In broiler chick-rearing, the color is usually acquired by synthetic carotenoids in addition to broiler diets (25–80 mg/kg feed), often represented by β-apo-8′-carotenal. In the past fifteen years, the demand for organic food products originating from free-range reared chicks started to grow, with a more directed awareness of the quality of meat and egg. Various investigations have been reporting microorganisms, such as the oleaginous red yeasts genus Rhodotorula sp., as fast-growing unicellular eukaryotes able to synthesize natural pigments. Rhodotorula sp. represents a perfect choice as a natural resource due to the capacity to adapt easily to the environment valuing low-cost sources of nutrients for their metabolism and growth. The biodiversity and the ecology effects establish novel boundaries regarding Rhodotorula sp. productivity enhancement and control of biological risks. It is, therefore, necessary to review the current knowledge on the carotenoid synthesis of Rhodotorula sp. In this paper, we aimed to address the pathways of obtaining valuable yeast carotenoids in different conditions, discussing yeast biosynthesis, bioengineering fermentative evaluation, carotenoid extraction, and the techno-economic implication of valuable pigment additives on poultry nutrition. Finally, the pro-existent gaps in research are highlighted, which may clear the air on future studies for bio-carotenoid engineering.

Influence of Natural Zeolites Supplemented with Inorganic Selenium on the Productive Performance of Dairy Cows

Enzootic Bovine Leukosis: Surveillance Measures and Control Program in the Northern Dobruja Area of Romania Between 2017 and 2020

This research aims to establish the behaviour of geomembranes used for base sealing and for covering municipal waste facilities. The geomembranes used for base sealing are subjected to leachate pressure and to the action of chemical and microbiological pollutants. Geomembranes used for covering waste facilities are subjected to the action of precipitation water and released gases. This paper analyzes the following: the permeability mechanism of geomembranes made of polymers, the process of water vapours diffusion through polymers, diffusion flow, characteristic of permeability and influencing factors. The study also presents data on the permeability of some polymers - the most commonly used in the structure of geomembranes used in household waste facilities - as well as some of the results of ongoing research on the behaviour of high density polyethylene geomembranes in contact with the waste facilities' leachate. Diffusion was determined by measuring the weight of the vessel (water loss) daily for 30 days. The polymer influences the permeability and diffusion through the molecular and intermolecular chemical structure, the packing density, the degree of crystallinity, the crosslinking density and through the flexibility of the macromolecular chains. The results show that the permeability of polymeric geomembranes is comparable to that of a microporous material (cement stone, bentonite).

Background: In raising quails for meat production, great importance must be given to their nutrition, the use of the right compound feed suitable for them ensuring the achievement of higher performance. The aim of the research was to establish the influence of crude protein in compound feed on production performance in meat-type quails and their productive characterization. Methods: For the research, data were collected and statistically processed from Jumbo meat quails, youth and adults, during the years 2020 and 2021 in a farm specialized in quail growth. Result: It is recommended to use in the meat quail youth a compound feed with a protein value of 24.80% throughout the six weeks of growth because it ensures 15.00% superior performance (265.23±4.13 g/head at 42 days) compared to the reduction of the protein level at the age of 21 days from 24.80% to 22.50%. It is also recommended for laying quails to use a feed with a protein level of 21% which leads to significantly higher results (average 12-month laying percentage of 78.75±2.91%) compared to protein level of 18.20%.