Efficiency of using high-protein soybean meal in feeding broilers of cross-breed ROSS-PM3

. The use of high-protein soybean meal in broiler diets provided for 38 days of fattening obtaining live weight of 2,336 g, average daily gain in live weight of 60.4 g, which is higher than in the control group by 135 g and 3.5 g, respectively. The highest rates were observed in chickens that consumed compound feed with high protein soybean meal, which was characterized by a high content of crude protein (47.0%) and good protein solubility (77.8%). It is proved that the use of soybean meal with a high content of SP - 47.0% versus 42.0%, increases the live weight of chickens and reduces feed costs per 1 kilo of live weight gain.


Introduction
To actualize the genetic potential of modern broiler crosses, more and more demands are placed on the quality of the components that make up the compound feed [1][2][3][4]. The leading place among them is occupied by soy and sunflower meal.
The richest sources of essential amino acids, of course, are animal sources of protein. Today, the production of animal and vegetable proteins is 68 million tons per year, including 5.3 million tons of animal protein [5].
Due to the high price, components for the preparation of animal feed with animal protein are very often falsified, so in practice most diets for poultry, especially parent flocks, are composed mainly of plant sources of protein.
The biological value of such diets is increased by enrichment with synthetic amino acids [6,7].
Protein of animal origin is more complete due to the wide variety and better ratio of amino acids, their greater bioavailability compared to protein of plant origin, but it is more scarce and expensive.
At present, quite a lot of research has been carried out to study the feeding of poultry by various diets in order to reduce, up to the complete exclusion, protein of animal origin and replace it with vegetable, provided that the biological value of the diets is preserved [8][9][10].
However, the question of optimal sources of vegetable protein in diets for broiler chickens is not well understood. Therefore, the study of this issue is relevant and important in theoretical and practical terms.
The purpose of these studies was to study the zootechnical and economic indicators of broiler chickens growing when they are fed compound feed with high protein soybean meal produced by Sodruzhestvo LLC, and its comparative assessment with a meal from another manufacturer.
The content of crude protein in the meal of LLC Sodruzhestvo was 47.0%, in the meal of LLC Ussuriysk it was 42.0%.

Materials and methods
The studies were carried out in 2018 in the conditions of JSC "Lindovskaya Poultry Factory -Breeding Plant" on broilers of the ROSS-PM3 cross from Day 1 to Day 38 of fattening.
The birds were kept in the same type of housing with equipment for feeding broilers in Russian-made cages 2B-3. The temperature and humidity conditions, the front of feeding, watering, and also the bird density were the same in the control and experimental groups and corresponded to the recommendations of VNITIP and manufacturers of the ROSS PM3 cross [11].
In four experimental groups there were 70347 goals, and in four control groups -70208 heads of broiler chickens. Broilers were fed granular compound feed with nutritional value according to the norms of the crosspoultry feed manufacturer. Up to 10 days of age, broilers consumed starter feed, from 11 to 24 days -a grower, then up to 38 days -a finisher. The experimental design is presented in Table 1.
The diet composition of the experimental and control groups is presented in Table. 2. Table 1. Experiment design.

Group
Feeding Features Control The main ration with the introduction of soybean meal produced by Ussuriysk LLC Primorsky Krai Experimental The main ration with the introduction of soybean meal produced by LLC Sodruzhestvo Kaliningrad Feeding chickens up to 10 days of age of high protein soybean meal as part of the starter contributed to an increase in their live weight by 1.9%. At 24 days and 38 days of age -by 4.8% and 6.1%, respectively. When using high-protein soybean meal in the experimental group, the average daily gain in live weight was 60.4 g in total, and was higher than the control by 6.1%. The increased increase in live weight ensured its best conversion. For the entire period of fattening, the cost of feed per 1 kg of increase in live weight in the experimental groups was 1.80 kg, and in the control -1.87 (or which is 3.9% less than in the control). The diets of the experimental and control groups were similar in composition, with the exception of soybean meal. Since a higher protein meal was used, this allowed to reduce the input as the meal itself -by 5.1% for the starter, by 2.2% for the grower and by 0.5% for the finisher, as well as the essential amino acids-lysine -by 33, 3% for the starter, 60.0% for the grower and 50.0% for the finisher, methionine -100, 66.6% for the starter and grower, respectively, threonine -25.05% for the starter, 16, 6% -for grower and finisher. The composition of the diet for the control groups are shown in table 2. A decrease in the intake of soybean meal in the diet in the control group did not adversely affect its nutritional value. Nutritional rations for the experimental and control groups are given in tables 4 and 5, respectively.  Table 6 presents the zootechnical indicators of broiler fattening using high protein soybean meal.

Conclusion
Thus, the introduction into the broiler diets of high protein soybean meal produced by Sodruzhestvo LLC at all stages of feeding increases the productivity of the livestock, improves feed conversion and the use of nutrients. So, the live weight of broilers upon completion of fattening in the experimental group was higher than the control by an average of 135 g, while reducing feed costs by 70 g per 1 kg of gain in live weight. In addition, the introduction of this meal in broiler diets at different stages of fattening can reduce the input of synthetic amino acids into the diets.