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Biomedical subjects

T Dzhankov

Publications and source records attributed to T Dzhankov.

6 recordsLinked to original sources
PubMed1986

[Effect of density during the raising of broilers on their morbidity and mortality].

Studied was the effect of biotic ecologic factors and their dynamic at varying density of raising broilers at equal abiotic factors. The experiments were carried out in two production buildings of the same type. A cage of low density (16.6 birds/m2) was placed on a premise of high density (23.6 birds/m2), and vice versa--a cage of high density (23.6 birds/m2) was placed on a premise of low density (16.6 birds/m2). It was found that density of raising had a definite bearing on both morbidity and mortality rates. At lower density they ranged from 6.84 to 9.74 per cent, and at higher density--from 10.67 to 14.07 per cent, whereupon by the end of the fattening period certain changes were observed in the behaviour of birds (anxiety, inadequate locomotion movements). Diseases that were transmitted transovarially and diseases such as cannibalism affected greater number of birds when these were raised at higher density. It was concluded that density of raising influenced both the abiotic and biotic factors, and its integral effect could be evaluated as that of a stress factor when higher numbers of birds were raised on unit area. This invariably had a bearing on the rates of morbidity and mortality. The approach that has been used so far in optimizing the microclimatic parameters only (at higher density of raising) was shown to be partial as the effectiveness of production is governed by the action of biotic factors as well. This makes it necessary to study their effect.

Animal Husbandry↗
PubMed1984

[Amino acid bioconversion in the feed for broilers under different breeding rates].

Two experiments were carried out under productional conditions with a total of 69 520 broiler birds (four-line hybrids, crosses of White Plymouth Rock x Cornish ) --one in the spring and one in the summer. The birds were grown in a poultry house at density of 16.6 per sq. m. of floor area and in cage at the rate of 23.6 per sq. m. (an enclosure on the same premise). On another premise the birds were kept at 23.6 and 16.6 per sq. m., respectively. Every 15 days the amino acids and the protein were determined in the white meat, and each feed batch was checked as regards its crude protein and amino acid content. It was found that the bioconversion of the amino acids of the feed into amino acids of the white meat was acted upon by a constellation of biotic and abiotic ecologic factors. Dicisive was the effect of the biotic factors. It is stated that the present approach to optimize only the elements of the microclimate at higher rates of broiler raising is insufficient. It is necessary to study the biotic ecologic factors in detail as the base of optimization of the homotypic and heterotypic reactions.

Amino Acids↗
PubMed1984

[Poultry meat production with varying densities in raising the broilers].

Tests were carried out at two densities of raising the broilers on productional premises--16.6 and 23.6 per 1 m2 of flooring. Both the prophylactic programme and the conditions of tending and feeding were one and the same on the premises used. Each one of these was supplied with a cell in which birds were kept at the same density value as that on the other premise. Thus, four groups were formed in all: I--broilers kept at the rate of 16.6 per sq. m, II--broilers raised on the premise at 23.6/m2, III--broilers kept in a cell at 16.6 on the same premise where the other birds were kept at 23.6, and IV--broilers kept at 23.6 per sq. m. on the premise where the rate concerning the other birds was 16.6. The basic integral indices of the production effectiveness as well as the bioconversion of the dietary amino acids were followed up. It was found that during the transitional period the lower productional results with the broilers raised at higher densities were due to the action of biotic factors, and, more specifically, to the changes in the homotypical reactions that were the result of the higher density of raising. In the summer season the pesimal effect produced was a complex one, including not only the biotic factors but also the unfavourable action of the temperature and humidity regime.

Amino Acids↗
PubMed1984

[Evaluation of abiotic ecological factors and their dynamics at various densities in raising broilers].

Three productional experiments were carried out in which the broilers were kept on unified premises under one and the same technology, but at various densities of raising: 14.4 and 23.4/sq. m., and 16.6 and 23.6/sq. m. with the second and third experiment. The dynamic, light intensity, and content of toxic gases along with the homogenization of air in the birds' vital zone were followed up. Differences were established which were defined by the higher density of raising, and which, acting as a constellation on the organism might lower the effectiveness of the technologies employed.

Air↗
PubMed1982

[Effect of population density during raising on amino acid levels in the serum and various organs of broilers].

Experiments were carried out on a productional premise of controlled microclimate. Broilers were raised under one and the same conditions of keeping and feeding at two density values - 14 and 22 birds per 1 m2 of the flooring area. The level of amino acids was followed up in the blood serum, liver, and the red and white muscles of the broilers of the two groups. It was found that at higher rates of population (22 birds per 1 m2) the biotic-ecologic factors were influenced the integral effect being the activation of catabolism of proteins in the body of birds. At higher density the amount of amino acids in these organs was found to drop, changes being observed also in the amino acid profile. Nitrogen in the feed was also influenced positively in terms of its conversion into amine nitrogen.

Amino Acids↗