Indicators of meat productivity of turkeys of various crosses

In the raw material zone of baby food producers in the Krasnodar Territory, a large Ermakov farm supplies turkey to the Branch “Plant of canned meat for children Tikhoretsky JSC “Danon Russia”. According to the results of the slaughter of five-month-old turkey of two crosses, White broad-breasted and Hybrid Converter, high indicators of meat productivity were established: slaughter yield (81.2 and 85.0 %), yield of meat suitable for baby food 62 % and 65 % , the yield of white breast meat 23 and 25 %, respectively, for the White broad-breasted and Hybrid Converter crosses. In terms of meat yield from five-month-old turkeys, the advantage of the Hybrid Converter cross has been proven. On the basis of the studies carried out, it can be concluded that the meat of the turkey of the White broad-breasted and Hybrid Converter crosses have a high biological value in terms of chemical and amino acid composition.


Introduction
The market demand for lean turkey meat determines the great potential for increasing the production of dietary poultry meat [1]. According to BusinesStat estimates, from 2015 to 2020, sales of turkey meat in Russia increased by 40 % [3][4][5]. The rearing of young turkeys for meat deserves serious attention [6]. With relatively low costs in the industrial and farm conditions of the Krasnodar Territory, it is possible to fully satisfy the demand for dietary meat and produce baby food products from the meat of the best adapted crosses.
Most pediatricians recommend the inclusion of turkey meat in the diet of children at an early age (8-10 months) as one of the first foods because of the high levels of protein, haem iron and zinc in muscle tissue [4]. Turkey meat is rich in vitamin B12, folic acid, selenium, potassium, magnesium, iron, phosphorus. The recommended daily (or dietary) allowance (RDA) for selenium for adults is 0.055 mg / day, while the WHO and FAO have set the daily tolerated dose at the rate of 0.4 mg / day [7].
In the United States, meat turkeys are distinguished depending on the age and degree of calcification of the keel bone (sternum). Slaughter weight is reached within 84 -140 days, depending on gender and season. Males and females are raised separately [8].
Turkey meat in the Krasnodar Territory is produced all year round, and this can become an important source of increasing meat production and expanding its range. Although the turkey has a longer period to reach marketable condition compared to broiler chickens, in retail trade, turkey meat is twice as expensive.
White broad-breasted turkeys dominate in our region. They are characterized by excellent meat qualities, high maturity and egg production, good presentation of carcasses. This bird was highly regarded in Russia and became one of the most widespread. At present, manufacturers consider Big-6, Byut-8, and Canadian broad-breasted, Moscow bronze, White broad-breasted and Hybrid converter crosses the best for growing for meat. The Canadian Hybrid Converter is a medium-heavy cross with high productivity in a variety of keeping conditions. The cross Hybrid Converter is based on a bronze broadbreasted, as well as a white Dutch turkey. The hybrid is characterized by unpretentiousness, vitality and endurance.

Research methodology
The objects of research were turkeys of two medium crosses Hybrid Converter and White broad-breasted.
The main purpose of our research was to study and compare the meat productivity of the Hybrid Converter and White broad-breasted turkeys at the optimal age of their sale for meat.
Subjects of research -composition and nutritional value of the diet, feed consumption per 1 kg of live weight gain, dynamics of live weight, meat productivity, morphological composition of the carcass, chemical composition and energy value of meat, meat safety indicators in accordance with the standard requirements for baby food [SSRF 52820-2007].
The biochemical composition of meat samples was investigated in the laboratories of the Argus test center of the Krasnodar Research Centre for Animal Husbandry and Veterinary Medicine. The mass fraction of moisture was determined by drying the sample according to the standard procedure. Protein mass fraction -by the Kjeldahl photometric method, fat mass fraction -using a Soxhlet extraction apparatus; mass fraction of ash -by ashing; the mass fraction of calcium -by the method of flame atomic absorption spectroscopy; mass fraction of phosphorus -by spectrophotometric method. The energy value of turkey meat (E kcal / 100 g of meat) was calculated by the formula (1): E = 4.0 P + 9.0 F + 4.0 C (1) B -Is the mass of protein, g / 100 g of meat; F -mass of fat, g / 100 g of meat; C -mass of carbohydrates, g / 100 g of meat. The coefficients for proteins, fats and carbohydratesare 4.0; 9.0; 4.0.
The Ermakov farm (Kopanskoy khutor, Krasnodar Territory) supplies turkey to the Branch "Factory of children's canned meat Tikhoretsky JSC "Danon Russia ". Scientific and economic studies to study the meat productivity of turkeys of two crosses were carried out in accordance with the experimental scheme (Table 1, Fig. 1).  One control and one experimental group of one-week-old turkeys vaccinated against Newcastle disease were formed using the method of analog pairs. The birds were kept in identical conditions of a standard room in separate sections of 50 heads for each group, separated by a net for 25 males and 25 females. The turkey chicks were kept without a run in a dry room, without drafts, on open dry ground, with a replaceable straw bedding (  Feeding and drinking took place self-pecking from semi-automatic feeders and conical hanging drinkers. The feeding ration in the experiment was a standard compound feedgroats and granules according to the periods of growth and fattening (start; growth; finish ( Table 2).
The diet is nutritionally complete in relation to the needs of turkeys (NRC, 1994) and meets safety requirements for baby food.
In our diet, the content of methionine, which plays an important role in the enrichment of meat with selenium, is 30% higher than the recommended norms. The increased methionine content in the diet, exceeding the NRC (1994) recommendations by 50 %, resulted in higher meat productivity, but reduced the pH and dry matter content to 21 % [1].
At the age of five months (154 days), after 6 hours of starvation, a control slaughter was carried out for birds with a live weight as close as possible to the average for the group (15 ♀ and 15 ♂ from each group, n = 30). Cutting and boning of gutted turkey carcasses was carried out according to the standard methodology of the All-Russian Research Institute of the Poultry Processing Industry. We determined: live weight, carcass weight, slaughter yield, chemical composition of meat, quality characteristics of turkey meat, including the muscle and bone index -the ratio of muscle tissue without skin to bone and the ratio of muscle tissue with skin to bone, safety (the content of residual amounts of toxic substances of a technogenic and biological nature). When studying the chemical composition of compound feeds of the ration, their high nutritional value was established (Table 2).

Research results and discussion
In the period from the beginning of the experiment for 3 months, in the first group, the daily live weight gain was 79.0 g for females, 105.0 g for males. In the second group, the live weight gain of the Hybrid Converter was 101.0 and 136.0 g respectively.
From three to five months in the first group, the daily live weight gain was 64.0g for females, 140.0 g for males. In the second group, the increase in live weight of the Hybrid Converter was 64.9 and 186.0g, respectively. Thus, the daily live weight gain of the birds under the age of three months was 30 times more intense in comparison with the growth rate from 3 to 5 months (Table 3). The feed consumption for the entire experiment period per head in the first group was 28.5 kg for females and 37.9 kg for males. In the second group, the feed consumption per experiment per head for females and males was 28.6 and 43.9 kg, respectively. Feed consumption per 1 kg of live weight gain was 2.6 and 2.1 kg for females and males of the first group, and 2.2 and 1.9 kg for the second group. According to the authors' data, for Big-6 turkeys, the average feed conversion rate was 2.8 [9]. Turkeys of the Hybrid Converter cross also surpassed the White broad-breasted cross in terms of Pre-slaughter weight -by 30.6; the weight of a semi-gutted carcass -by 36.7; slaughter yield -by 3.8 %; gutted carcass weight -by 38.3 %. Breast with skin and bone accounted for 34.5 and 37.2 % in gutted turkey carcasses of the White broad-breasted and Hybrid Converter crosses, respectively (Table 5). Note: * -p <0.05 In general, the results of anatomical dressing showed that males and females of the Hybrid Converter had higher slaughter rates. The morphological composition of the carcasses of females and males of two crosses was assessed in terms of the yield of edible and inedible parts, as well as the meat-and-bone index for carcasses and the muscle-bone index for carcasses and breasts (Tables 6 and 7). The morphological analysis of carcasses and the indices for assessing the meat qualities of the studied crosses indicate a significant advantage of the Hybrid Converter cross in terms of such indicators as gutted carcass weight, flesh, meat (see Tables 6, 7). The chemical composition of the total minced meat from white and dark meat of males and females (for the production of canned baby food) is shown in Table 8. In the total minced meat from the carcasses of males and females of the White broadbreasted and Hybrid Converter crosses, the fat content amounted -8.73 ± 0.02 and 7.29 ± 0.01%, respectively. In the total minced white and dark meat of males and females of the Hybrid Converter cross, suitable for the production of canned food for children, there is 7.7% more protein mass fraction compared to the White broad-breasted cross. However, according to other authors [7, 10 -17], the average mass fraction of protein in turkey meat (16.87%) was significantly lower than in our experiment (22.15 ± 0.03 and 23.87 ± 0.03 g / 100 g of natural meat) for crosses White broad-breasted and Hybrid Converter, respectively  [9]. The need for digestible protein, primarily for essential amino acids, is higher in a child's body than in an adult [4]. The results of research on the protein value of total minced meat from white and dark meat of the White broad-breasted and Hybrid Converter crosses showed that it is optimally balanced in terms of amino acids (Table 9). Table 9. Amino acids and quality indicators of total minced meat protein from natural white and red turkey meat of two crosses, g / kg (n = 12). The amino acid rate relative to the ideal protein for young children (FAO WHO) is higher than 82 %, with the exception of leucine (in the meat protein of two crosses, the leucine deficiency is about 30 %). The amino acid rate of tryptophan is set at 100 %, and that of lysine, histidine, and methionine is more than 100 % ( Table 10). Studies of samples of total minced meat of the cross White broad-breasted and Hybrid Converter showed that the residual amounts of toxic substances of a technogenic and biological nature, antibiotics, pesticides and toxic microorganisms, are at the lower permissible levels and detection limits (Table 11).  When studying the microelement composition of the meat of turkeys of two crosses, it was found that in terms of the content of macro-and microelements, it corresponds to the needs of the child's body in macro-and microelements (Table 12). Note: * -p <0.05* An increased content of the essential microelement selenium was found in the turkey meat of the White broad-breasted and Hybrid Converter crosses 0.32 ± 0.02 and 0.35 ± 0.01 mg / kg, respectively. The permissible level of selenium in raw meat for baby food has not yet been regulated. The selenium requirement for a child under 1 year old is 0.012 mg / day; 1-3 years -0.015 mg / day; from 3 to 12 years old -0.020 mg / day. Thus, for a three-year-old child, 46 g of turkey meat from the White broad-breasted cross or 43 g of turkey meat from the Hybrid Converter will provide the daily requirement for selenium.

Conclusion
In the raw material zone of baby food producers in the Krasnodar Territory, a large Ermakov farm supplies turkey to the Branch "Plant of canned meat for children Tikhoretsky JSC "Danon Russia". According to the results of the slaughter of five-monthold turkey of two crosses, White broad-breasted and Hybrid Converter, high indicators of meat productivity were established: slaughter yield (81.2 and 85.0 %), yield of meat suitable for baby food -62 % and 65 % , the yield of white breast meat -23 and 25 %, respectively, for the White broad-breasted and Hybrid Converter crosses. In terms of meat yield from five-month-old turkeys, the advantage of the Hybrid Converter cross has been proven. On the basis of the studies carried out, it can be concluded that the meat of the turkey of the White broad-breasted and Hybrid Converter crosses have a high biological value in terms of chemical and amino acid composition. Turkey meat of both crosses had a high protein quality indicator (PQI -7.1 and 7.2), optimal in relation to the need of young children for essential amino acids. In terms of safety indicators, turkey meat of the White broad-breasted and Hybrid Converter crosses met the SSRF 52820-2007 requirements for meat raw materials for baby food.