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.
G05-1582 How to Reduce Heat Stress in Dairy Cattle
The ideal temperature range for dairy cattle is between 25oF and 65oF. Once the temperature goes above 80oF, cattle reduce feed intake, which has a negative impact on production. At 90oF or above, there usually is a dramatic decrease in milk production ranging from 3 percent to 20 percent. Humidity also plays a significant part in heat stress. There are three temperature-humidity ranges of concern. A temperature of 100oF and 20 percent humidity is the range in which serious measures are begun to ease the stress on the cattle. Some type of cooling should be started. The danger occurs as the temperature nears 100oF and 50 percent humidity. The lethal range for cattle is 100oF and 80 percent humidity. Since cattle sweat at only 10 percent of the human rate, they are more susceptible to heat stress. This is the reason dairy cattle need mechanical means to reduce heat, such as body sprinkling to aid in evaporation and effective air movement systems to aid in cooling. Stale, stagnant air can reach dangerous or lethal areas in a short time. Therefore, it is essential to have rapid movement of air in any confined area. During times of heat stress feed intake is reduce by 8 percent to 12 percent or more. This reduction in feed intake reduces volatile fatty acid production in the rumen, resulting in decreased production. G1582
The role of early lithification in development of chalky porosity in calcitic micrites: Upper Cretaceous chalks, Egypt
Abstract Petrological and geochemical examination of Upper Cretaceous chalks from the Abu Roash area and Bahariya Oasis (Egypt) provide insights into factors which control porosity development in fine-grained calcitic carbonates. Petrological studies indicate that primary skeletal fabrics of coccoliths and foraminifera in micrites of Abu Roash are well preserved. In contrast, primary skeletal fabrics of the Bahariya Oasis chalks are pervasively altered. Geochemical analysis of these chalks reveals a striking contrast in composition. The high porosity chalks at Bahariya Oasis have depleted isotopic values ( δ 13 C = −5.0‰, δ 18 O = −8.9‰ PDB ) and low concentrations of trace elements (Sr and Na). In contrast, the low porosity chalks at Abu Roash are less depleted in terms of their isotopic values ( δ 13 C = 1.0‰, δ 18 O = −4.0‰ ) and possess elevated concentrations of Sr, Na, Fe and Zn. Importantly, fracture and collapse veins, present only at Abu Roash, are filled with calcite whose δ18O value is coincident with that of altered micrites at Bahariya Oasis. The lithic fragments cemented by this calcite, however, retain compositions identical to other lithified limestones at Abu Roash. Differences in fabric and chemistry of the pelagic marine micrites observed between Abu Roash and Bahariya Oasis reflect the degree of early lithification and compaction prior to exposure and meteoric diagenetic alteration associated with regional Late Cretaceous/pre-Eocene subaerial unconformity.