lohmann brown-classic Lohmann sandy (n=20) (n=20) X±Sx Cv % X±Sx Cv % 1st day 39,15±0,24 2,78 35,85±0,24 3,03 1st week 70,75±0,46 2,92 67,45±0,40 2,70 4th week 266,75±0,70 0,70 248,7±1,053 1,89 8th week 674,1±1,17 0,77 615,25±0,86 0,63 12 weeks 1017,8±1,27 0,55 956,2±1,18 0,55 16th week 1219,1±1,17 0,42 1156,8±1,32 0,51 20 weeks 1429,25±0,80 0,25 1377,95±0,82 0,26 30 weeks 1695,65±11,12 2,93 1616,7±9,39 2,59 40th week 1746,2±15,67 4,01 1645,2±10,78 2,93 50 weeks 1781,9±16,01 4,02 1663,15±9,53 2,56 80th week 1893,9±16,47 3,88 1685,75±8,32 2,20 “Lohmann brown-classic” crossbred chickens dominated by 11,1% in the difference between both crossbred chickens. In conclusion, it can be said that among the crosses, “Lohmann brown-classic” chickens have an advantage over “Lohmann sandy” chickens in the same feeding conditions, and the level of feed coverage is high (Fig. 1) is distinguished by In our experiments, the age dynamics of chicks (Fig. 1) was measured by weighing and recorded in a notebook. https://eglobalcongress.com/index.php/egc E- Global Congress Hosted online from Dubai, U. A. E., E - Conference. Date: 30th May, 2023 Website: https://eglobalcongress.com/index.php/egc ISSN (E): 2836-3612 11 | P a g e The absolute and daily growth indicators of poultry indicate the extent of their development and acceleration. The absolute and daily growth of chickens changes in the dynamics of their age within a certain period, which, above all, allows us to cover the feed with products and keep the feed at a moderate level. Absolute and daily growth indicators are considered indicators of feed consumption, that is, feed conversion. The absolute growth indicators in our experiments are presented in Figure 1 below. Figure 1. Absolute growth of chicks belonging to the Lomann brown-classic and Lomann centi crosses, grams From the data presented in Figure 1, it can be said that if the 1st-week chicks had the same live weight, by the 4th week, the "Lohmann brown-classic" crossbred chicks had an absolute growth. indicator was 196.0 grams, and this indicator was 181.25 grams in chicks belonging to the "Lohmann sandy" cross, chicks of the first cross prevailed by 14.8 grams. Summary 31.6 181.5 366.6 340.9 200.6 210.5 238.7 28.5 17.9 22.6 31.6 196 407.5 343.7 201.3 221.5 266.4 50.5 35.7 112 1 S T W E E K 4 T H W E E K 8 T H W E E K 1 2 W E E K S 1 6 T H W E E K 2 0 W E E K S 3 0 W E E K S 4 0 T H W E E K 5 0 W E E K S 8 0 T H W E E K II-Lohmann sandy I-Lomann brown-classic https://eglobalcongress.com/index.php/egc E- Global Congress Hosted online from Dubai, U. A. E., E - Conference. Date: 30th May, 2023 Website: https://eglobalcongress.com/index.php/egc ISSN (E): 2836-3612 12 | P a g e Keeping this tendency in the dynamics of the age of chicks, the absolute growth indicators from the 4th to the 8th week of the first group were 407.35 grams, which prevailed by 7.5% compared to the second group. By the 50th week, it was 43.6% higher, making 50.55 grams. LIST OF USED LITERATURE 1.Sarokin V.V “Gigiena soderjanie ptitsi” //j. Ptitsevodstvo №4. Moscow. 1998 p.212-217. 2. Furforo M., Robbo F., Russo M. et all. Le Immunoglobuline IgA, IgM, IgG nella popolazine scolastica della provincia di Savona. -Minerva Pediat., 1979, Vol. 31, N5, p. 331-334. 3. https://webferma.com/pticevodstvo/kuri/porodi/crosses/loman-braun-dlya- podvorya.html https://eglobalcongress.com/index.php/egc https://webferma.com/pticevodstvo/kuri/porodi/crosses/loman-braun-dlya-podvorya.html https://webferma.com/pticevodstvo/kuri/porodi/crosses/loman-braun-dlya-podvorya.html