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.
Performance of lactating dairy cattle in three different cooling systems
Ninety–six Holstein cows (initial days in milk (DIM) = 115) and 60 first–calf heifers (initial DIM = 97) were used 
to evaluate the effectiveness of three ventilation systems used to relieve heat stress. Thirty–two multiparous cows and 
20 first–calf heifers were assigned pens having one of three mechanical ventilation systems: 1) a single row of 0.9–m (36–in.) 
fans, spaced at 7.3–m (24–ft) intervals over the free stalls and over the feed line (AF), 2) 1.4–m (56–in.) ceiling fans, spaced 
at 3.7–m (12– ft) intervals over the free stalls (CF), and 3) poly–tube longitudinal cooling over the free stalls (PT). Fans in 
each treatment ran continuously when the temperature exceeded 22.2 
 
C (72 
 
F). Humidstats were not used in the fan or 
sprinkler control systems. Identical feed line sprinkler systems were installed in each pen. Sprinklers ran when the temperature 
exceeded 23.9 
 
C (75 
 
F), with a designed application of 3.0 L/m per application cycle (0.5 gal/24 in.) of feeding space per 
cycle. Milk production for cows housed in the pen using AF system [40.1 kg/day (88.4 lb/day)] was greater than the production 
of cows in the pens cooled using either the PT [37.6 kg/day (82.9 lb/day)] or the CF [37.1 kg/day (81.7 lb/day)] (P < 0.05). 
The AF system led to lower respiration rates (75.3 per min) as compared to CF (83.5 per min) and PT (82.3 per min) systems 
(P < 0.05). Average change in body condition score was +0.32, +0.18, and +0.22 for the cows housed in AF, PT, and CF pens, 
respectfully. Treatment differences in milk production by mature cows were numerically greater than for first–calf heifers. 
Milk production for treatments AF, CF, and PT, respectively, by mature cows was 42.3, 39.6, and 37.3 kg/day (93.5, 87.3, and 
82.3 lb/day) and by first–calf heifers was 37.9, 35.6, and 36.8 kg/day (83.5, 78.4, and 81.1 lb/day).
Novel method for the determination of the methoxyl content in lignin by headspace gas chromatography.
The paper reports on a headspace gas chromatographic (HS-GC) method for the determination of methoxyl in lignin. The method involves the quantitive cleavage of methoxyl with hydroiodic acid (HI) to form methyl iodide in a closed headspace sample vial at 130 °C for 30 min. After HI has been added, the sample is neutralized by injecting a sodium hydroxide solution; the methyl iodide in the vial was determined by HS-GC using a flame ionization detector. The results showed that the method has an excellent measurement precision (RSD < 0.69%) and accuracy (RSD < 3.5%) for the quantification of methoxyl content in lignin. The present method is simple and accurate and can be used for the efficient determination of methoxy1 content in lignin and related materials.