Análise do investimento em climatização para bovinos de leite em sistema de alojamento free-stall

The difficulty in adapting European dairy cows breeds in Brazil affect considerably the milk production sector. Brazilian climatic conditions are not totally favorable and the development of new tecnologies is needed for the animals express their genetic potential, as well as their best feed conversion. An economical analysis of the applied investment in the free-stall climatization equipment in dairy housing, for estimating studies related to profit, possibility of return investment as well as time for this return is necessary. The objective of this research was to evaluate the influence of climatization investment in the milk production process and analyze the economical aspect of this investment. There were used 470 high productive dairy cows with genetic and morphologic homogeneous characteristics, and analyzed in two similar periods. Investment calculations were done using Excell®. The results were satisfactory and the invested capital was proved to return to the producer in a short term, 57 days.

Gases e ruídos em edificações para suínos: aplicação das normas NR-15, CIGR e ACGIH

Swine production represents an important segment of Brazilian economy, and the possibility of increasing production is eminent mainly if considered the low pork consumption when compared to other meat and the consumption of other countries. The increasing need in the international market demands show that in a near future the commercial barriers will be based on welfare, in the protection of the environment as well as in the worker's legislation. Little knowledge is available in the subject of worker's standards in the environmental agents in rural activities as well as the air quality under Brazilian conditions. The objectives of this research were to apply the main used standards related to noise and gases and to estimate occupational risk using measurements of noise level, hydrogen sulfide, methane and oxygen in swine housing, in piglet's nursery and finishing. The results showed that the continuous noise level were below the one found in the standards, however there were observed differences (P < 0.05) in relation to the noise level measured in piglet's nursing cages and in semi-slatted floor. The respective concentrations of hydrogen sulfide and methane were less than 1 ppm and less than 0,1% by volume, which was lower than the recommended limits in NR-15, CIGR and ACGIH. The oxygen level was 21% in average.

Avaliação térmica de placas de argamassa de cimento e casca de arroz aquecidas por resistência elétrica

An alternative proposal for floor heating system by means of electric resistance for both chick and piggy installation is presented in this work. Several formulations of rice husk and cement mortar boards were used. An electronic device controlled all board temperature. This system presented a good efficiency design. The conventional cement mortar mixed with rice husk showed a better performance.