Tag Archives: THI.

872–878 C.G.S. Teles Jr., R.S. Gates, M. Barbari, L. Conti, G. Rossi, M.O. Vilela, C.F.F. Souza and I.F.F. Tinôco
A software to estimate heat stress impact on dairy cattle productive performance
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A software to estimate heat stress impact on dairy cattle productive performance

C.G.S. Teles Jr.¹, R.S. Gates², M. Barbari³*, L. Conti³, G. Rossi³, M.O. Vilela¹, C.F.F. Souza¹ and I.F.F. Tinôco¹

¹Federal University of Viçosa, Department of Agricultural Engineering, Av. Peter Henry Rolfs, s/n Campus University of Viçosa CEP: 36570-900, Viçosa, Minas Gerais, Brazil
²University of Illinois, Department of Agricultural and Biological Engineering, 1304 West Pennsylvania Avenue, US61820, Urbana-IL, United States of America
³University of Florence, Department of Agriculture, Food, Environment and Forestry, Via San Bonaventura, 13, IT50145 Firenze, Italy
*Correspondence: matteo.barbari@unifi.it; carlosgutembergjr@hotmail.com

Abstract:

The aim of this study is to develop a computational tool, based on the Temperature and Humidity Index value, to characterize the thermal environment in dairy cattle barns and to evaluate the impact of thermal stress on productive performance. The software for the thermal environment prediction, and determination of the influence of heat stress on dairy cow productivity (Ambi + Leite) was developed using the C# programming language in the Microsoft Visual C# 2010 Express Integrated Development Environment. The following scenario was considered for the program test: air temperature 32°C, relative air humidity 70% and milk production potential in thermoneutrality condition 20 kg cow-1 day-1. The prediction of the thermal environment based on the simulated situations indicates that the animals are submitted to a moderate heat stress condition with THI equal to 82.81. In this condition a decrease of approximately 26% in milk production and a reduction of 4 kg cow-1 day-1 in food intake was calculated. In conclusion, the developed software can be a practical tool to assist the producer in making-decision processes.

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245-252 J. Papez and P. Kic
Heating and ventilation in milking parlours
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Heating and ventilation in milking parlours

J. Papez* and P. Kic

Czech University of Life Sciences Prague, Faculty of Engineering, Kamycka 129, 16521 Prague 6, Czech Republic; *Correspondence: papez@tf.czu.cz

Abstract:

The aim of this paper is to show the results of the measurement of main microclimatic parameters (temperature and relative humidity) in milking parlours and compare the obtained results with values recommended in relevant standards. Temperature and relative humidity can affect animal welfare as well as the well-being of workers. These parameters were measured in three rotary milking parlours with herringbone type of stalls, each for 24 dairy cows. Two of these milking parlours were built in 2001 and one was built in 2009. Measurements were taken during the winter and summer periods, under extremely cold or high temperature conditions. Measurements were taken during the milking process for about two hours using suitable sensors for measurement of indoor temperature and relative humidity. The data of outside temperature and relative humidity were also obtained and compared with indoor data. The final results of the research were generalized. It is obvious from the results of measurements of selected milking parlours that heating and ventilation of milking parlours is insufficient. To set up adequate heating power, the heat balance of milking parlours was calculated. For adequate ventilation, the necessary flow of fresh air was calculated for both winter and summer periods. Also the methods of how to achieve these air flows are presented.

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