Tag Archives: environmental conditions

629–638 R.R. Andrade, I.F.F. Tinôco, F.C. Baêta, M. Barbari,, L. Conti, P.R. Cecon, M.G.L. Cândido, I.T.A. Martins and C.G.S. Teles Junior
Evaluation of the surface temperature of laying hens in different thermal environments during the initial stage of age based on thermographic images
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Evaluation of the surface temperature of laying hens in different thermal environments during the initial stage of age based on thermographic images

R.R. Andrade¹, I.F.F. Tinôco¹, F.C. Baêta¹, M. Barbari²,*, L. Conti², P.R. Cecon¹, M.G.L. Cândido¹, I.T.A. Martins¹ and C.G.S. Teles Junior¹

¹ University of Viçosa, Department of Agricultural Engineering of Federal, Av. Peter Henry Rolfs, s/n Campus University of Viçosa, BR36570-900, Viçosa, Brazil
² University of Firenze, Department of Agricultural, Food and Forestry Systems, Via San Bonaventura, 13, IT50145 Firenze, Italy
*Correspondence: matteo.barbari@unifi.it; rafaella.andrade@ufv.br

Abstract:

The initial stage of laying hens requires important care in relation to the thermal environment, in view of the good development of the birds, the obtaining of good quality pullets and, consequently, the adequate laying rate of adult birds.
The aim of the present study was to study, through thermographic images, the variation of the superficial temperature of laying birds of the Lohmann LSL Lite line, from one to forty-two days of age, submitted to different thermal environments. For this experiment, 864 layer chicks were distributed homogeneously in four climatic chambers. The characterization of the different environments was as follows: thermal comfort conditions (32.8 °C–20.2 °C), two cold stress levels (28.0 °C–17.9 °C and 25.5 °C–17.3 °C) and one level of heat stress (37.4 °C–23.3 °C). The black globe temperature and humidity index (BGHI) was also calculated during the trials. The data were evaluated through the Tukey test, adopting the level of 5% of probability. Via infrared thermography the temperatures of head, body and shank of the laying birds were recorded. The results showed effect (P < 0.05) of the temperature of each environment on the surface temperature of the birds. Along with the rise of the ambient temperature, an increase in the surface
temperature (head and shank) was found.
Under the recommended comfort treatment, the performance of laying birds during the earlystage, related to the superficial temperature of the birds shows the best values with temperature ranges of 32.8 °C–20.2 °C and BGHI values between 82.3 ± 1.3 and 66.4 ± 1.3.

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687–693 L.C.S.R. Freitas, I.F.F. Tinôco, F.C. Baêta, M. Barbari, L. Conti, C.G.S. Teles Júnior, M.G.L. Cândido, C.V. Morais and F.C. Sousa
Correlation between egg quality parameters, housing thermal conditions and age of laying hens
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Correlation between egg quality parameters, housing thermal conditions and age of laying hens

L.C.S.R. Freitas¹, I.F.F. Tinôco¹, F.C. Baêta¹, M. Barbari²*, L. Conti², C.G.S. Teles Júnior¹, M.G.L. Cândido¹, C.V. Morais¹ and F.C. Sousa¹

¹ Federal University of Viçosa, Department of Agricultural Engineering, Avenue Peter Henry Rolfs, University Campus, BR36570-900, Viçosa-MG, Brazil
² University of Firenze, Department of Agricultural, Food and Forestry Systems, Via San Bonaventura, 13, IT50145 Firenze, Italy
*Correspondence: matteo.barbari@unifi.it; leticia.ramos@ufv.br

Abstract:

High environmental temperatures cause a decrease in feed consumption by laying hens and, as a consequence, a reduction of productive performance and egg weight. The hens age is a factor influencing the albumen quality that tends to be more liquefied in older hens. Such variable is analysed by the determination of the Haugh Unit.
The correlations between the egg quality variables (egg weight and Haugh Unit), the  thermohygrometric conditions in the facility and the age of laying hens were determined in the study and evaluated based on the Pearson correlation coefficient (r) and their significance at the 5% level. The microclimatic data and the eggs were collected in 20 points of poultry facility with birds of 43, 56, 69, 79 and 86 weeks of age, totalling 100 samples.
The results show significant correlations between egg weight and temperature (r = -0.238), egg weight and hens age (r = 0.310), Haugh Unit index and hens age (r = -0.256); a non-significant correlation between the quality parameters with the relative humidity of the air inside the barn. The egg weight had a weak negative correlation with the ambient temperature and a weak positive correlation with the hens age. Concerning the Haugh Unit, a weak negative correlation with the age of the animals was found. The weak or non-existent correlation of temperature with egg quality parameters can be due to the environmental conditions that remained in the range of thermal comfort for the animals during the trials.

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1486-1493 R. Simson, L. Tartlan, E. Nugis and V. Eremeev
The effect of fertilizer and growing season on tuber dry matter and nitrate content in potato
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The effect of fertilizer and growing season on tuber dry matter and nitrate content in potato

R. Simson¹*, L. Tartlan², E. Nugis¹ and V. Eremeev³

¹Estonian Crop Research Institute, Department of Plant Biotechnology, Aamisepa 1, EE48309 Jõgeva, Estonia
²Estonian Research Institute of Agriculture, Department of Plant Sciences, Teaduse 13, 75501 Saku, Estonia
³Estonian University of Life Sciences, Department of Field Crop and Grassland Husbandry, Kreutzwaldi 1, EE51014 Tartu, Estonia
*Correspondence: reijo.simson@etki.ee

Abstract:

Field trials with two potato varieties were undertaken at the Estonian Research Institute of Agriculture in 2005 and 2006. Year 2005 was generally optimal for potato growth but year 2006 was dry and very warm, hence, it was adverse for growth. The effect of fertilizing on two main traits of potato, i. e. tuber dry matter (DM) and nitrate content was examined. Five rates of compound fertilizer were applied, N50P20K85, N70P28K119, N90P36K153, N110P44K187 and N130P52K221. Results indicated that DM content was largely determined by variety but it also depended on fertilizer amounts and particular environmental conditions of a year. Nitrate content of tubers was quite clearly dependent upon variety, but growing season had significant effect on final nitrate content in tubers. Water stress during early and main bulking periods resulted in high tuber nitrate levels. In order to gain tuber yield fit for intended use, it is necessary to manage nutrient acquisition based on expected yield and nutrient supply from soils.

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