In tropical countries, at high temperatures, several physiological rearrangements occur in cows as they attempt to facilitate heat dissipation and/or reduce metabolic heat production. Following exposure to heat, cattle appear to acclimatize within 2-7 weeks. The failure of homeostasis at high temperatures may lead to reduced productivity or even death. The situation is even worse when humidity adds to high temperature. Livestock with elevated body temperature exhibit lower DMI and growth with less efficiency, reducing profitability for dairy farms in hot and humid climates. Shading of feed and water also offers production advantages. Although several elaborate methods for reducing heat stress in cows have been reported, simple shade materials appear to be the most cost-effective methods that are currently applicable to tropical developing countries. Different materials are being used to provide shade during warm weather. The shade material determines the microclimate-it should be light, strong, durable, weatherproof, good looking and a bad conductor of heat, and free from tendency to condense moisture inside. This review discusses various shade materials and their advantages and disadvantages in different situations.

An attempt was made to study the effect of different shade materials on physiological, behavioural, biochemical and hormonal responses in crossbred Vrindavani calves during the summer seasons in the Cattle and Buffalo Farm of Indian veterinary Research Institute, Izatnagar, India. During experiment, 28 crossbred calves were divided into four groups: thatch shading roof (T1), agro-net shading roof -60% light diffusion (T2), asbestos with canvas shading roof (T3) and well-grown tree (T4). The daily macroand microclimate data were recorded at 0900 and 1400 h. The data for each ongoing behavioural activity were recorded by closed circuit television consecutively for three days for each animal in each group from 1000 to 1700 h. Blood was also collected at 0, 15, 30, 45, 60, 75 and 90 days of the experimental period for estimation of different biochemical parameters. The microclimate, that is, maximum and minimum temperatures, relative humidity and temperature humidity index of the roof, was lower in the T2 group. There was significantly more (P < .05) time spent in shade structure by the T2 group as compared to other groups. Among the behaviour, feeding, rumination, resting and sleeping activities were more in the T2 group, whereas standing, moving, drinking, time spent near water tank and abnormal behaviour (cross-sucking, licking) were more in T3 and T4. Among the blood parameters, haemoglobin was significantly higher (P < .05) while, Serum Glutamic Oxaloacetic Transaminase and Alkaline Phosphatase were significantly lower in the T2 group. ARTICLE HISTORY

Aim: The present study was carried out on cattle and buffalo farm of Indian Veterinary Research Institute, Izatnagar (Uttar Pradesh) to determine the effect of different shade materials on physiological performance in Vrindavani crossbred calves during the summer. Materials and Methods:Twenty-eight crossbred calves were divided into four groups viz. Thatch shading roof (T1), agro-net shading roof -60 % light diffusion (T2), asbestos with canvas shading roof (T3) and well-grown tree (T4). The recording of macro and micro climate as well as the physiological parameters viz. rectal temperature and respiration rate were recorded at 9:00 AM and 2:00 PM for 2 consecutive days at every fortnight interval. Result:The microclimate viz. maximum and minimum, relative humidity, temperature humidity index and surface temperature of the roof was lower in T2 group in the summer season. The physiological responses viz. rectal temperature and respiration rate was significantly higher in T4. Conclusion:During the summer season both thatch and agro-net shade material helped in better relieving the summer stress.

The characteristics, production and reproduction performance of Gangatiri cattle was investigated by visiting 142 farmer families in 37 villages under Buxar and Itahri blocks of Buxar district of Bihar. The study revealed that the coat colour of Gangatiri cattle were milky white and light grey, and the face was long and narrow. The estimated body weight of cattle in the breeding tract were 83.02±0.20, 132.06±0.71, 172.24±0.31, 326.45±0.70 and 261.63±0.26 kg, at various stages, viz. calves less than one year, 1-3 year males, 1-3 year females, adult males and adult females, respectively. The body length and height at withers of Gangatiri cattle were nearly equal to each other whereas the chest girth was prominent in all stages of age. The mean lactation length, peak yield, age at first calving, service period and dry period were 230.24±7.44 days, 4.52Â0.31 kg, 56.63±0.63 months, 129.45±3.63 days and 169.26±10.18 days under farmers' management. Among the kinds of different farming systems adopted by the farmers, the practice of agriculture along with rearing of Gangatiri cattle was prominent followed by other farming systems in the breeding tract. Regression of different dependent variables such as number of cattle, quantity of concentrate fed and the occurrence of diseases on the income generated from Gangatiri cattle (independent variable) were 2.66, 4.15 and -5.91, respectively.

Aim:The aim was to assess the seroprevalence of B. abortus and Leptospira hardjo in the cattle population of Bihar, this work was carried out.Materials and Methods:Randomly selected 450 cattle from nine districts of Bihar were serologically screened for antibodies against L. hardjo and B. abortus. DAS-ELISA for leptospira and AB-ELISA for brucella were carried out. Based on the results prevalence in each district and the state are reported herewith.Results and Discussion:In this study, it was found that the seroprevalence of L. hardjo was 9.11% and that of B. abortus was 12.2% in Bihar. Indigenous cattle were found to be less susceptible to leptospirosis and brucellosis even though they accounted for 83.11% of the study population.Conclusion:Although there was no acute disease, antibodies detected against L. hardjo and B. abortus in the cattle population indicated the presence of chronic and subclinical infection, which could challenge the fertility of the animals.