Search PubMed⌕ Search

Biomedical subjects

R Petkov

Publications and source records attributed to R Petkov.

49 records · Page 3Linked to original sources
PubMed1984

[Microbiological studies of pheasant meat].

Investigations were carried out to establish the total count of aerobic mesophiles and that of coliform bacteria, enterococci, staphylococci, micrococci, and sulfite-reducing clostridia in the meat and internal organs of pheasants that were eviscerated up to 30 and 60 minutes following their killing. It was demonstrated that the total counts of all bacteria mentioned rose 2.8, 2.4, and 2.2 times when studying the meat and viscera of pheasants 60 min after killing as against those found 30 min after killing. Determined was the species composition of the isolated microflora. No Salmonella bacteria, pathogenic staphylococci, and sulfite-reducing clostridia were isolated.

Animals↗
PubMed1984

[Fatty acid content of the lipid fraction of the meat of chickens fed mixed feeds with added bacterial protein].

Studies were carried out to establish the content of fatty acids in the lipid fraction of the meat of birds that were given combined feeds with the supplement of bacterial protein. A Perkin Elmer gas chromatograph with a flame-ionization detector were used to evaluate the fatty acid content. It was found that with the increase in the bacterial protein content of the feed mixtures there was a rising trend in the sum total of the unsaturated fatty acids (C16:1, C18:1, C18:2) and a lowering one of the saturated fatty acids (C14, C16, C18) as against their content in the meat of the control group.

Animal Feed↗
PubMed1984

[Quality of meat from lambs fattened on feed mixtures with added bacterial protein].

Physico-chemical, microbiologic, and histologic investigations were carried out with meat and parenchymal organs of lambs offered feed mixtures with a supplement of bacterial protein on methanol basis in fattening the animals up to 35 kilograms. The addition of 5 per cent bacterial protein which replaced in terms of protein equivalent 60 per cent of the sunflower oil meal and totally the amount of urea in the mixtures had no negative effect on the physical and chemical composition of the meat and its biologic value. Histologically, no degenerative changes in the skeletal muscles and parenchymal organs were found. There was hypofunction of the thyroid gland in the test lambs. No pathogenic and occasionally pathogenic organisms were found in the sampled meat and organs.

Animal Feed↗
PubMed1984

[Chemical composition of pheasant meat].

Studied was meat of twelve pheasants aged 2 years and weighing up to 1.5 kg. Established was the content of water, the total, extractive, and protein nitrogen, fats, ashes, and the valuable proteins (tryptophane) and the incomplete proteins (hydroxiproline). It was demonstrated that the proteins of the pectoral muscles had a higher nutritive value as against those of the thigh muscles.

Animals↗
PubMed1984

[Chemical and microbiological studies of the meat of broilers fed mixed feeds with a bacterial protein supplement].

Physico-chemical and microbiologic studies were carried out with meat of broilers that had been offered combined feed mixtures in which part of the soybean meal protein was replaced by microbial one through the incorporation of 4, 8, and 12 per cent industrial single cell protein. The bacterial protein was shown to have no adverse effect on the physico-chemical composition of poultry meat. Demonstrated was a trend toward the separation in individual layers of more fats in the carcass with the increase in the percent of biomass of the combined feed mixtures for poultry. Considering the content of total nitrogen, fats, and ashes in the poultry meat most expedient was the incorporation of 4 percent single-cell protein in the feed mixtures for broilers. No pathogenic and conditionally pathogenic organisms were found in the meat of broilers.

Animal Feed↗
PubMed1984

[Chemical composition of the meat from does].

The meat was studied of 9 does killed at the age of 2.5 years and live weight of up to 35 kg. Ascertained were the contents of water; the total, extractive, and protein nitrogen; fats; ash; essential amino acids ( triptophane ) and nonessential ( hydroxiproline ) proteins. Determined was also the nutritive value of meat. It was found that the proteins of musculus gracilis have higher nutritive value as compared with those of the neck muscles between the fifth and the seventh vertebra.

Animals↗
PubMed1978

Ultrastructure of the collagen fibril. I. Some features of the structure of the collagen fibril.

In the human ovary, thyroid gland and in the rat tail tendon the plasma membrane of fibroblasts may "disappear" or "dissolve", leading to a direct contact of the cytoplasm with extracellular space. Extracellular filaments and collagen fibrils may grow directly out of the cytoplasm and from extracellular vesicles and cellular remnants. The filaments are complex structures composed of 3 to 5 subfilaments. Adjacent collagen fibrils are connected with interfibrillar bridges. In the rat tail tendon 2 different types and opposite orientated fibrils are found. After enzymatic treatment it becomes clear that the collagen fibril has a tridimensional organization and is composed of filaments and amorphous cementing matrix. The matrix is easily affected by various enzymes and washed away, revealing thus the inner spiral structure of the fibril.

Adolescent↗
PubMed1978

Ultrastructure of the collagen fibril. II. Evidence of the spiral organization of the fibril.

Unfixed tissue from the human ovary, the tail tendon and skin from the tail of rats are incubated in 5% solutions of uranyl acetate. The collagen fibrils of all tissues are decomposed and display an obvious tridimensional spiral structure on all levels. The fibril is a complex biopolymer constructed out of filaments, surrounded by and associated with an amorphous cementing matrix. The filaments consist of 3 to 5 subfilaments with a thickness of 30--45 A spirally wound around one another. The filaments are twisted along the length of the axis of the fibril under a definite angle of inclination and a pitch of the spiral equal to 1.04--1.12 micrometer for the ovary and from 2.6 to over 5.6 micrometer for the tail tendon. The cross striations seem to spring out of the nodular thickenings along the filaments. Bridge-like connections corresponding to the separate striations are established between adjacent fibrils. A new tridimensional structure model of the collagen fibrils is proposed.

Animals↗