Adaptive Mechanisms of Goat to Heat Stress

Goat is popularly known as ‘poor man’s cow’, rears mostly by the rural people due to better adaptive capability to harsh environment. Heat stress either hot or cold; negatively influence the goat productive and reproductive performance. Both survivability and reproductive performance of goat most often depend on its ability to cope with heat stressor. Goats can rears in a wide range of environment and geography may it be hilly terrain or undulating topography due to cope with the heat stress via combination of behavioral, morphological, physiological, biochemical, metabolic, hormonal and molecular changes at the gene level. All these adaptive mechanisms and genes are important for the assessment of heat stress, adaptability and strategies for management, production of heat-tolerant transgenic goat using advance biotechnological tools for sustainable goat production in challenged environment due to climate change.

A thermal stressor, propranolol and LTM formation in freshly collected Lymnaea

A heat stressor (1h at 30o C) in Lymnaea stagnalis before operant conditioning training of aerial respiration is sufficient to enhance long-term memory (LTM) formation in average cognitive-ability, laboratory-reared, inbred snails. However, in freshly collected outbred snails the same heat stressor blocks LTM formation in smart cognitive phenotype but not in average cognitive phenotype strains. Here we hypothesize that: 1) preventing the stress associated with the heat stressor before training allows LTM to form in the smart phenotype strains ; and 2) alleviating the stress before a memory recall session allows a formed LTM to be recalled in the smart phenotype strains. We found that an injection of propranolol, which mitigates the stressor, before snails experience the heat stressor enabled two strains of the smart phenotype snails to form LTM formation, consistent with our first hypothesis. However, the injection of propranolol before a memory test session, did not alleviate a memory recall block in the smart phenotype snails. Thus, our second hypothesis was not supported. Thus, smart cognitive phenotype snails encountering a heat stressor have an inability to form LTM, but this inability can be overcome by the pre-injection of propranolol.

Evaluation of aspirin (ASA) in broiler chicken during hot dry summer using zoo technical, molecular and physio-biochemical tools

The present study was undertaken to evaluate the efficacy of aspirin as anti-heat stressor. Broiler chicks were reared on a standard diet up to 14 days of age. Thereafter, the chicks were randomly distributed into three dietary treatment groups viz., T1 (Control group: Standard diet), T2 (Standard diet with aspirin@250 mg/kg) and T3 (Standard diet with aspirin@500 mg/kg). Each treatment was having five replicates of eight birds per replicate. Experiment was carried out during hot-dry (April-May, 30.0±0.70 to 37.0±1.40C, Rh, %: 58.05±1.32 to 70.11±0.82) summer. Feed intake and live weight gain was comparable among the treatments but FCR, protein and energy efficiency improved significantly (P less than 0.001) on aspirin supplementation. The relative yield of thymus and bursa at 4th and 6th week of age improved significantly (P less than 0.05). The percentage of protein, aspartate transaminase (AST) and alanine transaminase (ALT) increased significantly (P less than 0.001) due to aspirin supplementation at 4th as well as 6th week of age. While H:L ratio, serum corticosteron and serum cholesterol (only at 42nd day of age) decreased significantly (P less than 0.001) in aspirin supplemented groups at 28th as well as 42nd day of age. Supplementation of aspirin at 500 mg/kg reduced relative expression of HSP70 in jejunum tissues during 28th or 42nd day of age. It can be concluded that aspirin supplementation 500 mg/kg in diet of heat stressed broilers improved performance as well as welfare..

Effects of an Infusion of Morphine into the Accumbens Nucleus upon Acquisition of Hypoalgesic and Fear Responses in Rats Exposed to a Heat Stressor

Four experiments examined the effects of an infusion of morphine into the accumbens nucleus upon the aversive conditioning that can occur in rats exposed to the heated floor of a hot-plate apparatus. An infusion of morphine into the accumbens nucleus but not into the caudoputamen or into the prefrontal cortex impaired the acquisition of a conditioned hypoalgesic (Experiment 1) and fear (Experiment 4) response. This impairment was dose-dependent (Experiment 2) and mediated by opioid receptors in the accumbens nucleus, because it was removed by a systemic (Experiment 3a) or by an accumbal (Experiment 3b) infusion of naloxone. The results were attributed to an antagonism between the reinforcement process for aversive conditioning and the appetitive properties of an accumbal infusion of morphine.