Adjusting Dairy Housing in Hot Climates to Meet Animal Welfare Requirements
Small dairy farms in hot climates are encountering several problems caused by the design flaws of the implemented housing designs. Consequently, heat stress increase and milk yield dramatically decreases, which leads to economic deficiency of the farm. One key issue is to develop simple means to rectify the design flaws with minimum costs. In order to develop feasible means, design flaws were detected on-site in 14 small dairy farms in Egypt to exemplify the flaws of housing designs in arid and semi-arid zones. A package of interconnected solutions is suggested to rectify the design flaws. Subsequently, the maximum temperature, dry-bulb temperature, black-globe temperature, dew point, relative humidity, shaded area, and air velocity were measured inside the rectified vs. non-rectified cowsheds and compared after conducting the statistical analysis. On the other hand, the Temperature-Humidity Index (THI) and Black Globe Humidity Index (BGHI) were calculated to find out the level of heat stress affecting the dairy cows. Furthermore, the milk yield, respiration rate, skin temperature, feed intake were recorded and compared. Moreover, the costs of the developed means were calculated and a feasibility study was carried out. The results show that the developed means are effective and feasible, where the heat stress decreased (THI decreased from 94.6 to 83.7; dry-bulb temperature decreased from 42.7 to 33.6 oC) and the average milk production increased from 18 to 26 kg/day.cow. Consequently, the costs were minimized and the revenues were maximized, which achieve economic efficiency for the farm where the profit increased by about 427 $/cow.year. -------------------------------------------------------------------------------------------------------- Assistant Professor, Agricultural Engineering Department, Faculty of Agriculture, Cairo University, Gammaa Street, 12613 Giza, Egypt * Corresponding Author, Email: samer@cu.edu.eg Please Cite This Article As : M. Samer. 2010. Adjusting Dairy Housing in Hot Climates to Meet Animal Welfare Requirements. J. Exp. Sci. 1(3): 14-18.
MATHEMATICAL MODELING AND SPARK MAPPING OF DAIRY FARMSTEAD LAYOUT IN HOT CLIMATES
A tool has been developed in order to assist farm designers in planning farmstead layouts for dairy farms in hot climates. A mathematical model was developed. Subsequently, the tool is developed by integrating the mathematical model into an electronic spark map. The spark map (decision tree) specifies the farm dimensions, farm total area, and farm perimeter. Furthermore, it calculates the capital investment and the fixed, variable, and total costs of the farm fence. On the other hand, the mathematical model of the spark map requires some input data, such as the dimensions of the farm buildings and the distances between them. According to these data, the spark map will make calculations and show the output data automatically. Data of 4 dairy farms were used to carry out the model validation. The differences between actual and calculated values were determined, and the standard deviations were calculated. The coefficients of variation were between 5 and 7%.
Genetics of the phenotypic evolution in sheep: a molecular look at diversity-driving genes
Background After domestication, the evolution of phenotypically-varied sheep breeds has generated rich biodiversity. This wide phenotypic variation arises as a result of hidden genomic changes that range from a single nucleotide to several thousands of nucleotides. Thus, it is of interest and significance to reveal and understand the genomic changes underlying the phenotypic variation of sheep breeds in order to drive selection towards economically important traits. Review Various traits contribute to the emergence of variation in sheep phenotypic characteristics, including coat color, horns, tail, wool, ears, udder, vertebrae, among others. The genes that determine most of these phenotypic traits have been investigated, which has generated knowledge regarding the genetic determinism of several agriculturally-relevant traits in sheep. In this review, we discuss the genomic knowledge that has emerged in the past few decades regarding the phenotypic traits in sheep, and our ultimate aim is to encourage its practical application in sheep breeding. In addition, in order to expand the current understanding of the sheep genome, we shed light on research gaps that require further investigation. Conclusions Although significant research efforts have been conducted in the past few decades, several aspects of the sheep genome remain unexplored. For the full utilization of the current knowledge of the sheep genome, a wide practical application is still required in order to boost sheep productive performance and contribute to the generation of improved sheep breeds. The accumulated knowledge on the sheep genome will help advance and strengthen sheep breeding programs to face future challenges in the sector, such as climate change, global human population growth, and the increasing demand for products of animal origin.