P C Chandran

Behavioural, biochemical and hormonal responses of heat-stressed crossbred calves to different shade materials

ABSTRACT 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 macro- and microclimate data were recorded at 0900 and 1400u2005h. 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 1700u2005h. 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 (Pu2009<u2009.05) 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 (Pu2009<u2009.05) while, Serum Glutamic Oxaloacetic Transaminase and Alkaline Phosphatase were significantly lower in the T2 group.

Heat stress and effect of shade materials on hormonal and behavior response of dairy cattle: a review

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 2–7xa0weeks. 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.

The effects of PPR on the reproductive health of Black Bengal goats and the possible role played by oxidative stress

Outbreaks of Peste des petits ruminants (PPR) viral disease in Black Bengal goats were investigated from the middle Indo-Gangetic Plains of India. Clinical profile of PPR-affected flocks was recorded from four different outbreak sites of the region. The PPR outbreak was diagnosed serologically using commercially available sandwich ELISA kit. Relatively, low mortality rate (mean 26.75%) for PPR outbreak was recorded due to the endemic status of the disease. To understand the role of oxidative stress in PPR virus pathogenesis, various oxidant and antioxidant parameters in goats infected with PPR were estimated and compared with the uninfected/healthy goats of the same flock. The measured high level of pro-oxidant malondialdehyde (MDA) obtained from lipid peroxidation along with lower levels of anti-oxidants viz. superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) in PPR-affected Black Bengal goats suggests oxidative stress as one of the mechanism of pathogenesis of PPR virus. In addition, the correlation of oxidative stress due to PPR and the resulting reproductive disorders in the female goats were evaluated. The abortion in pregnant does observed during PPR outbreak was proportional to debility and oxidative stress manifested during PPR infection. The reproductive performance of recovered female goats in the period of 18xa0months of monitoring was significantly compromised in terms of kidding and twinning frequency. The mortality rate in kids born from PPR-recovered goats was significantly higher compared to those from health goats in the first 9xa0months post-recovery. From the present study, it may be concluded that together with the PPR virus, infection in goats and the resulting oxidative stress play a vital role for abortion and reduced post-reproductive performance in Black Bengal female goat.

Impact of Environmental Stressors on the Performance of Backyard Poultry

The present study was conducted to determine the effect of different climatic parameters on production performance of Vanaraja poultry birds under deep litter system of rearing. The experiment was carried out at the hatchery unit of Bihar Veterinary College, Patna. A total of 129 birds were used for the study. Different climatic parameters such as temperature, relative humidity and temperature–humidity index were studied. Based upon average daily dry and wet bulb temperatures, temperature–humidity index values of the shed were calculated. The evaluation of egg production rate and external and internal egg quality traits at different climatic parameters was carried out. The overall average temperature, relative humidity, temperature–humidity index in different months of Bihar ranged from 16.67xa0±xa00.23 to 33.08xa0±xa00.28, from 46.60xa0±xa02.40 to 90.20xa0±xa01.12 and from 64.84xa0±xa00.30 to 85.94xa0±xa00.38, respectively. Egg production, fertility, hatchability on total egg set and on fertile egg set was significantly lower at the temperature–humidity index range from 85.53xa0±xa00.18 to 85.94xa0±xa00.38 (May–August). temperature–humidity index values inside the shed in the month of May–August suggested that the birds were in stress during the experiment. However, there was negligible effect of temperature–humidity index on egg quality. It was concluded that during the extremes of temperature–humidity index (>85) the performance of the Vanaraja birds in terms of egg production was less.

Seroprevalence of Brucella abortus and Leptospira hardjo in cattle.

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.

Non-genetic factors affecting birth weight of shahabadi lambs

A study was undertaken in 105 flocks in the breeding tract (Buxar, Bhojpur and Rohtas districts of Bihar) of Shahabadi sheep to analyse the effect of non-genetic factors (location, flock size, season, sex, and type of birth,) on birth weight. The overall least squares mean of birth weight in Shahabadi lambs was 2.34±0.03 kg. All the non-genetic factors except flock size had significant (P<0.01) effect on birth weight. Lambs reared at Buxar and Bihiya blocks of Buxar district, winter season, male lambs and lambs born as single, registered higher birth weights. The findings of the study could be useful to breeders for considering these factors which had significant effect on the birth weight during the selection of animals for future breeding programme.